Spectroscopic, electrochemical, magnetic and structural investigations of dimanganese-(II/II) and mixed-valence-(II/III)-tetraiminodiphenolate complexes

• Autor(a) principal: Rocha,Julio C. da
• Data de Publicação: 2014
• Outros Autores: Poneti,Giordano, Ferreira,Janaina G., Ribeiro,Ronny R., Nunes,Fábio S.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532014000800025
• topic: dimanganese macrocyclic complexes; tetraiminodiphenolate; magnetic properties; spectroeletrochemistry; crystal structure

Synthesis, spectroscopic [electron paramagnetic resonance (EPR), UV-Vis and Fourier transform infrared spectroscopy (FTIR)], magnetic and spectroeletrochemical properties of [MnII2(tidf)(OAc)(ClO4)(MeOH)] (tidf = a Robson type macrocyclic ligand obtained through condensation of 2,6-diformyl-4-methylphenol and 1,3-diaminopropane) are reported. Compound [MnII2(tidf)(OAc)(ClO4)(MeOH)] shows a weak antiferromagnetic behavior with exchange coupling constant J = -1.59(1) cm-1. UV-Vis and EPR spectroelectrochemical response after oxidation of complex [MnII2(tidf)(OAc)(ClO4)(MeOH)] detected the stabilization of mixed-valence Mn2(II/III) species in solution showing spectral features similar to the ones of the isolated mixedvalence [MnII MnIII(tidf)Br3(H2O)2] compound. Crystallization of [MnII2(tidf)(OAc)(ClO4)(MeOH)] surprisingly produced the trimanganese complex [Mn3III/II/III(tidf)2(µ-OAc)2](ClO4)2, not observed in solution. It contains two pentacoordinated [MnIII(tidf)]+ units, each one connected to a central hexacoordinated MnII ion through one µ-phenolate and one µ-acetate bridge.