| Abstract: The new monomeric complexes of [M(MPA)2(Im)2]·2H2O (1: M=Co; 2: M=Ni) (HMPA=5-methyl-1H-pyrazole-3-carboxylic acid, Im=imidazole) were synthesized by the reaction of HMPA and Im with M(OAc)2·4H2O (M=Co, Ni), respectively. The compounds were characterized by elemental analysis, IR spectra, single crystal X-ray diffraction, thermogravimetric analysis and cyclic voltammetry. The structural parameters of 1 and 2 were analyzed as follows: 1, monoclinic, P21/n, a=0.847 02(16) nm, b=1.461 5(3) nm, c=0.899 67(17) nm, β=101.759(6)°, V=1.090 3(4) nm3, Z=2; 2, monoclinic, P21/n, a=0.853 59(6) nm, b=1.451 77(9) nm, c=0.889 83(6) nm, β=102.382 0(10)°, V=1.077 04(12) nm3, Z=2. Metal ions have all octahedral geometry coordinated by two nitrogen atoms from two Im molecules, two nitrogen atoms and two oxygen atoms from two MPA- ligands. In both complexes, the independent components [M(MPA)2(Im)2]·2H2O are connected by two kinds of intermolecular hydrogen bonds (N-H…O and C-H…O) to form a three-dimensional supramolecular architecture. Electrochemical property of the complex shows that electron transfer of M(Ⅱ) between M(Ⅲ) (M=Co, Ni) in electrolysis is quasi-reversible process. CCDC: 848231, 1; 848232, 2. |
