Synthesis and structure of Re4(μ3-Te)4(TeBr2) 4Br8

Article abstract of DOI:10.1002/zaac.19966220208

Re₄(μ₃-Te)₄(TeBr₂) ₄Br₈ is obtained from the elements at 550°C in an evacuated glass ampoule. The diamagnetic compound forms air-stable, metallic lustre black crystals crystallizing in the tetragonal space group 14 with a = 1120.2(2), c = 1393.5(3) pm, and Z = 2. The crystal structure is built up by isolated cluster molecules Re₄(μ₃-Te)₄(TeBr₂) ₄Br₈ occupying the centres 4 at 1/2, 1/2, 0 and 0, 0, 1/2. The inner sceleton is formed by a Re₄Te₄ heterocubane unit with short Re-Re distances of 277 and 283 pm, which can be discussed as single bonds. Each Re atom coordinates in addition two Br^- ligands and one TeBr₂ molecule. For Re therefore results the oxidation state +IV. Reaction of Re₄(μ₃-Te)₄(TeBr₂) ₄Br₈ with I₂ yields (TeI₄)4. ? Johann Ambrosius Barth 1996.