酚醛基质苯并咪唑螯合树脂的合成及配位性能

通过1,4-对苯二酚二缩水甘油醚和2,2′-二苯并咪唑二乙胺反应合成四苯并咪唑单体(TBMZ)，经甲醛等缩合生成酚醛聚合物为基质的苯并咪唑螯合树脂(PTBMZs)。 新型螯合树脂配基含量达2.1~3.02 mmol/g。新树脂及其单体结构经13C核磁共振谱、FT-IR红外光谱、元素分析和DSC分析确证。 测定了Cu2+、Ni2+、Zn2+、Cd2+和Co2+氯化物在pH值为1.0~6.0的缓冲溶液中的配位容量。 实验结果表明，该类螯合树脂对Cu2+有高度的选择性，KCuX≥4.3非竞争条件下，PTBMZ-1的最大配位容量为1.15 mmol/g(pH=5.0，Cu2+)，PTBMZ-2的最大配位容量为0.97 mmol/g(pH=5.0，Cu2+)，配基占有率分别为35.9%，33.4%。 PTBMZ-1树脂对Cu2+吸附较快，t1/2=21 min。 电子顺磁共振谱和FT-IR光谱分析结果表明，形成n(金属离子)∶n(配基)=1∶2的螯合物为主。

Synthesis,Characterization and Adsorption toward Divalent-ions of Bisbenzimidazole Supported on Phenol-formaldehyde

A couple of new benzimidazole chelating resins,bisbenzimidazole supported on phenol-formaldehyde(PTBMZs),were synthesized by phenolformaldehyde condensation of tetrabenzimidazole ligand.The PTBMZs have a 2.06~3.02 mmol of ligand content per gram of the resin.Their structures were characterized by solid-state 13C crossing-polarization and magic-angle spinning(CP MAS) NMR,FT-IR spectroscopy.Batch adsorption capacities were determined for the chloride of some divalent metal cations in buffer solutions in the pH rang of 1.0 to 6.0.The adsorption capacities of the PTBMZ-1 under non-competitive condition are 1.15 mmol/g for Cu2+ at pH=5 and the ligand occupations are 35.7%.Elemental analysis and electron paramagnetic resonance(EPR) studies suggested that complexes with the metal cation to ligand ratio of mainly 1∶ 2 were formed on the BBEAH modified resins via tridentate chalete structure.