CRYSTAL-STRUCTURE, ELECTRONIC-STRUCTURE, AND TEMPERATURE-DEPENDENT RAMAN-SPECTRA OF TL[AG(CN)(2)] - EVIDENCE FOR LIGAND-UNSUPPORTED ARGENTOPHILIC INTERACTIONS

The structure of thallium dicyanoargentate(I) has been determined crys tallographically. The crystal structure shows an Ag-Ag distance of 3.1 1 Angstrom. This is the shortest Ag-Ag distance reported for any silve r dicyanide salt whose crystal structure has been determined. Raman sp ectra of the compound show four nu(C-N) peaks that are well-resolved i n the 10-80 K temperature range. This result agrees well with group th eory analysis. Extended Huckel calculations using relativistic wave fu nctions have been carried out for two models which describe the intera ctions between the Ag(CN)(2)(-) ions within the crystal structure of T l[Ag(CN)(2)]. The results of these calculations indicate the formation of potential wells at short Ag-Ag distances. The data in this study s uggest the significance of ligand-unsupported silver-silver interactio ns (argentophilicity) in Tl[Ag(CN)(2)]. Tl-Ag interactions are determi ned 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) Angstr om, b = 14.685(3) Angstrom, c = 8.566(2) Angstrom, beta = 91.66(2)degr ees, Z = 8, R = 0.0643, and R-w = 0.0899.