HYPERCONJUGATION AND CHARGE-DISTRIBUTION IN ALICYCLIC ALCOHOLS AND EXO-NORBORNOL AND ENDO-NORBORNOL

Ab initio and MM2 calculations are used to investigate charge distribu tions in selected alcohols (methanol, ethanol, 2-propanol and t-butano l and exo- and endo-norbornol). The calculated net atomic charges obta ined using full optimized geometries with a range of basis sets (STO-3 G,4-31G, 6-31G*) indicates that selected carbon and hydrogen atoms in the proximity of a nonbonding oxygen lone pair are more negatively ch arged and the carbon-hydrogen bonds are longer than usual. Analysis of the fully optimized geometries, HOMO population and net atomic charge s suggests that the differences in charge distribution on the carbon a nd hydrogen atoms and their bond lengths can be explained in terms of hyperconjugation.