The document outlines Marina Freitag's Ph.D. defense presented on Sep 28th 2011. It discusses three topics: 1) Electrochromic properties of viologen cucurbituril complexes. Viologens like methylviologen were encapsulated in cucurbit[7]uril and bound to TiO2 films for use in electrochromic devices. 2) Synthesis of alkyl and aryl viologen derivatives for inclusion in cucurbituril. 3) Fluorescence properties of tolyl-viologen derivatives and their encapsulation and binding in cucurbituril, characterized using NMR and emission titration. The encapsulation prevented aggregation and quenching, and modulated the photophysical properties
Supramolecular host and guest design pptAfrina Jasy
This presentation summarizes concepts in supramolecular host-guest design, including:
- Host-guest chemistry involves noncovalent interactions between a host molecule and guest, such as electrostatic interactions or hydrogen bonding.
- Successful host-guest complexes rely on complementarity between the host's binding sites and the guest's structure, as well as preorganization of the host.
- Common noncovalent interactions that contribute to host-guest binding include ion-dipole interactions, hydrogen bonding, van der Waals forces, π-π interactions, and hydrophobic effects. The interplay of these interactions allows for selective and stable complex formation.
- Host design considerations include selectivity, complementarity between binding sites
The Born-Oppenheimer approximation, proposed in 1927 by physicists Max Born and J. Robert Oppenheimer, treats the motions of nuclei and electrons in molecules separately. It approximates that the nuclei in a molecule are stationary relative to the rapidly moving electrons. This allows molecular structure and properties to be determined by first solving the electronic Schrodinger equation at fixed nuclear positions, and then adding the internuclear repulsion energy to obtain the total internal energy of the molecule. As a result of this approximation, molecules have well-defined shapes determined by the equilibrium positions of their nuclei.
This document discusses the history and key concepts of supramolecular chemistry. It describes supramolecular chemistry as the study of intermolecular interactions and self-assembly of molecules into higher order structures. It notes that supramolecular systems act as a bridge between living and non-living matter. The document also outlines different ways of studying supramolecular systems, such as investigating synthetic or natural systems. It provides examples of applications like sensing, drug delivery, and molecular imaging.
This document provides an overview of supramolecular chemistry. It begins with a brief history and definitions of key terms like supramolecular chemistry and self-assembly. It then describes various types of non-covalent interactions that hold supramolecular structures together, such as hydrogen bonding, metal-ligand interactions, π-π stacking, and hydrophobic effects. Examples are given of self-assembled structures like grids, helicates, and polyhedral cages. The document concludes by noting the increasing sophistication of supramolecular systems incorporating components like fullerenes and nanoparticles for applications in nanotechnology.
This chapter discusses carbocations, which are positively charged carbon-containing ions that are highly reactive intermediates in organic chemistry. Carbocations have six electrons in the outer shell of the central carbon atom. They are stabilized by electron-donating groups and destabilized by electron-withdrawing groups. Carbocations undergo various reactions including reactions with nucleophiles, elimination reactions, rearrangement reactions, and additions to unsaturated systems. Non-classical carbocations are also discussed.
Dicyclohexylcarbodiimide (DCC) is an organic compound that is commonly used as a synthetic reagent to couple amino acids during peptide synthesis. It was first introduced for this purpose in 1955. DCC is a waxy white solid with a sweet odor that is highly soluble in organic solvents but insoluble in water. It has a low melting point, which allows it to be easily melted and handled. DCC is commonly used to catalyze esterification reactions and form amide bonds, as well as synthesize peptides, ethers, acid anhydrides, and lactones. One of its key applications is in the synthesis of beta-lactam rings in penicillin.
The document discusses the Passerini reaction, which is a three-component reaction involving an aldehyde or ketone, carboxylic acid, and isocyanide. The reaction was discovered by Mario Passerini in 1921 and represents one of the earliest examples of a multicomponent reaction. The Passerini reaction has high atom economy and proceeds in one pot under mild conditions to produce α-acyloxy amide products. It has various applications in combinatorial chemistry, total synthesis of natural products, and pharmaceutical synthesis.
Supramolecular host and guest design pptAfrina Jasy
This presentation summarizes concepts in supramolecular host-guest design, including:
- Host-guest chemistry involves noncovalent interactions between a host molecule and guest, such as electrostatic interactions or hydrogen bonding.
- Successful host-guest complexes rely on complementarity between the host's binding sites and the guest's structure, as well as preorganization of the host.
- Common noncovalent interactions that contribute to host-guest binding include ion-dipole interactions, hydrogen bonding, van der Waals forces, π-π interactions, and hydrophobic effects. The interplay of these interactions allows for selective and stable complex formation.
- Host design considerations include selectivity, complementarity between binding sites
The Born-Oppenheimer approximation, proposed in 1927 by physicists Max Born and J. Robert Oppenheimer, treats the motions of nuclei and electrons in molecules separately. It approximates that the nuclei in a molecule are stationary relative to the rapidly moving electrons. This allows molecular structure and properties to be determined by first solving the electronic Schrodinger equation at fixed nuclear positions, and then adding the internuclear repulsion energy to obtain the total internal energy of the molecule. As a result of this approximation, molecules have well-defined shapes determined by the equilibrium positions of their nuclei.
This document discusses the history and key concepts of supramolecular chemistry. It describes supramolecular chemistry as the study of intermolecular interactions and self-assembly of molecules into higher order structures. It notes that supramolecular systems act as a bridge between living and non-living matter. The document also outlines different ways of studying supramolecular systems, such as investigating synthetic or natural systems. It provides examples of applications like sensing, drug delivery, and molecular imaging.
This document provides an overview of supramolecular chemistry. It begins with a brief history and definitions of key terms like supramolecular chemistry and self-assembly. It then describes various types of non-covalent interactions that hold supramolecular structures together, such as hydrogen bonding, metal-ligand interactions, π-π stacking, and hydrophobic effects. Examples are given of self-assembled structures like grids, helicates, and polyhedral cages. The document concludes by noting the increasing sophistication of supramolecular systems incorporating components like fullerenes and nanoparticles for applications in nanotechnology.
