This document describes a study probing the structural adaptability of [V3O5(SeO3)3]n2n- layers in organically templated vanadium selenites. The study involved 84 chemical reactions with 14 organic amines under different conditions. A decision tree was constructed using the experimental data to derive chemical hypotheses about the requirements for forming these layers. It was found that three criteria must be met: 1) hydrogen bonding stabilization with specific oxide ions requiring a primary ammonium site on the organic amine, 2) use of compact ammonium cations for charge matching with layers, and 3) control of competition between organic and NH4+ cations through reagent choice and concentrations. Seven new compounds containing
I. Novel, One-Pot Reactions towards Molecular Alkaline Earth Species, II. Exp...Yuriko Takahashi
Yuriko Takahashi is a PhD candidate at Syracuse University exploring one-pot reactions to synthesize molecular alkaline earth species using benign methods. She has also evaluated how weak interactions influence the thermal properties and volatility of compounds for metal organic chemical vapor deposition. Her research involves inert gas techniques, NMR studies, crystallography, thermogravimetric analysis, and ligand synthesis. She finds that redox transmetallation using BiPh3 provides an environmentally friendly alternative to organomercury compounds for alkaline earth synthesis, with reaction rates significantly faster than direct metallation. Exploring weak intermolecular interactions may help determine structure-property relationships for improving volatility in MOCVD applications.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
International Journal of Engineering and Science Invention (IJESI)inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
The document reports the crystal structures of two isomeric compounds: 2-(4-nitrophenyl)-3-phenyl-2,3-dihydro-4H-1,3-benzothiazin-4-one (I) and 2-(2-nitrophenyl)-3-phenyl-2,3-dihydro-4H-1,3-benzothiazin-4-one (II). Compound (I) crystallizes in the triclinic space group P1, while compound (II) crystallizes in the monoclinic space group P21/n. Both compounds contain a six-membered thiazine ring fused to a benzene ring that ad
This document summarizes the synthesis of tris(4-((E)-2-nitro-3-(phenylamino)prop-1-enyl)phenyl)amine from a Baylis–Hillman adduct. Specifically, it details the reaction of tris(4-((E)-3-bromo-2-nitroprop-1-enyl)phenyl)amine with aniline to yield the target compound in 95% yield. The synthesis demonstrates the utility of bromo derivatives of Baylis–Hillman adducts as intermediates for generating novel trisubstituted triallylamines. Characterization of the product by NMR spectroscopy is also discussed.
The document describes a new flexible synthesis of pyrazoles that allows for varying substituents at the C3 and C5 positions of the pyrazole ring. The synthesis involves coupling protected alkynols with acid chlorides to form alkynyl ketones, which are reacted with hydrazine to install the pyrazole nucleus. Alcohol deprotection and conversion to chlorides provides access to 5-substituted 3-(chloromethyl)- or 3-(2-chloroethyl)pyrazoles. These chlorides can then undergo nucleophilic substitution to generate other polyfunctional pyrazoles. The significance is that substituents at C5 control the steric environment around the pyrazole N-H
Synthesis of substituted 1, 2, 4-triazole derivatives by Microwave irradiationIOSR Journals
Various substituted Triazole-Thiol containing different functional group have been synthesized by microwave method. The title product 1-[(3H-indol-2-ylamino) methyl]-4-phenyl-4, 5-dihydro-1H-1, 2, 4-triazole-3-thiol is synthesized by using amino benzothiazole. The final structures have been established on the basis of their chemical analysis and spectral data. All micro-wave synthesized compounds results into good yield as compared to conventional method of which fluoro substituted compound shows maximum yield.
Micellar Effect On Dephosphorylation Of Bis-4-Chloro-3,5-Dimethylphenylphosph...IOSR Journals
The rate enhancement depends on the hydrophobicity of the nucleophile. The micellar catalyzed reaction between bis-4-chloro-3,5-dimethylphenylphosphate ester and hydroxide or hydroperoxide anions has been examined in buffered medium (pH 8-10). First order rate constant (Kψ) for the reaction of hydroxide ion with bis-4-CDMPP go through maxima with the increasing concentration of cetyltrimethylammoniumbromide (CTABr). Micelles of CTABr very effective catalyst to the reactions of phosphate diesters. Rate constants measured with OH2- ions are approximately twice and thrice than that of OH- ions in presence of CTABr.
I. Novel, One-Pot Reactions towards Molecular Alkaline Earth Species, II. Exp...Yuriko Takahashi
Yuriko Takahashi is a PhD candidate at Syracuse University exploring one-pot reactions to synthesize molecular alkaline earth species using benign methods. She has also evaluated how weak interactions influence the thermal properties and volatility of compounds for metal organic chemical vapor deposition. Her research involves inert gas techniques, NMR studies, crystallography, thermogravimetric analysis, and ligand synthesis. She finds that redox transmetallation using BiPh3 provides an environmentally friendly alternative to organomercury compounds for alkaline earth synthesis, with reaction rates significantly faster than direct metallation. Exploring weak intermolecular interactions may help determine structure-property relationships for improving volatility in MOCVD applications.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
International Journal of Engineering and Science Invention (IJESI)inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
The document reports the crystal structures of two isomeric compounds: 2-(4-nitrophenyl)-3-phenyl-2,3-dihydro-4H-1,3-benzothiazin-4-one (I) and 2-(2-nitrophenyl)-3-phenyl-2,3-dihydro-4H-1,3-benzothiazin-4-one (II). Compound (I) crystallizes in the triclinic space group P1, while compound (II) crystallizes in the monoclinic space group P21/n. Both compounds contain a six-membered thiazine ring fused to a benzene ring that ad
This document summarizes the synthesis of tris(4-((E)-2-nitro-3-(phenylamino)prop-1-enyl)phenyl)amine from a Baylis–Hillman adduct. Specifically, it details the reaction of tris(4-((E)-3-bromo-2-nitroprop-1-enyl)phenyl)amine with aniline to yield the target compound in 95% yield. The synthesis demonstrates the utility of bromo derivatives of Baylis–Hillman adducts as intermediates for generating novel trisubstituted triallylamines. Characterization of the product by NMR spectroscopy is also discussed.
The document describes a new flexible synthesis of pyrazoles that allows for varying substituents at the C3 and C5 positions of the pyrazole ring. The synthesis involves coupling protected alkynols with acid chlorides to form alkynyl ketones, which are reacted with hydrazine to install the pyrazole nucleus. Alcohol deprotection and conversion to chlorides provides access to 5-substituted 3-(chloromethyl)- or 3-(2-chloroethyl)pyrazoles. These chlorides can then undergo nucleophilic substitution to generate other polyfunctional pyrazoles. The significance is that substituents at C5 control the steric environment around the pyrazole N-H
Synthesis of substituted 1, 2, 4-triazole derivatives by Microwave irradiationIOSR Journals
Various substituted Triazole-Thiol containing different functional group have been synthesized by microwave method. The title product 1-[(3H-indol-2-ylamino) methyl]-4-phenyl-4, 5-dihydro-1H-1, 2, 4-triazole-3-thiol is synthesized by using amino benzothiazole. The final structures have been established on the basis of their chemical analysis and spectral data. All micro-wave synthesized compounds results into good yield as compared to conventional method of which fluoro substituted compound shows maximum yield.
Micellar Effect On Dephosphorylation Of Bis-4-Chloro-3,5-Dimethylphenylphosph...IOSR Journals
The rate enhancement depends on the hydrophobicity of the nucleophile. The micellar catalyzed reaction between bis-4-chloro-3,5-dimethylphenylphosphate ester and hydroxide or hydroperoxide anions has been examined in buffered medium (pH 8-10). First order rate constant (Kψ) for the reaction of hydroxide ion with bis-4-CDMPP go through maxima with the increasing concentration of cetyltrimethylammoniumbromide (CTABr). Micelles of CTABr very effective catalyst to the reactions of phosphate diesters. Rate constants measured with OH2- ions are approximately twice and thrice than that of OH- ions in presence of CTABr.
The document provides details on the entry test for MBBS/BDS programs in NUMS. It outlines the paper pattern, including the number and types of questions in Chemistry, Biology, and Physics. It then provides extensive summaries of the Chemistry and Biology syllabi, covering topics like physical chemistry, inorganic chemistry, organic chemistry, cell biology, microbiology, human physiology, infectious diseases, biotechnology, and ecology. The test aims to evaluate students' understanding of core concepts in these subject areas through 180 multiple choice questions.
Kinetics of Substituted Bis- and Mono-azo Dyes as Corrosion Inhibitors for Al...Al Baha University
This investigation is designed to apply an advanced kinetic^thermodynamic model on the data obtained from acidic and alkaline corrosion of aluminium using bis- and mono-azo dyes as corrosion inhibitors.
This document summarizes a study that synthesized and characterized mixed ligand complexes of L-leucine and sulfamethoxazole with Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and Hg(II) ions. The complexes were prepared in ethanol-water solution and characterized using techniques like FT-IR, UV-Vis, magnetic susceptibility, and conductivity measurements. FT-IR analysis indicated that both ligands act as bidentate ligands, coordinating through carboxylate and amine groups for L-leucine and sulfonyl oxygen and amine nitrogen for sulfamethoxazole. The complexes were also found to have octahedral geometry and
Synthesis and Catalytic Application of Chiral 1,1′-Bi-2-naphtholand Biphenant...DrMAdamSayah
Synthesis and Catalytic Application of Chiral 1,1′-Bi-2-naphtholand Biphenanthrol-Based Pincer Complexes- Selective Allylation of Sulfonimines with Allyl Stannane and Allyl Trifluoroborate
Preserved flora and organics in impact melt brecciasCarlos Bella
This document discusses the preservation of organic matter and plant remains in impact melt breccias found in Argentina. Analyses found centimeter-scale leaf fragments encapsulated in the impact glass that exhibited remarkable cellular-level preservation. Organic matter was also detected, including polycyclic aromatic hydrocarbons, alkanes, and pigment-like structures similar to chlorophyll. Heating experiments showed temperatures above 1500°C were required to preserve morphology, suggesting the impact process rapidly quenched and encapsulated the organic material. These findings demonstrate the potential for impact events to preserve biomarkers of early life on Mars.
