Donor‐Acceptor Complexes of Tellurium Polycationic Clusters with Cyanogen

Abstract

AbstractThe reactions of cyanogen with Te6[AsF6]4 and Te4[AsF6]2 in SO2 solutions yield Te6[AsF6]4·1.5C2N2 (1) and Te4[AsF6]2·C2N2 (2) as red crystals in quantitative yield. The complexes 1 and 2 are also generated in moderate yield by the reaction of Te, AsF5 and C2N2 in liquid SO2, but by‐products are formed. These reactions show the ability of cyanogen to act as a donor towards tellurium polycations. In the crystal structures, discrete octahedral [AsF6]– ions are present and linear cyanogen molecules, which coordinate the tellurium atoms of the polycations η2 by both nitrogen atoms. In the crystal structure of 1, the trigonal‐prismatic Te64+ clusters are bridged by cyanogen molecules to one‐dimensional zig‐zag chains. The crystal structure of 2 contains square‐planar Te42+ clusters, which are bridged by cyanogen molecules to two‐dimensional sheets. The complexes 1 and 2 represent the first chalcogen polycationic cluster compounds containing a nitrogen ligation. The new compounds are unstable with respect to loss of cyanogen but stable under an atmosphere of C2N2. The Raman spectra of 1 and 2 were investigated and assigned. A serviceable and convenient way to handle air‐sensitive and cold liquids by a transfer needle technique is described.