1-苯基-3-甲基-4-苯甲酰吡唑啉酮-5萃取镓的研究

首次报道了1-苯基-3-甲基-4-苯甲酰吡唑啉酮-5(HPMBP)萃取镓的热力学和动力学, 指出在体系中形成Ga(PMBP)3(H2O)2萃合物, 配体PMBP既有一次溶剂化作用, 又有二次溶剂化作用, 并得到红外光谱和核磁共振谱的证实。镓的萃取过程为水相化学反应控制, 决速步骤为一次溶剂化过程: Ga^3^++HPMBP→Ga(PMBP)^2^++H^+。添加剂三辛基氧化膦(TOPO)不影响HPMBP萃取镓的分配比, 但降低了HPMBP萃取镓的正向速率, 表明动力学抑萃作用与热力学抑萃作用无对应关系。

Extraction of gallium(III) with HPMBP

The extraction equilibrium and kinetics of galium(III) from hydrochloric acid solutions with 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5-(HPMBP) in carbon tetrachloride have been investigated. The composition of the extracted species was found to be Ga(PMBP)3.2H2O via the method of slopes, IR and NMR spectra. The values of Kex, ΔH ⅲ, ΔGⅲ and ΔSⅲ at 298K were calculated. The extraction kinetics of Ga(III) was studied with the growing drop method. The extraction rate equation can be expressed as Rf=kf[Ga^3^+][HL](o). The activation energy of the reaction was calculated to be 15.9kJ.mol^-^1. The rate determing step was deduced to take place in water phase: Ga^3^++HL→ GaL^2^++H^+, which is an immediate coordination process.