Synthesis,Structure and Slow Magnetization Relaxation of Co(Ⅱ) Complexes from a Flexible Imidazole-based Ligand

The employment of a flexible imidazole-based ligand(H_2L), condensed from 1 Himidazole-2-carbaldehyde and 1,2-bis(aminooxy)ethane, and Co²⁺ salt has led to the formation of Co(Ⅱ) complexes Co(H_2L)_2Cl]Cl·4CH_3OH(1) and Co(H_2L)(NCS)_2]_2·2C_4H₁₀O(2), in the presence of different anions, i.e, Cl-and SCN-, respectively. Single-crystal X-ray analyses show that complex 1 with a square pyramid(C_4v) local environment exhibits a two-dimensional(2D)layered(4,4)-net framework and complex 2 displays a dinuclear molecule box with a T_d local environment. By comparison between complexes 1 and 2, the versatile configuration of ligand including cis-and trans-form isomer has a significant effect on the structures of the resulting complexes. The magnetic properties of 1 and 2 are also investigated. The ac magnetic susceptibility revealed that 2 exhibits the characteristic of slow magnetization relaxation.