Reactions of Cu3(dppm)3(μ3-OH)(ClO4)2 (dppm = bis-(diphenylphosphino) methane) with Soft Heterocumulenes

The reaction of [Cu3(dppm)3(μ3-OH)](ClO4)2 (1) with heterocumulenes (Xdouble bond; length as m-dashCdouble bond; length as m-dashS; X = NPh, NMe and S) has been studied. The μ3-OH ligand inserts into PhNCS and MeNCS only in the presence of methanol. Insertion products are formed in accord with earlier observations made with copper(I)–aryloxides. On heating, the insertion products convert to a S bridged cluster [Cu4(dppm)4(μ4-S)](ClO4)2 (8), having a tetrameric core. However, in the reaction with CS2, 1 is converted to 8 even at room temperature in the presence of methanol. On the other hand, the dimeric complex [Cu2(dppm)2(CH3CN)4](ClO4)2, reacts with CS2 to give (diphenylphosphinomethyl)-diphenylphosphine sulfide, Ph2P–CH2–P(double bond; length as m-dashS)Ph2 (dppmS), which forms the complex [Cu(dppmS)2]ClO4 (9). A single crystal X-ray crystallographic study of 9, the first copper(I) complex of dppmS has been taken up to confirm the mono-oxidation of the dppm ligand and the nuclearity of the complex. Reactions of complex 1 with heterocumulenes and with elemental sulfur, are compared.