THE PREPARATION AND REACTIONS WITH DONOR LIGANDS OF [MOBRI(CO)3(NCME)2]

Equimolar quantities of fac-[Mo(CO)3(NCMe)3] {prepared in situ by reacting [Mo(CO)6] in refluxing acetonitrile for 24 h} and BrI react at 0-degrees-C to give the seven-coordinate complex [MoBrI(CO)3(NCMC)2] (1). Complex 1 reacts with 1 equivalent of L (L = PPh3, ASPh3 or SbPh3) to initially give the mono(acetonitrile) complexes [MoBrI(CO)3(NCMe)L], which subsequently dimerize to afford [Mo(mu-I)Br(CO)3L]2. Reaction of 1 with 2 equivalents of L (L = PPh3, AsPh3 Or SbPh3) gives the bis(ligand) compounds [MoBrl(CO)3L2]. The preparation and characterization of a series of new mixed-ligand complexes [MoBrl(CO)3LL'] [L = PPh3, L' = AsPh3; L = PPh3, L' = SbPh3; L = AsPh3, L' = SbPh3; L = PPh3, AsPh3 and SbPh3; L' = SPPh3, SC(NH2)2 and SC(NMe2)2] are also described. Equimolar quantities of LL [LL = Ph2P(CH2)nPPh2 (n = 1-3); 1,10-phen] and [MoBrl(CO)3(NCMe)2] react to afford the acetonitrile displaced products [MoBrl(CO)3(LL)] in high yield. The synthesis of the novel, dicarbonyl five different ligand compound [MoBrI(CO)2(NCMe)(SbPh3)2] is also reported.