REDUCTION REACTIONS OF BINUCLEAR MANGANESE MOLYBDENUM COMPLEXES CONTAINING S(2)CPR(3) AND BIDENTATE P-DONOR BRIDGES - X-RAY STRUCTURE OF [MNMO(SNPH(3))(CO)(4)(MU-TEDIP)(MU-S(2)CPCY(3))]

The reduction of the substituted derivatives [MnMo(CO)(5)(mu-Br)(mu-L-L)(mu-S(2)CPR(3))] (1, L-L = dmpm or tedip), with NaHg produces anions (2) that, upon reaction with ClSnPh(3), give neutral tetracarbonyls [MnMo(SnPh(3))(CO)(4)(mu-L-L)(mu-S(2)CPR(3))] (3). An X-ray structure determination of 3a (L-L = tedip, R = Cy) demonstrates the addition of SnPh(3) to Mo and migration of the central carbon atom of the S(2)CPR(3) from Mo to Mn. Simultaneous loss of one carbonyl group from the manganese atom allows a change of coordination of S(2)CPR(3) from eta(1);eta(3) (in 1) to eta(3);eta(2) (in 3). The tetracarbonyls 3 can also be prepared by reaction of the triphenylstannylhexacarbonyl derivatives [MnMo(CO)(6)(SnPh(3))(mu-S(2)CPR(3))] with bidentate donors L-L (dmpm or tedip), through substitution of one CO group on each metal.