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

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.