UNIT – I Nomenclature of Organic Compounds and Reaction Intermediates
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Density Functional Theory Study of Substituent Effects on the 1,3
Density Functional Theory Study of Substituent Effects on the 1,3-Dipolar Cycloaddition Mechanism Pengliag Sun1, Meng Liu2, Wei Pu1, Yi Jin1, Shixi Liu1, Qiue Cao1, and Zhongtao Ding1 1Yunnan University 2Chinese Academy of Sciences May 29, 2020 Abstract In this study, we performed density functional theory calculations using the B3LYP, M052X, M062X, and APFD functionals to investigate substituent effects on the mechanism of 1,3-dipolar cycloaddition, a classical and effective method for the synthesis of heterocyclic compounds. The results showed that changing the substituents on the chloroxime compounds affects the energy level of the highest occupied molecular orbital and consequently, the progress of the reaction. Finally, it provided an effective idea for this kind of reaction in the design of organic synthesis and the necessary theoretical basis for revealing the course of this reaction. Abstract In this study, we performed density functional theory calculations using the B3LYP, M052X, M062X, and APFD functionals to investigate substituent effects on the mechanism of 1,3-dipolar cycloaddition, a classical and effective method for the synthesis of heterocyclic compounds. The results showed that changing the substituents on the chloroxime compounds affects the energy level of the highest occupied molecular orbital and consequently, the progress of the reaction. Finally, it provided an effective idea for this kind of reaction in the design of organic synthesis and the necessary theoretical basis for revealing the course of this reaction. Keywords: -
Chapter 14 Chemical Kinetics
Chapter 14 Chemical Kinetics Learning goals and key skills: Understand the factors that affect the rate of chemical reactions Determine the rate of reaction given time and concentration Relate the rate of formation of products and the rate of disappearance of reactants given the balanced chemical equation for the reaction. Understand the form and meaning of a rate law including the ideas of reaction order and rate constant. Determine the rate law and rate constant for a reaction from a series of experiments given the measured rates for various concentrations of reactants. Use the integrated form of a rate law to determine the concentration of a reactant at a given time. Explain how the activation energy affects a rate and be able to use the Arrhenius Equation. Predict a rate law for a reaction having multistep mechanism given the individual steps in the mechanism. Explain how a catalyst works. C (diamond) → C (graphite) DG°rxn = -2.84 kJ spontaneous! C (graphite) + O2 (g) → CO2 (g) DG°rxn = -394.4 kJ spontaneous! 1 Chemical kinetics is the study of how fast chemical reactions occur. Factors that affect rates of reactions: 1) physical state of the reactants. 2) concentration of the reactants. 3) temperature of the reaction. 4) presence or absence of a catalyst. 1) Physical State of the Reactants • The more readily the reactants collide, the more rapidly they react. – Homogeneous reactions are often faster. – Heterogeneous reactions that involve solids are faster if the surface area is increased; i.e., a fine powder reacts faster than a pellet. 2) Concentration • Increasing reactant concentration generally increases reaction rate since there are more molecules/vol., more collisions occur. -
INFORMATION to USERS This Manuscript Has Been Reproduced
INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer primer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, prim bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g^ maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand comer and continuing from left to right in equal sections with small overlaps. Each original is also photographed in one exposure and is included in reduced form at the back of the book. Photographs included in the original manuscript have been reproduced xerographically in this copy. Higher quality 6” x 9” black and white photographic prints are available for any photographs or illustrations appearing in this copy for an additional charge. Contact UMI directly to order. A Bell & Howell Intormaiion Company 300 North Zeeb Road Ann Arbor Ml 46106*1346 USA 313/761-4700 800.521-0600 EXPLORATORY PHOTOCHEMISTRY OF POLYFLUORINATED ARYL AZIDES IN NEUTRAL AND ACIDIC MEDIA DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the Graduate School of The Ohio State University By Hongbin Zhai ***** The Ohio State University 1995 Dissertation Committee: Approved By Matthew S. -
