College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, P. R. China.
Dalton Trans. 2012 Mar 28;41(12):3424-30. doi: 10.1039/c2dt12145j. Epub 2012 Feb 3.
Treatment of [CuCl(2)(bppyH(2))] (1, bppyH(2) = 2,6-di(1H-pyrazol-3-yl)pyridine) with 2 equiv. of AgNO(3) in DMF gave rise to a binuclear Cu(II) complex [Cu(2)(bppyH)(2)(NO(3))(2)] (bppyH = 2-(pyrazol-3-yl)-6-(pyrazolate)pyridine) (2). Complex 2 was characterized by elemental analysis, IR and single crystal X-ray diffraction. Complex 2 has a dimeric structure in which the two Cu(ii) centers are bridged by a couple of the in situ-generated bppyH(-) anions. Each Cu(II) center is further coordinated by one O atom of a NO(3)(-) anion and three N atoms of one bppyH(-) anion. Complex 2 exhibited a higher catalytic activity in the polymerization of methyl methacrylate (MMA) than the precursor complex 1. Even though the ratio of catalyst to MMA was raised up to 1 : 1500, the PDI for 2 (reaction time was fixed at 4 h) is 1.63 and the conversion is up to 72%. The effects of solvent, reaction temperature and the ratio of MMA to catalyst were also investigated.
用 2 当量的 AgNO3 在 DMF 中处理 [CuCl2(bppyH2)](1,bppyH2=2,6-二(1H-吡唑-3-基)吡啶),得到双核 Cu(II)配合物 [Cu2(bppyH)(2)(NO3)2](bppyH=2-(吡唑-3-基)-6-(吡唑烷)吡啶)(2)。配合物 2 通过元素分析、IR 和单晶 X 射线衍射进行了表征。配合物 2 具有二聚体结构,其中两个 Cu(ii)中心由一对原位生成的 bppyH(-)阴离子桥接。每个 Cu(II)中心进一步由一个 NO3(-)阴离子的一个 O 原子和一个 bppyH(-)阴离子的三个 N 原子配位。与前体配合物 1 相比,配合物 2 在甲基丙烯酸甲酯(MMA)聚合中表现出更高的催化活性。即使催化剂与 MMA 的比例高达 1:1500,2 的 PDI(反应时间固定为 4 小时)为 1.63,转化率高达 72%。还研究了溶剂、反应温度和 MMA 与催化剂的比例的影响。