The structure of thallium dicyanoargentate(I) has been determined crystallographically. The crystal structure shows an Ag-Ag distance of 3.11 Å. This is the shortest Ag-Ag distance reported for any silver dicyanide salt whose crystal structure has been determined. Raman spectra of the compound show four nu(C)(-)(N) peaks that are well-resolved in the 10-80 K temperature range. This result agrees well with group theory analysis. Extended Hückel calculations using relativistic wave functions have been carried out for two models which describe the interactions between the Ag(CN)(2)(-) ions within the crystal structure of Tl[Ag(CN)(2)]. The results of these calculations indicate the formation of potential wells at short Ag-Ag distances. The data in this study suggest the significance of ligand-unsupported silver-silver interactions (argentophilicity) in Tl[Ag(CN)(2)]. Tl-Ag interactions are determined to be insignificant in the compound. Tl[Ag(CN)(2)] crystallizes in the monoclinic space group P2(1)/c (No. 14), with a = 7.798(1) Å, b = 14.685(3) Å, c = 8.566(2) Å, beta = 91.66(2) degrees, Z = 8, R = 0.0643, and R(w) = 0.0899.

The excited-state properties of the layered compounds M[Au(CN)2]3 and M[Ag(CN)2]3 (with M = Eu3+) have been examined. Exclusive excitation of the host ions Au(CN)2-and Ag(CN)2-leads to photoluminescence (PL) from the Eu3+ ion, indicating host to guest excited-state energy transfer. The donor Au(CN)2-and Ag(CN)2-emissions are totally quenched at all temperatures. The emission intensity from Eu[Ag(CN)2]3, [EuAg], increases with a temperature increase while the intensity for Eu[Au(CN)2]3, [EuAu], decreases. High-resolution PL data obtained at 78 K indicate that the Eu3+ ion occupies a single site in [EuAg], while multiple-site occupations are indicated in [EuAu] . The covalent Au-Au and Ag-Ag interactions in the two compounds are analyzed by comparing the splittings in the 5Do -'Fl transitions of Eu3+ as well as the intensity ratios of the electric dipole (5Do -7F2) and the magnetic dipole (5Do -7FI) transitions.