pi-Coordination of silver and copper to mercury bis-alkynyls: Synthesis and structural characterization

The reactions between the mercury-dialkynyl complexes [Hg(C=CR)(2)] (R = C6 H5, -C6H4-CH3-4, and -C(CH3)(3)) and a series of Ag(I) and Cu(I) compounds are reported. Compounds with the general formula [Hg(C=CR)(2)Cu-2(CH3CN)(4) ] [PF6](2), [Hg(C=CR)(2)M-2(L)(2)]X-2 (M = Ag, Cu; R = C6H5, -C6H4-CH3-4, a nd -C(CH3)(3); L = 2,2'-bipyridine, 1,10-phenanthroline; X = PF6 or BF4), a nd {[Hg(C=CR)(2)Ag] [BF4]}(n) (R = C6H5 and -C6H4-CH3-4) resulted from thes e reactions. In these complexes the silver and copper atoms are pi -coordin ated to the alkynyls' triple bonds. Crystal structures of three of these co mplexes have been obtained, confirming the formulation and in two instances revealing weak anion cation interactions. The structure of {[Hg(C=CTol)(2) Ag] [BF4]}(n) has been shown to be a polymer comprised of helices cross-lin ked by C-H . . . pi interactions.