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

An earlier study describing the exchange of the mu-acetato ligands of Re-2(mu-O2CCH3)Cl-4(mu-dppm)(2) (1) and cis-Re-2(mu-O2CCH3)(2)Cl-2(mu-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 Re-2(mu-O2CC6H4N)Cl-4(mu-dppm)(2) (7) and cis-Re-2(-O2C6H10CO2Et)(2)Cl-2(mu-dppm)(2) (11) have been isolated, as well as the trimetallic complex cis-Re2Cl2(mu-dppm)(2) [(mu-O2CC5H4)(2)Fe] (14) that is formed from the reaction of 2 with (C5H4CO2H)(2)Fe. The crystal structures of 7, 11 and 14 are reported.