Abstract
The near-ultraviolet spectrum of copper(11) acetate monohydrate consists of at least two bands centred at 360 and 325 nm, and polarized parallel and perpendicular to the copper-copper axis, respectively. From the temperature dependence of intensity the two bands are identified as singlet-singlet transitions. Their polarizations and intensities are consistent with the charge transfer assignments, lAlg → lA2u [b2u(py) → bIg(x2-y2)] and lAlg → lEu [eg(px) → bu2(x2-y2)], where b2u(py) and eg(px) are nonbonding ligand molecular orbitals composed of out-of-plane and in-plane oxygen 2p-orbitals, respectively.