This chapter discusses carbocations, which are positively charged carbon-containing ions that are highly reactive intermediates in organic chemistry. Carbocations have six electrons in the outer shell of the central carbon atom. They are stabilized by electron-donating groups and destabilized by electron-withdrawing groups. Carbocations undergo various reactions including reactions with nucleophiles, elimination reactions, rearrangement reactions, and additions to unsaturated systems. Non-classical carbocations are also discussed.
Dicyclohexylcarbodiimide (DCC) is an organic compound that is commonly used as a synthetic reagent to couple amino acids during peptide synthesis. It was first introduced for this purpose in 1955. DCC is a waxy white solid with a sweet odor that is highly soluble in organic solvents but insoluble in water. It has a low melting point, which allows it to be easily melted and handled. DCC is commonly used to catalyze esterification reactions and form amide bonds, as well as synthesize peptides, ethers, acid anhydrides, and lactones. One of its key applications is in the synthesis of beta-lactam rings in penicillin.
The document discusses the Passerini reaction, which is a three-component reaction involving an aldehyde or ketone, carboxylic acid, and isocyanide. The reaction was discovered by Mario Passerini in 1921 and represents one of the earliest examples of a multicomponent reaction. The Passerini reaction has high atom economy and proceeds in one pot under mild conditions to produce α-acyloxy amide products. It has various applications in combinatorial chemistry, total synthesis of natural products, and pharmaceutical synthesis.
THE DCC I.E. DICYCLOCARBODIIMDE IS A REAGENT AND HERE THE DETAIL ACCOUNT ON IT IS GIVEN INCLUDING MOLECULAR WEIGHT, STRUCTURE, SYNTHESIS AND PHYSICAL PARAMETERS AND APPLICATIONS FOR OTERS SYNTHESIS ARE ALSO DISCUSSED, THE DIFFERENT SYNTHESIS WITH DCC COMBINATION ARE ALSO MENTIONED
Materials Modelling: From theory to solar cells (Lecture 1)cdtpv
This document provides an overview of a mini-module on materials modelling for solar energy applications. It introduces the lecturers and outlines the course structure, which includes lectures on modelling, interfaces, and multi-scale approaches. It also describes a literature review activity where students will present a research paper using materials modelling in photovoltaics. Recommended textbooks are provided on topics like bonding in solids, computational chemistry, and density functional theory for solids.
This presentation is the introduction to Density Functional Theory, an essential computational approach used by Physicist and Quantum Chemist to study Solid State matter.
Ionic Liquids : Green solvents for the futureMrudang Thakor
Ionic Liquids are entirely made up of Ions also known as Room Temperature Ionic Liquids (RTILs).
They are in demand because of their unmatchable uses and applications in the field of chemistry.
The document discusses density functional theory (DFT) and its implementation in the VASP software. It explains key concepts like the Kohn-Sham approach for approximating the many-body Schrodinger equation and the use of pseudopotentials and plane wave basis sets. It also summarizes some example calculations done in VASP like determining the binding energy of O2, equilibrium lattice constant of Cu, and band structures of Si and graphene. Key input and output files of VASP are also outlined.
Retrosynthetic analysis, definition, importance, disconnection approach, one group two group disconnection logical and illogical disconnection approach compounds containing two nitrogen atom retrosynthetic analysis of camphor, cartisone, reserpine
A DFT & TDDFT Study of Hybrid Halide Perovskite Quantum DotsAthanasiosKoliogiorg
Perovskite quantum dots (QDs) constitute a novel and rapidly developing field of nanotechnology with promising potential for optoelectronic applications. However, few perovskite materials for QDs and other nanostructures have been theoretically explored. In this study, we present a wide spectrum of different hybrid halide perovskite cuboid-like QDs with the general formula of FABX3 (A = (NH2)CH(NH2), B = Pb, Sn, Ge, and X = Cl, Br, I) with varying sizes below and near the Bohr exciton radius. Density functional theory (DFT) and time-dependent DFT calculations were employed to determine their structural, electronic, and optical properties. Our calculations include both stoichiometric model, proved to be close to experimental results where available, and our results reveal several materials with high optical absorption and application-suitable electronic and optical gaps. Our study highlights the potential as well as the challenges and issues regarding nanostructured halide perovskite materials, laying the background for future theoretical and experimental work.
Crown ethers
NOMENCLATURE
GENERAL SYNTHESIS OF CROWN ETHER
AZA CROWN
CRYPTAND
APPLICATIONS
1. SYNTHETIC APPLICTION
Esterification
Saponification
Anhydride formation
Potassium permanganate oxidation
Aromatic substitution reactions
Elimination reactions
Displacement reaction
Generation of carbenes
Superoxide anion
Alkylations – 1. o-alkylations
2. c-alkylations
3. n-alkylations
2. ANALYTICAL APPLICATION
Determination of gold in geological samples
Super critical fluid extraction of trace metal from solid and liquid materials
Application of ionic liquids in analytical chemistry
Oxidation and determination of aldehydes
Crown ethers are used in the laboratory as phase transfer catalyst
OTHER APPLICATION
It is used in photocynation
Resolution of racemic mixture
Benzoin condensation
Hetrocyclisation
Synthesis of furanones
Acetylation of secondary amines in presence of primary amine
In this talk I will discuss different approximations in DFT: pseduo-potentials, exchange correlation functions.
The presentation can be downloaded here:
http://www.attaccalite.com/wp-content/uploads/2022/03/dft_approximations.odp
Microwave Assisted Synthesis of Metallic NanostructuresJoyce Joseph
The document discusses microwave assisted synthesis of metallic nanostructures. Some key points:
1) Microwave irradiation can be used to synthesize a variety of metallic nanostructures like spheres, sheets, rods, wires, and dendrites.
2) Microwave heating allows for faster, cleaner reactions compared to traditional heating methods. It enables selective heating and precise temperature control.
3) Examples demonstrate synthesizing gold nanoparticles within minutes using microwave heating, stabilizers, and reducing agents, achieving smaller, more uniform particles than traditional heating.
