A novel dirhenium(III) complex with bridging picolinate and methoxide ligands from the reaction between cis-Re2(μ-O2CCH3)2Cl4(H2O)2 and picolinic acid

The reaction of cis-Re2(μ-O2CCH3)2Cl4(H2O)2 with picolinic acid (Hpic) affords either the diamagnetic, metal–metal bonded, dirhenium(III) complex Re2(μ-OMe)(μ:η2-pic)(η2-pic)3Cl (1) or the mononuclear rhenium(V) complex ReO(η2-pic)2Cl (2), depending on whether mixed methanol/ethanol or acetone/ethanol solvent mixtures are used. The structures of 1 and 2 have been established by X-ray crystallography. Complex 1 is unusual in having a bridging methoxide and bridging picolinate ligand in an edge-sharing bioctahedral structure in which the Re–Re bond distance of 2.4588(4) Å is unusually short for what is a formal Re–Re double bond.