Ab initio studies on organophosphorus compounds. Part 1. Monoanionic methylphosphonate and methylphosphinate and their nitrogen and sulfur analogues

Abstract

The effects of sulfur and nitrogen substituents on the properties of 23 different analogues of monoanionic methylphosphonates and methylphosphinates have been investigated by an ab initio method with 3-21G(*) and 6-31G* basis sets. Conformational analyses were performed on all compounds with rotational bonds and the relative energies of conformers were studied. The effects of nitrogen and sulfur substituents were compared in terms of geometries, charge distributions and torsional barriers. In addition, the total energy changes of model reactions between the analogues were investigated. On the basis of the model reactions the most stable compounds were methylphosphonte (1), methylphosphonamidate (7) and methylphosphindithioate (20).