Elementary Reaction Models for CO Electrochemical Oxidation on an Ni/YSZ Patterned Anode
Elementary Reaction Models for CO Electrochemical Oxidation on an Ni/YSZ Patterned Anode The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Citation Shi, Yixiang, et al. “Elementary Reaction Models for CO Electrochemical Oxidation on an Ni/YSZ Patterned Anode.” ASME 2010 8th International Fuel Cell Science, Engineering and Technology Conference: Volume 2, 14-16 June, 2010, Brooklyn, New York, ASME, 2010, pp. 159–66. © 2010 by ASME As Published http://dx.doi.org/10.1115/FuelCell2010-33205 Publisher ASME International Version Final published version Citable link http://hdl.handle.net/1721.1/119260 Terms of Use Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. Proceedings of the ASME 2010 Eighth International Fuel Cell Science, Engineering and Technology Conference FuelCell2010 June 14-16, 2010, Brooklyn, New York, USA FuelCell2010-33205 ELEMENTARY REACTION MODELS FOR CO ELECTROCHEMICAL OXIDATION ON AN NI/YSZ PATTERNED ANODE Yixiang Shi1,2 Won Yong Lee Ahmed F. Ghoniem 1 Department of Mechanical Engineering Department of Mechanical Engineering Department of Mechanical Engineering Massachusetts Institute of Technology, Massachusetts Institute of Technology, Massachusetts Institute of Technology, Cambridge, MA, USA, 02139 Cambridge, MA, USA, 02139 Cambridge, MA, USA, 02139 2 Department of Thermal Engineering, Tsinghua University, Beijing, China, 100084 measurements for CO electrochemical oxidation on ABSTRACT nickel/yttria-stabilized zirconia (Ni/YSZ) patterned anode, and examine Analysis of recent experimental impedance spectra and possible limiting steps in CO oxidation kinetics. -
Electrochemistry and Photoredox Catalysis: a Comparative Evaluation in Organic Synthesis
molecules Review Electrochemistry and Photoredox Catalysis: A Comparative Evaluation in Organic Synthesis Rik H. Verschueren and Wim M. De Borggraeve * Department of Chemistry, Molecular Design and Synthesis, KU Leuven, Celestijnenlaan 200F, box 2404, 3001 Leuven, Belgium; [email protected] * Correspondence: [email protected]; Tel.: +32-16-32-7693 Received: 30 March 2019; Accepted: 23 May 2019; Published: 5 June 2019 Abstract: This review provides an overview of synthetic transformations that have been performed by both electro- and photoredox catalysis. Both toolboxes are evaluated and compared in their ability to enable said transformations. Analogies and distinctions are formulated to obtain a better understanding in both research areas. This knowledge can be used to conceptualize new methodological strategies for either of both approaches starting from the other. It was attempted to extract key components that can be used as guidelines to refine, complement and innovate these two disciplines of organic synthesis. Keywords: electrosynthesis; electrocatalysis; photocatalysis; photochemistry; electron transfer; redox catalysis; radical chemistry; organic synthesis; green chemistry 1. Introduction Both electrochemistry as well as photoredox catalysis have gone through a recent renaissance, bringing forth a whole range of both improved and new transformations previously thought impossible. In their growth, inspiration was found in older established radical chemistry, as well as from cross-pollination between the two toolboxes. In scientific discussion, photoredox catalysis and electrochemistry are often mentioned alongside each other. Nonetheless, no review has attempted a comparative evaluation of both fields in organic synthesis. Both research areas use electrons as reagents to generate open-shell radical intermediates. Because of the similar modes of action, many transformations have been translated from electrochemical to photoredox methodology and vice versa. -
