Cleavage of mixed tetrapnicogen trisulphide cage molecules by a cobalt(II)-ligand system. Crystal structure of the solid solution of [(tppme)Co(As 2S)]BF 4 and [(tppme)Co(PAsS)]BF 4

Abstract

A solid solution of the mixed cage molecules PAs 3S 3 (50%) and P 2As 2S 2 (50%) reacts with Co(BF 4) 2·6H 2O in the presence of 1,1,1-tris(diphenylphosphinomethyl)ethane (tppme) yielding a crystalline material in good yield. The results of single crystal X-ray diffraction study and 31P NMR and analytical data show that the product consists of a solid solution of the [(tppme)Co(As 2S)]BF 4 and [(tppme)Co(PAsS)]BF 4 compounds in ca. 2.3 1 ratio. The crystals are monoclinic, space group P2 1/ n, with a 17.016(7), b 20.584(9), c 13.083(6) Å, β 104.86(6)°, Z = 4. The metal atom is in a six-coordinate environment formed by the tppme P atoms and the atoms of the heterocyclic As 2S or PAsS unit, which is η 3-bonded to the metal. The formation of these units from the solid solution of cage molecules provides insight into the process of cleavage of the latter molecules, assisted by the metalligand fragment.