排序方式: 共有60条查询结果,搜索用时 15 毫秒
51.
52.
Complexes with the unsymmetrical Schiff base can be used effectively as the stimulated metal protein and catalyst with higher activity. In order to obtain an unsymmetrical bis-Schiff base, Elder[1] suggested that the nickel bis-Schiff base complex was prepared firstly, then the corre-sponding unsymmetrical bis-Schiff base was synthesized by stripping the ligand from this com-plex with dimethylglyoxime. The resulting product with an additional —NH2 group may be con-densed with another aldehy… 相似文献
53.
54.
EPR characters of three new gadolinium complexes with noncydic polyether Schiff bases in powder or organic solvents, including various oxyethylene chain lengths and different substituting groups in ligands, are investigated respectively. Some regularities are summed up. The difference of EPR character in various solvents, particularly at different temperatures, has been examined. The 'single peak effect' due to THF solvent at low temperature is observed for the first time. This phenomenon is explicated. 相似文献
55.
镧通常存在于独居石、硅铈石、褐帘石、镧石、氟碳铈矿及氟碳酸钙铈矿等矿物中,在这些矿物内镧的含量除铈以外比其他希土元素都要高一些,如在独居石中就含 La_2O_3 14~30%。氧化镧常用来制造无色光学玻璃,能使玻璃明亮洁净,对还原焰无感应,当焙烧和在阳光下不变色。在制坦克潜望镜的棱镜中含有60%氧化镧,它能使棱镜的折射率介于好的燧石玻璃与金刚石之间,在陶瓷工业方面镧与其他希土混合物用来制备温度系数等于零的绝缘体。含镧希土所制得的玻璃电极性能较好。在冶金工业方面常用含镧混合金属以改进电炉钢与平炉钢的物理性质,在镍铬合金中添加含镧的混合希土就 相似文献
56.
57.
58.
直链醚型Schiff碱与钴(Ⅱ)、镍(Ⅱ)配合物的合成、表征及其活性的研究 总被引:5,自引:0,他引:5
合成了双水杨醛缩二甘醇二胺(SALDA)及双水杨醛缩四甘醇二胺(SALTTA)两类直链醚型Schiff碱,并用于合成钴、镍的四种Schiff碱配合物,经分析,其组成为[M(SALDA)](NO3)2·H2O和[M(SALTTA)](NO3)2·nH2O,并以热重-差热分析、紫外、红外光谱以及核磁共振谱等方法研究了它们的配位作用.此类配合物能有效清除超氧阴离子自由基,具有明显的生物活性,并对甲基丙烯酸甲酯(MMA)聚合有催化效果,转化率~70%,分子量峰值可达100万. 相似文献
59.
稀土与直链醚-乙酰丙酮Schiff碱新配合物合成、形成机理 与波谱 总被引:7,自引:0,他引:7
首次合成了直链醚Schiff碱,乙酰丙酮缩二甘醇二胺(ACACDA),并以分步法得到它与稀土元素的九种新配合物:[Ln(ACACDA)~2(NO~3)](NO~3)~2·4H~2O(Ln=La,Pr,Nd,Sm,Gd,Tb,Er,Yb,Y)。以紫外、红外光谱,特别是500MHz的NMR谱表征了配合物,通过其形成机理探讨,证明配合物中配体采取烯胺式构型形成稳定共轭结构。研究了Gd配合物的EPR谱,呈"U"谱特征,并出现"零场效应",据此讨论了配合物中晶体场强度及Gd^3^+周围的局部对称性。 相似文献
60.