CHEMICAL KINETICS Pt 2 Reaction Mechanisms Reaction Mechanism
Reaction Mechanism (continued) CHEMICAL The reaction KINETICS 2 C H O +→5O + 6CO 4H O Pt 2 3 4 3 2 2 2 • has many steps in the reaction mechanism. Objectives ! Be able to describe the collision and Reaction Mechanisms transition-state theories • Even though a balanced chemical equation ! Be able to use the Arrhenius theory to may give the ultimate result of a reaction, determine the activation energy for a reaction and to predict rate constants what actually happens in the reaction may take place in several steps. ! Be able to relate the molecularity of the reaction and the reaction rate and • This “pathway” the reaction takes is referred to describle the concept of the “rate- as the reaction mechanism. determining” step • The individual steps in the larger overall reaction are referred to as elementary ! Be able to describe the role of a catalyst and homogeneous, heterogeneous and reactions. enzyme catalysis Reaction Mechanisms Often Used Terms •Intermediate: formed in one step and used up in a subsequent step and so is never seen as a product. The series of steps by which a chemical reaction occurs. •Molecularity: the number of species that must collide to produce the reaction indicated by that A chemical equation does not tell us how step. reactants become products - it is a summary of the overall process. •Elementary Step: A reaction whose rate law can be written from its molecularity. •uni, bi and termolecular 1 Elementary Reactions Elementary Reactions • Consider the reaction of nitrogen dioxide with • Each step is a singular molecular event carbon monoxide. -
Chemical Kinetics Reaction Mechanisms
Chemical Kinetics π Kinetics is a study of the rate at which a chemical reaction occurs. π The study of kinetics may be done in steps: Determination of reaction mechanism Prediction of rate law Measurement of reaction rates Comparison of predicted and measured rates Reaction Mechanisms π Up to now, we have written chemical reactions as “net” reactions—a balanced chemical equation that shows the initial reactants and final products. π A “reaction mechanism” shows the “elementary” reactions that must occur to produce the net reaction. π An “elementary” reaction is a chemical reaction that actually takes place. 1 Reaction Mechanisms π Every September since the early 80s, an “ozone hole” has developed over Antarctica which lasts until mid-November. O3 concentration-Dobson units Reaction Mechanisms Average Ozone C oncentrati ons for October over H al l ey's B ay 350 300 250 200 150 100 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 Year 2 Reaction Mechanisms π The net reaction for this process is: → 2 O3(g) 3 O2(g) π If this reaction were an elementary reaction, then two ozone molecules would need to collide with each other in such a way to form a new O-O bond while breaking two other O-O bonds to form products: O O O → 3 O2 O O O Reaction Mechanisms π It is hard to imagine this process happening based on our current understanding of chemical principles. π The net reaction must proceed via some other set of elementary reactions: 3 Reaction Mechanisms π One possibility is: → Cl + O3 ClO + O2 ClO + ClO → ClOOCl ClOOCl → Cl + ClOO → ClOO Cl + O2 → Cl + O3 ClO + O2 → net: 2 O3 3 O2 Reaction Mechanisms π In this mechanism, each elementary reaction makes sense chemically: Cl O O → Cl-O + O-O O π The chlorine atom abstracts an oxygen atom from ozone leaving ClO and molecular oxygen. -
Heteroatom Substitution at Amide Nitrogen—Resonance Reduction and HERON Reactions of Anomeric Amides
