Bøger af Sambhu N (Indian Inst Of Technology Datta

The concept of a chemical bond evolved from a variety of experimental observations. It became useful to understand, at times even predict, the molecular structure, reactivity and mechanism of chemical reactions. Every aspect of the concept of bonding received a quantitative interpretation from the advent of quantum mechanics and its application to chemistry.In Lectures on Chemical Bonding and Quantum Chemistry the reader will find a comprehensive discourse on the basic interpretation of the chemical bond as well as current understanding in terms of a "dancing" molecule that not only travels, rotates and pulsates around an equilibrium molecular structure, but also interacts and collides with other molecules, thereby transferring linear and angular momentum characteristics and adjusting total energies. One will also find a thorough survey of quantum mechanical methodologies for calculation of molecular characteristics in specific states and their changes under spectroscopic transitions, tunneling, electron and proton transfer phenomena, and so on. Guides to more advanced levels of theory are also provided.

Organic materials with extraordinary magnetic properties promise a wide range of light, flexible, and inexpensive alternatives to familiar metal-based magnets. Individual organic molecules with high magnetic moments will be the foundation for design and fabrication of these materials. This book provides a systematic understanding of the structure and properties of organic magnetic molecules. After a summary of the phenomenon of magnetism at the molecular level, it presents a survey of the challenges to theoretical description and evaluation of the magnetic character of open-shell molecules, and an overview of recently developed methods and their successes and shortfalls. Several fields of application, including very strong organic molecular magnets and photo-magnetic switches, are surveyed. Finally, discussions on metal-based materials and simultaneously semiconducting and ferromagnetic extended systems and solids point the way toward future advances. The reader will find a comprehensive discourse on current understanding of magnetic molecules, a thorough survey of computational methods of characterizing known and imagined molecules, simple rules for design of larger magnetic systems, and a guide to opportunities for progress toward organic magnets.