π-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 = C 6 H 5, −C 6 H 4 −CH 3 -4, and −C(CH 3 ) 3 ) and a series of Ag(I) and Cu(I) compounds are reported. Compounds with the general formula [Hg(C⋮CR) 2 Cu 2 (CH 3 CN) 4 ][PF 6 ] 2, [Hg(C⋮CR) 2 M 2 (L) 2 ]X 2 (M = Ag, Cu; R = C 6 H 5, −C 6 H 4 −CH 3 -4, and −C(CH 3 ) 3; L = 2,2‘-bipyridine, 1,10-phenanthroline; X = PF 6 or BF 4 ), and {[Hg(C⋮CR) 2 Ag][BF 4 ]} n (R = C 6 H 5 and −C 6 H 4 −CH 3 -4) resulted from these reactions. In these complexes the silver and copper atoms are π-coordinated to the alkynyls' triple bonds. Crystal structures of three of these complexes have been obtained, confirming the formulation and in two instances revealing weak anion···cation interactions. The structure of {[Hg(C⋮CTol) 2 Ag][BF 4 ]} n has been shown to be a polymer comprised of helices cross-linked by C−H···π interactions.