This document describes the synthesis and characterization of mixed ligand complexes of Co(II), Ni(II), Cu(II) and Zn(II) with anthranillic acid and tributylphosphine. The complexes were prepared in a 1:2:2 molar ratio of metal to ligands and characterized using various spectroscopic techniques. The complexes were found to have octahedral geometry and were tested for their antimicrobial activity against various bacteria, showing high activity. In summary, mixed ligand metal complexes were successfully synthesized and showed antimicrobial properties.
The document describes the isolation and characterization of four new meroterpenoid metabolites, dhilirolides A-D, from cultures of the fungus Penicillium purpurogenum collected in Sri Lanka. Dhilirolides A-D have unprecedented carbon skeletons containing dhilirane or isodhilirane rings. Dhilirolide A was characterized by NMR and X-ray crystallography, confirming its complex structure. Dhilirolides B-D have similar structures to A but differ in oxidation states or positions of double bonds, as elucidated by NMR. The dhilirolides represent a new class of fungal secondary metabolites with potential biomedical applications.
This document provides an overview of 1,2,3-triazoles and their biological activities. It discusses various synthetic strategies for producing 1,2,3-triazoles, including Huisgen cycloaddition and palladium-catalyzed reactions. The document then summarizes research on the anticancer, anti-inflammatory, antitubercular, antiviral, and antibacterial activities of 1,2,3-triazole derivatives, noting several potent compounds and their mechanisms of action.
Synthesis, Characterization, Spectral (FT-IR, 1H, 13C NMR, Mass and UV) and B...Dr. Pradeep mitharwal
Bio-potent ligands, 2-hydroxy-N-phenylbenzamide hydrazinecarbothioamide(HPHTSCZH2) and 2-hydroxy-N-phenylbenzamide hydrazine carbodithioic benzyl ester (HPHCBESH2) have been synthesized by the condensation of 2-hydroxy-N-phenylbenzamide with hydrazinecarbothioamide and hydrazine carbodithioic benzyl ester, respectively and reacted with hydrated lanthanide chlorides. The coordination moieties of the ligands have been confirmed by various spectral studies. - See more at: http://www.sciencedomain.org/abstract.php?iid=271&id=16&aid=2488#sthash.6v3aFQIi.dpuf
The document summarizes experimental measurements and COSMO-RS predictions of (liquid + liquid) phase equilibria for mixtures of 1-alkyl-3-methylimidazolium methylsulfate ionic liquids ([mmim][CH3SO4] or [bmim][CH3SO4]) with alcohols, ethers, or ketones. Solubility measurements from 270 K to the boiling point of the solvent were performed visually. Complete miscibility was observed between the ionic liquids and alcohols up to a certain carbon chain length at 310 K. COSMO-RS predictions matched the experimental results better for [bmim][CH3SO4] mixtures than for [mmim
Influence of the alkyl chain length of alkyltriazoles on the corrosion inhibi...Al Baha University
Abstract. Steel is an important material and has been widely used in today's industrial production. Using organic
corrosion inhibitors is an effective means to prevent steel from corrosion. Generally, the molecular structures of
inhibitors can have a major impact on their corrosion inhibition efficiency. In this work, the influence of alkyl chain
length of three alkyltriazoles on the corrosion inhibition of iron has been investigated by density functional based tight
binding (DFTB) approach. Several typical descriptors such as frontier molecular orbital, adsorption energy, density of
states have been discussed in detail. Our findings will contribute to the understanding of the inhibition mechanism and
the designing of novel corrosion inhibitors.
This document describes the synthesis, spectral characterization, and biological screening of transition metal complexes of the ligand 2-(5-mercapto-1,3,4-oxadiazol-2-yl)phenol. A series of complexes were prepared using Cu(II), Co(II), Ni(II), and Zn(II) and characterized using analytical data, magnetic susceptibility, IR, UV-Vis, 1H NMR, 13C NMR, EPR, and other techniques. Spectral data suggest an octahedral geometry around the metal ion. Biological screening showed the complexes have antibacterial, antifungal, and DNA cleavage activities.
This document describes the crystal structure of the compound terbinafine, which was analyzed using X-ray single crystal diffraction. Key findings include:
- Terbinafine crystallizes in the monoclinic space group P21/n with unit cell parameters a=5.9181(3)Å, b=29.4239(14)Å, c=11.429 β=97.92 ̊, V=1971.24(16) Å3, Z=4.
- Two water molecules were present in the crystal structure unit cell and engaged in hydrogen bonding, providing stability to the structure.
- The two benzene rings in the structure are essentially planar, while the side
Ruthenium(III) Catalyzed Oxidation of Sugar Alcohols by Dichloroisocyanuric A...Ratnakaram Venkata Nadh
Kinetics of ruthenium(III) catalyzed oxidation of biologically important sugar alcohols (myo-inositol,
D-sorbitol, and D-mannitol) by dichloroisocyanuric acid was carried out in aqueous acetic acid—perchloric
medium. The reactions were found to be first order in case of oxidant and ruthenium(III). Zero order
was observed with the concentrations of sorbitol and mannitol whereas, a positive fractional order was found
in the case of inositol concentration. An inverse fractional order was observed with perchloric acid in oxidation
of three substrates. Arrhenius parameters were calculated and a plausible mechanism was proposed
Partial Molar Volumes of Tetra alkyl ammonium salts in 10%(W/W) 2-(Ethoxy) et...Premier Publishers
In this article densities and apparent molar volumes of Tetra alkyl ammonium bromide salts ( ) in 10% (W/W) 2-(Ethoxy) ethanol-water mixture is studied at 30o, 35o and 40oC. Partial molar volumes are divided into ionic components using different methods such as Conway et al. and Jolicoeur et al. The results are compared with the values of partial molar volumes of ions reported in literature for pure water. Decrease in hydrophobic hydration is noticed. This may be due to the addition of co-solvent 2-(Ethoxy) ethanol (confirming the conclusions drawn from our viscosity studies that in 2-(Ethoxy) ethanol-water mixture, the structuredness of water is reduced by the breaking of hydrogen bonds). The values are divided into and . Making use of the Padova’s equation values of salts are calculated. These are also divided into ionic contributions. Dimensions of ions have been calculated to understand solvation behavior. It is shown that the classification of salts into structure makers and structure breakers on the basis of the sign of is not valid for the present water rich mixed solvent system.
METALLO - BIOACTIVE COMPOUNDS AS POTENTIAL NOVEL ANTICANCER THERAPYijac123
Mono and bi-organometallic complexes of Cu(II), Ni(II), Mn(II), Zn(II) and Ag(I) complexes with
oxaloamide ligand has much potential as therapeutic and diagnostic agents. The ligand allows the
thermodynamic and kinetic reactivity of the metal ion to be controlled and also provide a scaffold for
functionalization. Specific examples involving the design of metal complexes as anticancer agents are
discussed. These complexes have been synthesized and characterized by (1H-NMR, mass, IR, UV-VIS,
ESR) spectra, magnetic moments and conductance measurements, elemental and thermal analyses. Molar
conductances in DMF solution indicates that, the complexes are non-electrolytes. The ESR spectra of solid
Cu(II) complexes (2-5) show an axial type indicating a d(X2-y2) ground state with a significant covalent
bond character. However, Mn(II) complex(9), shows an isotropic type indicating an octahedral geometry.
Cytotoxic evolution IC50 of the ligand and its complexes have been carried out. Cu(II) Complexes show
enhanced activity in comparison to the parent ligand or standard drug. Copper is enriched in various
human cancer tissues and is a co-factor essential for tumor angiogenesis processes. However, the use of
copper binding ligand to target tumor, copper could provide a novel strategy for cancer selective
treatment.
This document reports on the synthesis and characterization of a Schiff base ligand and its cobalt and copper metal complexes. The ligand N,N’-(2-hydroxybenzaldehyde)diamino diphenyl ether was synthesized by condensing 2-hydroxybenzaldehyde and 4,4’-diaminodiphenyl ether. Cobalt and copper complexes were prepared by reacting the ligand with cobalt chloride and copper chloride respectively. The ligand and complexes were characterized using techniques such as UV-visible, FTIR, and NMR spectroscopy. They exhibited octahedral geometry. The ligand and complexes were also screened for antimicrobial activity, with the copper complex showing the highest activity against Staphylococcus aureus.
This document repeatedly discusses an "Optimal Digital Lattice" without providing any further context or details about what an optimal digital lattice is or what it is used for. The document consists solely of the phrase "Optimal Digital Lattice" written multiple times without any other words.
The document provides details on the entry test for MBBS/BDS programs in NUMS. It outlines the paper pattern, including the number and types of questions in Chemistry, Biology, and Physics. It then provides extensive summaries of the Chemistry and Biology syllabi, covering topics like physical chemistry, inorganic chemistry, organic chemistry, cell biology, microbiology, human physiology, infectious diseases, biotechnology, and ecology. The test aims to evaluate students' understanding of core concepts in these subject areas through 180 multiple choice questions.
Kinetics of Substituted Bis- and Mono-azo Dyes as Corrosion Inhibitors for Al...Al Baha University
This investigation is designed to apply an advanced kinetic^thermodynamic model on the data obtained from acidic and alkaline corrosion of aluminium using bis- and mono-azo dyes as corrosion inhibitors.
