Conformational analyses of the five-membered palladacycles derived from 1-(1′-naphthyl)ethyldiphenylphosphine and its arsenic analogue

The conformational behaviors of the five-membered palladacycles derived from the ligands, 1-(1′-naphthyl)ethyldiphenylphosphine and 1-(1′-naphthyl)ethyldiphenylarsine were determined from their O,O′-acetylacetonate complexes. Despite the possibilities of both palladacycles to exist in both δ and λ conformations, these palladacycles were noted to be conformationally rigid and only one of these was adopted in both the solid state and in solution (CDCl3), as supported from their X-ray molecular structures and 2-D 1H-1H ROESY NMR studies, respectively.