Higher Excited States of Polyatomic Molecules, Volume III focuses on higher electronic excitations in polyatomic molecules, with emphasis on excitations beyond 50,000 cm-1. This book explores the various transitions on the basis of their orbital characteristics. Organized into 22 chapters, this volume begins with an overview of the relationships between spectra of different molecules and between the results of various types of spectroscopy. This book then discusses the higher excited states involving Rydberg excitation. Other chapters explore the higher excited states in all classes of biological, organic, and inorganic molecules. This text further discusses the progress in the area of higher excitations in polyatomic atoms and the technique of multiphoton ionization (MPI) spectroscopy that yields a remarkable amount of spectroscopic information applicable to the vacuum-ultraviolet region. The final chapter deals with the vacuum-ultraviolet spectroscopy of biological materials. Analytical chemists, photochemists, molecular spectroscopists, and researchers will find this book extremely useful.

Higher Excited States of Polyatomic Molecules, Volume III focuses on higher electronic excitations in polyatomic molecules, with emphasis on excitations beyond 50,000 cm-1. This book explores the various transitions on the basis of their orbital characteristics. Organized into 22 chapters, this volume begins with an overview of the relationships between spectra of different molecules and between the results of various types of spectroscopy. This book then discusses the higher excited states involving Rydberg excitation. Other chapters explore the higher excited states in all classes of biological, organic, and inorganic molecules. This text further discusses the progress in the area of higher excitations in polyatomic atoms and the technique of multiphoton ionization (MPI) spectroscopy that yields a remarkable amount of spectroscopic information applicable to the vacuum-ultraviolet region. The final chapter deals with the vacuum-ultraviolet spectroscopy of biological materials. Analytical chemists, photochemists, molecular spectroscopists, and researchers will find this book extremely useful.

Higher Excited States of Polyatomic Molecules, Volume I focuses on the spectra in the vacuum-ultraviolet region between 50,000 and 100,000 cm-1. This book explores the higher excitations in molecules beyond 50,000 cm-1. Organized into three chapters, this volume starts with an overview of the excited-state properties of a molecule and the excited-state ionization potential. This book then proceeds with a discussion of the original classification of the properties as well as the types of excitations observed in the vacuum-ultraviolet. Other chapters discuss photoelectron spectroscopy, which is an independent, self-sustaining branch of molecular spectroscopy. This text examines as well the distinction between valence shell and Rydberg excitations. The final chapter deals with several topics, including the saturated molecules that are classified as having all valence electrons, the alkene absorption spectra, and the spectroscopic data on boron compounds. Analytical chemists, photochemists, molecular spectroscopists, and researchers will find this book extremely useful.

Higher Excited States of Polyatomic Molecules, Volume II focuses on a higher level of activity in vacuum ultraviolet spectroscopy. This book explores the Rydberg states in atoms and molecules. Comprised of five chapters, this volume starts with an overview of the two-center unsaturated molecules that usually display sharp Rydberg transitions originating with the pi electrons. This book then discusses the unsaturated double bond that adds another dimension to the spectrum. Other chapters explore the optical spectrum of the amide group, which is the basic chromophoric unit in polypeptides. This text further discusses the all-electron calculations of the electronic structure of the amide group that is performed in Gaussian orbital basis sets. This book considers as well the prominent characteristic of Rydberg excitations in benzene. The final chapter deals with the biological molecules that are polyfunctional in general. Analytical chemists, photochemists, molecular spectroscopists, and researchers will find this book extremely useful.

Excited States, Volume 3 deals with excited states and covers topics ranging from two-photon molecular spectroscopy in liquids and gases to time evolution of excited molecular states. Product energy distributions in the dissociation of polyatomic molecules are also discussed, along with the mechanism of optical nuclear polarization in molecular crystals and vibronic interactions and luminescence in aromatic molecules with non-bonding electrons. Comprised of five chapters, this volume begins with a didactic treatment of the theory of simultaneous two-photon absorption spectroscopy from the point of view concerned primarily with molecular gases and liquids. The basic theoretical quantity is shown to be an absorption tensor, as contrasted with the absorption vector of one-photon spectroscopy. The next chapter considers the time evolution of a molecular system interacting with a photon wave packet. The theory is applied to handle photon scattering from several physical models for molecular level structure in excited electronic states of polyatomic molecules. The remaining chapters explore various polyatomic decomposition processes and the basic features governing the internal energy distribution of the fragments; optical nuclear polarization in molecular crystals and vibronic interactions; and luminescence in aromatic molecules with non-bonding electrons. This book should be of interest to chemists and molecular physicists.

This volume focuses on the use of quantum theory to understand and explain experiments in organic chemistry. High level ab initio calculations, when properly performed, are useful in making quantitative distinctions between various possible interpretations of structures, reactions and spectra. Chemical reasoning based on simpler quantum models is, however, essential to enumerating the likely possibilities. The simpler models also often suggest the type of wave function likely to be involved in ground and excited states at various points along reaction paths. This preliminary understanding is needed in order to select the appropriate higher level approach since most higher level models are designed to describe improvements to some reasonable zeroth order wave function. Consequently, most of the chapters in this volume begin with experimental facts and model functions and then progress to higher level theory only when quantitative results are required.In the first chapter, Zimmerman discusses a wide variety of thermal and photochemical reactions of organic molecules. Gronert discusses the use of ab initio calculations and experimental facts in deciphering the mechanism of ?-elimination reactions in the gas phase. Bettinger et al focus on carbene structures and reactions with comparison of the triplet and singlet states. Next, Hrovat and Borden discuss more general molecules with competitive triplet and singlet contenders for the ground state structure. Cave explains the difficulties and considerations involved with many of the methods and illustrates the difficulties by comparing with the UV spectra of short polyenes. Jordan et al discuss long-range electron transfer using model compounds and model Hamiltonians. Finally, Hiberty discusses the breathing orbital valence bond model as a different approach to introducing the crucial åã correlation that is known to be important in organic reactions.