Stepwise metal-promoted conversion of η2-CS2 into η2-SO. Synthesis and crystal structure of the complex [(triphos)Rh(µ-SO)2Rh(triphos)][BPh4]2·HCONMe2[triphos = MeC(CH2PPh2)3]
Abstract
Nucleophilic attack by PEt3 at the carbon atom of the η2-CS2 ligand in (tirphos)RhCl(η-2-CS2)[triphos = MeC(CH2PPh2)3] yields the η1-phosphoniodithiocarboxylate complex (triphos)RhCl(S2CPEt3), which reacts with dioxygen to give the η2-dithiocarbonate complex (triphos)RhCl(S2CO), treatment of which with NaBPh4 gives [(triphos)Rh(S2CO)]BPh4; reaction of the latter with O2 generates the novel µ-SO complex [(triphos)Rh(µ-SO)2Rh(triphos)][BPh4]2·HCONMe2, X-ray analysis of which shows that each bridging SO molecule is η2-bonded to one metal centre via O and S, and η1-bonded to the other metal via S.