The X-ray structure of (Tl[Au(C(6)Cl(5))(2)])(n), 1, consists of 1-D linear polymer chains parallel to the crystallographic z axis. The crystal structure of 1 has channels that run parallel to these chains with interatom distances in the range 3.231-4.076 A. There are holes in these channels with diameters as large as 10.471 A, which can accommodate a variety of solvents. Complex 1 displays reversible vapochromic emission and absorption spectral behavior when the solid is exposed to a variety of organic vapors such as acetone, acetonitrile, triethylamine, acetylacetone, tetrahydrothiophene, 2-fluoropyridine, tetrahydrofuran, and pyridine. Complex 1 is luminescent at room temperature and at 77 K in the solid state. UV excitation at 495 nm leads to an emission at 531 nm.

The luminescence in a series of new bimetallic gold-silver vapochromic structures can be efficiently switched among different colors simply by exposure to solvent vapors. The emission color in these systems is controlled by both aurophilic interactions and halogen bonding, which affect the emission energy through different orbitals.

The synthesis, structural characterization, and the study of the photophysical properties of complexes [Au 2 Ag 2 (C 6 F 5 ) 4 (NtCCH 3 ) 2 ] n (1) and [Au 2 Cu 2 (C 6 F 5 ) 4 (NtCCH 3 ) 2 ] n (2) have been carried out. The crystal structure of both complexes consists of polymeric chains formed by repetition of Au 2 Ag 2 or Au 2 Cu 2 units built up by metallophilic Au(I)‚‚‚M(I) interactions that are linked through Au(I)‚‚‚Au(I) interactions. Complexes 1 and 2 are brightly luminescent in the solid state at room temperature and at 77 K with lifetimes in the nanosecond range. Both compounds 1 and 2 undergo oligomerization in solution, as observed through UV-vis and excitation spectra in acetonitrile solutions at high concentrations. Thus, a correlation between the excitation spectra in solution at different concentrations and the absorption spectra in the solid state for complex 1 can be established. Time-dependent DFT calculations agree well with the experimental results and support the idea of that the origin of the luminescence of these complexes arises from orbitals located in the tetranuclear Au 2 M 2 units.