The co-ordination of small molecules by manganese(II) phosphine complexes. Part 6. The reaction of carbon disulphide with dihalophosphinemanganese(II) and dihalophosphinebis(tetrahydrofuran)manganese(II) complexes to form dimeric carbon disulphide-bridged complexes [{Mn(PR 3)X 2} 2CS 2] and [{Mn(PR 3)X 2(THF) 2} 2CS 2

Abstract

The Mn(PR 3)X 2 and Mn(PR 3)X 2(THF) 2 complexes (PR 3 = PR 3 n, PBu 3 n, PPhMe 2, PPhEt 2, PPhPr 2 n; X = Cl, br. I) react with carbon disulphide in diethylether to form the insoluble [{Mn(PR 3)X 2} 2CS 2] and [{Mn(PR 3)X 2(THF) 2} 2CS 2] complexes. Electron paramagnetic and electronic spectra are consistent with pseudotetrahedral and pseudooctahedral co-ordination geometries, respectively, for the carbon disulphide complexes. The infrared spectra are consistent with bridging CS 2 ligands. The carbon disulphide moieties are bound strongly; heating [{Mn(PR 3)X 2} 2CS 2] in vacuo at 80°C for long periods does not displace the CS 2. Heating [{Mn(PR 3)X 2(THF) 2} 2CS 2] displaces the tetrahydrofuran and [{Mn(PR 3)X 2} 2CS 2] are formed. The CS 2 ligands cannot be displaced by dioxygen, but dioxygen is displaced from [Mn(PR 3)X 2(O 2)] by carbon disulphide to form [{Mn(PR 3)X 2} 2CS 2].