Reaction behaviour of dinuclear copper(I) complexes with m-xylyl-based ligands towards dioxygen

Intramolecular ligand hydroxylation was observed during the reactions of dioxygen with the dicopper(I) complexes of the ligands L-1 (L-1 = alpha,alpha'-bis[(2-pyridylethyl)amino]-m-xylene) and L-3 (L-3 = alpha,alpha'-bis[N-(2-pyridylethyl)-N-(2-pyridylmethyl)amino]-m-xylene). The dinuclear copper(I) complex [Cu2L3](ClO4)(2) (3) and the dicopper(II) complex [Cu-2(L-1-O)(OH)(ClO4)]ClO4 (1) were characterized by single-crystal X-ray structure analysis. Furthermore, phenolate-bridged complexes were synthesized with the ligand L-2-OH (structurally characterized [Cu-2(L-2-O)Cl-3] (7) with L-2 = alpha,alpha'-bis[N-methyl-N-(2-pyridylethyl)amino]-m-xylene; synthesized from the reaction between [Cu-2(L-2-O)(OH)](ClO4)(2) (2) and Cl-) and Me-L-3-OH: [Cu-2(Me-L-3-O)(mu-X)](ClO4)(2).nH(2)O (Me-L-3-OH = 2,6-bis[N-(2-pyridylethyl)- N-(2-pyridylmethyl)amino]-4-methylphenol and X = C3H3N2- (prz) (4), MeCO2- (5) and N-3(-) (6)). The magnetochemical characteristics of compounds 4 - 7 were determined by temperature-dependent magnetic studies, revealing their antiferromagnetic behaviour [-2J (in cm(-1)) values: -92 for 4, -86 for 5 and -88 for 6; -374 for 7].