This document summarizes a study that synthesized and characterized mixed ligand complexes of L-leucine and sulfamethoxazole with Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and Hg(II) ions. The complexes were prepared in ethanol-water solution and characterized using techniques like FT-IR, UV-Vis, magnetic susceptibility, and conductivity measurements. FT-IR analysis indicated that both ligands act as bidentate ligands, coordinating through carboxylate and amine groups for L-leucine and sulfonyl oxygen and amine nitrogen for sulfamethoxazole. The complexes were also found to have octahedral geometry and
Synthesis and Catalytic Application of Chiral 1,1′-Bi-2-naphtholand Biphenant...DrMAdamSayah
Synthesis and Catalytic Application of Chiral 1,1′-Bi-2-naphtholand Biphenanthrol-Based Pincer Complexes- Selective Allylation of Sulfonimines with Allyl Stannane and Allyl Trifluoroborate
Preserved flora and organics in impact melt brecciasCarlos Bella
This document discusses the preservation of organic matter and plant remains in impact melt breccias found in Argentina. Analyses found centimeter-scale leaf fragments encapsulated in the impact glass that exhibited remarkable cellular-level preservation. Organic matter was also detected, including polycyclic aromatic hydrocarbons, alkanes, and pigment-like structures similar to chlorophyll. Heating experiments showed temperatures above 1500°C were required to preserve morphology, suggesting the impact process rapidly quenched and encapsulated the organic material. These findings demonstrate the potential for impact events to preserve biomarkers of early life on Mars.
This document describes the synthesis and characterization of mixed ligand complexes of Co(II), Ni(II), Cu(II) and Zn(II) with anthranillic acid and tributylphosphine. The complexes were prepared in a 1:2:2 molar ratio of metal to ligands and characterized using various spectroscopic techniques. The complexes were found to have octahedral geometry and were tested for their antimicrobial activity against various bacteria, showing high activity. In summary, mixed ligand metal complexes were successfully synthesized and showed antimicrobial properties.
The document describes the isolation and characterization of four new meroterpenoid metabolites, dhilirolides A-D, from cultures of the fungus Penicillium purpurogenum collected in Sri Lanka. Dhilirolides A-D have unprecedented carbon skeletons containing dhilirane or isodhilirane rings. Dhilirolide A was characterized by NMR and X-ray crystallography, confirming its complex structure. Dhilirolides B-D have similar structures to A but differ in oxidation states or positions of double bonds, as elucidated by NMR. The dhilirolides represent a new class of fungal secondary metabolites with potential biomedical applications.
This document provides an overview of 1,2,3-triazoles and their biological activities. It discusses various synthetic strategies for producing 1,2,3-triazoles, including Huisgen cycloaddition and palladium-catalyzed reactions. The document then summarizes research on the anticancer, anti-inflammatory, antitubercular, antiviral, and antibacterial activities of 1,2,3-triazole derivatives, noting several potent compounds and their mechanisms of action.
Synthesis, Characterization, Spectral (FT-IR, 1H, 13C NMR, Mass and UV) and B...Dr. Pradeep mitharwal
Bio-potent ligands, 2-hydroxy-N-phenylbenzamide hydrazinecarbothioamide(HPHTSCZH2) and 2-hydroxy-N-phenylbenzamide hydrazine carbodithioic benzyl ester (HPHCBESH2) have been synthesized by the condensation of 2-hydroxy-N-phenylbenzamide with hydrazinecarbothioamide and hydrazine carbodithioic benzyl ester, respectively and reacted with hydrated lanthanide chlorides. The coordination moieties of the ligands have been confirmed by various spectral studies. - See more at: http://www.sciencedomain.org/abstract.php?iid=271&id=16&aid=2488#sthash.6v3aFQIi.dpuf
The document summarizes experimental measurements and COSMO-RS predictions of (liquid + liquid) phase equilibria for mixtures of 1-alkyl-3-methylimidazolium methylsulfate ionic liquids ([mmim][CH3SO4] or [bmim][CH3SO4]) with alcohols, ethers, or ketones. Solubility measurements from 270 K to the boiling point of the solvent were performed visually. Complete miscibility was observed between the ionic liquids and alcohols up to a certain carbon chain length at 310 K. COSMO-RS predictions matched the experimental results better for [bmim][CH3SO4] mixtures than for [mmim
Influence of the alkyl chain length of alkyltriazoles on the corrosion inhibi...Al Baha University
Abstract. Steel is an important material and has been widely used in today's industrial production. Using organic
corrosion inhibitors is an effective means to prevent steel from corrosion. Generally, the molecular structures of
inhibitors can have a major impact on their corrosion inhibition efficiency. In this work, the influence of alkyl chain
length of three alkyltriazoles on the corrosion inhibition of iron has been investigated by density functional based tight
binding (DFTB) approach. Several typical descriptors such as frontier molecular orbital, adsorption energy, density of
states have been discussed in detail. Our findings will contribute to the understanding of the inhibition mechanism and
the designing of novel corrosion inhibitors.
This document describes the synthesis, spectral characterization, and biological screening of transition metal complexes of the ligand 2-(5-mercapto-1,3,4-oxadiazol-2-yl)phenol. A series of complexes were prepared using Cu(II), Co(II), Ni(II), and Zn(II) and characterized using analytical data, magnetic susceptibility, IR, UV-Vis, 1H NMR, 13C NMR, EPR, and other techniques. Spectral data suggest an octahedral geometry around the metal ion. Biological screening showed the complexes have antibacterial, antifungal, and DNA cleavage activities.
This document describes the crystal structure of the compound terbinafine, which was analyzed using X-ray single crystal diffraction. Key findings include:
- Terbinafine crystallizes in the monoclinic space group P21/n with unit cell parameters a=5.9181(3)Å, b=29.4239(14)Å, c=11.429 β=97.92 ̊, V=1971.24(16) Å3, Z=4.
- Two water molecules were present in the crystal structure unit cell and engaged in hydrogen bonding, providing stability to the structure.
- The two benzene rings in the structure are essentially planar, while the side
Ruthenium(III) Catalyzed Oxidation of Sugar Alcohols by Dichloroisocyanuric A...Ratnakaram Venkata Nadh
Kinetics of ruthenium(III) catalyzed oxidation of biologically important sugar alcohols (myo-inositol,
D-sorbitol, and D-mannitol) by dichloroisocyanuric acid was carried out in aqueous acetic acid—perchloric
medium. The reactions were found to be first order in case of oxidant and ruthenium(III). Zero order
was observed with the concentrations of sorbitol and mannitol whereas, a positive fractional order was found
in the case of inositol concentration. An inverse fractional order was observed with perchloric acid in oxidation
of three substrates. Arrhenius parameters were calculated and a plausible mechanism was proposed
Partial Molar Volumes of Tetra alkyl ammonium salts in 10%(W/W) 2-(Ethoxy) et...Premier Publishers
In this article densities and apparent molar volumes of Tetra alkyl ammonium bromide salts ( ) in 10% (W/W) 2-(Ethoxy) ethanol-water mixture is studied at 30o, 35o and 40oC. Partial molar volumes are divided into ionic components using different methods such as Conway et al. and Jolicoeur et al. The results are compared with the values of partial molar volumes of ions reported in literature for pure water. Decrease in hydrophobic hydration is noticed. This may be due to the addition of co-solvent 2-(Ethoxy) ethanol (confirming the conclusions drawn from our viscosity studies that in 2-(Ethoxy) ethanol-water mixture, the structuredness of water is reduced by the breaking of hydrogen bonds). The values are divided into and . Making use of the Padova’s equation values of salts are calculated. These are also divided into ionic contributions. Dimensions of ions have been calculated to understand solvation behavior. It is shown that the classification of salts into structure makers and structure breakers on the basis of the sign of is not valid for the present water rich mixed solvent system.
METALLO - BIOACTIVE COMPOUNDS AS POTENTIAL NOVEL ANTICANCER THERAPYijac123
Mono and bi-organometallic complexes of Cu(II), Ni(II), Mn(II), Zn(II) and Ag(I) complexes with
oxaloamide ligand has much potential as therapeutic and diagnostic agents. The ligand allows the
thermodynamic and kinetic reactivity of the metal ion to be controlled and also provide a scaffold for
functionalization. Specific examples involving the design of metal complexes as anticancer agents are
discussed. These complexes have been synthesized and characterized by (1H-NMR, mass, IR, UV-VIS,
ESR) spectra, magnetic moments and conductance measurements, elemental and thermal analyses. Molar
conductances in DMF solution indicates that, the complexes are non-electrolytes. The ESR spectra of solid
Cu(II) complexes (2-5) show an axial type indicating a d(X2-y2) ground state with a significant covalent
bond character. However, Mn(II) complex(9), shows an isotropic type indicating an octahedral geometry.
Cytotoxic evolution IC50 of the ligand and its complexes have been carried out. Cu(II) Complexes show
enhanced activity in comparison to the parent ligand or standard drug. Copper is enriched in various
human cancer tissues and is a co-factor essential for tumor angiogenesis processes. However, the use of
copper binding ligand to target tumor, copper could provide a novel strategy for cancer selective
treatment.
This document reports on the synthesis and characterization of a Schiff base ligand and its cobalt and copper metal complexes. The ligand N,N’-(2-hydroxybenzaldehyde)diamino diphenyl ether was synthesized by condensing 2-hydroxybenzaldehyde and 4,4’-diaminodiphenyl ether. Cobalt and copper complexes were prepared by reacting the ligand with cobalt chloride and copper chloride respectively. The ligand and complexes were characterized using techniques such as UV-visible, FTIR, and NMR spectroscopy. They exhibited octahedral geometry. The ligand and complexes were also screened for antimicrobial activity, with the copper complex showing the highest activity against Staphylococcus aureus.
This document repeatedly discusses an "Optimal Digital Lattice" without providing any further context or details about what an optimal digital lattice is or what it is used for. The document consists solely of the phrase "Optimal Digital Lattice" written multiple times without any other words.
