Luminescent Chains Formed from Neutral, Triangular Gold Complexes Sandwiching TlI and AgI. Structures of {Ag([Au(μ-C2,N3-bzim)]3)2}BF4·CH2Cl2, {Tl([Au(μ-C2,N3-bzim)]3)2}PF6·0.5THF (bzim = 1-Benzylimidazolate), and {Tl([Au(μ-C(OEt)NC6H4CH3)]3)2}PF6·THF, with MAu6 (M = Ag+, Tl+) Cluster Cores

It has been found that several trinuclear complexes of AuI interact with silver and thallium salts to intercalate Ag+ and Tl+ cations, thereby forming chains. The resulting sandwich clusters center the cations between the planar trinuclear moieties producing structures in which six AuI atoms interact with each cation in a distorted trigonal prismatic coordination. The resultant (B3AB3B3AB3)∞ pattern of metal atoms also shows short (∼3.0 Å) aurophilic interactions between BAB molecular centers. These compounds display a strong visible luminescence, under UV excitation, which is sensitive to temperature and the metal ion interacting with the gold. X-ray crystal structures are reported for Ag([Au(μ-C2,N3-bzim)]3)2BF4·CH2Cl2 (P , Z = 2, a = 14.4505(1)Å; b = 15.098(2)Å; c = 15.957(1)Å; α = 106.189(3)°; β = 103.551(5)°; γ = 101.310(5)°); Tl([Au(μ-C2,N3-bzim)]3)2PF6·0.5C4H8O (P , Z = 2, a = 15.2093(1)Å; b =15.3931(4)Å; c = 16.1599(4)Å; α = 106.018(1)°; β = 101.585(2)°; γ=102.068(2)°); and Tl([Au(μ-C(OEt)NC6H4CH3)]3)2PF6·C4H8O (P2(1)/n, Z = 4, a = 16.4136(3)Å; b = 27.6277(4)Å; c = 16.7182(1)Å; β = 105.644(1)°). Each compound shows that the intercalated cation, Ag+ or Tl+, coordinates to a distorted trigonal prism of six AuI atoms. The counteranions reside well apart from the cations between the cluster chains.