Cu[Al(ORF)4] Starting Materials and their Application in the Preparation of [Cu(Sn)]+ (n=12, 8) Complexes

Naked copper…? A newly developed simple two-step route to weakly coordinated CuI starting materials that were used to prepare novel copper–cyclosulfur adducts, including the first M+–S12 complex (see figure, RF= C(CF3)3, C(CH3)(CF3)2, or CH(CF3)2). Reactions with the [Al{OC(CF3)3}4]− counterion mimic gas-phase chemistry inside a mass spectrometer (to form [Cu(S12)]+). An effective route to stable, almost-“naked” CuI salts of weakly coordinating anions (WCAs) of the type [Al(ORF)4]− has been developed. Born–Fajans–Haber cycles and theoretical calculations suggest that this methodology is useful for the generation of CuI salts regardless of the larger WCA used. The first homoleptic CuI–arene complex [Cu(1,2-F2C6H4)2]+[Al{OC(CF3)3}4]− (1), the first CuI–methylenechloride complex [Cu(CH2Cl2)Al{OC(CH3)(CF3)2}4] (2), and the donor-free dimer [CuAl{OCH(CF3)2}4]2 (3) were synthesized in quantitative yields by sonicating Li[Al(ORF)4] (RF=C(CF3)3, C(CH3)(CF3)2, or CH(CF3)2), AgF, and a three-fold excess of CuI in 1,2-F2C6H4 (1) or CH2Cl2 (2, 3). Substances 1–3 are good starting materials for further CuI chemistry, and the reaction of 1–3 with the weak Lewis base cyclooctasulfur gave the first CuI–sulfur complexes of type [Cu(S12)(S8)]+[Al{OC(CF3)3}4]− (4), [Cu(CH2Cl2)(S12)]+[Al{OC(CF3)3}4]− (5), [A1Cu(1,5-η1,η1-S8)CuA1] (6; A1=[Al{OC(CH3)(CF3)2}4]−), and a CuI–S8 1D coordination polymer with [Cu2(S8)2A22] (7; A2=[Al{OCH(CF3)2}4]−), as a monomeric repeat unit. Complexes 4 and 5 are the first example of any metal coordinated to cyclo-S12 and 4 is the first example of a complex having an element in two allotropic modifications as a ligand.