NCompass Live - http://nlc.nebraska.gov/ncompasslive/
June 29,2016
Libraries Without Borders is an international non-profit organization whose mission is to expand access to information by creating and supporting library programs around the world. Paloma Pradere and Kimmie Ross, from Libraries Without Borders, will join us to talk about their project, the Ideas Box, a portable library/multi-media center toolkit for refugee and vulnerable populations. This 'pop-up library' includes its own satellite internet connection and power supply, laptops, tablets, books and ebooks, as well as many educational, informational, and leisure resources. She will give an overview of where the Ideas Box has been implemented, its impact in those communities, and share ideas for next steps.
NCompass Live - 10/28/15
http://nlc.nebraska.gov/ncompasslive/
Want to know more about how the Golden Sower Award was started and how titles end up on the list each year? Golden Sower Chair, Kathy Schultz; Golden Sower Historian, Marsha Bradbury; and Library Commission staff member Sally Snyder will present the history and the process of the Golden Sower Award, including a look at the web site.
Big changes are coming again to E-rate, the federal program that provides discounts to assist schools and public libraries in the United States to obtain affordable Internet access and Connections. USAC has launched the E-Rate Productivity Center, EPC, for the 2016 Funding Year. This new online portal will be the main point of entry for all future E-rate interactions. With your organizational account you will use EPC to file forms, track your application status, communicate with USAC, and more.
What does your library need to know to use this new E-rate portal? In this workshop, Christa Burns, Nebraska’s State E-rate Coordinator for Libraries, will first cover the basics of the E-rate program and then show you how to access and use your account in EPC to submit your Funding Year 2016 E-rate application.
Este documento ofrece orientación sobre cómo realizar una historia clínica efectiva. Explica que una historia clínica debe incluir datos generales del paciente, motivo de consulta, revisión por sistemas, antecedentes personales y familiares, perfil social e información sobre el examen físico, pruebas complementarias, diagnóstico y tratamiento. También enfatiza la importancia de la observación, la comunicación y el juicio crítico para los médicos.
Este documento resume varias complicaciones crónicas asociadas con la diabetes, incluyendo la retinopatía diabética, nefropatía diabética, neuropatía diabética, complicaciones cutáneas, ateroesclerosis, y pie diabético. Describe los mecanismos patogénicos, signos y síntomas, y opciones de tratamiento para cada una.
This document discusses jaundice and provides information on its causes, presentation, evaluation and management. It defines jaundice as a yellowish discoloration of tissues caused by elevated bilirubin levels. Elevated bilirubin can be unconjugated or conjugated. The document describes approaches to determining the underlying etiology of jaundice including distinguishing between hepatocellular and cholestatic causes as well as intrahepatic and extrahepatic obstruction. Liver enzyme levels and other lab tests are discussed. Specific conditions that can cause jaundice like Gilbert's syndrome and Crigler-Najjar syndrome are also summarized.
Webinar - Coding Clubs: Youth Programming for Public Libraries - 2016-09-28TechSoup
Visit http://www.techsoupforlibraries.org for donated technology for libraries.
Does your library offer programs related to coding? Coding is quickly gaining traction as an essential digital skill in the 21st century, and many public libraries are offering coding classes for youth and adults as a way of promoting STEM education (Science, Technology, Engineering, and Math). The challenge is that coding is often a new skill for librarians and library staff who are responsible for offering programs. The good news is that you don’t have to be an expert in computer science to offer effective educational programs that teach coding skills. There are many free resources that can be used as a guide to starting a coding club at your library, no experience required.
See two examples of public libraries that have offered coding clubs using free curriculum provided by library partners.
-- The Memorial Hall Library (Andover, MA) offered a coding club in 2016 in partnership with Girls Who Code, a nonprofit organization that provides a framework and curriculum for coding clubs.
-- The Piscataway Library (New Jersey) just completed their second round of their Computer Science Club using the free Google CS curriculum. This theme centered around Fashion & Design.
Seminario Le fonti integrate per l’analisi del turismo in Campania, Napoli 15 dicembre 2016
Università degli studi di Napoli “Parthenope” Villa Doria d’Angri Sala Convegni via Francesco Petrarca, 80
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A copper-catalyzed synthesis of N-sulfonylamidines is reported via a three-component coupling of sulfonyl azides, terminal alkynes, and trialkylamines. The reaction involves the formation of a ketenimine intermediate through 1,3-dipolar cycloaddition of the sulfonyl azide and copper acetylide, which is then trapped by the trialkylamine to form the N-sulfonylamidine product. The method provides a practical route for synthesizing functionalized N-sulfonylamidines in good yields under mild conditions.
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-(5-bromo-2-hydroxybenzy-lidene) isonicotinohydrazide (H2La
), N0
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2. The results indicate that the catechols undergo a 1,4 Michael addition reaction with 4-hydroxycoumarin upon electrochemical oxidation, producing coumestan derivative products.
3. Electrochemical synthesis of the coumestan derivatives was successfully performed in an undivided cell in good yield and purity using controlled-potential electrolysis. The products were characterized using various analytical techniques.
A new Schiff base 4-chlorophenyl)methanimine
(6R,7R)-3-methyl-8-oxo-7-(2-phenylpropanamido)-5-thia-1-
azabicyclo[4.2.0]oct-2-ene-2-carboxylate= (HL)= C23H20
ClN3O4S) has been synthesized from β-lactam antibiotic
(cephalexin mono hydrate(CephH)=(C16H19N3O5S.H2O) and 4-
chlorobenzaldehyde . Figure(1) Metal mixed ligand complexes
of the Schiff base were prepared from chloride salt of
Fe(II),Co(II),Ni(II),Cu(II),Zn(II) and Cd (II), in 50% (v/v)
ethanol –water medium (SacH ) .in aqueous ethanol(1:1)
containing and Saccharin(C7H5NO3S) = sodium hydroxide.
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NMR for ligand and melting point molar conductance, magnetic
moment. and determination the percentage of the metal in the
complexes by flame(AAS). The ligands and there metal
complexes were screened for their antimicrobial activity against
four bacteria (gram + ve) and (gram -ve) {Escherichia coli,
Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus}.
The proposed structure of the complexes using program, Chem
office 3D(2006). The general formula have been given for the
prepared mixed ligand complexes Na2[M(Sac)3(L)], M(II) = Fe
(II), Co(II) , Ni(II), Cu (II), Zn(II) , and Cd(II).
HL= C29H24 ClN3O4S, L= C29H23 ClN3O4S -.
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2) Thiosaccharin forms both sulfur-bridged and nitrogen/sulfur-bridged complexes with a triosmium cluster.
3) The complexes undergo phosphine substitution reactions to install phosphine ligands on the metal centers.
2009_Nguyen et al._Journal of Organometallic ChemistryHuyen Lyckeskog
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Ruthenium catalysts were found to efficiently catalyze the amidation of C-H bonds on heteroaryl-substituted arenes and heteroarenes using sulfonyl azides. Cationic ruthenium(II) complexes with silver additives were the most effective catalysts, allowing for amidations of electron-rich and electron-deficient substrates with good functional group tolerance. Mechanistic studies indicated a reversible, electrophilic ruthenation involving C-H activation followed by reaction with the azide.
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Triethylamine-catalyzed reactions of malononitrile, carbon disulfide, and various oxiranes produce functionalized 2-(1,3-oxathiolan-2-ylidene)malononitriles in good yields. The reaction occurs under mild conditions in toluene with triethylamine as base. The products contain a polarized carbon-carbon double bond, as shown by 13C NMR spectroscopy. A range of substituted oxiranes participate in the reaction, affording diverse oxathiolane products in high regioselectivity.
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2) Various synthesis methods were used to produce different crystal structures, including NaFe3(HPO3)2(H2PO3)6 and Fe2(HPO3)3, which were characterized using techniques like single crystal X-ray diffraction.
3) Based on the crystal structures and oxidation states of iron, Fe2(HPO3)3 and NaFe(H2PO4)3·H2O show the most potential for sodium ion batteries, though further electrochemical studies are needed.
Reduction of cu o and cu2o with h2 h embedding and kinetics effects in the ...Luciana Pirone
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1) CuO reduces directly to metallic copper without forming intermediate copper suboxides like Cu4O3 or Cu2O under normal hydrogen flow rates.
2) The reduction of CuO is easier than the reduction of Cu2O, with apparent activation energies of 14.5 kcal/mol and 27.4 kcal/mol, respectively.
3) During CuO reduction, the system can reach metastable states and react with hydrogen instead of
This document summarizes a method for producing silver nanowires through a soft, self-seeding polyol process. Combined characterization techniques show that nanosized TiO2 particles have been incorporated into the channels of mesoporous silica films (MSTFs) while retaining the hexagonal mesostructure. XPS analysis further confirms the presence of both an anatase-like TiO2 phase and isolated [TiO4] units in the framework or on pore surfaces of the TiO2/MSTFs composites.
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This document summarizes the synthesis, crystal structure, and properties of triphenylguanidinium perrhenate hemihydrate. Key points include:
- Triphenylguanidinium perrhenate hemihydrate, [(C6H5NH)3C]ReO4 · 0.5H2O (I), was successfully synthesized and its crystal structure was determined via X-ray diffraction.
