Crystal Structures and Magnetic Properties of Novel μ-Carboxylato-μ-Hydroxo-Bridged Binuclear Copper(II) Complexes with 1,10-Phenanthroline

Abstract

Abstract Novel μ-carboxylato-μ-hydroxo-bridged binuclear copper(II) complexes with 1,10-phenanthroline, [Cu2(OH)(RCOO)(phen)2]X2·H2O (where R = H, X = BF4 (1); R = CH3, X = NO3 (2); R = C2H5, X = NO3 (3)) were prepared and characterized by elemental analyses, electronic spectra, magnetic susceptibilities, and X-ray structure analysis. The magnetic susceptibility data conform to the usual dimer equation. The −2J values are −109 cm−1 for 1, −111 cm−1 for 2, and −109 cm−1 for 3, indicating that a strong ferromagnetic spin coupling exists in these complexes. The crystal structures of 2 and 3 were determined by the single-crystal X-ray diffraction method. The crystallographic data are: Compound 2, monoclinic, P21/n, a = 8.107 (10), b = 18.554 (9), c = 18.616 (7) Å, β = 99.14 (6)°, V = 2765 (6) Å3, Z = 4, R = 0.045 for 3274 observed unique reflections; compound 3, monoclinic, P21/n, a = 7.981 (10), b = 18.352 (8), c = 19.247 (8) Å, β = 97.98 (7)°, V = 2792 (4) Å3, Z = 4, R = 0.047 for 3220 reflections. These complexes have very novel roof-shaped binuclear units with dihedral angles (122.8° for 2 and 122.7 ° for 3) observed between two basal planes of CuO2N2. These small dihedral angles are mainly attributed to the strong ferromagnetic exchange interaction in the present complexes.