4) Microwave synthesis has advantages like short reaction times, low energy input, selective heating, and ability to control morphology of nanostructures produced. It is considered a green chemistry approach
This document provides instructions and questions for an internal assessment test in Green Chemistry for a Bachelor of Science in Chemistry (Honours) program. It lists 7 questions related to topics in green chemistry, including examples of atom-economical and uneconomical reactions, calculating atom economy, limitations of using yields and atom economy as efficiency measures, examples of green organic reactions using microwave irradiation, the relationship between green chemistry and sustainable development, green syntheses of specific compounds highlighting green chemistry principles, and assessing whether a given conversion follows green chemistry principles. Students are instructed to answer any 5 of the 7 questions in their own words within the allotted time and provide their name, registration details, and university on the answer paper.
This document discusses computational methods for theoretical chemistry. It describes how quantum chemical calculations can be used to simulate molecular structures, vibrational frequencies, and spectra. The main computational methods covered are molecular mechanics, semi-empirical quantum chemistry, and ab initio quantum chemistry. Molecular mechanics uses classical physics approximations while quantum chemistry methods solve the Schrodinger equation using different levels of approximation.
Supramolecular chemistry involves the use of non-covalent interactions to assemble molecular subunits into well-defined superstructures. Jean-Marie Lehn introduced the term "supramolecular chemistry" to describe chemistry beyond the molecule using intermolecular forces. Examples of supramolecular assemblies include crown ethers, cyclodextrins, and calixarenes which act as hosts for guest molecules through molecular recognition. Supramolecules can also self-assemble through mechanisms like programmed recognition using specific interactions or "fuzzy" interactions resulting in structures found in nature like cell membranes.
MERITS OF MICROWAVE ASSISTED REACTIONS
DEMERITS OF MICROWAVE ASSISTED REACTIONS
MECHANISM OF MICROWAVE HEATING
EFFECTS OF SOLVENTS IN MICROWAVE ASSISTED SYNTHESIS
MICROWAVE VERSUS CONVENTIONAL SYNTHESIS
MICROWAVE INSTRUMENTATION
VARIOUS TYPES OF MICROWAVE ASSISTED ORGANIC REACTIONS
APPLICATIONS OF MICROWAVE ASSISTED REACTIONS
An overview of the use of the Marcus Theory to calculate the energies of transition states.
Contributed by: Elizabeth Greenhalgh, Amanda Bischoff, and Matthew Sigman, University of Utah, 2015
Graduate lectures (Organic Synthesis in Water)Anthony Coyne
These two lectures give an overview of organic synthesis using water as a solvent. This is aimed towards final year undergraduates and graduate students in chemistry
synthetic Reagents and its application DiazomethaneFirujAhmed2
Diazomethane is a yellow, poisonous, potentially explosive compound with the chemical formula CH2N2. It is a valuable synthetic reagent that is used for methylation reactions and in the synthesis of heterocyclic compounds. Diazomethane can be prepared through Pechmann's method involving the reaction of methylamine with ethyl chlorofomate or through hydrolysis of an ethereal solution of an N-methyl nitrosamide with aqueous base. It is chemically very reactive and transforms functional groups, making it useful for a variety of synthetic applications.
BIOS 203 Lecture 4: Ab initio molecular dynamicsbios203
This document discusses ab initio molecular dynamics simulation methods. It provides an overview of different simulation techniques that range from fully quantum to mixed quantum-classical approaches. These methods allow researchers to study molecular phenomena with varying degrees of accuracy and system sizes. The document also outlines key concepts like the Schrodinger equation and Born-Oppenheimer approximation that are fundamental to these simulation approaches.
Electron transfer between methyl viologen radicals and graphene oxidekamatlab
Methyl viologen radicals are capable of transferring electrons to graphene oxide and partially restore the sp2 network. The reduced graphene oxide serves as a scaffold to anchor Ag nanoparticles. The growth of these silver nanoparticles is dictated by the ability of RGO to store and shuttle electrons. The RGO/Ag nanocomposites discussed in the present work offer new opportunities to design next generation photocatalysts.
Visit our website, KamatLab.com, for the latest news, publications, and research from our group.
THE DCC I.E. DICYCLOCARBODIIMDE IS A REAGENT AND HERE THE DETAIL ACCOUNT ON IT IS GIVEN INCLUDING MOLECULAR WEIGHT, STRUCTURE, SYNTHESIS AND PHYSICAL PARAMETERS AND APPLICATIONS FOR OTERS SYNTHESIS ARE ALSO DISCUSSED, THE DIFFERENT SYNTHESIS WITH DCC COMBINATION ARE ALSO MENTIONED
Materials Modelling: From theory to solar cells (Lecture 1)cdtpv
This document provides an overview of a mini-module on materials modelling for solar energy applications. It introduces the lecturers and outlines the course structure, which includes lectures on modelling, interfaces, and multi-scale approaches. It also describes a literature review activity where students will present a research paper using materials modelling in photovoltaics. Recommended textbooks are provided on topics like bonding in solids, computational chemistry, and density functional theory for solids.
This presentation is the introduction to Density Functional Theory, an essential computational approach used by Physicist and Quantum Chemist to study Solid State matter.
Ionic Liquids : Green solvents for the futureMrudang Thakor
Ionic Liquids are entirely made up of Ions also known as Room Temperature Ionic Liquids (RTILs).
They are in demand because of their unmatchable uses and applications in the field of chemistry.
The document discusses density functional theory (DFT) and its implementation in the VASP software. It explains key concepts like the Kohn-Sham approach for approximating the many-body Schrodinger equation and the use of pseudopotentials and plane wave basis sets. It also summarizes some example calculations done in VASP like determining the binding energy of O2, equilibrium lattice constant of Cu, and band structures of Si and graphene. Key input and output files of VASP are also outlined.
