Discovering Chemistry With Natural Bond Orbitals

FRANK WEINHOLD, PhD, is Emeritus Professor of Physical and Theoretical Chemistry at the University of Wisconsin–Madison. Professor Weinhold has served on the editorial advisory boards of the International Journal of Quantum Chemistry and Russian Journal of Physical Chemistry. He is the author of more than 170 technical publications and software packages, including the natural bond orbital program.CLARK R. LANDIS, PhD, is Professor of Inorganic Chemistry at the University of Wisconsin–Madison. He has received teaching and lectureship awards for his contributions to chemical education. Dr. Landis's research focuses on catalysis in transition metal complexes.

• Preface xi 1 Getting Started 11.1 Talking to your electronic structure system 11.2 Helpful tools 31.3 General $NBO keylist usage 41.4 Producing orbital imagery 6Problems and exercises 82 Electrons in Atoms 102.1 Finding the electrons in atomic wavefunctions 102.2 Atomic orbitals and their graphical representation 132.3 Atomic electron configurations 182.4 How to find electronic orbitals and configurations in NBO output 232.5 Natural atomic orbitals and the natural minimal basis 29Problems and exercises 313 Atoms in Molecules 343.1 Atomic orbitals in molecules 353.2 Atomic configurations and atomic charges in molecules 393.3 Atoms in open-shell molecules 44Problems and exercises 494 Hybrids and Bonds in Molecules 514.1 Bonds and lone pairs in molecules 524.2 Atomic hybrids and bonding geometry 604.3 Bond polarity, electronegativity, and Bent’s rule 714.4 Hypovalent three-center bonds 784.5 Open-shell Lewis structures and spin hybrids 824.6 Lewis-like structures in transition metal bonding 86Problems and exercises 895 Resonance Delocalization Corrections 925.1 The natural Lewis structure perturbative model 935.2 Second-order perturbative analysis of donor–acceptor interactions 965.3 $Del energetic analysis [integrated ESS/NBO only] 1055.4 Delocalization tails of natural localized molecular orbitals 1135.5 How to $CHOOSE alternative Lewis structures 1175.6 Natural resonance theory 123Problems and exercises 1336 Steric and Electrostatic Effects 1356.1 Nature and evaluation of steric interactions 1366.2 Electrostatic and dipolar analysis 145Problems and exercises 1537 Nuclear and Electronic Spin Effects 1557.1 NMR chemical shielding analysis 1567.2 NMR J-coupling analysis 1627.3 ESR spin density distribution 168Problems and exercises 1738 Coordination and Hyperbonding 1768.1 Lewis acid–base complexes 1788.2 Transition metal coordinate bonding 1938.3 Three-center, four-electron hyperbonding 204Problems and exercises 2069 Intermolecular Interactions 2099.1 Hydrogen-bonded complexes 2109.2 Other donor–acceptor complexes 2179.3 Natural energy decomposition analysis 223Problems and exercises 22710 Transition State Species and Chemical Reactions 23110.1 Ambivalent Lewis structures: the transition-state limit 23210.2 Example: bimolecular formation of formaldehyde 23610.3 Example: unimolecular isomerization of formaldehyde 24310.4 Example: SN2 halide exchange reaction 246Problems and exercises 24911 Excited State Chemistry 25211.1 Getting to the “root” of the problem 25211.2 Illustrative applications to NO excitations 25611.3 Finding common ground: NBO versus MO state-to-state transferability 26911.4 NBO/NRT description of excited-state structure and reactivity 27711.5 Conical intersections and intersystem crossings 282Problems and exercises 289Appendix A: What’s Under the Hood? 297Appendix B: Orbital Graphics: The NBOView Orbital Plotter 300Appendix C: Digging at the Details 302Appendix D: What If Something Goes Wrong? 304Appendix E: Atomic Units (a.u.) and Conversion Factors 307Index 309

“Following this text’s clear explanations, even readers with limited backgrounds in quantum mechanics will learn how to perform sophisticated explorations of modern bonding and valency concepts.”  (Chimie Nouvelle, 1 March 2013)