109637-07-2Relevant academic research and scientific papers
Novel reactions of the [BPh4]- salt of the bifunctional complex [(triphos)Rh(S2CO)]+ (triphos = MeC(CH2PPh2)3): One-electron reduction, cleavage of B-H and B-C bonds, and metathesis of CS2-like heteroallene molecules
Bianchini, Claudio,Meli, Andrea,Laschi, Franco,Vizza, Francesco,Zanello, Piero
, p. 227 - 233 (2008/10/08)
The redox properties of the Rh(III) dithiocarbonate complex [(triphos)Rh(S2CO)] [BPh4] ([1][BPh4]) have been studied in detail. One-electron reduction of [1][BPh4] gives the stable, paramagnetic Rh(II) derivative (triphos)Rh(S2CO) (4), which maintains the square-pyramidal (SQ) structure of the Rh(III) precursor as determined by ESR spectroscopy. The complex [1][BPh4] is able straightforwardly to cleave a B-H bond from BH3 to yield the hydride (triphos)RhH(S2CO) (5). In the presence of [Cu(PPh3)3] [ClO4] B-C bond cleavage occurs to give the σ-phenyl complex (triphos)RhPh(S2CO) (9). Compound [1][BPh4] reacts with CS2 or SCNR with evolution of COS and formation of trithiocarbonate [(triphos)Rh(S2CS)] [BPh4] (10) or dithiocarbonimidates [(triphos)Rh(S2CNR)] [BPh4] (R = Ph (11), Et (12)), respectively. Trithiocarbonate 10 and dithiocarbonimidates 11 and 12 are readily converted into each other with evolution of CS2 or SCNR by reaction with SCNR or CS2, respectively. The nature of the functionality that connects the two sulfur atoms of the 1,1-dithio ligands (i.e. >C=O, >C=S, or >C=NR) is of crucial importance in determining the electronic structure of the four-membered RhS2C metalla ring and, consequently, many physical and chemical properties of the complexes. The fluxional behavior in solution of a family of five-coordinate 1,1-dithio metal complexes of triphos is discussed on the basis of ESR and NMR techniques.
