Reactions of the cationic bis(chelate) rhodium complex [Rh(P-O)(2)](+) with SO2, CS2 and O-2/SO2

The cationic bis(chelate) complex [Rh(PO)(2)][BPh(4)] (1) (PO: eta(2)(O, P)-chelated (C6H11)(2)PCH2CH2OCH3 ligand) reacts with CS2 and SO2 to form the eta(2)(C, S)-coordinated carbon disulfide complex [RhCS2(PO)(2)][BPh(4)] (2) and the square-pyramidal eta(1)-SO2 complex [Rh(eta(1)-SO2)(PO)(2)][BPh(4)] (4) respectively. According to the IR spectra, in complex 4 the RhSO2 fragment adopts a pyramidal geometry. Upon treatment of the eta(2)-oxygen rhodium complex [RhO2(PO)(2)][BPh(4)] (3) with SO2, the sulfato-O,O'-rhodium complex [RhSO4(PO)(2)][BPh(4)] (5) is accessible. The same compound is also available if complex 4 is reacted with oxygen. Rh-103 NMR investigations afford additional evidence for the coordination geometry in the complexes 1, 3, 4 and 5.