Synthesis, spectral characterization and crystal structure of Ni(II) pyridoxal thiosemicarbazone complexes and their recyclable catalytic application in the nitroaldol (Henry) reaction in ionic liquid media
作者:Rajendran Manikandan、Panneerselvam Anitha、Govindan Prakash、Paranthaman Vijayan、Periasamy Viswanathamurthi
DOI:10.1016/j.poly.2014.07.018
日期:2014.10
The molecular structure of the complex [Ni(L2)PPh3] (2) was determined by single-crystal X-ray diffraction, which reveals a distorted square planar geometry around the nickel(II) ion. The nitroaldol reaction was studied in detail using the nickel(II) complexes as catalysts in a homogeneous solution formed by an ionic liquid and methanol. The effect of solvent, ionic liquid, time, temperature, catalyst
摘要由[NiCl2(PPh3)2]与三齿席夫碱配体,吡ido醛硫代半碳zone(L1),吡ido醛N-甲基硫代半碳carb(L2)反应合成了新型方形平面镍(II)配合物1、2和3。乙醇中的吡-醛和吡ido醛N-苯基硫代半碳酮(L3)。这些配合物已通过元素分析,IR,UV-Vis,1H NMR,31P NMR和ESI-MS光谱进行了表征。配合物[Ni(L2)PPh3](2)的分子结构是通过单晶X射线衍射确定的,该结构揭示了镍(II)离子周围扭曲的正方形平面几何形状。在由离子液体和甲醇形成的均相溶液中,使用镍(II)配合物作为催化剂,对硝基羟醛反应进行了详细的研究。溶剂,离子液体,时间,温度,还研究了催化剂的负载量和反应中配体部分的取代基。以高达97%的高产率获得β-硝基醇产物。根据反应质量的ESI-MS光谱监测,初步提出了一种两步的底物添加机理。