Retrosynthetic analysis, definition, importance, disconnection approach, one group two group disconnection logical and illogical disconnection approach compounds containing two nitrogen atom retrosynthetic analysis of camphor, cartisone, reserpine
A DFT & TDDFT Study of Hybrid Halide Perovskite Quantum DotsAthanasiosKoliogiorg
Perovskite quantum dots (QDs) constitute a novel and rapidly developing field of nanotechnology with promising potential for optoelectronic applications. However, few perovskite materials for QDs and other nanostructures have been theoretically explored. In this study, we present a wide spectrum of different hybrid halide perovskite cuboid-like QDs with the general formula of FABX3 (A = (NH2)CH(NH2), B = Pb, Sn, Ge, and X = Cl, Br, I) with varying sizes below and near the Bohr exciton radius. Density functional theory (DFT) and time-dependent DFT calculations were employed to determine their structural, electronic, and optical properties. Our calculations include both stoichiometric model, proved to be close to experimental results where available, and our results reveal several materials with high optical absorption and application-suitable electronic and optical gaps. Our study highlights the potential as well as the challenges and issues regarding nanostructured halide perovskite materials, laying the background for future theoretical and experimental work.
Crown ethers
NOMENCLATURE
GENERAL SYNTHESIS OF CROWN ETHER
AZA CROWN
CRYPTAND
APPLICATIONS
1. SYNTHETIC APPLICTION
Esterification
Saponification
Anhydride formation
Potassium permanganate oxidation
Aromatic substitution reactions
Elimination reactions
Displacement reaction
Generation of carbenes
Superoxide anion
Alkylations – 1. o-alkylations
2. c-alkylations
3. n-alkylations
2. ANALYTICAL APPLICATION
Determination of gold in geological samples
Super critical fluid extraction of trace metal from solid and liquid materials
Application of ionic liquids in analytical chemistry
Oxidation and determination of aldehydes
Crown ethers are used in the laboratory as phase transfer catalyst
OTHER APPLICATION
It is used in photocynation
Resolution of racemic mixture
Benzoin condensation
Hetrocyclisation
Synthesis of furanones
Acetylation of secondary amines in presence of primary amine
In this talk I will discuss different approximations in DFT: pseduo-potentials, exchange correlation functions.
The presentation can be downloaded here:
http://www.attaccalite.com/wp-content/uploads/2022/03/dft_approximations.odp
Microwave Assisted Synthesis of Metallic NanostructuresJoyce Joseph
The document discusses microwave assisted synthesis of metallic nanostructures. Some key points:
1) Microwave irradiation can be used to synthesize a variety of metallic nanostructures like spheres, sheets, rods, wires, and dendrites.
2) Microwave heating allows for faster, cleaner reactions compared to traditional heating methods. It enables selective heating and precise temperature control.
3) Examples demonstrate synthesizing gold nanoparticles within minutes using microwave heating, stabilizers, and reducing agents, achieving smaller, more uniform particles than traditional heating.
4) Microwave synthesis has advantages like short reaction times, low energy input, selective heating, and ability to control morphology of nanostructures produced. It is considered a green chemistry approach
This document provides instructions and questions for an internal assessment test in Green Chemistry for a Bachelor of Science in Chemistry (Honours) program. It lists 7 questions related to topics in green chemistry, including examples of atom-economical and uneconomical reactions, calculating atom economy, limitations of using yields and atom economy as efficiency measures, examples of green organic reactions using microwave irradiation, the relationship between green chemistry and sustainable development, green syntheses of specific compounds highlighting green chemistry principles, and assessing whether a given conversion follows green chemistry principles. Students are instructed to answer any 5 of the 7 questions in their own words within the allotted time and provide their name, registration details, and university on the answer paper.
This document discusses computational methods for theoretical chemistry. It describes how quantum chemical calculations can be used to simulate molecular structures, vibrational frequencies, and spectra. The main computational methods covered are molecular mechanics, semi-empirical quantum chemistry, and ab initio quantum chemistry. Molecular mechanics uses classical physics approximations while quantum chemistry methods solve the Schrodinger equation using different levels of approximation.
Supramolecular chemistry involves the use of non-covalent interactions to assemble molecular subunits into well-defined superstructures. Jean-Marie Lehn introduced the term "supramolecular chemistry" to describe chemistry beyond the molecule using intermolecular forces. Examples of supramolecular assemblies include crown ethers, cyclodextrins, and calixarenes which act as hosts for guest molecules through molecular recognition. Supramolecules can also self-assemble through mechanisms like programmed recognition using specific interactions or "fuzzy" interactions resulting in structures found in nature like cell membranes.
MERITS OF MICROWAVE ASSISTED REACTIONS
DEMERITS OF MICROWAVE ASSISTED REACTIONS
MECHANISM OF MICROWAVE HEATING
EFFECTS OF SOLVENTS IN MICROWAVE ASSISTED SYNTHESIS
MICROWAVE VERSUS CONVENTIONAL SYNTHESIS
MICROWAVE INSTRUMENTATION
VARIOUS TYPES OF MICROWAVE ASSISTED ORGANIC REACTIONS
APPLICATIONS OF MICROWAVE ASSISTED REACTIONS
An overview of the use of the Marcus Theory to calculate the energies of transition states.
Contributed by: Elizabeth Greenhalgh, Amanda Bischoff, and Matthew Sigman, University of Utah, 2015
Graduate lectures (Organic Synthesis in Water)Anthony Coyne
These two lectures give an overview of organic synthesis using water as a solvent. This is aimed towards final year undergraduates and graduate students in chemistry
synthetic Reagents and its application DiazomethaneFirujAhmed2
Diazomethane is a yellow, poisonous, potentially explosive compound with the chemical formula CH2N2. It is a valuable synthetic reagent that is used for methylation reactions and in the synthesis of heterocyclic compounds. Diazomethane can be prepared through Pechmann's method involving the reaction of methylamine with ethyl chlorofomate or through hydrolysis of an ethereal solution of an N-methyl nitrosamide with aqueous base. It is chemically very reactive and transforms functional groups, making it useful for a variety of synthetic applications.
BIOS 203 Lecture 4: Ab initio molecular dynamicsbios203
This document discusses ab initio molecular dynamics simulation methods. It provides an overview of different simulation techniques that range from fully quantum to mixed quantum-classical approaches. These methods allow researchers to study molecular phenomena with varying degrees of accuracy and system sizes. The document also outlines key concepts like the Schrodinger equation and Born-Oppenheimer approximation that are fundamental to these simulation approaches.
