The researchers are developing new copper photocatalysts as more sustainable alternatives to ruthenium complexes commonly used in photoredox reactions. They synthesized copper complexes by first making dichlorinated phenanthroline ligands, then reacting them with copper sources to form homoleptic and heteroleptic complexes. These copper photocatalysts were evaluated in an alkylation reaction and yielded products ranging from 1% to 59%, demonstrating their potential as replacements for ruthenium complexes which are toxic, rare, and expensive.
Cross-Coupling of Unactivated Arenes: Direct Arene C-H Bond Arylation (Concepts of C-H Activation/Functionalization and its Recent Developments), Importance in the Drug Discovery Research
Cross-Coupling of Unactivated Arenes: Direct Arene C-H Bond Arylation (Concepts of C-H Activation/Functionalization and its Recent Developments), Importance in the Drug Discovery Research
Solventless reaction in green chemistryAfrin Nirfa
Solventless reactions or solid state reactions are one of the principles involved in green chemistry. these reactions are more useful because the toxicity of solvents are reduced, easy to handle, cheaper and makes environment friendly.
Light-Induced Controlled Free Radical Polymerization of Methacrylates Using I...Pawan Kumar
A novel visible light mediated catalytic system
based on low cost iron complex, that is, Fe(bpy)3(PF)6 photocatalyst
that initiates and control the free radical polymerization
of methacrylates using ethyl a-bromoisobutyrate (EBriB) as an
initiator and 20 watt LED as light source is developed. The
polymerization is initiated with turning the light on and immediately
terminated by turning the light off. In addition, the
molecular weight of polymer can be varied by changing the
ratio of monomer and initiator. The merits of the present methodology
lie in the use of low cost less precious, highly abundant
iron-based photocatalyst, avoidance of sacrificial donor
and need of lower catalyst amount under visible light. The
optimum amount of catalyst and initiator were established and
successful polymerization of various methacrylates was
achieved under the optimized polymerization conditions.
Visible Spectrophotometric Determination of Gemigliptin Using Charge Transfer...Ratnakaram Venkata Nadh
A visible spectrophotometric method was developed and validated for the determination of gemigliptin present in bulk drug and tablet formulation. It involves an indirect method of charge transfer complex formation in presence of NBS, metol and suphanilic acid. Gemigliptin was subjected to oxidation with excess amount of oxidant (NBS) and the unconsumed NBS oxidizes metol to give p-N-methylbenzoquinone monoamine (PNMM) which in turn forms a charge transfer complex with sulphanilic acid. Then validated the above developed method as per the current ICH guidelines. An excellent correlation coefficient (> 0.999) was found for the obtained regression equation
(y = –0.0302x + 0.928) in the range of 2.0–30.0 μg mL-1. The method was found to be simple and rapid because it does not involve any solvent extraction. The recovery levels of the drug were in the range 99.92 – 100.08.
Study of electrical properties of Polythiophene and its compositesIOSR Journals
Conducting polymers are known to have significant electrical properties which can be improved by strong oxidizing power of oxidizing agents like V2O5. In the current study oxidative polymerization of the thiophene monomers was done to obtain Polythiophene for converting it into its composites with V2O5 to study their improved electrical nature. The electrical properties of pure Polythiophene, pure V2O5, PTh- V2O5 composite 1:2 (thiophene: V2O5) and PTh- V2O5 composite 2:1(thiophene: V2O5) were studied by carrying out current voltage measurements. It can be stated that the increased concentration of V2O5 is responsible for the increased current flow through the polymer matrix. The study is explained on the basis of fact that oxidizing power leads to removal of higher number of charge carriers from the backbone thereby causing increases in current flow. Such conducting polymers have wide range of applications in the field of Metal ions detectors, molecular electronics, conductive adhesive, electrical displays, electromagnetic shields, chemical, biochemical and thermal sensors, rechargeable batteries, solid electrolytes, optical computers and ion exchange membrane
This module is designed to provide an introduction into the basic physics of a special class of materials : functional oxides, in specific conducting oxides for example semiconductor, photocatalyst, superconductor, electrochromic, noncentrosymmetric, ionic conductor, magnetic and magnetoresistance oxides.
