Novel triphospholyl and diphosphastibolyl lead(II) complexes

PbCl2 reacted with the triphospholyl ring anion [P3C2Bu2t](-) to afford the hexaphospha-plumbocene [Pb(eta(5)-P3C2Bu2t)(2)] 3 which has been character ised by multinuclear NMR spectroscopy. In contrast the reaction between PbC l2 and the diphosphastibolyl ring anion [P2SbC2Bu2t](-) led to the organo-a ntimony cage compound [P4Sb2C4Bu4t] 4 via an oxidative coupling route. Both the heteroleptic plumbocenes [Pb(eta(5)-EP2C2Bu2t)(eta(5)-C5Me5)] (E=P 5, E=Sb 6) could be prepared by treatment of the corresponding hetero-ring ani on with a mixture of PbCl2 and Li(C5Me5) (for 5) or the half sandwich compl ex [Pb(eta(5)-C5Me5)Cl] (for 6). Both complexes were characterised by multi nuclear NMR spectroscopy and single crystal X-ray diffraction studies. The novel, structurally characterised, hetero-bimetallic complex [Pb(eta(5)-P3C 2Bu2t)(mu-Cl)(2)Li(tmen)(2)] 7 could be synthesised by carrying out the rea ction of PbCl2 with [Li(dme)(3)][P3C2Bu2t] in tmen rather than dme. This co mpound was found to be highly fluxional in solution even at low temperature .