Electron transfer between methyl viologen radicals and graphene oxidekamatlab
Methyl viologen radicals are capable of transferring electrons to graphene oxide and partially restore the sp2 network. The reduced graphene oxide serves as a scaffold to anchor Ag nanoparticles. The growth of these silver nanoparticles is dictated by the ability of RGO to store and shuttle electrons. The RGO/Ag nanocomposites discussed in the present work offer new opportunities to design next generation photocatalysts.
Visit our website, KamatLab.com, for the latest news, publications, and research from our group.
This document defines depression and describes its symptoms. Depression is an illness that involves mood, body, and thoughts, affecting eating, sleep, feelings of self-worth, and thinking. It lists specific symptoms like hopelessness, guilt, loss of interest, social isolation, sleep issues, fatigue, crying, suicidal thoughts, restlessness, difficulty concentrating, and persistent physical problems. It also describes types of depression like major depression, dysthymia, and bipolar disorder. It notes factors that can contribute to or trigger depression at different stages of life. The document outlines myths about depression and treatments options, including therapy, medication, and electroconvulsive therapy. It advises being supportive of those suffering from depression.
This document summarizes observations and interviews about day laborers who gather at a Home Depot parking lot seeking work opportunities. It finds that while technically not allowed inside the store, security generally allows the men to use restrooms and get food. The men wait for potential employers to arrive and offer work in tasks like drywall, framing, and roofing. One anonymous laborer was interviewed, saying he does this work to support his family, finding jobs every 2-3 hours paying around $80. He notes Americans typically pay more than other ethnicities.
Kajian tindakan ini bertujuan meningkatkan pencapaian pelajar dalam mata pelajaran Geografi melalui penggunaan strategi pembelajaran koperatif. Data dikumpul melalui soal selidik, ujian pra dan pasca, serta pemerhatian. Hasilnya menunjukkan peningkatan pencapaian pelajar selepas pembelajaran koperatif dijalankan. Strategi ini membantu meningkatkan kolaborasi dan penguasaan konsep di kalangan pelajar.
This document discusses different reading techniques. It explains that there are different purposes for reading, such as for pleasure, specific information, or absorbing information. It provides tips for each purpose, such as reading more rapidly for pleasure versus taking time to absorb information. The document also provides general tips for improving reading skills, such as ensuring good eye health and reading posture. It emphasizes that reading speed should match the reading purpose.
Ketiga dokumen memberikan resep untuk membuat jagung bakar dengan berbagai bumbu dan topping seperti bumbu pedas manis dengan saus sambal dan tomat, bumbu keju, serta kentang goreng dengan cara mendaur ulang proses penggorengannya untuk menghasilkan tekstur dan rasa yang lebih gurih.
This document discusses compound words, which are words made up of two smaller words. Compound words can be understood by knowing the meanings of the individual words, such as "bluebird" meaning a bird that is blue. However, some compound words do not directly relate to the definitions of the words that comprise them, like "butterfly" or "hotdog". There are also different types of compound words including closed compounds without spaces, open compounds with spaces, and hyphenated compounds. The document was prepared by a student as an example of different compound word types and structures.
Marcellin Champagnat was born in 1789 in France and grew up on a farm, helping with the family's flock of sheep. He felt called to the priesthood and struggled with his studies but persevered. In 1817, he founded the Marist Brothers with two other men to educate children in rural areas. The order grew rapidly under his leadership. He insisted the Brothers focus on the children's spiritual and moral education in addition to academics. Marcellin experienced many hardships but always relied on his deep devotion to the Virgin Mary. He died in 1840 after dedicating his life to the children and Brothers. He was beatified in 1955 and canonized in 1999.
This document provides information about adjectives including their characteristics, order of use when modifying nouns, comparative and superlative forms, exceptions to the rules, and examples distinguishing adjectives from other parts of speech like nouns and pronouns. It includes objectives, definitions of adjectives, explanations of comparative and superlative forms, irregular adjectives, choosing the correct adjective, misused words, comparisons within groups, and assignments for students to practice identifying and forming adjectives.
Lectures 7-8: Charge and Energy Transfer, Photosynthesis, Biofulescdtpv
1. The document discusses charge and energy transfer processes in organic semiconductors and photosynthesis. It describes how excitons are created and transported via Förster energy transfer to reaction centers.
2. At reaction centers, charge separation occurs across a semiconductor heterojunction in a process similar to what happens in organic photovoltaics. The free charges are then used to drive chemical reactions like water oxidation.
3. Photosynthesis has an overall energy conversion efficiency of around 5% due to losses from light absorption, photon requirements for glucose production, and seasonal growth conditions. Precise protein structures facilitate efficient energy funneling to reaction centers.
The document discusses conducting polymers and their conductivity properties. It explains that doping polymers with electron acceptors like iodine or arsenic fluoride increases their conductivity by orders of magnitude. Doping leads to the formation of polarons and bipolarons, which are positively charged defects that act as charge carriers within the conjugated polymer framework, enabling high conductivity. The conductivity of conducting polymers depends on the number and mobility of these charge carriers.
Scientific & Technological Perspective:
Future of Energy Storage With
Graphene Oxide (GO)
Paper Presentation
By
Radhey Shyam Meena
In
International Conference On
Advanced in Power Generation From
Renewable Energy Sources
APGRES 2015, June 15-16, 2015
Rajasthan Technical University Kota
This document discusses polyacetylene, an organic polymer that can conduct electricity. It describes how polyacetylene was first synthesized in 1970 using a Ziegler-Natta catalyst. Polyacetylene exists in two forms, cis and trans. The document also explains how doping polyacetylene with oxidizing or reducing agents can increase its conductivity, and some applications of conductive polymers including rechargeable batteries, sensors, transistors, LEDs, solar cells, and electromagnetic shielding.
Polymers become conducting when they have conjugated double bonds along their carbon backbone that allow for electron movement. There are two types of conducting polymers - p-type polymers that conduct positive holes and n-type polymers that conduct negative electrons. Important examples include polyacetylene, polyaniline, and PEDOT. Potential applications of conducting polymers include uses in batteries, solar cells, LEDs, electromagnetic shielding, and anti-static coatings due to their ability to combine electrical conductivity with plastic-like mechanical properties.