It will cover several essential topics on the crystal structure of the functional oxides and relating the structure to the intriguing properties that the oxides have. In this module, the synthesis, preparation and characterisation of several functional oxides (with properties stated above) will be elucidated. Part of the course will focus on the development of functional oxide in nanoscale.
Overviews on the current and possible future technological applications of the functional oxides and other issues relevant for applications will be explored and presented via several case studies that will be presented and discussed. The ultimate aim of this course is to evoke interest of participants in this fascinating class of materials and also to equip them with essential knowledge on the pressing fundamental challenges in the formation, synthesis and applications of electronic functional oxides.
Solventless reaction in green chemistryAfrin Nirfa
Solventless reactions or solid state reactions are one of the principles involved in green chemistry. these reactions are more useful because the toxicity of solvents are reduced, easy to handle, cheaper and makes environment friendly.
Light-Induced Controlled Free Radical Polymerization of Methacrylates Using I...Pawan Kumar
A novel visible light mediated catalytic system
based on low cost iron complex, that is, Fe(bpy)3(PF)6 photocatalyst
that initiates and control the free radical polymerization
of methacrylates using ethyl a-bromoisobutyrate (EBriB) as an
initiator and 20 watt LED as light source is developed. The
polymerization is initiated with turning the light on and immediately
terminated by turning the light off. In addition, the
molecular weight of polymer can be varied by changing the
ratio of monomer and initiator. The merits of the present methodology
lie in the use of low cost less precious, highly abundant
iron-based photocatalyst, avoidance of sacrificial donor
and need of lower catalyst amount under visible light. The
optimum amount of catalyst and initiator were established and
successful polymerization of various methacrylates was
achieved under the optimized polymerization conditions.
Visible Spectrophotometric Determination of Gemigliptin Using Charge Transfer...Ratnakaram Venkata Nadh
A visible spectrophotometric method was developed and validated for the determination of gemigliptin present in bulk drug and tablet formulation. It involves an indirect method of charge transfer complex formation in presence of NBS, metol and suphanilic acid. Gemigliptin was subjected to oxidation with excess amount of oxidant (NBS) and the unconsumed NBS oxidizes metol to give p-N-methylbenzoquinone monoamine (PNMM) which in turn forms a charge transfer complex with sulphanilic acid. Then validated the above developed method as per the current ICH guidelines. An excellent correlation coefficient (> 0.999) was found for the obtained regression equation
(y = –0.0302x + 0.928) in the range of 2.0–30.0 μg mL-1. The method was found to be simple and rapid because it does not involve any solvent extraction. The recovery levels of the drug were in the range 99.92 – 100.08.
Study of electrical properties of Polythiophene and its compositesIOSR Journals
Conducting polymers are known to have significant electrical properties which can be improved by strong oxidizing power of oxidizing agents like V2O5. In the current study oxidative polymerization of the thiophene monomers was done to obtain Polythiophene for converting it into its composites with V2O5 to study their improved electrical nature. The electrical properties of pure Polythiophene, pure V2O5, PTh- V2O5 composite 1:2 (thiophene: V2O5) and PTh- V2O5 composite 2:1(thiophene: V2O5) were studied by carrying out current voltage measurements. It can be stated that the increased concentration of V2O5 is responsible for the increased current flow through the polymer matrix. The study is explained on the basis of fact that oxidizing power leads to removal of higher number of charge carriers from the backbone thereby causing increases in current flow. Such conducting polymers have wide range of applications in the field of Metal ions detectors, molecular electronics, conductive adhesive, electrical displays, electromagnetic shields, chemical, biochemical and thermal sensors, rechargeable batteries, solid electrolytes, optical computers and ion exchange membrane
This module is designed to provide an introduction into the basic physics of a special class of materials : functional oxides, in specific conducting oxides for example semiconductor, photocatalyst, superconductor, electrochromic, noncentrosymmetric, ionic conductor, magnetic and magnetoresistance oxides.