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1. Probing structural adaptability in templated vanadium selenites
Philip D.F. Adler a
, Rosalind Xu a
, Jacob H. Olshansky a
, Matthew D. Smith a
, Katherine C. Elbert a
,
Yunwen Yang a
, Gregory M. Ferrence c
, Matthias Zeller b
, Joshua Schrier a
, Alexander J. Norquist a,⇑
a
Department of Chemistry, Haverford College, Haverford, PA 19041, USA
b
Department of Chemistry, Youngstown State University, Youngstown, OH 44555, USA
c
Department of Chemistry, Illinois State University, Normal, IL 61790, USA
a r t i c l e i n f o
Article history:
Received 29 September 2015
Accepted 20 November 2015
Available online 2 December 2015
Keywords:
Vanadium selenites
Formation hypotheses
Hydrothermal
Machine learning
Decision tree
a b s t r a c t
The structural adaptability of [V3O5(SeO3)3]n
2nÀ
layers in organically templated vanadium selenites was
determined using a three step approach involving (i) an 84 reaction study with 14 distinct organic amines
and 6 different reaction conditions, (ii) decision tree construction using both dependent and independent
variables, and (iii) the derivation of chemical hypotheses. Formation of [V3O5(SeO3)3]n
2nÀ
layers requires
that three criteria be met. First, compound stabilization through hydrogen-bonding with specific nucle-
ophilic oxide ions is needed, requiring the presence of a primary ammonium site on the respective
organic amine. Second, layer formation is facilitated through the use of compact ammonium cations that
are able to achieve charge density matching with the anionic layers. Third, competition between organic
ammonium cations and NH4
+
, which affects product formation, can be controlled through reagent choice
and initial reactant concentrations. This approach to elucidate structural adaptability is generalizable and
can be applied to a range of chemical systems.
Ó 2015 Elsevier Ltd. All rights reserved.
1. Introduction
Many solid state structure types can be formed with a wide
range of chemical compositions. These ‘adaptable’ structures;
including perovskites [1,2], spinels [3], garnets [4], and lyonsites
[5] to name a few, are able to incorporate a host of different metal
cations yet still preserve their inherent connectivities. Such struc-
ture types can exhibit a host of desirable physical properties, many
of which can be tuned via cation substitution, and have been the
focus of intense interest for many decades. Understanding the
extent of a structure type’s adaptability allows for one to predict
which compositions might be stable, leading to the development
of tolerance factors [6,7], based upon ionic radii. Unfortunately,
such strategies are not easily extended to inorganic organic hybrid
materials owing to the lack of a single metric that describes the
complex properties of the organic components.
Much like the structure types discussed above, inorganic
organic hybrid materials [8–12] can possess a wide range of inter-
esting physical properties, including catalytic activity, molecular
sieving, gas adsorption [13], nonlinear optical properties [14],
and the more recent emergence of hybrid perovskite [15,16] pho-
tovoltaics [17–21]. A primary challenge in probing structural
adaptability in these structures stems from the complexity of both
the organic structure and the types of interactions that can exist
between the organic and inorganic components in materials such
as metal–organic frameworks [22–24], supramolecular compounds
[25–28] and organically templated metal oxides [8,9]. The pres-
ence of covalent, ionic and coordination bonds, as well as hydro-
gen-bonding, van der Waals forces and p–p stacking can make
the structural analyses of these interactions difficult [29]. Addi-
tionally, the synthesis of such compounds often involves solution
phase techniques, which can preclude product stoichiometry con-
trol [30].
The approach to elucidating structural adaptability in this report
focuses on templated [V3O5(SeO3)3]n
2nÀ
layer-containing com-
pounds and involves three stages. First, 84 chemical reactions were
conducted using 14 distinct organic amines and 6 different sets of
reaction conditions, in order to cover the maximal descriptor space
for reactions from which this layer topology can be formed. Second,
a decision tree was constructed using both dependent and
independent variables from the experimental data. Third, a series
of chemical hypotheses, derived from the decision tree using the
informed understanding of a chemist, were used to illuminate the
bounds on structural adaptability for templated [V3O5(SeO3)3]n
2nÀ
layer-containing compounds. Seven new compounds containing
http://dx.doi.org/10.1016/j.poly.2015.11.038
0277-5387/Ó 2015 Elsevier Ltd. All rights reserved.
⇑ Corresponding author at: Haverford College, 370 Lancaster Avenue, Haverford,
PA 19041, USA. Tel.: +1 (610) 896 2949; fax: +1 (610) 896 4963.
E-mail address: anorquis@haverford.edu (A.J. Norquist).
URL: http://www.haverford.edu/chem/Norquist/ (A.J. Norquist).
Polyhedron 114 (2016) 184–193
Contents lists available at ScienceDirect
Polyhedron
journal homepage: www.elsevier.com/locate/poly
2. templated [V3O5(SeO3)3]n
2nÀ
layers were synthesized, six of which
were structurally characterized using single crystal X-ray
diffraction.
2. Experimental
2.1. Materials
NH4VO3 (99%), NaVO 3 (anhydrous, 99.9%), SeO2 (99.4%), H2SeO3
(98%), ethylenediamine (en, P99%), 1,3-diaminopropane (1,3-dap,
P99%), 1,4-diaminobutane dihydrochloride (1,4-dab, P99.0%),
1,5-diaminopentane (1,5-dap, P97%), 1,6-diaminohexane (1,6-
dah, 98%), spermine (P97%), 3-aminoquinuclidine dihydrochloride
(3-aqn, 98%), 3-aminopyrrolidine dihydrochloride (3-apyr, 98%),
2-(aminomethyl)piperidine (2-amp, 97%), N,N,N’,N’-tetram-
ethylethylenediamine (tmed, 99%), piperazine (pip, 99%),
2-methylpiperazine (2-mpip, 95%), 2,5-dimethylpiperazine (2,5-
dmpip, 98%), and 1,4-diazabicyclo [2.2.2] octane (dabco, P99.0%)
were purchased from Sigma–Aldrich. All reagents were used as
received. Deionized water was used in these syntheses.
2.2. Syntheses
All reactions were conducted in either 23 mL poly(fluoro-ethy-
lene-propylene) lined pressure vessels or 15 mL polypropylene
bottles. Initial reaction pHs were controlled by the addition of
4 M HCl and 4 M NaOH. The reactions were heated to a set temper-
ature and allowed to soak. The reactions were then cooled to room
temperature at a rate of 6 °C hÀ1
to promote the growth of large
single crystals. Autoclaves and bottles were opened in air, and
products were recovered via vacuum filtration. No additional crys-
talline or amorphous reaction products were observed.
[C3H12N2][V3O5(SeO3)3]ÁH2O (1) was synthesized as sheet-like
black-green crystals through the reaction of 0.1102 g
(9.42 Â 10À4
mol) NH4VO3, 1.0912 g (9.83 Â 10À3
mol) SeO2,
0.4341 g (5.86 Â 10À3
mol) 1,3-dap, and 6.056 g (3.36 Â 10À1
mol)
H2O. The reaction was heated at 110 °C for 24 h in 23 mL poly(flu-
oro-ethylene-propylene) lined pressure vessels; initial pH was set
to 3. IR data (cmÀ1
): O–H, 3567; C–H, 2871; N–H, 1626, 1596,
1540, 1498, 1475; V@O, 974; Se–O, 830. EA obsd (calc): C 5.19%
(5.09%); H 1.96% (2.00%); N 3.92% (4.00%); V 22.02% (21.60%); Se
33.91% (33.50%).
[C4H14N2][V3O5(SeO3)3] (2) was synthesized as sheet-like black-
green crystals through the reaction of 0.1382 g (1.18 Â 10À3
mol)
NH4VO3, 1.131 g (1.02 Â 10À2
mol) SeO2, 0.0930 g (5.77 Â 10À4
mol) 1,4-dab, and 2.055 g (1.14 Â 10À1
mol) H2O. The reaction
was heated at 110 °C for 24 h in 23 mL poly(fluoro-ethylene-
propylene) lined pressure vessels; initial pH was set to 3. IR data
(cmÀ1
): C–H, 2919; N–H, 1656, 1525, 1465, 1385; V@O, 985,
968; Se–O, 829. EA obsd (calc): C 6.72% (6.82%); H 1.29% (2.00%);
N 3.89% (4.00%); V 21.17% (21.70%); Se 32.74% (33.70%).
[C10H30N4][V3O5(SeO3)3]2 (3) was synthesized as sheet-like
black-green crystals through the reaction of 0.1327 g
(1.13 Â 10À3
mol) NH4VO3, 1.039 g (9.36 Â 10À3
mol) SeO2,
0.2055 g (1.02 Â 10À3
mol) spermine, and 9.053 g (5.02 Â 10À1
mol) H2O. The reaction was heated at 110 °C for 24 h in 23 mL
poly(fluoro-ethylene-propylene) lined pressure vessels; initial pH
was set to 3. IR data (cmÀ1
): C–H, 2849; N–H, 1634, 1581, 1527,
1465, 1414, 1385; V@O, 982, 966; Se–O, 825. EA obsd (calc): C
8.36% (8.37%); H 1.50% (2.10%); N 3.84% (3.90%); V 21.22%
(21.30%); Se 31.49% (33.10%).
[C4H12N2][V3O5(SeO3)3] (4) was synthesized as sheet-like black-
green crystals through the reaction of 0.1468 g (1.20 Â 10À3
mol)
NH4VO3, 0.4460 g (4.02 Â 10À3
mol) SeO2, 0.1953 g (1.23 Â 10À3
mol) 3-apyr, and 9.072 g (5.03 Â 10À1
mol) H2O. The reaction was
heated at 90 °C for 24 h in 23 mL poly(fluoro-ethylene-propylene)
lined pressure vessels; initial pH was set to 3. IR data (cmÀ1
): C–
H, 2996; N–H, 1635, 1596, 1532; V@O, 977; Se–O, 826. EA obsd
(calc): C 6.52% (6.84%); H 1.73% (1.70%); N 3.65% (4.00%); V
21.29% (21.80%); Se 33.15% (33.80%).
[C6H16N2][V3O5(SeO3)3]ÁH2O (5) was synthesized as rod-like
black-green crystals through the reaction of 0.1512 g
(1.29 Â 10À3
mol) NH4VO3, 1.3820 g (1.07 Â 10À2
mol) SeO2,
0.0891 g (7.80 Â 10À4
mol) 2-amp, and 2.126 g (1.18 Â 10À1
mol)
H2O. The reaction was heated at 90 °C for 48 h in 15 mL polypropy-
lene bottles; initial pH was set to 5. IR data (cmÀ1
): O–H, 3448; C–
H, 2851; N–H, 1636, 1611, 1541, 1488, 1458; V@O, 982; Se–O, 822.
