First example of bidentate coordination of the octahedral rhenium(III) cluster anion to a 3d-transition metal ion: Assembly of 2D coordination network [{Cu(NH3)3}2{Re6S8(OH)4(μ-OH)2}]·8H2O

Abstract

A new 2D coordination polymer, [{Cu(NH3)3}2{Re6S8(OH)4(μ-OH)2}]·8H2O (1), has been prepared as a result of reactivity studies of the octahedral rhenium cluster anion [Re6S8(OH)6]4− in a system containing Cu2+ cations in aqueous ammonia. The compound was characterized by means of IR spectroscopy, thermal analysis, elemental analysis and single-crystal X-ray diffraction analysis. The structure determination revealed the presence of neutral layers containing Cu2+ cations surrounded by three NH3 molecules, located midway between two different [Re6S8(OH)6]4− cluster anions. The cluster anion displays an unprecedented bidentate coordination to Cu2+, occurring via the μ3-S ligand (Cu⋯S, 2.996(3)Å) and O atom of a terminal OH group (Cu–O, 1.986(7)Å). The resultant Cu(II) coordination environment can be described as a stretched octahedral geometry (4+2).