Synthesis, structure, and magnetic properties of two new copper(II) complexes with pseudohalide ligands. A dimer [Cu2(μ1,1-NCO)2(NCO)2(phen)2] with NCO bridge and ferromagnetic coupling and a mononuclear {[Cu(meso-cth)(CN)]ClO4·H2O}2 with two independent

Two new copper(II) complexes with pseudohalide ligands have been synthesized and their crystal structures have been determined by X-ray diffraction: a dinuclear complex [Cu2(μ1,1-NCO)2(NCO)2(phen)2] (1) in which two cyanate ligands form an end-on bridge between the two copper(II) atoms and the two other act as terminal ligands, and a mononuclear complex {[Cu(meso-cth)(CN)]ClO4·H2O}2 (2) with two independents [Cu(meso-cth)(CN)] units pseudorelated by a symmetric center, were phen is 1,10-phenantroline and meso-cth is 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclo-tetradecane. Magnetic susceptibility data, measured from 2 to 300 K, show ferromagnetic coupling for the dinuclear complex 1. These data were fitted to an equation derived from the Hamiltonian H=−JS1S2, given the parameters J=+13.75 cm−1, g=2.17. Complex 2 shows Curie law behavior (θ=0).