First Oxido-Bridged Cubo-Octahedral Hexanuclear Rhenium Clusters

The
first discrete hexanuclear metal clusters with cores adopting
the M6(μ-O)12 cubo-octahedral topology
have been synthesized in the course of a simple one-pot reaction.
We present a new class of rhenium clusters which are the first hexanuclear
rhenium complexes with 12 bridging ligands and the first clusters
with octahedrally arranged Re atoms bridged only by O atoms forming
a unique cube-like Re6(μ-O)12 unit. Our
synthetic strategy demonstrates a new approach to the syntheses of
polynuclear rhenium complexes under mild conditions. We discovered
that the [Re6(μ-O)12­(3-Mepy)6]­BPh4 cluster compound has the ability to undergo
reversible or/and quasireversible redox reactions without changing
spatial structure and overall geometry. Subsequently, a reduction
reaction of [Re6(μ-O)12­(3-Mepy)6]­BPh4 was performed successfully and almost quantitatively
resulting in the formation of the molecular [Re6(μ-O)12­(3-Mepy)6] complex.