Magnetostructural Properties of Some Doubly-Bridged Phenoxido Copper(II) Complexes
Salah S. Massoud, Febee R. Louka, Madison T. Dial, Nahed M.H. Salem, Roland C. Fischer, Ana Torvisco, Franz A. Mautner, Kai Nakashima, Makoto Handa, Masahiro Mikuriya
Abstract
Three new tripod tetradentate phenolate-amines (H2L1, H2L4 and H2L9), together with seven more already related published ligands, were synthesized, and characterized. With these ligands, two new dinuclear doubly-bridged-phenoxido copper(II) complexes (3, 4), and six more complexes (1, 2, 5–8), a new trinuclear complex (9) with an alternative doubly-bridged-phenoxido and –methoxido, as well as the 1D polymer (10) were synthesized, and their molecular structures were characterized by spectroscopic methods and X-ray single crystal crystallography. The Cu(II) centers in these complexes exhibit distorted square-pyramidal arrangement in 1–4, mixed square pyramidal and square planar in 5, 6, and 9, and distorted octahedral (5+1) arrangements in 7 and 8. The temperature dependence magnetic susceptibility study over the temperature range 2–300 K revealed moderate–relatively strong antiferromagnetic coupling (AF) (|J| = 289–145 cm−1) in complexes 1–6, weak-moderate AF (|J| = 59 cm−1) in the trinuclear complex 9, but weak AF interactions (|J| = 3.6 & 4.6 cm−1) were obtained in 7 and 8. No correlation was found between the exchange coupling J and the geometrical structural parameters of the four-membered Cu2O2 rings.