J. Koller, J. Grdadolnik, D. Hadzi
Jul 31, 1992
Citations
0
Influential Citations
11
Citations
Journal
Journal of Molecular Structure-theochem
Abstract
Abstract Complexes of tetramethylammonium with water, formate and dimethylphosphate were studied by ab initio calculations using the 3-21G* basis set. Optimized geometries and electron populations were examined with respect to hydrogen bonding effects. These are revealed by the increase of positive charge on the affected hydrogen atoms and negative charges of the respective carbon atoms. Notable elongations of CH bonds appear in the complexes formed with oxyanions but not those with water. More than one methyl group engages in hydrogen bonding of tetramethylammonium but the effects of bonding are most pronounced with one CH3 group, except for water which bonds equally to the hydrogen atoms of two of its methyl groups. Hydrogen bonding results in red shifts of the antisymmetric CH3 stretching vibration of up to 60 cm−1.