Preparation and structures of tetrameric and dimeric manganese carbonyl complexes incorporating thiosalicylato ligands

Orthomanganated N,N-dimethylbenzamide reacts with SO2 to give a tetra-manganese complex Mn-4(thsa)(2)(CO)(16) (thsa=thiosalicylate=2-thiobenzoate di-anion) which an X-ray structure determination shows to contain four Mn(CO)(4) units linked by two triply bridging (S,O,O) thsa ligands. Another product identified after aerobic work-up was the disulphide [2-((OOC)-O--)C6H4S-](2). Reaction of thiosalicylic acid with BrMn(CO)(5) in the presence of Et(3)N gave good yields of [Et(3)NH](2)[Mn-2(thsa)(2)(CO)(6)], the anion of which contains two [Mn(eta(2)-thsa)(CO)(3)](-) units doubly-linked via the S atoms.