Complexation of hydrophosphoranes: possible mechanism and coordination activity

Complexation of (4S,9S)-4,9-diethyl-2,11-dioxa-5,8-diaza-1 lambda (5)-phosp hatricyclo[6.3.0.0(1.5)]undecane (1) and 3,3,8,8-tetramethyl-1,6-dioxa-4,9- diaza-5 lambda (5)-phosphaspiro[4,4]nonane (2) with [Rh(CO)(2)Cl](2); 2,3,7 ,8-dibenzo-1,6-dioxa-4,9-diaza-5 lambda (5)-phosphaspiro-[4,4]nonane (3) wi th [Rh(CO)(2)Cl](2) and [MCl2(COD)] (M = Pd, Pt); (2S,7S)-2,7-dimethyl-1,4, 6,9-tetraoxa-5 lambda (5)-phosphaspiro[4,4]nonane (4) with [Rh(CO)(2)Cl](2) and [PdCl2(COD)] has been studied. The products have been characterized by H-1-, H-2-, C-13-, P-31-NMR, IR spectroscopy, laser desorption mass spectr ometry and X-ray photoelectron spectroscopy. A possible mechanism for hydro phosphoranes complexation is discussed. A correlation between Lewis basicit y and coordination activity has been found for ligands 1-3. Phosphorane 4 w as shown to coordinate by means of the P(III)-tautomer. (C) 2000 Elsevier S cience B.V. All rights reserved.