The crystal structures of tetra­kis­(μ-n-butyrato-κ2O:O′)bisbromidorhenium(III) and tetra­kis­(μ-n-butyrato-κ2O:O′)bischlorido­rhenium(III) aceto­nitrile disolvate

摘要

The title complexes, [Re2Br2(O2CC3H7)4], (>1), and [Re2(O2CC3H7)4Cl2]·2CH3CN, (>2), both exhibit paddlewheel structures with four carboxyl­ate ligands bridging two Re^III atoms. The Re—Re distances are 2.2325 (2) and 2.2299 (3) Å, indicating quadruple bonds between the Re^III atoms in each complex. Both complexes contain an inversion center at the mid-point of the Re—Re bond. The Re—Br bond [2.6712 (3) Å] in (>1) is 0.1656 (6) Å longer than the Re—Cl distance [2.5056 (5) Å] of (>2). In (>2), the N atom of each co-crystallized aceto­nitrile solvent mol­ecule is nearly equidistant between and in close contact with two carboxyl­ate C atoms.