It will cover several essential topics on the crystal structure of the functional oxides and relating the structure to the intriguing properties that the oxides have. In this module, the synthesis, preparation and characterisation of several functional oxides (with properties stated above) will be elucidated. Part of the course will focus on the development of functional oxide in nanoscale.
Overviews on the current and possible future technological applications of the functional oxides and other issues relevant for applications will be explored and presented via several case studies that will be presented and discussed. The ultimate aim of this course is to evoke interest of participants in this fascinating class of materials and also to equip them with essential knowledge on the pressing fundamental challenges in the formation, synthesis and applications of electronic functional oxides.
Visible Spectrophotometric Determination of Gemigliptin Using Charge Transfer...Ratnakaram Venkata Nadh
A visible spectrophotometric method was developed and validated for the determination of gemigliptin present in bulk drug and tablet formulation. It involves an indirect method of charge transfer complex formation in presence of NBS, metol and suphanilic acid. Gemigliptin was subjected to oxidation with excess amount of oxidant (NBS) and the unconsumed NBS oxidizes metol to give p-N-methylbenzoquinone monoamine (PNMM) which in turn forms a charge transfer complex with sulphanilic acid. Then validated the above developed method as per the current ICH guidelines. An excellent correlation coefficient (> 0.999) was found for the obtained regression equation
(y = –0.0302x + 0.928) in the range of 2.0–30.0 μg mL-1. The method was found to be simple and rapid because it does not involve any solvent extraction. The recovery levels of the drug were in the range 99.92 – 100.08.
Formulation and operation of a Nickel based methanation catalystSakib Shahriar
The objective of this experiment was to get a firsthand experience of the preparation of a catalyst for methanation reaction and to evaluate the performance of the catalyst in a fixed bed tubular reactor. In the first part of the experiment a nickel-based catalyst was synthesized. The catalyst will have nickel as the active component and alumina as the support. the catalyst precursor was prepared by co-precipitation from a solution of nitrate salts of nickel and aluminum. The precipitate was filtered out, washed, dried and calcined to obtain the catalyst. In the second part, the catalyst was activated and performance analysis was done alone with loaded in a fixed bed reactor. The percentage conversion of CO to CH4 was 96.38% and the selectivity of CH4 production to CO2 production was 3.348.
Copper catalyzed synthesis of N-Heterocycles containing one M-atomssusercbfc01
This presentation is based on my literature review on the topic Copper catalysed synthesis of N-Heterocycles containing one N-atom. I have prepared it using Mobile.A better presentation would have been prepared on laptop but option wasn't available for me
Metal-organic hybrid: Photoreduction of CO2 using graphitic carbon nitride su...Pawan Kumar
A novel heteroleptic iridium complex supported on graphitic carbon nitride was synthesized and used for photoreduction of carbon dioxide under visible light irradiation. The methanol yield obtained after 24 h irradiation was 9934 μmol g−1cat (TON 1241 with respect to Ir) by using triethylamine (TEA) as a sacrificial donor, which was significantly higher as compared to the semiconductor carbon nitride 145 μmol g−1cat under identical conditions. The presence of triethylamine was found to be vital for the higher methanol yield. After the reaction, the photocatalyst could easily be recovered and reused for subsequent six runs without significant loss in photo activity.
Metal-organic hybrid: Photoreduction of CO2 using graphitic carbon nitride su...Pawan Kumar
A novel heteroleptic iridium complex supported on graphitic carbon nitride was synthesized and used
for photoreduction of carbon dioxide under visible light irradiation. The methanol yield obtained after
24 h irradiation was 9934 mmol g1cat (TON 1241 with respect to Ir) by using triethylamine (TEA) as a
sacrificial donor, which was significantly higher as compared to the semiconductor carbon nitride
145 mmol g1cat under identical conditions. The presence of triethylamine was found to be vital for the
higher methanol yield. After the reaction, the photocatalyst could easily be recovered and reused for
subsequent six runs without significant loss in photo activity.