Graphene is a two-dimensional material made of a single layer of carbon atoms arranged in a honeycomb lattice. It was awarded the 2010 Nobel Prize in Physics. Graphene has highly desirable properties such as high conductivity, strength, and thinness. Unlike silicon, electrons in graphene behave like massless particles and can flow freely without an energy barrier. This gives graphene potential to revolutionize electronics by allowing much faster and more efficient devices.
Decolourization of textile waste water and dye effluentمحمد حسنین شبیر
This document provides an overview of a seminar on decolorization of textile wastewater and dye effluents. It discusses the composition of textile wastewater, effects of dye effluents, and need for treatment. It then summarizes various treatment methods including chemical (oxidation, Fenton's reagent), physical (adsorption, membrane filtration), and biological treatments. It provides details on specific treatment processes and their advantages and disadvantages for dye removal.
The document summarizes research into using different surface morphologies of cuprous oxide (Cu2O) nanocrystals for solar cell applications. Nanocubes and nanooctahedrons were synthesized and characterized. Photoelectrochemical tests found that nanooctahedrons had increased photocatalytic activity and stability over nanocubes. Both nanocrystal types showed higher external quantum efficiency and solar cell efficiency than silicon-based cells. The results indicate that controlling nanocrystal morphology can optimize materials for inexpensive and efficient solar technologies.
The document discusses surface modification of nanoparticles to improve their properties and applications. Surface modification can make nanoparticles more hydrophilic, hydrophobic, conductive or anticorrosive. Functionalizing nanoparticle surfaces is necessary to optimize properties for use in various fields like engineering, medicine and biology. Common modification techniques discussed are NMR, FTIR, RAMAN spectroscopy, and TEM imaging. Surface modification can improve nanoparticle dispersion, enhance coatings for scratch/corrosion resistance, and develop transparent, wear resistant or superhydrophobic coatings.
This document describes a novel approach for the electrochemical immobilization of proteins onto graphite electrode microarrays using diazonium chemistry. Specifically, proteins are first modified with an aniline derivative and then diazotated to form an aryl diazonium function. This allows the modified proteins to then be directly electro-addressed and covalently grafted onto the electrodes through reduction of the diazonium groups. Characterization with XPS and cyclic voltammetry confirmed successful grafting of a diazonium monolayer. As a proof of concept, rabbit IgG was immobilized and specifically detected the presence of anti-rabbit IgG antibodies, demonstrating the potential of this new strategy for spatially addressing different biological
synthesis of semiconducting polymers for possible application in [autosaved]Boniface Y. Antwi
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Similar to Cucurbituril[7] Host - Viologen Guest Complexes: Electrochromic and Photochemical Properties (20)
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Cucurbituril[7] Host - Viologen Guest Complexes: Electrochromic and Photochemical Properties
1. Marina Freitag
Advisor: Prof. Elena Galoppini
Rutgers University – Newark
Ph.D. defense presented on: Sep 28th 2011
2. Outline
1. Introduction
1. Nanostructured Metal Oxide Interfaces
2. Background
3. The Cucurbituril Family
4. Inclusion of Methylviologen in Cucurbit[7]uril
2. Electrochromic properties of Viologen Cucurbituril complexes
1. Redox Active Compounds on TiO2
2. Viologens and their Synthesis
3. Host-guest Complexes
4. Electrochromic Devices
5. Characterization
6. Conclusions
3. Fluorescence properties of Tolyl-Viologen derivatives
1. Introduction
2. Viologen derivative synthesis
3. NMR titration
4. Emission titration
5. Quantum yield
6. Lifetime
7. Characterization
8. Conclusions
2
3. Metal Oxide Nanoparticles
Synthesis, characterization, and modification of nanoparticles and nanostructures
Differences in the bandgap
between metals, semiconductors
(metal oxides) and insulators
3
4. Surface Functionalization Methods
Cathode (Au)
Electrolyte
For LED, solar cell and sensors
applications, nanoparticle TiO2 layer
functionalization is necessary
Anode (FTO)
Glass
DSSC
trapping in
cavities
covalent binding
physisorption
• Alternative method to attach molecules to semiconductors
• Shield the guest from the heterogeneous interface
• Lead to new chemical, photophysical and electrochemical properties
4
5. The Hosts
e-
e-
U. H. Brinker, J.-L. Mieusset, Molecular Encapsulation: Organic Reactions in Constrained Systems, John Wiley and
Sons, 2010
M. Freitag , E. Galoppini, Energy & Environmental Science, 2011 5
6. Pioneering Work
• Possible to find matching host
• High complexation constants
• Structural modification of guest with
anchor group is not needed
• Prevents aggregates
• Improves Chemical stability
• Prevents quenching
• Shields guest from semiconductor
surface
H. Choi et al., Angew. Chem. Int. Ed., 2009, 48, 1.
P. Piotrowiak et al., Pure Appl. Chem., 2003, 75, 1061
C. Pagba et al., J. Am. Chem. Soc. 2004, 126, 9888. 6
S. A. Haque et al., Adv. Mater., 2004, 16, 1177.1
7. Cucurbituril Family
• Macrocyclic host consisting of glycoluril repeating units
• Particularly high affinity for positively charged compounds
• Commercially available 7
8. Cucurbit[7]uril
• Solubilization and prevention of
aggregation with CB[7]
• Negative electrostatic potential, leads
to a preference of cationic guests
• Condensation of glycoluril with
formaldehyde
• Changing the temperature of the
reaction to between 750C and 900C
to access other sizes of cucurbiturils
(CBs)
• Fractional dissolution and fractional
crystallization to separate different
cucurbituril homologues
8
9. Electrochromism of Viologens
• Highly efficient excited-state electron acceptor E°(MV2+*/MV•+) = 3.65 V
• Fast photoreduction (< 250 fs)
