Reaction chemistry of 1,1′-ferrocene dicarboxylate towards M(ii) salts (M = Co, Ni, Cu): solid-state structure and electrochemical, electronic and magnetic properties of bi- and tetrametallic complexes and coordination polymers

Abstract

The synthesis and characterisation of a series of novel complexes of type [((tmeda)M-OC(O)-fc-(micro-CO(2)))(2)(micro-H(2)O)] (M = Co, ; M = Ni, ), zwitter-ionic [((pmdta)(H(2)O)Cu(+)-OC(O)-fc-CO(2)(-))(CH(3)OH)] (), and coordination polymer [(tmeda)Cu((OC(O))(2)fc)](n) () (fc = ferrocene-1,1'-diyl, (eta(5)-C(5)H(4))(2)Fe; tmeda = N,N,N',N'-tetramethylethylenediamine; pmdta = 1,1,4,7,7-N,N,N',N'',N''-pentamethyldiethylenetriamine) composed of ferrocene dicarboxylates and [(tmeda)/(pmdta)M](2+) entities is reported. These complexes could be prepared from [M(NO(3))(2)(tmeda)] (M = Co, ; M = Ni, ; M = Cu, ) and [Cu(NO(3))(2)(pmdta)] (), respectively, with stoichiometric amounts of 1,1'-ferrocene dicarboxylic acid () in presence of [n-Bu(4)N]OH-H(2)O. The molecular structures of , , , and in the solid state have been determined by single-crystal X-ray structure analysis. Electrochemical and UV-vis-NIR spectroscopic studies of these complexes are discussed in terms of electronic communication between the redox-active transition metals. In addition, the magnetic properties of and have been studied by susceptibility measurements vs. temperature. In complex , the two cobalt(ii) ions are antiferromagnetically coupled, while in the Ni-Ni coupling is ferromagnetic with J approximately +2.2(1) cm(-1).