 Professor, Born 1941
B.A. 1962, University of Colorado - Boulder
A.M. 1964, Harvard University
Ph.D. 1967, Harvard University
Room: 8305h
Phone: 608-262-0263
Email: weinhold@chem.wisc.edu
Position: Emeritus Professor
F. Weinhold and C. R. Landis, Valency and Bonding: A Natural Bond Orbital Donor-Acceptor Perspective (Cambridge U. Press, 2003). M. L. DeRider, S. J. Wilkens, M. J. Waddell, L. E. Bretscher, F. Weinhold, R. T. Raines, and J. L. Markley, "Collagen Stability: Insights from NMR Spectroscopic and Hybrid Density Functional Computational Investigations of the Effect of Electronegative Substituents on Prolyl Ring Conformations," J. Am. Chem. Soc. 124 , 2497-2505 (2002). S. J. Wilkens, W. M. Westler, F. Weinhold, and J. L. Markley, "Trans-Hydrogen-Bond h2 J NN and h1 J NH Couplings in the DNA A-T Base Pair: Natural Bond Orbital Analysis" (Communication), J. Am. Chem. Soc. 124 , 1190-1191 (2002). W. M. Westler, F. Weinhold, and J. L. Markley, "Quantum Chemical Calculations on Structural Models of the Catalytic Site of Chymotrypsin: Comparison of Calculated Results with Experimental Data from NMR Spectroscopy," J. Am. Chem. Soc. 124 , 14373-14381 (2002). R. Ludwig and F. Weinhold, "Quantum Cluster Equilibrium Theory of Liquids: Isotopically Substituted QCE/3-21G Model Water," Z. Phys. Chem. 216 , 659-674 (2002). R. Ludwig. J. Behler, B. Klink, and F. Weinhold, "Molecular Composition of Liquid Sulfur," Angew. Chem. 114 , 3331-3335 (2002); Angew. Chem. Int. Ed. Engl. 41 , 3199-3202 (2002). F. Weinhold, "News & Views: A New Twist on Molecular Shape," Nature 411 , 539-541 (2001). S. J. Wilkens, W. M. Westler, J. L. Markley, and F. Weinhold, "Natural J-Coupling Analysis," J. Am. Chem.Soc. 123 , 12026-12036 (2001). F. Weinhold and C. R. Landis, "Natural Bond Orbitals and Extensions of Localized Bonding Concepts," Chem. Educ. Res. Pract. Eur. 2 , 91-104 (2001). L. Goodman, V. Pophristic, and F. Weinhold, "Origin of Methyl Internal Rotation Barriers," Acc. Chem. Res. 32 , 983-993 (1999). F. Weinhold, "Natural Bond Orbital Methods," in Encyclopedia of Computational Chemistry. P. v.R. Schleyer et al. (Eds.), (John Wiley & Sons, Chichester, UK, 1998), Vol. 3, pp. 1792"1811.
| Research Description
Our work focuses on development and application of ab initio molecular quantum mechanics to advance understanding of chemical structure and reactivity. We study a broad range of phenomena (including organic, inorganic, and biophysical systems [1]), employing techniques applicable to molecules, supramolecular clusters, and condensed phases. The ultimate goal is development of unifying chemical concepts that build on powerful modern technology for solving Schr"dinger's equation to improve the scope, accuracy, and usefulness of chemical theory.
A foundation of our research program is Natural Bond Orbital (NBO) analysis [2]. NBO-based methods were developed in our group, providing a general bridge to describe complex numerical wavefunctions in the familiar language of chemical bonding theory. These methods lead to a mathematically rigorous "Lewis structure" representation of the wavefunction, with associated bonds, hybrids, and other valence descriptors determined in optimal fashion. The NBOs thereby provide a "chemist's basis set" that can be used to compare, contrast, and comprehend many levels of ab initio and density functional theory in a rigorous and consistent manner. The current NBO 5.0 program [3] is widely incorporated in modern electronic structure packages (including Gaussian, Jaguar, ADF, GAMESS, Columbus, Q-Chem, NWChem, PQS) and used by computational chemistry researchers throughout the world.
NBO-based techniques have demonstrated particular effectiveness in elucidating resonance-type stereoelectronic and steric factors in covalent and noncovalent phenomena, including the torsional and H-bonding interactions that underlie protein folding processes [4-6]. Recently, new NBO-based analysis methods have been developed for NMR properties, including J-coupling and chemical shielding, providing important new insights into structure and function of complex biomolecules [7-9]. In collaboration with the Landis group, NBO-based methods are also being employed to extend localized bonding and hybridization concepts in transition metal species, leading to a coherent and comprehensive pedagogical picture of Lewis-like bonding patterns in main-group and transition group chemistry [10]. NBO-based methods are also being extended to analysis of photoexcited and radical species [11]. A particular focus of current research involves the remarkable class of "pi-star" charge-transfer complexes, exemplified by nitrosyl cation (NO+) complexation with aromatics.
We are also engaged in ongoing theoretical and experimental investigations of the nature of hydrogen bonding and related types of supramolecular association. The key theoretical tool is Quantum Cluster Equilibrium (QCE) theory, a method developed in our group to determine equilibrium cluster distributions and phase properties of strongly associated liquids and solids [12,13]. QCE theory combines the rigorous methods of ab initio quantum chemistry for the cluster partition functions with the standard machinery of quantum statistical thermodynamics for the equilibrium cluster populations at chosen temperature and pressure. A fully ab initio treatment of cluster energetics allows QCE to incorporate the important non-pairwise-additive "cooperative" effects of donor-acceptor interactions that are commonly neglected or misrepresented in empirical simulation potentials.
Last Updated: October 9, 2003.
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