1-苯基-3-甲基-4-萘乙酰基-吡唑啉酮-5 (PMNAP)缩2-氨基苯并咪唑(2-AB)席夫碱及其过渡金属配合物的合成、光谱表征与质谱鉴定

在非水溶剂中合成出一种新型席夫碱试剂(H2L): 1-苯基-3-甲基-4-萘乙酰基-吡唑啉酮-5 (PMNAP)缩2-氨基苯并咪唑(2-AB)及其过渡金属铜、铅、镍和钴配合物. 由元素分析、综合滴定和质谱数据推测出配合物的组成为ML•H2O, 通过红外光谱、紫外光谱、热重谱和核磁共振氢谱对配体和配合物进行了结构表征, 同时建立了合成体系的液相色谱分离和质谱鉴定方法, 在线得到了配体共存的三种异构体和目标配合物及其相应的质谱信息. 综合各种分析结果显示: 配体在测试条件下以酮式和烯醇式结构共存, 配位时酮式可能转化为烯醇式结构, 按去质子的方式以吡唑啉酮环羟基和H2O上的两个O原子以及亚胺基上的N原子和苯并咪唑环上的含氢N原子与中心离子成键, 配合物的配位数为4.

Synthesis, Characterization by Spectra and Identification by HPLC- MS of Schiff Base Derived from 1-Phenyl-3-methyl-4-naphthyl- aceto-4,5-dihydropyrazol-5-one (PMNAP) and 2-Aminobenz- imidazole (2-AB) and Its Transitional Metal Complexes

A novel Schiff base (H2L) derived from 1-phenyl-3-methyl-4-naphthylaceto-4,5-dihydropyra- zol-5-one (PMNAP) and 2-aminobenzimidazole (2-AB), and its copper, lead, nickel and cobalt complexes have been synthesized in the nonaqueous solvent. The formula of the four complexes was confirmed to be ML•H2O based on the elemental analysis, complexometric titration and mass spectral data. Their molecular structures were characterized by IR, UV, TG and 1H NMR. Moreover, an analytical method of the synthetic system of complexes by HPLC-MS was developed and three coexisting isomers of the ligand and its complexes and their corresponding MS data were observed on line. The integrated analytical results show that the novel ligand coexists in ketoform and enolform structures under the measuring conditions, the ketoform structure may change into the enolform structure during the coordination and bonds with the central ion by two O atoms of the enolized hydroxyl group of pyrazolone ring and H2O and the N atom of the imine group and the N atom containing H of benzimidazole ring by losing the proton. And the coordination number of these complexes is four.