Metal-organic hybrid: Photoreduction of CO2 using graphitic carbon nitride su...Pawan Kumar
A novel heteroleptic iridium complex supported on graphitic carbon nitride was synthesized and used
for photoreduction of carbon dioxide under visible light irradiation. The methanol yield obtained after
24 h irradiation was 9934 mmol g1cat (TON 1241 with respect to Ir) by using triethylamine (TEA) as a
sacrificial donor, which was significantly higher as compared to the semiconductor carbon nitride
145 mmol g1cat under identical conditions. The presence of triethylamine was found to be vital for the
higher methanol yield. After the reaction, the photocatalyst could easily be recovered and reused for
subsequent six runs without significant loss in photo activity.
our journals has been fields of pharmaceutical and biological sciences are witnessing rapid advancements driven by innovative research and technological breakthroughs. As the demand for novel therapies and understanding of biological mechanisms continues to grow, there is a pressing need for disseminating high-quality original research and reviews in reputable international journals.
Contact Url :https://iajpb.com/contactus.php#1
Scientific development is an ever-evolving journey, driven by the exchange of data and ideas among researchers across the globe.One such remarkable publication dedicated to facilitating this exchange within the fields of Pharmacy and Bio Sciences is the Indo-American Journal of Pharma and Bio Sciences of the journals to publish paper.
Environmental Catalysis Module: Students examines different types of catalytic systems, including heterogeneous and homogeneous catalysis. Depending on the knowledge they gained during activities, the students are then asked to design their projects.
Our Project: Methanol Synthesizer Catalyst : A catalyst composed of copper alloys with ceria (cerium-oxide) nanoparticles, sometimes also mixed with titania. The catalyst were exposed to pressure of 0.5 atom of CO2 and 4.5 atom of H2 at a range of reaction temperatures 500-600 Kalvin.
By: ABJ_ Cobalt8, Ali Bin Jassim Secondary Independent School for Boys.
1. Michael R. Hurst, Thomas G. Trimble, Cassidy L. Kotelman, Wesley A. Deutscher, and Katrina H. Jensen
Black Hills State University
1200 University Blvd, Spearfish, SD 57799
Katrina.Jensen@bhsu.edu
Evaluation of Copper Photocatalysts in the Enantioselective α–Alkylation of Aldehydes
Catalysts act to increase the rate of reactions by lowering the
activation energy required. We are working to develop new
reactions using a chiral catalyst and a photoredox catalyst with the
goal of developing effective and efficient methods to synthesize
small molecules.
In reactions utilizing photoredox catalysis, light energy is absorbed
by a catalyst, moving the catalyst into an excited state. From this
high energy level, it can donate or accept an electron from organic
reagents.
light
Energy
photo-
excitation
Ground State Excited State
oxidation
– e–
Oxidized State
In our research, we are attempting to develop copper catalysts
for photoredox reactions. Currently, reported photoredox
reactions1 use ruthenium and iridium complexes; however,
copper would make for a more sustainable alternative as it is
earth-abundant, and relatively inexpensive. Furthermore,
bisphenanthroline copper complexes2 are known with similar
photophysical properties to Ru(bpy)3
2+.
1J. W. Tucker, C. R. J. Stephenson J. Org. Chem. 2012, 77, 1617-1622
2D. V. Scaltrito, D. W. Thompson, J. A. O’Callaghan, G. J. Meyer Coord. Chem. Rev. 2000,
208, 243-266
Photoredox catalysis shows great potential in chemical synthesis
due to the inherent reactivity of the free radical intermediates
that can be selectively accessed. Instead of relying on specialized
photochemical equipment, this reaction methodology only
necessitates the light of a standard light bulb, reducing costs and
boosting efficiency.
This dichlorinated 1,10-phenanthroline derivative is then reacted
with a number of possible substituents to yield a given ligand.
Shown here is the theoretical synthesis of (dap):
Research reported in this publication was supported by an
Institutional Development Award (IDeA) from the National
Institute of General Medical Sciences of the National Institutes of
Health under grant number P20GM103443. The content is solely
the responsibility of the authors and does not necessarily
represent the official views of the National Institutes of Health.