• Reversible color change
H. J. Kim, W. S. Jeon, Y. H. Ko and K. Kim, Proc. Natl. Acad. Sci. U. S. A., 2002, 99, 5007.
K. Kim, N. Selvapalam, Y. H. Ko, K. M. Park, D. Kim, K. J. Kim, Chem. Soc. Rev., 2007, 36, 267.
9
10. Viologen@CB[7] Complexes
• Thermodynamically and kinetically stable
complexes in aqueous solutions
• Reversible electrochemical behavior in
solution
• Ion-dipole interaction between positively
charged guests and carbonyl oxygen's at the
portals of CB[7]
Kim, K. Proc. Natl. Acad. Sci. U.S.A. 2002, 99, 5007 10
11. Outline
1. Introduction
1. Nanostructured Metal Oxide Interfaces
2. Background
3. The Cucurbituril Family
4. Inclusion of Methylviologen in Cucurbit[7]uril
2. Electrochromic properties of Viologen Cucurbituril complexes
1. Redox Active Compounds on TiO2
2. Viologens and their Synthesis
3. Host-guest Complexes
4. Electrochromic Devices
5. Characterization
6. Conclusions
3. Fluorescence properties of Tolyl-Viologen derivatives
1. Introduction
2. Viologen derivative synthesis
3. NMR titration
4. Emission titration
5. Quantum yield
6. Lifetime
7. Characterization
8. Conclusions
11
12. Alkyl Viologen Derivatives Bound to MOn
1V
• Use of anchoring groups for binding on TiO2
• Electrolyte: LiClO4, Ferrocene, γ-Butyrolactone
• Problems and side effects: dimerization,
insolubility of the neutral species
Cummins, D., Boschloo, G., Ryan, M., Corr, D., Rao, S. N.Fitzmaurice, D. J. Phys. Chem. B, 2000, 104, 1144
12
14. Alkyl Viologen Synthesis
Synthesis of phosphonated viologen (4) and carboxylated viologen (5) by
Menshutkin reaction
Cummins, D., Boschloo, G., Ryan, M., Corr, D., Rao, S. N.Fitzmaurice, D. J. Phys. Chem. B, 2000, 104, 1144 14
15. Aryl Viologen Synthesis MTV2+
MTV2+ (2) was synthesized as shown, using an adaptation of the Zincke reaction
by Yamaguchi and coworkers to obtain asymmetric viologen derivatives.
Yamaguchi, I., Higashi, H., Shigesue, S., and Shingai, S. Tetrahedron Lett. 2007, 48, 7778
Zincke, T. H. and Weisspfenning, G. J. Liebigs Ann. Chem. 1913, 396, 103
15
16. Cucurbituril complexes bound to MOn
• Role of Cucurbituril: prevention of side
reactions and as binding unit to TiO2
• Binding from aqueous solution
• Inclusion confirmed by 1H NMR in
solution and UV-VIS of electrochromic
windows
FTO-TiO2
16
20. Complexation and Binding
Chemisorption (or physisorption) of MV2+@CB[7] or MTV2+@CB[7] was done by
immersing the films in an aqueous solution with the complex (0.5 mM) for 24 h.
MOn preparation:
sol-gel technique
TiO2/ ZrO2 Binding
24h
MOn blank Viologen@CB[7]/MOn
• Equimolar amounts of MV2+ (or MTV2+) and CB[7] were dissolved in distilled
water (100 mL) to form the guest@host complex and stirred overnight.
• Formation of the complexes in solution was monitored by 1HNMR in D2O.
• It was observed that the complexation is fast (minutes).
20
21. Construction of ECW
Vinyl mask TiO2 film Binding of the complex
FTO substrate
Counter electrode
Final device
Assembly with
thermoplastic
Surlyn
21
22. Cyclic Voltammetry in Solution
E11/2,V E21/2, V CV in 0.1 M phosphate buffer
Compound (ΔEp, mV (ΔEp, mV (pH 7.0) of 0.05 mM solutions
vs Ag/AgCl) vs Ag/AgCl)
MV2+ -0.661 -0.975
MV2+@CB[7 -0.681 -0.992
MTV2+ -0.704
MTV2+@CB[7 -0.767 22
23. Cyclic Voltammetry of ECW
MV2+ @CB[7] ECW
MTV2+ @CB[7] ECW
• The CVs of electrochromic windows prepared from MV2+@CB[7] and
MTV2+@CB[7]
• Both complexes show a semi-reversible two-electron reduction process
• The complex formation and the physisorption to TiO2 are necessary to
bring the unsubstituted viologens close to the semiconductor surface
• Control experiment: free Methylviologen shows no binding to MOn
23
24. Absorption Spectra in Solution
Dication Radical Cation
1.0 1.00
2+
MV .+
MV
2+
0.8
MV @CB[7] 0.75
.+
MV @CB[7]
Absorbance a.u.
Absorbance a.u.
0.6
0.50
0.4
0.25
0.2
0.0 0.00
200 300 400 500 500 600 700 800
Wavelength [nm] Wavelength [nm]
• One-electron-reduced species were measured in solution at -0.6 V in the
presence and absence of one equivalent of CB[7]
• Broad absorption band centered at 600 nm 24
25. Absorption Spectra in Solution
Dication Radical Cation
1.0 1.00
2+ .+
MTV MTV
2+ .+
MTV @CB[7] MTV @CB[7]
0.8
0.75
Absorbance a.u.
Absorbance a.u.
0.6
0.50
0.4
0.25
0.2
0.00
0.0
500 600 700 800
200 300 400 500
Wavelength [nm] Wavelength [nm]
• The spectra of the complexes were essentially identical to those of the
free compounds. 25
26. Absorption Spectra of ECW Colored State
• Absorption spectra of MV2+@CB[7]/TiO2 andMTV2+@CB[7]/TiO2 measured in an
electrochromic window after application of -0.6 V
• Broad band around 600 nm
• Consistent with the absorption spectrum of the corresponding radical cations
• Coloration was reversible for over 20 switching cycles between bleached and
colored state 26
27. Conclusions
• Complexes of methylviologen (MV2+) and 1-methyl-1’-p-tolyl-4,4’-
bipyridinium dichloride (MTV2+) were encapsulated in a molecular host, CB[7],
and physisorbed onto the surface of TiO2 nanoparticle films
• Proof-of-concept demonstrated the electrochromic properties of two viologen
guests encapsulated inside a cucur[7]bituril host where the host was bound
to the surface of the semiconductor
• No need for synthetic modifications of the molecules with binding groups
• Electrochromic windows were prepared using viologen@CB[7]-modified TiO2
films cast on FTO electrodes.