EA obsd (calc): C 10.42% (9.63%); H 2.65% (2.40%); N 3.62% (3.70%);
V 21.15% (20.40%); Se 31.38% (31.70%).
[C7H14N2][V3O5(SeO3)3]ÁH2O (6) was synthesized as sheet-like
black crystals through the reaction of 0.1402 g (1.15 Â 10À3
mol)
NaVO3, 0.6758 g (6.09 Â 10À3
mol) SeO2, 0.1987 g (9.98 Â 10À4
mol) 3-aqn, and 6.068 g (3.37 Â 10À1
mol) H2O. The reaction was
heated at 150 °C for 24 h in 23 mL poly(fluoro-ethylene-propylene)
lined pressure vessels; initial pH was set to 3. IR data (cmÀ1
): O–H,
Table 1
Crystallographic data for compounds 1–6.
Compound [C3H12N2][V3O5(SeO3)3]Á
H2O (1)
[C4H14N2]
[V3O5(SeO3)3] (2)
[C10H30N4]
[V3O5(SeO3)3]2 (3)
[C4H12N2]
[V3O5(SeO3)3] (4)
[C6H16N2][V3O5(SeO3)3]Á
H2O (5)
[C7H14N2][V3O5(SeO3)3]Á
H2O (6)
Formula C3H14N2O15Se3V3 C4H14N2O14Se3V3 C10H30N4O28Se6V6 C4H12N2O14Se3V3 C6H18N2O15Se3V3 C7H16N2O15Se3V3
Formula
weight
707.85 703.86 1433.76 701.85 747.92 759.93
Space group P21/m (No. 12) P 1 (No. 2) P 1 (No. 2) P 1 (No. 2) P 1 (No. 2) P 1 (No. 2)
a (Å) 6.3205(8) 6.321(5) 6.3084(17) 6.3279(2) 6.3115(2) 6.3318(2)
b (Å) 19.766(3) 11.427(5) 12.101(3) 10.4185(4) 12.8782(5) 11.7591(4)
c (Å) 13.2127(17) 12.229(5) 12.405(3) 13.2291(5) 13.2312(5) 13.2393(5)
a (°) 90 112.361(5) 65.392(3) 105.404(2) 116.6228(14) 104.2796(16)
b (°) 97.314(2) 90.220(5) 88.996(4) 96.327(2) 96.0053(16) 97.2709(16)
c (°) 90 97.005(5) 81.339(4) 101.654(2) 97.1663(17) 100.1350(17)
V (Å3
) 1637.3(4) 809.6(8) 850.0(4) 811.00(5) 938.16(6) 925.34(6)
Z 4 2 1 2 2 2
qcalc 2.871 2.887 2.801 2.874 2.647 2.727
k (Å) 0.71073 0.71073 0.71073 0.71073 0.71073 0.71073
T (K) 100(2) 100(2) 100(2) 100(2) 100(2) 100(2)
l (mmÀ1
) 8.429 8.518 8.115 8.503 7.363 7.467
R1
a
0.0337 0.0458 0.0313 0.0634 0.0552 0.0143
wR2
b
0.0803 0.1075 0.0768 0.1853 0.1293 0.0385
a
R1 = R||Fo| À |Fc||/R|Fo|.
b
wR2 = [Rw(Fo
2
À Fc
2
)2
/[Rw(Fo
2
)2
]1/2
.
P.D.F. Adler et al. / Polyhedron 114 (2016) 184–193 185
3. 3384; C–H, 3113, 2918; N–H, 1628, 1522, 1457; V@O, 981; Se–O,
826. EA obsd (calc): C 10.97% (11.09%); H 1.91% (2.10%); N 3.64%
(3.70%); V 19.24% (20.20%); Se 39.04% (31.30%).
Compound 7 was synthesized as clusters of black-green crystals
through the reaction of 0.1345 g (1.10 Â 10À3
mol) NH4VO3,
1.1383 g (1.03 Â 10À2
mol) SeO2, 0.0647 g (6.00 Â 10À4
mol) 1,5-
dap, and 2.0528 g (1.1139 Â 10À1
mol) H2O. The reaction was
heated at 110 °C for 24 h in 23 mL poly(fluoro-ethylene-propylene)
lined pressure vessels; initial pH was set to 3. IR data (cmÀ1
): O–H,
3408; C–H, 2988; N–H, 1627, 1599, 1558, 1541; V@O, 980; Se–O,
832. EA obsd: C 6.16%; H 4.09%; N 2.89%; Se 28.17%; V 15.79%.
2.3. Single crystal X-ray diffraction
Data were collected using a Bruker AXS Smart Apex CCD, ApexII
CCD or Quest CMOS diffractometers with Mo Ka radiation
(k = 0.71073 Å). The Smart Apex and ApexII instruments featured
fine focus sealed tube X-ray sources with graphite monochroma-
tors. The Quest CMOS instrument is an IlS microsource with a
laterally graded multilayer (Goebel) mirror for monochromatiza-
tion. A single crystal was mounted on a Mitegen micromesh mount
using a trace of mineral oil and cooled in situ to 100(2) K for data
collection. Frames were collected, reflections were indexed and
processed, and the files scaled and corrected for absorption using
APEX2 [31]. The heavy atom positions were determined using
SIR92 [32]. All other non-hydrogen sites were located from Fourier
difference maps. All non-hydrogen sites were refined using aniso-
tropic thermal parameters using full matrix least squares proce-
dures on Fo
2
with I 3r(I). Hydrogen atoms were placed in
geometrically idealized positions. All calculations were performed
using Crystals v.14.23c [33]. Relevant crystallographic data are
listed in Table 1.
2.4. Powder X-ray diffraction
Powder diffraction patterns were recorded on a GBC-Difftech
MMA powder diffractometer. Samples were mounted on glass
plates. Calculated powder patterns were generated from single
crystal data using ATOMS v.6.0 [34]. Powder X-ray diffraction pat-
terns were consistent with patterns predicted from the refined
structures of 1–6. No evidence of additional phases was observed.
2.5. Infrared spectroscopy
Infrared measurements were obtained using a Perkin Elmer FT-
IR Spectrum 1000 spectrophotometer. Samples were diluted with
spectroscopic grade KBr and pressed into pellets. Scans were col-
lected over the range of 400–4000 cmÀ1
.
2.6. Bond valence sums
Bond valence sums [35] calculations were performed using
parameters compiled by Brese and O’Keeffe [36]. Complete tables
of bond valence sums for compounds 1–6 are available in the
Supporting information.
2.7. Electronic structure calculations
Solid-state electronic structure calculations were performed
using ABINIT v.6.4.1 [37,38]. ABINIT calculations used the
Perdew-Burke-Ernzerhof generalized gradient approximation
Table 2
A list of the descriptors included in the decision tree creation, separated by function.
Type Subset Descriptor
Reaction Stoichiometry Amine amount (moles)
Vanadium amount (moles)
Selenium amount (moles)
Conditions Initial pH
Time at maximum temperature
Maximum temperature
Amine Amine structure Chain length
Molecular weight
Bond count
Nitrogen count
Primary ammonium site (yes/no)
Cyclic structure (yes/no)
Spherical (yes/no)
Amine acidity Minimum pKa
Maximum pKa
Charge density Maximal projection area/nitrogen
General properties Reagent is an HCl salt (yes/no)
Inorganics Vanadium counter ions Vanadium source contains NH4
+
(yes/no)
Vanadium source contains Na+
(yes/no)
Fig. 1. Polyhedral representation of the [V3O5(SeO3)3]n
2nÀ
layers found in compounds 1–7 and [C2H10N2][V3O5(SeO3)3]Á1.25H2O. Green and orange polyhedra represent
[V4+
O6] and [V5+
O6], respectively, while purple and red spheres represent selenium and oxygen. ELF isosurfaces are shown with a boundary condition of 0.96. (Color online)
186 P.D.F. Adler et al. / Polyhedron 114 (2016) 184–193
4. (PBE-GGA) exchange–correlation functional, norm-conserving
Troullier-Martins pseudopotentials, a planewave basis set with
energy cutoff of 25 Hartrees, a 6 Â 6 Â 6 Monkhorst–Pack k-point
sampling grid, and experimental crystal structures. Electron local-
ization functions (ELFs) were calculated from the self-consistent
valence electron densities and visualized using Vesta v.3.2.1 [39].
2.8. Non-covalent interaction (NCI) Index calculations
NCI analyses were performed using CRITIC 2 version 1.0 [40,41]
to generate promolecular densities from the default numerical
free-atom densities, using an approach similar as described in a
previous report [29]. The extraction of isosurfaces corresponding
to particular interactions was performed using Mathematica
10.0.0.0 (see Supporting information), and visualized using Vesta
v. 3.2.1.
2.9. Decision tree generation
A decision tree was generated using the program Weka [14],
and is a J48 decision tree, which is a java implementation of the
C4.5 decision tree algorithm [15]. The algorithm is provided with
the full set of descriptors, which are provided in the Supplemen-
tary data, and selects the descriptors that produces the ‘best’ split
of the data. See Table 2 for a list of descriptors. Heuristically, the
best split is the one that most accurately separates the greatest
number of results. In order to aid interpretation of the decision
tree, a correlation matrix was calculated between all of the molec-
ular descriptors that had been calculated. This correlation matrix is
available in the Supplementary data. Training and testing was per-
formed on all 84 reactions. Maximal projection areas were calcu-
lated using ChemAxon Calculator Plugin [42].
