SYNTHESIS OF DIMANGANESE COMPLEXES CONTAINING MIXED BRIDGING PHOSPHIDO LIGANDS - CRYSTAL-STRUCTURES OF [MN-2(MU-PPH(2))(MU-PPHMN(CO)(5))(CO)(8)] AND [MN-2(MU-PPHH)(MU-PPHCOME)(CO)(8)]

The synthesis of a number of dimanganese complexes each containing two different bridging phosphido ligands is reported. The complex [Mn-2(mu-PPh(2))(mu-PPhH)(CO)(8)] (1) is prepared by the reaction of [Mn-2(CO)(10)] firstly with PPh(2)H followed by reaction with PPhH(2) in decalin. The reaction of 1 with CCl4 gives [Mn-2(mu PPh(2))(mu-PPhCl)(CO)(8)] (2) and deprotonation of 1 with n-BuLi followed by reaction of the deprotonated species with RX (X = halide) or [Mn(CO),Br] gives the complexes [Mn-2(mu-PPh(2))(mu-PPhR)(CO)(8)] (R = Me(3a), Et(3b), CH(2)COMe(3c) or CO(2)Et(3d)) and [Mn(mu-PPh(2)){mu-PPhMn(CO)(5)}(CO)(8)] (4). The deprotonation of [Mn-2(mu-PPhH)(2)(CO)(8)] with one equivalent of n-BuLi and subsequent reaction with MeCOCl gives [Mn-2(mu-PPhH)(mu-PPhCOMe)(CO)(8)] (5) which exists in solution as a mixture of isomers. The structures of [Mn-2(mu-PPh(2)){mu-PPhMn(CO)(5)}(CO)(8)] (4) and of trans-[Mn-2(mu-PPhH)(mu-PPhCOMe)(CO)(8)] (5) have been determined by single-crystal X-ray studies. All the complexes have been characterized spectroscopically and by elemental analysis.