Atmospheric CO2 fixation leads to a unique bridged complex and coordination induced ligand hydrolysis to a [CuII] complex

Abstract: Atmospheric CO2 fixation in basic medium (initial pH 8.5) leads to a novel hydrogencarbonate single-oxygen bridged dicopper(II) complex from the dinucleating ligand H3L (2-methyl-2-(2′-hydroxyphenyl)-1,3-bis[4-methyl-4-(2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine). The same reaction in neutral medium (initial pH 6) gives the monocopper(II) complex [CuII(HL1)]·2ClO4 (2) of the zwitterionic ligand (HL1), following 2-(2′-hydroxyphenyl) imidazolidine ring and terminal (2-hydroxyphenyl)methylimine hydrolysis. Both 1 ·4H2O and 2 have been characterized by IR and UV–Vis spectroscopy, conductivity measurements and X-ray crystallography. Variable temperature (2–300K) magnetic measurements show that complex 1 ·4H2O exhibits weak intramolecular antiferromagnetic coupling. [Copyright &y& Elsevier]