3. Results and discussion
The [V3O5(SeO3)3]n
2nÀ
layers shown in Fig. 1 are observed in a
range of different organically templated vanadium selenites, in
which a diverse set of organic amines are included. [C2H10N2]
[V3O5(SeO3)3]Á1.25H2O [43] contains ethylenediammoniun cations,
[C2H10N2]2+
, while compounds 1–7 include [1,3-dapH2]2+
, [1,4-
dapH2]2+
, [spermineH4]4+
, [3-apyrH2]2+
, [2-ampH2]2+
[3-aqnH2]2+
,
and [1,5-dapH2]2+
respectively. While these amines differ in struc-
ture and charge, their corresponding [V3O5(SeO3)3]n
2nÀ
layers are
essentially the same. These layers consist of clusters comprised
of six edge shared [VO6] polyhedra, which are linked to one
another by [SeO3]2À
groups. The vanadium oxide clusters contain
both V4+
and V5+
centers, whose oxidation states were determined
using bond valence sums. The V4+
sites are located on the ends of
each cluster, while the V5+
sites occupy the four central sites. The
coordination polyhedra containing V4+
sites are shown in green
while those containing V5+
are shown as orange octahedra in
Figs. 1–4. The calculated bond valence sums for the V4+
sites in
compounds 1–6 range from 4.17 to 4.22 vu, while the V5+
sites have
values of 4.99–5.11 vu. Corresponding differences in V–Obridging and
V–Oterminal bond lengths are observed. See Table 3. The decreased
bond distances in V5+
–O with respect to V4+
–O are a result of the
increased charge on the vanadium center.
The three-dimensional structures of compounds 1–6 and
[C2H10N2][V3O5(SeO3)3]Á1.25H2O [43] are similar to one another.
The organic cations reside between [V3O5(SeO3)3]n
2nÀ
layers, creat-
ing three-dimensional hydrogen-bonding networks. Some com-
pounds, [C2H10N2][V3O5(SeO3)3]Á1.25H2O, 1, 5 and 6, contain
occluded water molecules, which also participate in the hydro-
gen-bonding networks. Three-dimensional packing figures are
shown in Figs. 2–4.
The existence of a series of compounds containing isotypic
[V3O5(SeO3)3]n
2nÀ
layers, despite the presence of a range of
Fig. 2. Three-dimensional packing figures of (a) [C2H10N2][V3O5(SeO3)3]Á1.25H2O,
(b) [C4H14N2][V3O5(SeO3)3] (1) and (c) [C4H14N2][V3O5(SeO3)3] (2). Green and
orange polyhedra represent [V4+
O6] and [V5+
O6], respectively, while purple, red,
blue, white and gray spheres represent selenium, oxygen, nitrogen, carbon and
hydrogen, respectively. Organic ammonium cation hydrogen atoms have been
omitted for clarity. (Color online)
P.D.F. Adler et al. / Polyhedron 114 (2016) 184–193 187
5. structurally diverse organic amines and a large set of different
reported inorganic structures in templated vanadium selenites
[43–52], prompted us to consider the bounds on the structural
adaptability for these layers. Two questions were raised. First,
which amines can possibly be incorporated into compounds con-
taining [V3O5(SeO3)3]n
2nÀ
layers? Second, for the amines than can
be incorporated, how do the synthetic windows differ between
amines? To answer these questions, 84 individual reactions were
conducted, containing 6 different sets of reaction conditions and
14 distinct organic amines.
The amines included in this study were selected to cover a
range in both structural and chemical diversity. Amines containing
only primary (en, 1,3-dap, 1,4-dab, 1,5-dap, 1,6-dah), only sec-
ondary (pip, 2-mpip, 2,5-dmpip), or only tertiary sites (tmed,
dabco) were used as well as amines containing both primary and
secondary (spermine, 3-apyr, 2-amp) and primary and tertiary
(3-aqn). A range of both linear amines and cyclic amines were cho-
sen. The linear amines ranged in length from en to 1,6-dah and
spermine. Structural diversity within the cyclic amines was
achieved by using both bicyclic structures (3-aqn, dabco) and cyc-
lic structures with pendant methyl groups (2-mpip, 2,5-dmpip).
The structures of the 14 amines used in this study are shown in
Fig. 5. The six different sets of reaction conditions provide a range
of reaction compositions, temperatures, reactions times and initial
pH values. The outcomes of the 84 reactions conducted are shown
in Fig. 6, with red and green squares indicating the absence and
presence of products containing [V3O5(SeO3)3]n
2nÀ
layers, respec-
tively. Hatched green squares indicate that a compound containing
[V3O5(SeO3)3]n
2nÀ
layers was synthesized, in addition to a least one
other phase.
Our domain expertise was used in the selection of descriptors in
this study, see Table 2. Descriptors were chosen to ensure that all
major differences between reactions and reactants were included.
Specific attention was paid to the structures of the organic mole-
cules, as these variations represent some of the largest differences
between individual reactions. The reaction descriptors include sto-
ichiometry (amounts of the amine, vanadium and selenium) and
conditions (pH, temperature and time). Reactant descriptors for
the inorganic components are focused on the counter ions in the
vanadium source (either NH4
+
or Na+
). No descriptors were included
for the selenium source. Amine descriptors include those that
describe structure (C: N ratio, chain length, molecular weight,
nitrogen count, bond count, and presence or absence of primary
ammonium sites, cyclic structures or spherical structures (bicy-
cles)), acidity (minimum and maximum pKa) and charge density
(maximal projection area/N). The amine area/N descriptor was
included to probe the role of charge density matching in these
reactions. This concept, largely developed by Ferey et al., requires
charge balance between the cationic and anionic components of
the structure for crystallization to occur. The amine areas were cal-
culated using ChemAxon as the maximal projection areas. Formal
charges on the cations scale with the number of ammonium sites.
Descriptors that are strongly correlated to other descriptors (intro-
ducing redundancies), chemically meaningless or contain missing
values should not be included in this type of analysis.
Two approaches to the generation of decision trees exist. Deci-
sion trees optimized for predictive purposes are ‘pruned’ as an
aspect of the algorithm, whereby branches on the tree for which
the evidence is tenuous are removed to prevent over-modeling.
Decision trees optimized for explanatory purposes are not pruned,
and generally yield more precise categorizations of the data on
which they are trained. The goal of ‘pruned’ decisions tree is to cat-
egorize the training data as precisely as possible, allowing complex
patterns to be found in the data. Cross-validation is not required
because no statistical meaning is derived from the decision tree,
but it is therefore essential to have a domain expert (in this case,
a chemist) ensure that splits in the tree make chemical sense.
The decision tree shown in Fig. 7 is optimized for explanatory pur-
poses and was created without pruning because the intended pur-
pose of this tree was to generate chemical hypotheses regarding
the reactions involved. These hypotheses cannot be generated in
isolation from the expert chemist; the chemical understanding of
such an expert is requisite to extract meaning from the descriptors.
Inspection of the decision tree shown in Fig. 7 exposes the limits
to the compositional adaptability of [V3O5(SeO3)3]n
2nÀ
layers in
templated compounds. Specifically, the reaction and reactant char-
Fig. 3. Three-dimensional packing figure of [C10H30N4][V3O5(SeO3)3]2 (3). Green and orange polyhedra represent [V4+
O6] and [V5+
O6], respectively, while purple, red, blue,
white and gray spheres represent selenium, oxygen, nitrogen, carbon and hydrogen, respectively. Organic ammonium cation hydrogen atoms have been omitted for clarity.
(Color online)
188 P.D.F. Adler et al. / Polyhedron 114 (2016) 184–193
6. Fig. 4. Three-dimensional packing figures of (a) [C4H12N2][V3O5(SeO3)3] (4), (b) [C6H16N2][V3O5(SeO3)3]ÁH2O (5) and (c) [C7H14N2][V3O5(SeO3)3]ÁH2O (6). Green and orange
polyhedra represent [V4+
O6] and [V5+
O6], respectively, while purple, red, blue, white and gray spheres represent selenium, oxygen, nitrogen, carbon and hydrogen,
respectively. Organic ammonium cation hydrogen atoms have been omitted for clarity. (Color online)
P.D.F. Adler et al. / Polyhedron 114 (2016) 184–193 189
7. acteristics required for layer formation under any of the reaction
conditions explored can be determined. Moreover, for amines that
are able to be incorporated into [V3O5(SeO3)3]n
2nÀ
compounds, we
can understand the variable ‘success’ rates as a function of reaction
conditions. Three specific hypotheses were generated. First, amines
must include a primary ammonium site in order to satisfy the
hydrogen-bonding requirements of the [V3O5(SeO3)3]n
2nÀ
layers.
Second, charge density matching [53,54] is required for the stabi-
lization of [V3O5(SeO3)3]n
2nÀ
layer-containing compounds. Third,
the use of NH4VO3 as a reagent introduces alternate products that
compete with the desired phases.
It is clear from the reaction grid that amines without primary
ammonium sites do not form [V3O5(SeO3)3]n
2nÀ
-layer containing
compounds under any of the reaction conditions explored. See
Fig. 6. The importance of this property is indicated by the fact that
the first selector in the decision tree is the presence or absence of
primary ammonium sites on the organic ammonium cations,
shown in the blue component of Fig. 7. Five of the amines tested
in this study (tmed, pip, 2-mpip, 2,5-dmpip and dabco) do not con-
tain primary ammonium cations and are not incorporated into
compounds containing [V3O5(SeO3)3]n
2nÀ
layers in any of the 84
reactions conducted. Templated vanadium selenites with different
inorganic structures have, however, been reported for pip [52], 2-
mpip [44,46], 2,5-dmpip [46], and dabco [43], which suggests that
these amines are not completely incompatible with vanadium
selenite structures. As such, their absence in [V3O5(SeO3)3]n
2nÀ
layer containing phases needs to be explained. Inspection of the
three-dimensional packing arrangements of [C2H10N2][V3O5
(SeO3)3]Á1.25H2O and compounds 1–6, shown in Figs. 2–4, reveals
that the primary ammonium sites reside on the same general position
in each compound. A pocket exists within each [V3O5(SeO3)3]n
2nÀ
layer, sitting between four adjacent vanadium oxide dimers. See
Fig. 8. It is in this pocket that the primary ammonium cations
reside, donating three hydrogen bonds to neighboring oxide
anions. In each case, the hydrogen-bond acceptors include the only
terminal Se@O oxide anion sites, which exhibit the highest nucle-
ophilicities [55–61], as determined using bond valence sums
[35,36], rendering them attractive to hydrogen bond donors. The
hydrogen-bonding interactions in these pockets were identified
and visualized using non-covalent interaction (NCI) index calcula-
tions. Three distinct isosurfaces, corresponding to N–HÁ Á ÁO hydro-
gen bonds, were observed in each hydrogen-bonding pocket,
confirming their assignment. Graphics of these isosurfaces and
NCI fingerprints are available for compounds 1–6 in the Supple-
mentary data. The formation of hydrogen-bonding interactions in
these pockets stabilizes the [V3O5(SeO3)3]n
2nÀ
layers and allows
for product formation.
