title: Silver(I) 1,3-butadiynediide and two related silver(I) double salts containing the C4(2-) dianion.
abstract: Ag2C4, the second silver carbide to be fully characterized, has been synthesized as a light-gray powder (contaminated with metallic silver) that is explosive at high temperature (130 degrees C) and sensitive to mechanical shock, rather like the well-known prototype Ag2C2. In the pair of hydrated double salts Ag2C4.6AgNO3.nH2O (n = 2, 3), the nearly linear, centrosymmetric 1,3-butadiyne-1,4-diyl dianion C42-exhibits an unprecedented mu8-coordination mode, each terminal being capped by four sigma-bonded silver(I) atoms with pi-interaction to one of them.
authors.affiliation: Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, PR China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.forename: Thomas C W
authors.initials: TC
authors.lastname: Mak