• These windows exhibited reversible color switching upon application of -0.8
27
V, corresponding to the formation of intensely blue radical cations
28. Outline
1. Introduction
1. Nanostructured Metal Oxide Interfaces
2. Background
3. The Cucurbituril Family
4. Inclusion of Methylviologen in Cucurbit[7]uril
2. Electrochromic properties of Viologen Cucurbituril complexes
1. Redox Active Compounds on TiO2
2. Viologens and their Synthesis
3. Host-guest Complexes
4. Electrochromic Devices
5. Characterization
6. Conclusions
3. Fluorescence properties of Tolyl-Viologen derivatives
1. Introduction
2. Viologen derivative synthesis
3. NMR titration
4. Emission titration
5. Quantum yield
6. Lifetime
7. Characterization
8. Conclusions
28
30. Cucurbituril Encapsulation of Fluorescent Dyes
• Increase of quantum yield
• Longer lifetimes
• Enhanced photostability
Marquez, C.; Huang, F.; Nau, W. M. IEEE Trans. • Protected towards quenchers
NanoBiosci. 2004, 3, 39.
• Prevents disaggregation
• Solubilization
• Change in absorption and emission
properties
A. Hennig, M. Florea, D. Roth, T. Enderle, W. M. Nau,
Supramolecular Chemistry, 2007 (19) 55–66
30
31. The Viologens
“For example, MV2+ will quench the fluorescence of species
such as excited state [Ru(bipy)3] 2+.
A few workers have claimed that methyl viologen dication will
fluoresce, although it is now considered that much of the
‘fluorescence’ reported is in fact due to minute traces of p. 211
highly fluorescenig ’oxo’-viologen compounds as impurities.”
Fluorescent
OXO-Bipyridilium
Compounds
BUT…
The fluorescence and excited state properties of MV2+ were thoroughly
characterized for the first time by Kohler and coworkers a decade ago.
A.W.-H. Mau, J.M. Overbeek, J.W. Loder, W.H.F. Sasse, J. Chem. Soc., Faraday Trans. 2, 1986,82, 869. 31
40. DFT and CIS Calculations
• S0, S1 and T1 states of DTV2+
• Indicating the inter-ring dihedral angles
• The (S0-S1) and (S1-T1) and
intramolecular reorganization energies
• The three semi planar rings exhibit
alternating bond lengths.
• Bonds with length changing by more
than 0.025 Å, contraction in red and
lengthening in green
40
41. Electrochromic Properties
UV-VIS spectra of DTV2+ in water before and UV-VIS spectra of DTV2+ @CB[7] in water
after reduction before and after reduction
1.5
1.5
2+
1.0 DTV DTV.+ 2+ .+
1.0
DTV DTV
Absorbance a.u.
Absorbance a.u.
330 nm 400 nm
335 nm 400 nm
0.5
0.5
0.0
0.0
300 400 500 600
300 400 500 600
Wavelength [nm] Wavelength [nm]
• Viologen was reduced electrochemically by applying -1.0 V
and chemically with 1M NaOH in Methanol
41
42. Electrochromic Properties
Emission spectra of DTV2+ in water before and Emission spectra of DTV2+ @CB[7] in water
after reduction before and after reduction
25
600 em=475 nm
em=527 nm
20
500
2+
DTV
2+ DTV
Intensity a.u.
15 400
Intensity a.u.
ex=350 nm
300
10
200
ex=350 nm
5
.+ 100
DTV .+
DTV
0 0
400 450 500 550 600 650 400 450 500 550 600 650
Wavelength [nm] Wavelength [nm]
• Viologen was reduced electrochemically by applying a
voltage of -1.0 V and chemically with 1M NaOH in Methanol
42
43. Complex on Metal Oxide Surface
2+
8 DTV @CB[7] on ZrO2
em= 480 nm
7
6 •Fluorescence spectra of the
5
DTV2+@CB[7] bound to ZrO2
Emission a.u.
4
•ZrO2 is an insulator, similar
3
morphology to the semiconductor
2
TiO2
1
ex= 350 nm
0
400 450 500 550 600
Wavelength [nm]
43
44. Conclusions
Use of Cucurbituril as a Host
• Encapsulation of fluorescent dyes in Cucurbituril can lead to numerous
applications
• Benefits of encapsulation: solubilization, deaggregation, photostabillization
• Pronounced enhancement of fluorescence
• Prolonged lifetime
• Restriction of conformational changes
• Binding unit to the metal oxide nanoparticles
New Viologen Derivative DTV2+
• First viologen derivative showing fluorescent properties
• DFT calculations confirm conformational effect
• Position of Methyl group in benzylic positions is key component
• Restriction of molecular mobility is necessary to enhance fluorescence (CB[7]
or Polymer matrix) 44
45. Acknowledgements
Advisor: Prof. Elena Galoppini
Thesis committee: Prof. Phillip Huskey of Rutgers University, Newark
Prof. Jenny Lockard of Rutgers University, Newark
Prof. Angel E. Kaifer of University of Miami, Florida
Collaborators: Prof. Piotr Piotrowiak, Prof. Lars Gundlach – Laser measurements
Prof. Carlo Bignozzi, Dr. Stefano Caramori – Research visit 2009
Prof. Richard Mendelsohn, Dr. Carol Flach – FT-IR-ATR Instrument
Research group: Prof. Jonathan Rochford, Prof. Olena Taratula, Dr. Sujatha Thyagarajan,
Dr. Yongyi Zhang, Andrew Kopecky, Keyur Chitre, Yan Cao
and Agnieszka Klimczak
Chemistry dept.: Prof. Philip W. Huskey, Prof. Frank Jordan and Prof. John Sheridan and all
professors and staff, former and current members of Rutgers Chemistry
Department Newark and especially to Judy Slocum, Monika Dabrowski
Lorraine McClendon, Paulo Vares and Maria Araujo
Financial support: Donors of the American Chemical Society Petroleum Research Fund
(ACS PRF #46663-AC10).
45