Molecular structure is the most basic information about a substance, determining most of its properties. Determination of accurate structures is hampered in that every method applies its own definition of "structure" and thus results from different sources can yield significantly different results. Sophisticated protocols exist to account for these
This book presents a detailed look at experimental and computational techniques for accurate structure determination of free molecules. The most fundamental property of a molecule is its structure – it is a prerequisite for determining and understanding most other important properties of molecules. The determination of accurate structures is hampered by a myriad of factors, subjecting the collected data to non-negligible systematic errors. This book explains the origin of these errors and how to mitigate and even avoid them altogether. It features a detailed comparison of the different experimental and computation methods, explaining their interplay and the advantages of their combined use. Armed with this information, the reader will be able to choose the appropriate methods to determine – to a great degree of accuracy – the relevant molecular structure.
This book provides a penetrating and comprehensive description of energy selected reactions from a theoretical as well as experimental view. Three major aspects of unimolecular reactions involving the preparation of the reactants in selected energy states, the rate of dissociation of the activated molecule, and the partitioning of the excess energy among the final products, are fully discussed with the aid of 175 illustrations and over 1,000 references, most from the recent literature. Examples of both neutral and ionic reactions are presented. Many of the difficult topics are discussed at several levels of sophistication to allow access by novices as well as experts. Among the topics covered for the first time in monograph form is a discussion of highly excited vibrational/rotational states and intramolecular vibrational energy redistribution. Problems associated with the application of RRKM theory are discussed with the aid of experimental examples. Detailed comparisons are also made between different statistical models of unimolecular decomposition. Both quantum and classical models not based on statistical assumptions are described. Finally, a chapter devoted to the theory of product energy distribution includes the application of phase space theory to the dissociation of small and large clusters. The work will be welcomed as a valuable resource by practicing researchers and graduate students in physical chemistry, and those involved in the study of chemical reaction dynamics.
The properties of chemical, pharmaceutical, and biological compounds depend mainly on their molecular structure, whose determination is of fundamental interest. This book examines and systematizes more than three hundred striking structural determinations of free molecules. Featuring high-quality structural data and presenting modern techniques of their determinations by quantum chemistry, high-resolution spectroscopy and electron diffraction, the book is an indispensable resource for graduate students and professional scientists specializing in structural chemistry and other related fields.
...Diatomic Molecules provides a systematic approach to quantitative analysis of molecular spectra of diatomic molecules, in particular infrared and Raman spectra. This analysis is used to extract precise information about not only molecular structure but also its associated electric and magnetic properties. This book is unique in its methodical treatment of the subject, and in the included collection of results and extensive bibliography. The first three chapters provide a thorough explanation of an empirical basis of infrared and Raman spectra, together with the theory behind techniques employed in their analysis. Succeeding chapters outline, among other topics, wave functions and matrix elements in relation to radial functions for potential energy, dipolar moment etc., and applications of lasers. Various methods are applied in analysis of frequency data and spectral intensities, and to effects of spin and intermolecular interaction. The many subjects are discussed in depth, with reviews of topics important in future progress of experiment and theory in molecular spectroscopy. Senior undergraduate and postgraduate students in chemistry and physics will find ..Diatomic Molecules a useful adjunct to their course texts, and it will prove invaluable to all researchers in spectroscopy.
In this Festschrift celebrating the career of Thom H. Dunning, Jr., selected researchers in theoretical chemistry present research highlights on major developments in the field. Originally published in the journal Theoretical Chemistry Accounts, these outstanding contributions are now available in a hardcover print format, as well as a special electronic edition. This volume provides valuable content for all researchers in theoretical chemistry and will especially benefit those research groups and libraries with limited access to the journal.
This series, established in 1965, is concerned with recent developments in the general area of atomic, molecular, and optical physics. The field is in a state of rapid growth, as new experimental and theoretical techniques are used on many old and new problems. Topics covered also include related applied areas, such as atmospheric science, astrophysics, surface physics, and laser physics. Articles are written by distinguished experts who are active in their research fields. The articles contain both relevant review material and detailed descriptions of important recent developments.
The importance of the potential surface model has led naturally to a large number of studies on the subject, where the emphasis has usually been placed on lower dimensional problems, such as the reaction dynamics of diatomic to four-atom systems, or conformational problems restricted to few internal rotations. The purposes and methods of this book are, however, somewhat different from those of most studies on potential surface problems. The emphasis here is placed on those fundamental properties of potential energy hypersurfaces that are general for higher dimensions, that is, for larger molecules. The study of these properties requires some of the tools of global analysis that are not among the routine mathematical techniques of quantum chemists: topology, homotopy, and homology. This book provides the reader with an introduction to the fundamentals and to some of the more recent developments in the theory of potential energy hypersurfaces. The text is fairly self-contained. It requires no previous mathematical knowledge from the reader beyond that needed in an undergraduate quantum chemistry course.
