The Reaction Path in Chemistry: Current Approaches and Perspectives

The Reaction Path in Chemistry: Current Approaches and Perspectives PDF Author: D. Heidrich
Publisher: Springer Science & Business Media
ISBN: 9401585393
Category : Science
Languages : en
Pages : 303

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Book Description
The so-called reaction path (RP) with respect to the potential energy or the Gibbs energy ("free enthalpy") is one of the most fundamental concepts in chemistry. It significantly helps to display and visualize the results of the complex microscopic processes forming a chemical reaction. This concept is an implicit component of conventional transition state theory (TST). The model of the reaction path and the TST form a qualitative framework which provides chemists with a better understanding of chemical reactions and stirs their imagination. However, an exact calculation of the RP and its neighbourhood becomes important when the RP is used as a tool for a detailed exploring of reaction mechanisms and particularly when it is used as a basis for reaction rate theories above and beyond TST. The RP is a theoretical instrument that now forms the "theoretical heart" of "direct dynamics". It is particularly useful for the interpretation of reactions in common chemical systems. A suitable definition of the RP of potential energy surfaces is necessary to ensure that the reaction theories based on it will possess sufficiently high quality. Thus, we have to consider three important fields of research: - Analysis of potential energy surfaces and the definition and best calculation of the RPs or - at least - of a number of selected and chemically interesting points on it. - The further development of concrete vers ions of reaction theory beyond TST which are applicable for common chemical systems using the RP concept.

The Reaction Path in Chemistry: Current Approaches and Perspectives

The Reaction Path in Chemistry: Current Approaches and Perspectives PDF Author: D. Heidrich
Publisher: Springer Science & Business Media
ISBN: 9401585393
Category : Science
Languages : en
Pages : 303

Get Book Here

Book Description
The so-called reaction path (RP) with respect to the potential energy or the Gibbs energy ("free enthalpy") is one of the most fundamental concepts in chemistry. It significantly helps to display and visualize the results of the complex microscopic processes forming a chemical reaction. This concept is an implicit component of conventional transition state theory (TST). The model of the reaction path and the TST form a qualitative framework which provides chemists with a better understanding of chemical reactions and stirs their imagination. However, an exact calculation of the RP and its neighbourhood becomes important when the RP is used as a tool for a detailed exploring of reaction mechanisms and particularly when it is used as a basis for reaction rate theories above and beyond TST. The RP is a theoretical instrument that now forms the "theoretical heart" of "direct dynamics". It is particularly useful for the interpretation of reactions in common chemical systems. A suitable definition of the RP of potential energy surfaces is necessary to ensure that the reaction theories based on it will possess sufficiently high quality. Thus, we have to consider three important fields of research: - Analysis of potential energy surfaces and the definition and best calculation of the RPs or - at least - of a number of selected and chemically interesting points on it. - The further development of concrete vers ions of reaction theory beyond TST which are applicable for common chemical systems using the RP concept.

Chemical Reactivity and Reaction Paths

Chemical Reactivity and Reaction Paths PDF Author: Gilles Klopman
Publisher: Wiley-Interscience
ISBN:
Category : Science
Languages : en
Pages : 392

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Book Description


Frontier Orbitals and Reaction Paths

Frontier Orbitals and Reaction Paths PDF Author: Kenichi Fukui
Publisher: World Scientific
ISBN: 9812795847
Category : Science
Languages : en
Pages : 563

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Book Description
A collection of selected papers on the Frontier Orbital Theory, with introductory notes. It provides the basic concept and formulation of the theory, and the physical and chemical significance of the frontier orbital interactions in chemistry, together with many practical applications. The formulation of the Intrinsic Reaction Coordinate and applications to some simple systems are also presented. The aim of this volume is to show by what forces chemical reactions are driven and to demonstrate how the regio- and stereo-selectivities are determined in chemical reactions. Students and senior investigators will gain insight into the nature of chemical reactions and find out how quantum chemical calculations are connected with chemical intuition.

CHEMICAL REACTIVITY AND REACTION PATHS.

CHEMICAL REACTIVITY AND REACTION PATHS. PDF Author: G KLOPMAN (ED.)
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description


Symmetry and Topology in Chemical Reactivity

Symmetry and Topology in Chemical Reactivity PDF Author: Pieter E. Schipper
Publisher: World Scientific
ISBN: 9789810215422
Category : Science
Languages : en
Pages : 292

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Book Description
This well-illustrated book develops, using only the ideas of basic quantum chemistry (e.g. perturbation and symmetry theory), a fundamental conceptual and theoretical framework for chemical reactivity. By feeding the role of symmetry and chemical group topology directly into the development, the analysis generates and explains the successful features of simpler reactivity theories (e.g. frontier orbital theory, the isolobal concept, PMO theory, the Woodward-Hoffmann rules), as well as defines their limitations. The unifying construct is that of a group-resolved correlation diagram, which is shown to represent the formal quantization of the electron arrow, replacing the concept of classical point electrons moving between groups with the concept of quantum electron matter waves which evolve with the evolving nuclear and chemical group structure. The use of the concept of chemical groups (functional group system, substituents, solvents) is central to the development, localising the evolutionary electrons within the functional groups and leading to an isolation and analytic definition of substituent and solvent (catalytic) effects as explicit functions of the reaction coordinate. Each archetypical reaction family is represented by fully-worked examples: viz. aliphatic nucleophilic substitution, aromatic electrophilic substitution, inorganic rearrangements, electrocyclic additions, Diels-Alder additions and addition stages in chiral reactions.

