Ab Initio Calculations on Phosphorus Compounds. II. Effects of Disubstitution on Ligand Apicophilicity in Phosphoranes
Geometry optimizations at the HF/3-21G(*) and HF/6-31G* levels of ab initio theory have been carried out for various isomers of model disubstituted phosphoranes PH3XY(X, Y═OH, CH3, NH2, and SH). Reasonable agreement was obtained between the optimized geometries and available crystal structure data for analogous compounds. The isomers were further characterized by frequency calculations. The MP2/6-31G*//6-31G* + ZPE energy data reveal that the interactions between the ligands are relatively small (0-4 kcal mol-1) for the most stable conformations of the isomers. Hence, for these conformations the apicophilicities (based upon monosubstituted phosphoranes) are approximately additive. The less stable PH3XY conformations are in general transition states or higher-order saddle points, and their interligand interactions are larger in magnitude (up to 10 kcal mol-1); the results with these conformations suggest that apicophilicities may not be as additive for some highly substituted phosphoranes.
P. Wang et al., "Ab Initio Calculations on Phosphorus Compounds. II. Effects of Disubstitution on Ligand Apicophilicity in Phosphoranes," Journal of Computational Chemistry, vol. 14, no. 5, pp. 522-529, Wiley-Blackwell, May 1993.
The definitive version is available at https://doi.org/10.1002/jcc.540140504
Keywords and Phrases
Crystal Structure; Isomers; Ligands; Phosphorus Compounds; Ab Initio Calculations; Ab Initio Theory; Crystal Structure Data; Frequency Calculations; Geometry Optimization; Optimized Geometries; Saddle Point; Transition State; Calculations
International Standard Serial Number (ISSN)
Article - Journal
© 1993 Wiley-Blackwell, All rights reserved.
01 May 1993