854589-33-6Relevant academic research and scientific papers
PH-dependent imidazolato bridge formation in dicopper complexes: Magnetic, electrochemical, and catalytic repercussions
Monte-Perez, Ines,Sosa, Ana M.,Bernes, Sylvain,Aliaga-Alcalde, Nuria,Ugalde-Saldivar, Victor M.,Gasque, Laura
, p. 4739 - 4749 (2012)
The dicopper complexes of two dinucleating ligands derived from 2-methylimidazole and 2 equiv. of an L-amino acid are presented (H 3bphenim derived from L-phenylalanine and H3bleuim derived from L-leucine). For each ligand L, three different protonation states for the complex, Cu2HL2+, Cu2L+, and Cu 2LOH, have been characterized in solution by potentiometric, spectrophotometric, and electrochemical techniques. X-ray diffraction studies enabled the characterization, in the solid state, of the [Cu 2(bphenim)]+ and [Cu2Hbleuim]2+ cations. Magnetic measurements showed that while only a very slight coupling could be detected in [Cu2Hbleuim]2+, [Cu 2(bphenim)]+ is strongly antiferromagnetically coupled. The extent of this coupling can also be appreciated from room temperature, pH-dependent EPR spectroscopic studies, where the signal is quenched at pH values where the imidazolato-bridged species is predominant. These observations are consistent with the cyclic voltammetric studies. The catecholase activity of the complexes in the form [Cu2L]+ is low, however, an important increase in activity is observed above pH = 8.5 where the concentration of the species [Cu2LOH] starts to become significant. Copyright
