This book introduces vibronic coupling density and vibronic coupling constant analyses as a way to understand molecular structure and chemical reactions. After quantum study, the behavior of electrons circulating around nuclei led to the principal concept that underlies all explanations in chemistry. Many textbooks have given plausible explanations to clarify molecular structurefor example, the bond elongation of ethylene under anionization and the nonplanar structure of ammonia. Frontier molecular orbital concepts were proposed to visualize the path of chemical reactions, and conventional explanations gave students a familiarity with molecular structures in terms of the electronic state. By contrast, this book offers a more rational and more convincing path to understanding. It starts from the ab initio molecular Hamiltonian and provides systematic, rational approaches to comprehend chemical phenomena. In this way, the book leads the reader to a grasp of the quantitative evaluation of the force applied under the molecular deformation process. As well, guidelines are offered for integrating the traditional hand-waving approach of chemistry with more rational and general VCD and VCC alternatives along with the outlook for newly functionalized chemical systems.

Provides a rational and convincing understanding of the frontier orbital theory Includes figures that are visualizations for tracing the paths of chemical reactions Leads the reader to a systematic realization of molecular structure in terms of electronic states

Autorentext
Tatsuhisa Kato received his Ph.D. from Kyoto University in 1984. His research interests include molecular spectroscopy, especially electron magnetic resonance and electron spin resonance (ESR) spectroscopy. He has clearly characterized the electronic and spin states of fullerene species by ESR spectroscopy and exercises worldwide leadership in fullerene chemistry. As of April 2020, he has published 157 articles in internationally renowned journals such as Nature, Science, and the Journal of the American Chemical Society. He was awarded the Society Award by the Society of Electron Spin Science and Technology, Japan, in 2017.Tohru Sato received his Ph.D. from Kyoto University in 1997. He is now the head of the theoretical research division and a professor at the Fukui Institute of Fundamental Chemistry (FIFC) at Kyoto University. He has continued his theoretical investigation of the interaction of the electronic state with molecular vibration and has proposed vibroniccoupling density (VCD) analysis. He applied his VCD analysis to many chemical processes, especially in chemical reactions, photo-excited processes, and the Jahn-Teller effect. Now he is expanding his VCD analysis into the application of predicting newly functionalized chemical systems. He has published 106 articles as of April 2020, and he won the Society of Computer Chemistry, Japan, (SCCJ) Award of the Year in 2016. Naoki Haruta received his Ph.D. from Kyoto University in 2016. He is now spending an exciting experience as a young theoretician collaborating with Prof. Sato at the Fukui Institute of Fundamental Chemistry (FIFC). His Ph.D. work on VCD analysis was carried out under Prof. Sato. He recently has expanded the scope of his work to include theoretical research into metal clusters and nano-structures. He has published 21 articles as of April 2020 and received the Kenichi Fukui Encouragement Award in 2019, the Young Scholar Lecture Award from theChemical Society of Japan in 2020, the PCCP Prize from the Royal Society of Chemistry in 2021, and others.

Inhalt

1. Introduction: What is understanding chemistry?.- 2. How the chemical processes are qualitatively explained by the simple molecular orbital theory.- 3. How the chemical processes are visualized and quantified by VCD and VCC.- 4. Relationship between Fukui function and VCD.- 5. Transition dipole moment density.- 6. Outlooks for new chemical systems by VCD and VCC.- 7. Appendix.