Nasibipour Mina, Safaei Elham, Wojtczak Andrzej, Jagličić Zvonko, Galindo Agustín, Masoumpour Marzieh Sadat
Department of Chemistry, College of Sciences, Shiraz University 71454 Shiraz Iran
Nicolaus Copernicus University, Faculty of Chemistry 87-100 Torun Poland.
RSC Adv. 2020 Nov 9;10(67):40853-40866. doi: 10.1039/d0ra06351g.
We report a new mononuclear molybdenum(iv) complex, MoOLL, in which L (2,4-di--butyl -semibenzoquinone ligand) has been prepared from the reaction of the -iminosemibenzoquinone form of a tridentate non-innocent benzoxazole ligand, L, and MoO(acac). The complex was characterized by X-ray crystallography, elemental analysis, IR and UV-vis spectroscopy and magnetic susceptibility measurements. The crystal structure of MoOLL revealed a distorted octahedral geometry around the metal centre, surrounded by one O and two N atoms of L and two O atoms of L. The effective magnetic moment ( ) of MoOLL decreased from 2.36 to 0.2 μ in the temperature range of 290 to 2 K, indicating a singlet ground state caused by antiferromagnetic coupling between the metal and ligand centred unpaired electrons. Also, the latter led to the EPR silence of the complex. Cyclic voltammetry (CV) studies indicate both ligand and metal-centered redox processes. MoOLL was applied as a catalyst for the oxidative cleavage of cyclohexene to adipic acid and selective oxidation of sulfides to sulfones with aqueous hydrogen peroxide.
我们报道了一种新型单核钼（IV）配合物MoOLL，其中L（2,4 - 二叔丁基 - 半苯醌配体）由三齿非无辜苯并恶唑配体L的 - 亚氨基半苯醌形式与MoO(acac)反应制备而成。该配合物通过X射线晶体学、元素分析、红外和紫外 - 可见光谱以及磁化率测量进行了表征。MoOLL的晶体结构显示金属中心周围为扭曲的八面体几何构型，由L的一个O原子、两个N原子以及L的两个O原子环绕。MoOLL的有效磁矩（ ）在290至2 K的温度范围内从2.36降至0.2 μ，表明金属与配体中心未成对电子之间的反铁磁耦合导致了单重基态。此外，后者导致该配合物的电子顺磁共振沉默。循环伏安法（CV）研究表明存在配体和金属中心的氧化还原过程。MoOLL被用作催化剂，用于将环己烯氧化裂解为己二酸以及用过氧化氢水溶液将硫化物选择性氧化为砜。