Acknowledgement is also made to the donors of the American
Chemical Society Petroleum Research Fund, the South Dakota
Biomedical Research Infrastructure Network, and Black Hills
State University for support of this research.
• Short-term goals
- Continue optimizing the reaction conditions to
improve product yield and enantiomeric excess,
evaluating factors such as light source, solvent
system, scale, and the ratio of reactants.
- Evaluate the scope of the alkylation reaction by
evaluating other aldehyde and α-bromocarbonyl pairs
as reaction partners.
- Utilize NMR assay to study product formation.
• Long-term goal
- Use the developed reaction methodology to target
natural products and other significant molecules for
synthesis. These would include biologically-active
compounds offering medicinal benefits such as
antimicrobial activity.
1H NMR
Reaction Conditions: 0.800 mL of solvent, 0.800 mmol octaldehyde, 0.400 mmol
diethylbromomalonate, 0.080 mmol chiral catalyst, 0.004 mmol photocatalyst, and
0.800 mmol 2,6-lutidine.
Reaction A is setup by
mixing a standard solution
with our photo catalyst
and chiral catalyst, then
placing mixture within 3
cm of a 26 watt light
source for ~18 hours.
A CHCl3 B C D E E’ F G
A
B
C
D
F
G
F
VI. Evaluating Photocatalysts
Reaction A:
In the alkylation reaction3 both chiral catalyst and photocatalyst
are required. These species act together in dual catalytic cycles.
3D. A. Nicewicz, D. W. C. MacMillan Science 2008, 322, 77-80
In this mechanism, a chiral catalyst reacts with an aldehyde to
properly orient it and improve its reactivity by forming an
enamine. This intermediate reacts with the free radical
intermediate formed during a photoredox reaction involving
Ru(bpy)3 and selectively forms a new carbon-carbon bond.
Our research has focused on using derivatives of copper(I)
bisphenanthroline complexes (Cu(phen’)2
+) in place of Ru(bpy)3.
# Time Area Area %
1 5.786 12.6 17.655
2 6.203 58.8 82.345
# Time Area Area %
1 5.889 120.4 50.423
2 6.352 118.4 49.577
A racemic form of our product was used as a
standard against which enantiomerically-
enriched products are evaluated.
Enantiomeric excess = 65%
This reaction was set up to the specifications
outlined in panel III.
To determine the enantiomeric excess of our products, an HPLC
assay was developed. The assay was run with 95:5 hexanes:IPA
through an Agilent Technologies 1260 Infinity series HPLC
loaded with an CHIRALPAK® AS-H column.
The first step in producing copper complex photocatalysts is ligand
synthesis. Ligands are synthesized by first forming a dichlorinated
1,10-phenathroline derivative, as shown4:
We examined photoredox catalysts in Reaction A shown below:
These ligands can then be formed into copper complexes via a
reaction with a copper source. Shown is the synthesis of
Cu(BINAP)(dap), a heteroleptic copper complex:
4J. Frey, T. Kraus, V. Heitz, J.P. Sauvage Chem. Eur. J. 2007, 13, 7584-7594
The complexes synthesized as described above were then
evaluated by measuring the alkylation product yield in Reaction A.
V. Photocatalyst SynthesisIII. Alkylation ReactionI. Introduction VII. Enantiomeric Excess
IV. Catalytic Cycle
II. Background and Significance
VIII. Future Research
IX. Acknowledgements
Heteroleptic:
Homoleptic:
Yield: 16% Yield: 59% Yield: 1%
Yield: 45% Yield: 37% Yield: 12% Yield: 11%
Cost per ounce
Ruthenium: $42.00
Copper: $0.14
Abundance in Earth’s Crust
Ruthenium: 0.000000099%
Copper: 0.0068%
Toxicity
Ruthenium: considered toxic and carcinogenic
Copper: considered moderately non-toxic
74%
37%
79%
76%
Left-to-right: Katrina Jensen, Hannah Owen, Michael Hurst,
Madison Jilek, Wesley Deutscher, Cheyloh Bluemel, Thomas Trimble
Left:
Ru(bpy)3Cl2 • 6H2O
Right:
Cu(BINAP)(dap)BF4