Assemblies of multiply bonded [Re2]n+ cores possessing bond orders of 3 or 3.5 that are linked by dicarboxylate bridges

Abstract

An earlier study describing the exchange of the μ-acetato ligands of Re₂(μ-O₂CCH₃)Cl₄(μ-dppm)₂ (1) and cis-Re₂(μ-O₂CCH₃)₂Cl₂(μ-dppm)₂ (2) by dicarboxylic acids has been expanded to include reactions with the monocarboxylic acid isonicotinic acid, and the dicarboxylic acids adipic acid, 4,4′-biphenyldicarboxylic acid, fumaric acid, trans-1,4-cyclohexanedicarboxylic acid and 1,1′-ferrocenedicarboxylic acid. Further examples of complexes that are “dimers-of-dimers” and triangular supramolecular assemblies involving retention of the basic electronic and molecular structures of the dirhenium units present in 1 and 2 have been obtained. In addition, the dirhenium complexes Re₂(μ-O₂CC₆H₄N)Cl₄(μ-dppm)₂ (7) and cis-Re₂(μ-O₂C₆H₁₀CO₂Et)₂Cl₂(μ-dppm)₂ (11) have been isolated, as well as the trimetallic complex cis-Re₂Cl₂(μ-dppm)₂[(μ-O₂CC₅H₄)₂Fe] (14) that is formed from the reaction of 2 with (C₅H₄CO₂H)₂Fe. The crystal structures of 7, 11 and 14 are reported.