Metallophilic Au(I)···M(I) Interactions (M = Tl, Ag) in Heteronuclear Complexes with 1,4,7-Triazacyclononane: Structural Features and Optical Properties

1,4,7-Triazacyclononane (TACN) has been used for the first time to support Au(i)⋯M [M = Tl(i), Ag(i)] metallophilic interactions in the formation of heteronuclear gold(i) complexes having luminescence properties. The compounds {[{Au(C6Cl5)2}Tl(TACN)]2}n (1), [{Au(C6F5)2}Tl(TACN)] (2), [{Au(C6Cl5)2}Ag(TACN)] (3), and [{Au(C6F5)2}{Ag(TACN)}2Au(C6F5)2] (4) have been synthesized by reacting TACN and the polymeric starting organometallic gold(i) compounds [{Au(C6X5)2}M]n (M = Ag(i), Tl(i); X = Cl, F) in a 1 : 1 molar ratio, in THF. 1, 3 and 4 have also been structurally characterized and their optical properties explained on the basis of their structural features with the support of TD-DFT calculations.