Helical 1D Coordination Polymers Structure and Magnetic Properties of catena -Poly[chloro(μ -({2-[(hydroxyimino)methyl]phenoxy}acetato- N, O, O,O)copper(II)]

A new compound [CuHLCl] n , where H 2 L is the product of the condensation reaction between 2-formylphenoxyacetic acid and hydroxylamine, has been synthesized and its crystal structure determined. The copper( II )atomisinanO 3 NCl co- ordination environment and the helical chains of the complex are formed by square-pyramidal copper( II ) ions bridged by anti - anti carboxylate ligands in basal-apical positions. The chloride ion acts as monodentate ligand and is involved in intramolecular hydrogen bonding to the oxime group. The results of magnetic susceptibility and EPR measurements performed on the polycrystalline sample over a wide temper- ature range are presented. The magnetic susceptibility data have been fitted by use of the linear chain model and J = − 2.5 cm − 1 as the value of antiferromagnetic interaction. The value of the exchange exceeds the Zeeman energy differ- ence for two adjacent magnetically nonequivalent copper centers, and signals of these centers are averaged out. The temperature dependence of the EPR spectra shows increases in the linewidth and the shifts of the signals as the temper- ature decreases, indicating a short-range-order effect in the chain. Shifts of the EPR signals in the Q-band were discovered for the orientations perpendicular to the chain direction as the temperature decreased below 10 K. The na- ture of this shift is discussed.