Non-innocent ligand behaviour of a bimetallic Cu complex employing a bridging catecholate

摘要: The geometric and electronic structure of a bimetallic Cu Schiff-base complex its one-electron oxidized form have been investigated. two salen units in the neutral 1 are linked via bridging catecholate function, coupling between Cu(II) d9 centres was determined to be weakly antiferromagnetic on basis solid-state magnetic studies (J = −3 cm−1), variable-temperature electron paramagnetic resonance (EPR) cm−1). Theoretical calculations (DFT) were agreement with experimental results −7 provided insight into mechanism for system. One-electron oxidation [1]+ which observed limited stability solution. ligand radical species solution, hole potentially localized redox-active dioxolene, phenolate ligands, or delocalized over entire Electrochemical experiments UV-vis-NIR spectroscopy, combination density functional theory calculations, locus degree delocalization this [1˙]+ experimentally dioxolene bridge small amount spin outer moieties predicted by calculations. This assignment aided comparison data Ni analogue (Inorg. Chem., 2011, 50, 6746). Raman spectrum (λex 413 nm) CH2Cl2 solution clearly exhibited new band at 1308 cm−1 1, supporting semiquinone formation. Variable-temperature EPR three-spin system did not provide definitive information interaction, possibly due very difference energy S 3/2 1/2 states and/or zero-field splitting, significant line-broadening. is consistent description overall as bridge-localized species.