Synthesis and electrochemical study of complexes of 2-methylthio-5-(pyridylmethylidene)-3,5-dihydro-4H-imidazol-4-ones with transition metals (Co, Ni, and Cu). Molecular structures of CuIIL1Cl2 (L1 is (5Z)-2-methylthio-3-phenyl-5-(α-pyridylmethylidene)-3,5-dihydro-4H-imidazol-4-one) and CoIIL2Cl2 (L2 is (5Z )-3-methyl-2-methylthio-5-(α-pyridylmethylidene)-3,5-dihydro-4H-imidazol-4-one)
作者:E. K. Beloglazkina、S. Z. Vatsadze、A. G. Majouga、N. A. Frolova、R. B. Romashkina、N. V. Zyk、A. A. Moiseeva、K. P. Butin
DOI:10.1007/s11172-006-0190-6
日期:2005.12
New transition metal (NiII, CoII, and CuII) complexes with 2-methylthio-5-(pyridyl-methylidene)-3,5-dihydro-4H-imidazol-4-ones were synthesized by the reaction of 5-(α-, β-, or γ-)pyridyl-substituted 2-methylthio-3,5-dihydro-4H-imidazol-4-ones with MCl2· nH2O. In the complexes with α-Py-substituted ligands, the metal atom has a tetrahedral coordination environment and is coordinated by the nitrogen atoms of the pyridine and thiohydantoin rings and two chloride anions. The results of electronic spectroscopy and magnetic susceptibility measurements suggest that the complexes with the β-and γ-Py-substituted ligands have polymeric structures, and the metal atoms in these complexes are in an octahedral environment. The molecular and crystal structures of CuIIL1Cl2 (L1 is (5Z)-2-methylthio-3-phenyl-5-(α-pyridylmethylidene)-3,5-dihydro-4H-imidazol-4-one) and CoIIL2Cl2 (L2 is (5Z)-3-methyl-2-methylthio-5-(α-pyridylmethylidene)-3,5-dihydro-4H-imidazol-4-one) were established by X-ray diffraction. Semiempirical quantum-chemical calculations were performed for 2-methylthio-5-(pyridylmethylidene)-3,5-dihydro-4H-imidazol-4-ones. The complexes, starting ligands, and metal chlorides were studied electrochemically. The mechanism of electro-oxidation and electroreduction of 2-methylthio-5-(pyridylmethylidene)-3,5-dihydro-4H-imidazol-4-ones and their cobalt, nickel, and copper complexes was proposed.
通过 5-(α-、β- 或 γ-)吡啶基取代的 2-甲硫基-3,5-二氢-4H-咪唑-4-酮与 MCl2- nH2O 的反应,合成了新的过渡金属(NiII、CoII 和 CuII)与 2-甲硫基-5-(吡啶基-亚甲基)-3,5-二氢-4H-咪唑-4-酮的配合物。在 α-Py 取代配体的配合物中,金属原子具有四面体配位环境,并由吡啶和硫代海因环的氮原子以及两个氯阴离子配位。电子能谱和磁感应强度测量结果表明,β 和 γ-Py 取代配体的配合物具有聚合结构,这些配合物中的金属原子处于八面体环境中。通过 X 射线衍射建立了 CuIIL1Cl2(L1 为 (5Z)-2-甲硫基-3-苯基-5-(α-吡啶基亚甲基)-3,5-二氢-4H-咪唑-4-酮)和 CoIIL2Cl2(L2 为 (5Z)-3-甲基-2-甲硫基-5-(α-吡啶基亚甲基)-3,5-二氢-4H-咪唑-4-酮)的分子和晶体结构。对 2-甲硫基-5-(吡啶基亚甲基)-3,5-二氢-4H-咪唑-4-酮进行了半经验量子化学计算。对配合物、起始配体和金属氯化物进行了电化学研究。提出了 2-甲硫基-5-(吡啶亚甲基)-3,5-二氢-4H-咪唑-4-酮及其钴、镍和铜配合物的电氧化和电还原机制。