A trinuclear cyanamidonitrate–copper(II) complex bridged by imidazolato ligands

Cyanamidonitrate (can− = NO2N(CN)−) forms with copper(II) ions and neutral base (Him = imidazole) a complex of the composition [Cu3(Him)8(im)2(NO3)2(can)2] where im stands for the imidazolato (deprotonated imidazole) ligand. The crystal structure reveals three Cu(II) atoms linked by two imidazolato groups in this trinuclear complex of the linear type [(can)(Him)3Cu(μ-im)Cu(Him)2(NO3)2(μ-im)Cu(Him)3(can)]. The terminal Cu atoms are pentacoordinated, whereas the central Cu atom has a strongly elongated octahedral coordination. The magnetic susceptibility measurements confirm that the exchange coupling constants of the adjacent Cu centers is strongly antiferromagnetic (J/hc = −115 cm−1). The magnetization per complex is M = 0.73 μB at B = 5 T and T = 5 K.