The need for charge density matching [53–55,62,63] between
the cationic organic and anionic inorganic components in the for-
mation of [V3O5(SeO3)3]n
2nÀ
layer-containing compounds is mani-
fested in the decision tree, highlighted as the green regions in
Fig. 7. The [V3O5(SeO3)3]n
2nÀ
layers exhibit little flection [61], with
ranges in layer metrics differing by only 0.4%. As the areas and
charges of the [V3O5(SeO3)3]n
2nÀ
layers in [C2H10N2][V3O5(SeO3)3]-
Á1.25H2O and compounds 1–6 are essentially fixed, the compo-
nents of the interlayer spaces must balance the negative charges
on these layers. The second selector in the decision tree quantifies
the charge density of the amine as being equal to the amine’s max-
imal projection area divided by the number of nitrogen atoms it
contains, with the assumption that each ammonium has a formal
charge of +1. Eleven of the twelve reactions involving amines with
high values fail to result in [V3O5(SeO3)3]n
2nÀ
layer-containing
compounds because the charge per unit area values are insufficient
for charge density matching to be achieved. 1,5-dap and 1,6-dah
are the two amines involved in these twelve reactions.
All of the linear diamines used in this study exist as +2 cations
under the conditions explored. Ethylenediamine (en), [1,3-
dapH2]2+
and [1,4-dapH2]2+
, are able to achieve charge density
matching with the [V3O5(SeO3)3]n
2nÀ
layers in [C2H10N2]
[V3O5(SeO3)3]Á1.25H2O, 1 and 2, respectively because their respec-
tive projection areas are small. Elongation of these cations to
[1,5-dapH2]2+
and [1,6-dahH2]2+
, in contrast, makes charge density
matching more difficult because cation charge remains fixed at +2,
while cation size increases. It was expected that the inclusion of
[1,5-dapH2]2+
or [1,6-dahH2]2+
would either be difficult or impossi-
ble, because the respective charge densities of these cations are
insufficient. As observed in Fig. 6, no reactions were successful
with 1,6-dah, regardless of the reaction composition or conditions
applied. A lone example of a [V3O5(SeO3)3]n
2nÀ
layer-containing
compound with [1,5-dapH2]2+
cations exists, denoted compound
7. As expected, this sample did not contain large high quality single
crystals, instead smaller crystallites of lower quality were
observed. These crystallites were of insufficient size and quality
for single crystal X-ray diffraction data collection. However,
Table 3
Bond length and bond valence ranges for V–O interactions in compounds 1–6.
Species Bond distances (Å) and bond valence ranges (vu)
V–Oterminal V–Obridging
V4+
–O 1.596(3)–1.609(7) 1.916(7)–2.516(3)
1.66–1.60 0.70–0.14
V5+
–O 1.584(8)–1.600(3) 1.735(5)–2.422(6)
1.81–1.73 1.20–0.19
Fig. 5. The fourteen amines used in this study.
190 P.D.F. Adler et al. / Polyhedron 114 (2016) 184–193
8. Fig. 6. Reaction outcomes as a function of conditions and amine identity.
Fig. 7. [V3O5(SeO3)3]n
2nÀ
layer formation decision tree. Selection of primary amines is shown in blue, selection by charge density matching is shown in green, and selection by
vanadium source is shown in red. Each reaction bin contains a specific reaction outcome value and numbers of reactions correctly and incorrectly assigned to that bin,
respectively. (Color online)
P.D.F. Adler et al. / Polyhedron 114 (2016) 184–193 191
9. formation of a [V3O5(SeO3)3]n
2nÀ
layer-containing compound is
supported by three lines of evidence. First, the powder X-ray
diffraction of 7 strongly resembles the patterns of 1–6. Powder
X-ray diffraction patterns for all compounds are available in the
Supplementary data. In each case, the two most intense peaks cor-
respond to reflections aligned with the [V3O5(SeO3)3]n
2nÀ
layers; 0
2 0/0 6 0 for 1, 0 1 1/0 3 3for 2 and 3, 0 1 0/0 3 3 0 for 4–6. This
suggests that while the [V3O5(SeO3)3]n
2nÀ
layers are present in 7,
periodicity between layers is less well defined owing to difficulty
in charge density matching. Second, the color of the crystallites is
similar to compounds 1–6, suggesting the presence of intervalence
charge transfer bands between adjacent V4+
and V5+
centers. A pho-
tograph of [C2H10N2][V3O5(SeO3)3]Á1.25H2O and compounds 1–7 is
available in the Supplementary data. Third, elemental analyses
resulted in an approximate 1:1 ratio between V and Se, which
corresponds to the stoichiometry of the [V3O5(SeO3)3]n
2nÀ
layers.
The [spermine H4]4+
cations in 3 differ distinctly from the other
linear amines described above in that they include four ammonium
centers on each cation and contain both primary and secondary
sites. Their increased nitrogen count and subsequent charge on
each [spermine H4]4+
cation, coupled with great molecular flexibil-
ity, enables these cations to achieve charge density matching with
the [V3O5(SeO3)3]n
2nÀ
layers. As shown in Fig. 3, the primary
ammonium sites reside in the hydrogen-bonding pockets shown
in Fig. 8, while the secondary ammonium sites donate hydrogen
bonds to alternate oxide anions. The cyclic amines, 3-apyr, 2-
amp and 3-aqn all have smaller projection areas per N with respect
to 1,5-dap and 1,6-dah, and so are able to provide the required
amount of charge per Å2
. These amines contain primary ammo-
nium sites that can stabilize the layers through hydrogen-bonding,
and they enable charge density matching.
The formation of [V3O5(SeO3)3]n
2nÀ
layer-containing com-
pounds requires the presence of vanadium, selenium and an
organic amine. The ways in which different reaction parameters
affect reaction outcomes are evident in the red portion of the deci-
sion tree. Specifically, reactions that involve either en or 1,3-dap
can meet all the requirements listed above (primary ammonium
site, charge density matching, high selenium concentrations) and
still fail to result in target compound type. For these reactions, a
distinct differentiation between the use of NH4VO3 and NaVO3 is
observed in the decision tree. The use of NaVO3 results in the for-
mation of [V3O5(SeO3)3]n
2nÀ
layer-containing compounds. In
contrast, reactions involving NH4VO3 are only successful when
either the amount of solvent water is low or when the amine
concentration is high. The implication of this is that [enH2]2+
and
[1,3-dapH2]2+
have difficulty competing with [NH4]+
during
crystallization. The pKa2 values of these amines are considerably
higher than those of the cyclic amines, meaning that these acidic
hydrogens have lower charges and are less electrophilic with
respect to other amines. Decreasing the amount of solvent water
and/or increasing the amount of the amine both result in better
synthetic outcomes because these changes result in higher amine
concentrations. The lower acidities of other amines (1,4-dab,
spermine, 3-apyr, 2-amp and 3-aqn) render them better able to
complete with [NH4]+
, and so the same dependencies on reaction
conditions are not observed for these compounds in the
decision tree.
4. Conclusion
The structural adaptability of [V3O5(SeO3)3]n
2nÀ
layers in tem-
plated vanadium selenites arises from complicated non-covalent
interactions between the cationic organic and anionic inorganic
components. Using the results of a series of experiments with
varying amine structure and reaction conditions, combined with
relevant molecular characteristic descriptors, enabled the construc-
tion of a decision tree that reveals new chemical hypotheses about
the rules governing layer formation. More generally, this approach
can be used to understand the factors governing structural adapt-
ability of inorganic–organic hybrid materials. Stabilization and
crystallization of [V3O5(SeO3)3]n
2nÀ
layers requires amines with
(a) primary ammonium sites, in order to satisfy the
hydrogen-bonding requirements of the [V3O5(SeO3)3]n
2nÀ
layers,
(b) sufficient charge densities to balance the charge of the
[V3O5(SeO3)3]n
2nÀ
-layer containing compounds, and (c) conditions
that bias the organic amines to form extended hydrogen-bonding
networks.
Acknowledgments
The authors acknowledge support from the NSF (Award No.
DMR-1307801), A.N. and J.S. acknowledge the Henry Dreyfus Tea-
cher-Scholar Awards Program and grants to Haverford College
from the HHMI Undergraduate Science Education Program. M.Z.
acknowledges support for the purchase of a diffractometer from
the NSF grant 1337296, the Ohio Board of Regents grant CAP-491
and from Youngstown State University. G.F. acknowledges the
NSF (Award No. CHE-1039689) for funding ISU’s X-ray diffractome-
ter. This research used computational resources of the National
Energy Research Scientific Computing Center (NERSC), which is
supported by the Office of Science of the U.S. Department of Energy
under Contract No. DE-AC02-05CH11231.
Fig. 8. Local hydrogen-bonding environments for the primary ammonium sites in compounds 1–6.
192 P.D.F. Adler et al. / Polyhedron 114 (2016) 184–193
10. Appendix A. Supplementary data
Supplementary data associated with this article can be found, in
the online version, at http://dx.doi.org/10.1016/j.poly.2015.11.038.
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