One-pot synthesis and structure of organochalcogen halides with mixed valence states

Treatment of the diorganodichalcogenides PhEEPh (E = Se, Te) with one equivalent of elemental halogen (bromine or iodine) in methanol followed by addition of a sulfur donor and one more equivalent of the corresponding organochalcogen trihalide PhTeX3 affords the mixed-oxidation-state organochalcogen halides [PhEII(L)PhE'X-IV(4)] (E = Se, Te; E' = Te; X = Br, I; L = thiourea, tetramethylthiourea) in a one-pot procedure. The X-ray structural analyses of these compounds suggest a strong dependence of the formation of supramolecular assemblies on the nature of the halogen bonded to the tellurium atom. The halogen can induce intramolecular and intermolecular secondary interactions among the heavy atoms simultaneously and, in addition to (TeX)-X-... and (XX)-X-... secondary bonds, intramolecular interactions of the type Te-...eta(6)-pi-aryl can be formed. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006).