Anion-Directed Solid-State Structures of Copper(I) and Silver(I) Adducts of Ruthenium Ethyne-1,2-diyl Compounds

Abstract

A number of group 11 salts, [MX] (M = Ag, X– = –O3SCF3, –O2CCF3, BF4–; M = Cu; X = Cl, Br) and [Cu(MeCN)4][PF6], were found to react in varying stoichiometries with ethyne-1,2-diyl compounds, [{Ru(CO)2(η-C5H4R)}2(μ2-C≡C)] (R = H, Me), to give a number of complex cations. The trication salts [Ag3({Ru(CO)2(η-C5H4Me)}2(μ2-η1:η1-C≡C))3](O3SCF3)3, [Ag3({Ru(CO)2(η-C5H4R)}2(μ2-η1:η1-C≡C))({Ru(CO)2(η-C5H4R)}2(μ2-η1:η2-C≡C))2](BF4)3, and [Cu3({Ru(CO)2(η-C5H4R)}2(μ2-η1:η2-C≡C))({Ru(CO)2(η-C5H4R)}2(μ2-η2-C≡C))](PF6)3 result from the use of the respective anion salts in their syntheses. Coordination of Ag+ by the ethyne-1,2-diyl complexes in the presence of F3CCO2– yields the tetranuclear complexes [Ag4({Ru(CO)2(η-C5H4R)}2(μ2-η2-C≡C))2](μ2-O2CCF3)4 (R = H, Me). The reaction of CuCl does not afford the discrete dimeric complexes normally observed for internal alkynes and metal alkynyl complexes but, rather, the 1-D polymer [Cu2(μ-Cl)2({Ru(CO)2(η-C5H4R)}2(η2-C≡C))](∞|∞), while CuBr gives the discrete dimer motif known in the literature. The solution structures at 1/2, 1/1, and 2/1 stoichiometries of Ag+/[{Ru(CO)2(η-C5H5)}2(μ2-C≡C)] have been probed spectroscopically, and the {Ru(CO)2(η-C5H4R)} environments appear to be equivalent and, likewise, the resonances attributable to their C≡C units. In a subsequent reaction of [{Ru(CO)2(η-C5H4R)}2(μ2-C≡C)] and AgBF4 use of a strict Ag+/ethyne-1,2-diyl ratio gave [Ag({Ru(CO)2(η-C5H5)}2(η2-C≡C))2](BF4). The analogous Cu+ adduct [Cu({Ru(CO)2(η-C5H5)}2(η2-C≡C))2](PF6) is observed, along with the tricopper(I) adduct from the reaction of [{Ru(CO)2(η-C5H4R)}2(μ2-C≡C)] and [Cu(NCMe)4](PF6). A combination of factors appears to control the solid-state structures of these coinage metal adducts, with the anion found to be that which influences the packing to the greatest extent.