molecules Review Heteroatom Substitution at Amide Nitrogen—Resonance Reduction and HERON Reactions of Anomeric Amides Stephen A. Glover * and Adam A. Rosser Department of Chemistry, School of Science and Technology, University of New England, Armidale, NSW 2351, Australia; [email protected] * Correspondence: [email protected] Received: 6 October 2018; Accepted: 24 October 2018; Published: 31 October 2018 Abstract: This review describes how resonance in amides is greatly affected upon substitution at nitrogen by two electronegative atoms. Nitrogen becomes strongly pyramidal and resonance stabilisation, evaluated computationally, can be reduced to as little as 50% that of N,N-dimethylacetamide. However, this occurs without significant twisting about the amide bond, which is borne out both experimentally and theoretically. In certain configurations, reduced resonance and pronounced anomeric effects between heteroatom substituents are instrumental in driving the HERON (Heteroatom Rearrangement On Nitrogen) reaction, in which the more electronegative atom migrates from nitrogen to the carbonyl carbon in concert with heterolysis of the amide bond, to generate acyl derivatives and heteroatom-substituted nitrenes. In other cases the anomeric effect facilitates SN1 and SN2 reactivity at the amide nitrogen. Keywords: amide resonance; anomeric effect; HERON reaction; pyramidal amides; physical organic chemistry; reaction mechanism 1. Introduction Amides are prevalent in a range of molecules such as peptides, proteins, lactams, and many synthetic polymers [1]. Generically, they are composed of both a carbonyl and an amino functional group, joined by a single bond between the carbon and nitrogen. The contemporary understanding of the resonance interaction between the nitrogen and the carbonyl in amides is that of an interaction between the lowest unoccupied molecular orbital (LUMO) of the carbonyl, π*C=O, and the highest occupied molecular orbital (HOMO) of the amide nitrogen (N2pz) (Figure1). -
Lithiation Reactions of 3-(4-Chlorophenyl)Sydnone and 3-(4-Methylphenyl)Sydnone
Wright State University CORE Scholar Browse all Theses and Dissertations Theses and Dissertations 2009 Lithiation Reactions of 3-(4-chlorophenyl)Sydnone and 3-(4-methylphenyl)Sydnone Nigel Ngonidzashe Chitiyo Wright State University Follow this and additional works at: https://corescholar.libraries.wright.edu/etd_all Part of the Chemistry Commons Repository Citation Chitiyo, Nigel Ngonidzashe, "Lithiation Reactions of 3-(4-chlorophenyl)Sydnone and 3-(4-methylphenyl)Sydnone" (2009). Browse all Theses and Dissertations. 966. https://corescholar.libraries.wright.edu/etd_all/966 This Thesis is brought to you for free and open access by the Theses and Dissertations at CORE Scholar. It has been accepted for inclusion in Browse all Theses and Dissertations by an authorized administrator of CORE Scholar. For more information, please contact [email protected]. LITHIATION REACTIONS OF 3-(4-CHLOROPHENYL) SYDNONE AND 3-(4- METHYLPHENYL) SYDNONE A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science By NIGEL NGONIDZASHE CHITIYO B.S., University Of Zimbabwe, 2002 2009 Wright State University WRIGHT STATE UNIVERSITY SCHOOL OF GRADUATE STUDIES November 12, 2009 I HEREBY RECOMMEND THAT THE THESIS PREPARED UNDER MY SUPERVISION BY Nigel Chitiyo ENTITLED Lithiation reactions of 3-(4-chlorophenyl) sydnone and 3-(4-methylphenyl) sydnone BE ACCEPTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF Master of Science. _________________________ Kenneth Turnbull, Ph.D. Thesis Director _________________________ Kenneth Turnbull, Ph.D. Department Chair Committee on Final Examination _________________________ Kenneth Turnbull, Ph.D. _________________________ Daniel M. Ketcha, Ph.D. _________________________ Eric Fossum, Ph.D. _________________________ Joseph F. Thomas, Ph.D. -
Lithiation Reactions of 3-(4-Chlorophenyl)Sydnone and 3-(4-Methylphenyl)Sydnone
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by CORE Wright State University CORE Scholar Browse all Theses and Dissertations Theses and Dissertations 2009 Lithiation Reactions of 3-(4-chlorophenyl)Sydnone and 3-(4-methylphenyl)Sydnone Nigel Ngonidzashe Chitiyo Wright State University Follow this and additional works at: https://corescholar.libraries.wright.edu/etd_all Part of the Chemistry Commons Repository Citation Chitiyo, Nigel Ngonidzashe, "Lithiation Reactions of 3-(4-chlorophenyl)Sydnone and 3-(4-methylphenyl)Sydnone" (2009). Browse all Theses and Dissertations. 