Halide-Capped Tellurium-Containing Macrocycles

The reaction of 1,1,2,3,3-pentamethyltrimethylenephosphinic acid (cycPO2H) with bis(p-methoxyphenyl)tellurium dichloride (1) affords a 12-membered macrocycle [((p-MeOC6H4)2Te)2(μ-O)(μ-cycPO2)(μ4-Cl)]2·C6H6 (2) in good yield. The latter reacts with sodium iodide to give [((p-MeOC6H4)2Te)2(μ-O)(μ-cycPO2)(μ4-I)]2·4C6H6 (3). 2 and 3 are isostructural dicationic macrocycles and contain a Te4P2O6 framework. An interesting aspect of both of these structures is that two counter halide atoms are present as capping ligands above and below the macrocyclic plane enabled by Te---X interactions. In contrast to the macrocyclic product obtained with diorganotellurium dihalide the reaction of diphenyltin dichloride with cycPO2H resulted in the formation of an oxygen-capped cluster [(PhSn)3(μ3-O)(μ-cycPO2)3(μ-OH)3][cycPO2]·CH3CN. The latter is formed by a Sn-Ph cleavage reaction.