Chemical Kinetics

Chemical Kinetics PDF Author: Luis Arnaut
Publisher: Elsevier
ISBN: 0080469345
Category : Science
Languages : en
Pages : 563

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Book Description
Chemical Kinetics bridges the gap between beginner and specialist with a path that leads the reader from the phenomenological approach to the rates of chemical reactions to the state-of-the-art calculation of the rate constants of the most prevalent reactions: atom transfers, catalysis, proton transfers, substitution reactions, energy transfers and electron transfers. For the beginner provides the basics: the simplest concepts, the fundamental experiments, and the underlying theories. For the specialist shows where sophisticated experimental and theoretical methods combine to offer a panorama of time-dependent molecular phenomena connected by a new rational. Chemical Kinetics goes far beyond the qualitative description: with the guidance of theory, the path becomes a reaction path that can actually be inspected and calculated. But Chemical Kinetics is more about structure and reactivity than numbers and calculations. A great emphasis in the clarity of the concepts is achieved by illustrating all the theories and mechanisms with recent examples, some of them described with sufficient detail and simplicity to be used in general chemistry and lab courses.* Looking at atoms and molecules, and how molecular structures change with time. * Providing practical examples and detailed theoretical calculations* Of special interest to Industrial Chemistry and Biochemistry

Frontier Orbitals and Reaction Paths

Frontier Orbitals and Reaction Paths PDF Author: Kenichi Fukui
Publisher: World Scientific
ISBN: 9810222416
Category : Science
Languages : en
Pages : 563

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Book Description
This book is a collection of selected papers on the Frontier Orbital Theory by Nobel prizewinner Kenichi Fukui (Chemistry 1981), with introductory notes. It provides the basic concept and formulation of the theory, and the physical and chemical significance of the frontier orbital interactions in chemistry, together with many practical applications. The formulation of the Intrinsic Reaction Coordinate and applications to some simple systems are also presented. The aim of this volume is to show by what forces chemical reactions are driven and to demonstrate how the regio- and stereo-selectivities are determined in chemical reactions. Students and senior investigators will gain insight into the nature of chemical reactions and find out how quantum chemical calculations are connected with chemical intuition.

Quantum Theory of Chemical Reactions

Quantum Theory of Chemical Reactions PDF Author: R. Daudel
Publisher: Springer Science & Business Media
ISBN: 9400995164
Category : Science
Languages : en
Pages : 249

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Book Description
This treatise is devoted to an analysis of the present state of the quantum theory of chemical reactions. It will be divided into three volumes and will contain the contributions to an international seminar organized by the editors. The first one, is concerned with the fundamental problems which occur when studying a gas phase reaction or a reaction for which the solvent effect is not taken into account. The two first papers show how the collision theory can be used to predict the behaviour of interacting small molecules. For large molecules the complete calculations are not possible. We can only estimate the reaction path by calculating important areas of the potential surfaces. Four papers are concerned with this important pro cess. Furthermore, in one of these, the electronic reorganization which occurs along the reaction path is carefully analyzed. ~~o papers are devoted to the discussion of general rules as aromaticity rules, symmetry rules. The last two papers are concerned with the electrostatic molecular poten tial method which is the modern way of using static indices to establish relations between structure and chemical reactivity. Volume II will be devoted to a detailed analysis of the role of the solvent and volume III will present important applications as reaction mechanisms, photochemistry, catalysis, biochemical reactions and drug design. SOME RECENT DEVELOPMENTS IN THE MOLECULAR TREATMENT OF ATOM-ATOM COLLISIONS.

Quantum Chemistry of Organic Compounds

Quantum Chemistry of Organic Compounds PDF Author: Vladimir I. Minkin
Publisher: Springer Science & Business Media
ISBN: 3642756794
Category : Science
Languages : en
Pages : 281

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Book Description
Chemistry is the science of substances (today we would say molecules) and their transformations. Central to this science is the complexity of shape and function of its typical representatives. There lies, no longer dependent on its vitalistic antecedents, the rich realm of molecular possibility called organic chemistry. In this century we have learned how to determine the three-dimensional structure of molecules. Now chemistry as whole, and organic chemistry in particular, is poised to move to the exploration of its dynamic dimension, the busy business of transformations or reactions. Oh, it has been done all along, for what else is synthesis? What I mean is that the theoretical framework accom panying organic chemistry, long and fruitfully laboring on a quantum chemical understanding of structure, is now making the first tentative motions toward building an organic theory of reactivity. The Minkin, Simkin, Minyaev book takes us in that direction. It incorporates the lessons of frontier orbital theory and of Hartree-Fock SCF calculations; what chemical physicists have learned about trajectory calculations of selected reactions, and a simplified treatment of all-important solvent effects. It is written by professional, accomplished organic chemists for other organic chemists; it is consistently even-toned in its presentation of contending approaches. And very much up to date. That this contemporary work should emerge from a regional university in a country in which science has been highly centralized and organic chemistry not very modern, invites reflection.

Insights Into the Mechanisms on Chemical Reactions

Insights Into the Mechanisms on Chemical Reactions PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
We report reaction paths for two prototypical chemical reactions: Li + HF, an electron transfer reaction, and OH + H2, an abstraction reaction. In the first reaction we consider the connection between the energetic terms in the reaction path Hamiltonian and the electronic changes which occur upon reaction. In the second reaction we consider the treatment of vibrational effects in chemical reactions in the reaction path formalism. 30 refs., 9 figs.