THIS INFORMATION IS OBSOLETE AND IS PROVIDED ONLY FOR ITS HISTORICAL VALUE

by R. C. Haddon, AT&T Bell Laboratories, Murray Hill, New Jersey 07974

The concept of hybridization of atomic orbital basis functions to produce spatially directed wave functions with the orientation necessary for bond formation is fundamental to the modern understanding of the molecular and electronic structure of molecules. The POAV theory has been developed to analyze a bonding situation which has become increasingly important in recent years, i.e., nonplanar conjugated organic molecules, which are usually considered to possess formal sp2 hybridization. It has been shown1,2 that, with a single assumption, it is possible to obtain analytical solutions for the hybridization in such compounds which, in turn, leads directly to the orientation of the p-orbital axis vectors (POAV) and hence to a measure of p-orbital alignment and overlap in distorted p-electron systems of known geometry. The p-orbital axis vector (POAV) analysis provides a vivid picture of the p-bonding in nonplanar conjugated organic molecules and the manner in which the s-system has rehybridized and adjusted to facilitate the maintenance of favorable p-orbital overlap. The method is nonparametric and merely requires the atomic coordinates of the molecule or molecular fragment for its implementation. The analysis is based on the s,p hybrid orthogonality relationships and the geometry of the s-skeleton. As such, the method provides the most logical and natural bridge between the s-p separability assumed in planar conjugated systems and the realities of p-bonding in nonplanar situations. The analysis is not recommended in circumstances in which the s-bond angles are less than 100°, but, with this provision, the method may be used with confidence (the technique provides a lower bound to the p-orbital alignment attained by most nonplanar conjugated organic molecules). _________

References:

1. POAV1: R. C. Haddon and L. T. Scott, Pure Appl. Chem., 58, 137 (1986). 2. POAV2: R. C. Haddon, Chem. Phys. Lett. (1986); J. Am. Chem. Soc. (1986). _________

FORTRAN 77 (CRAY 1) Lines of Code: 308