Written by a Nobel Laureate, this introduction to molecular spectroscopy covers rotational, vibrational, and electronic energy levels of diatomic molecules and ions; linear, nonlinear polyatomic radicals and ions; more. 1971 edition.

"Authoritative and clearly written."—Applied Optics The direct observation of short-lived free radicals and the consequent study of their structure and reactions have led to important developments in almost every branch of chemistry as well as in other areas. This volume by a Nobel laureate offers an excellent introduction to the essentials of molecular spectroscopy. The introductory chapter discusses experimental methods and illustrates the observed spectra of various molecules and free radicals. Subsequent chapters explore rotational, vibrational, and electronic energy levels of diatomic molecules and ions; radiative transitions; linear and nonlinear polyatomic radicals and ions; continuous and diffuse spectra; predissociation and pre-ionization; and recombination. The well-illustrated text features more than 100 figures and spectra. A distilled version of the author's monumental three-volume study, Molecular Spectra and Molecular Structure, it constitutes a superb resource for anyone wishing a concise but complete treatment of the fundamentals of molecular spectroscopy.

For beginners and specialists in other fields: the Nobel Laureate's introduction to atomic spectra and their relationship to atomic structures, stressing basics in a physical, rather than mathematical, treatment. 80 illustrations.

A biography of one of the most influential scientists in the twentieth century.

Physical Chemistry: An Advanced Treatise, Volume IV: Molecular Properties provides the aspects of the properties of single molecules and physical methods available for their determination. This book discusses linear polyatomic molecules, quantum-mechanical theory of vibrations, spectra of organic molecules, production and detection of free radicals, and force constants and molecular structure. The Hund's coupling cases for diatomic molecules, methods of measuring dipole moments, NMR spectra, and ESR spectra of organic species are also elaborated. This publication likewise covers the applications of the Mössbauer effect, electric deflection experiments, and effects of intramolecular motions on diffraction patterns. This volume is intended for graduate and physical chemistry students interested in molecular properties.

It is probably safe to predict that the future of chemistry is linked to the excited states of molecules and to other short lived species, ions and free radicals. Molecules have only one ground state but many excited states. However large the scope of normal, ground state chemistry might be, above and beyond it lies the world of excited states, each one having its own chemis try. The electronic transitions leading to the excited states, either discrete of continuous, are examined in molecular elec tronic spectroscopy. Electronic spectroscopy is the queen of all spectroscopies: for if we have the resolution we have everything. Vnfortunately, the chemist who is interested in the structure and reactions of larger molecules must often renounce all that infor mation. The spectra are complex and often diffuse; resolution does not always help. To understand such spectra he must look at whole families of molecules; to some extent structural analogies help. Let us call this chemical spectroscopy and handle it with care. In order to understand the properties of molecules we also need theory. We know that molecular problems are, in principle, soluble by the methods of quantum mechanics. Present time quan tum chemistry is able to provide a nearly accurate description of not too large molecules in their ground states. It is probablY again safe to predict that the future of quantum chemistry is connected with molecular excited states or, generally spoken, the accurate handling of the open-shell problem.

It is a great challenge in chemistry to clarify every detail of reaction processes. In older days chemists mixed starting materials in a flask and took the resul tants out of it after a while, leaving all the intermediate steps uncleared as a sort of black box. One had to be content with only changing temperature and pressure to accelerate or decelerate chemical reactions, and there was almost no hope of initiating new reactions. However, a number of new techniques and new methods have been introduced and have provided us with a clue to the examination of the black box of chemical reaction. Flash photolysis, which was invented in the 1950s, is such an example; this method has been combined with high-resolution electronic spectroscopy with photographic recording of the spectra to provide a large amount of precise and detailed data on transient molecules which occur as intermediates during the course of chemical reac tions. In 1960 a fundamentally new light source was devised, i. e. , the laser. When the present author and coworkers started high-resolution spectroscopic stud ies of transient molecules at a new research institute, the Institute for Molecu lar Science in Okazaki in 1975, the time was right to exploit this new light source and its microwave precursor in order to shed light on the black box.