Activation of CO2, CS2, and COS by α‐Diimine‐stabilized Gallylenes

Several gallylenes [LPhGaM(THF)n] stabilized by an α‐diimine ligand (LPh = [(2,6‐iPr2C6H3)NC(Ph)]2; M = Li, n = 3, 3‐Li; M = Na, n = 4, 3‐Na; M = K, n = 1, 3‐K) were prepared, which display diverse reactivities toward carbon dioxide and its sulfurized analogues. The reaction of 3 with CO2 yielded a trimeric carbonate complex [{LPhGa(CO3)2}3{μ‐K9(THF)6}] (4) and a dinuclear oxo‐carbonate complex {K2(THF)6}[LPhGa(μ‐CO3)(μ‐O)GaLPh] (5) in one pot through reductive disproportionation of CO2. For CS2, two ethenetetrathiolate gallium complexes, [M2(Solv)4][LPhGa(μ‐C2S4)GaLPh] (M = Na, Solv = THF, 6; M = K, Solv = DME, 7), were obtained via reductive coupling of CS2. In the case of COS, disproportionation gave a disulfide‐bridged complex [K2(THF)5] [LPhGa(μ‐S)2GaLPh] (8) at room temperature, but a dithiocarbonate [Na2(THF)6][LPhGa(S2CO)]2 (9) at low temperature, the latter being the first example of dithiocarbonates of p‐block elements.