Cu[Al(OR(F))4] starting materials and their application in the preparation of [Cu(S(n))]+ (n=12, 8) complexes

An effective route to stable, almost-"naked" Cu(I) salts of weakly coordinating anions (WCAs) of the type [Al(OR(F))4]- has been developed. Born-Fajans-Haber cycles and theoretical calculations suggest that this methodology is useful for the generation of Cu(I) salts regardless of the larger WCA used. The first homoleptic Cu(I)-arene complex [Cu(1,2-F2C6H4)2](+)[Al{OC(CF3)3}4]- (1), the first Cu(I)-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(OR(F))4] (R(F)=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 Cu(I) chemistry, and the reaction of 1-3 with the weak Lewis base cyclooctasulfur gave the first Cu(I)-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-eta1,eta1-S8)CuA1] (6; A1=[Al{OC(CH3)(CF3)2}4]-), and a Cu(I)-S8 1D coordination polymer with [Cu2(S8)2A(2)(2)] (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.