Complexation of hydrophosphoranes: possible mechanism and coordination activity

Complexation of (4S,9S)-4,9-diethyl-2,11-dioxa-5,8-diaza-1λ5-phosphatricyclo[6.3.0.01.5]undecane (1) and 3,3,8,8-tetramethyl-1,6-dioxa-4,9-diaza-5λ5-phosphaspiro[4,4]nonane (2) with [Rh(CO)2Cl]2; 2,3,7,8-dibenzo-1,6-dioxa-4,9-diaza-5λ5-phosphaspiro[4,4]nonane (3) with [Rh(CO)2Cl]2 and [MCl2(COD)] (M=Pd, Pt); (2S,7S)-2,7-dimethyl-1,4,6,9-tetraoxa-5λ5-phosphaspiro[4,4]nonane (4) with [Rh(CO)2Cl]2 and [PdCl2(COD)] has been studied. The products have been characterized by 1H-, 2H-, 13C-, 31P-NMR, IR spectroscopy, laser desorption mass spectrometry and X-ray photoelectron spectroscopy. A possible mechanism for hydrophosphoranes complexation is discussed. A correlation between Lewis basicity and coordination activity has been found for ligands 1–3. Phosphorane 4 was shown to coordinate by means of the P(III)-tautomer.