966. https://corescholar.libraries.wright.edu/etd_all/966 This Thesis is brought to you for free and open access by the Theses and Dissertations at CORE Scholar. It has been accepted for inclusion in Browse all Theses and Dissertations by an authorized administrator of CORE Scholar. For more information, please contact [email protected]. LITHIATION REACTIONS OF 3-(4-CHLOROPHENYL) SYDNONE AND 3-(4- METHYLPHENYL) SYDNONE A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science By NIGEL NGONIDZASHE CHITIYO B.S., University Of Zimbabwe, 2002 2009 Wright State University WRIGHT STATE UNIVERSITY SCHOOL OF GRADUATE STUDIES November 12, 2009 I HEREBY RECOMMEND THAT THE THESIS PREPARED UNDER MY SUPERVISION BY Nigel Chitiyo ENTITLED Lithiation reactions of 3-(4-chlorophenyl) sydnone and 3-(4-methylphenyl) sydnone BE ACCEPTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF Master of Science. _________________________ Kenneth Turnbull, Ph.D. Thesis Director _________________________ Kenneth Turnbull, Ph.D. Department Chair Committee on Final Examination _________________________ Kenneth Turnbull, Ph.D. -
Synthesis and Reactivity of Sydnone Derived 1,3,4-Oxadiazol
SYNTHESIS AND REACTIVITY OF SYDNONE DERIVED 1,3,4-OXADIAZOL- 2(3H)-ONES A thesis submitted in partial fulfillment of the Requirements for the degree of Master of Science By JONATHAN MICHAEL TUMEY B.S. Wright State University, 2015 2017 Wright State University WRIGHT STATE UNIVERSITY GRADUATE SCHOOL 11/28/2017 I hereby recommend that the thesis prepared under my supervision by Jonathan Michael Tumey entitled SYNTHESIS AND REACTIVITY OF SYDNONE DERIVED 1,3,4-OXADIAZOL-2(3H)-ONES be accepted in partial fulfillment of the requirements for the degree of Master of Science Kenneth Turnbull, Ph.D. Thesis Director David A. Grossie, Ph.D. Chair, Department of Chemistry Committee on Final Examination Kenneth Turnbull, Ph.D. Eric Fossum, Ph.D. Daniel Ketcha, Ph.D. Barry Milligan, Ph.D. Professor and Interim Dean of the Graduate School Abstract Tumey, Jonathan Michael, M.S. Department of Chemistry, Wright State University, 2017. Synthesis and Reactivity of Sydnone Derived 1,3,4-Oxadiazol-2(3H)-ones. 5-(Bromomethyl)- and 5-(trichloromethyl)-3-phenyl-1,3,4-oxadiazol-2(3H)-ones were synthesized from bromocarbonyl hydrazine intermediate salts and acid halides to provide further evidence for our proposed mechanism for the formation of oxadiazolone ring systems from sydnones. 5-(Bromomethyl)-3-phenyl-1,3,4-oxadiazol-2(3H)-one was a compound of interest due to its SN2 possibilities and three potential sites of diversification. The procedure to synthesize 5-(bromomethyl)-3-phenyl-1,3,4-oxadiazol- 2(3H)-one was developed originally by Madaram in the Turnbull lab, but was further optimized in the present work by altering the time, temperature and stoichiometric equivalents of the acid halide to provide high purity and excellent yields of the product. -
Direct Observation and Reactivity of Oxenium Ions Patrick James Hanway Iowa State University
Iowa State University Capstones, Theses and Graduate Theses and Dissertations Dissertations 2014 Direct observation and reactivity of oxenium ions Patrick James Hanway Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/etd Part of the Chemistry Commons Recommended Citation Hanway, Patrick James, "Direct observation and reactivity of oxenium ions" (2014). Graduate Theses and Dissertations. 13908. https://lib.dr.iastate.edu/etd/13908 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Direct observation and reactivity of oxenium ions by Patrick James Hanway A dissertation submitted to the graduate faculty in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Major: Organic Chemistry Program of Study Committee Arthur H. Winter, Major Professor William Jenks Theresa Windus Keith Woo Malika Jeffries EL Iowa State University Ames, Iowa 2014 ii TABLE OF CONTENTS Page ACKNOWLEDGEMENTS……………………………………………………… iii ABSTRACT……………………………………………………………………… vi CHAPTER 1. INTRODUCTION………………………………………………... 1 CHAPTER 2. DIRECT DETECTION AND REACTIVITY OF THE SHORT- LIVED PHENYLOXENIUM ION 17 CHAPTER 3. HETEROARYL OXENIUM IONS HAVE DIVERSE AND UNUSUAL LOW-ENERGY ELECTRONIC STATES 39 CHAPTER 4. DIRECT TIME-RESOLVED SPECTROSCOPIC OBSERVATION OF SINGLET AND TRIPLET p-BIPHENYLYL OXENIUM ION 55 CHAPTER 5. META-DIMETHYLAMINO PHENYLOXENIUM ION: STUDIES ON A GROUND-STATE TRIPLET ION 77 CONCLUSIONS……………………………………………………………….. 86 iii ACKNOWLEDGEMENTS I would like to start by thanking my advisor Dr.