TTABr 미셀 용액속에서 2-알킬벤즈이미다졸 음이온에 의해 추진되는 디페닐-4-니트로페닐 포스페네이트(DPNPIN)의 탈인산화반응

Abstract

This study is mainly focused on micellar effect of tetradecyltrimethyl ammonium bromide(TTABr) solution including alkylbenzimidazole(R-BI) on dephosphorylation of diphenyl-4-nitrophenylphosphinate(DPNPIN) in carbonate buffer(pH 10.7). Dephosphorylation of DPNPIN is accelerated by <TEX>$BI^{\Theta}$</TEX> ion in <TEX>$10^2$</TEX> M Carbonate buffer(pH 10.7) of <TEX>$4{\times}10^{-4}$</TEX> M TTABr solution up to 80 times as compared with the reaction in Carbonate buffer by no benzimidazole(BI) solution of TTABr. The value of pseudo first order rate constant(<TEX>$k_{\psi}$</TEX>) of the reaction in TTABr solution reached a maximum rate constant increasing micelle concentration. The reaction mediated by <TEX>$R-BI^{\Theta}$</TEX> in micellar solutions are obviously slower than those by <TEX>$BI^{\Theta}$</TEX>, and the reaction rate were decreased with increase of lengths of alkyl groups. It seems due to steric effect of alkyl groups of <TEX>$R-BI^{\Theta}$</TEX> in Stern layer of micellar solution. The surfactant reagent, TTABr, strongly catalyzes the reaction of DPNPIN with R-BI and its anion(<TEX>$R-BI^{\Theta}$</TEX>) in Carbonate buffer(pH 10.7). For example, <TEX>$4{\times}10^{-4}$</TEX> M TTABr in <TEX>$1{\times}10^{-4}$</TEX> M BI solution increase the rate constant(<TEX>$k_{\psi}=99.7{\times}10^{-4}1/sec$</TEX>) of the dephosphorylation by a factor ca. 28, when compared with reaction(<TEX>$k_{\psi}=3.5{\times}10^{-4}1/sec$</TEX>) in BI solution(without TTABr). And no TTABr solution, in BI solution increase the rate constant(<TEX>$k_{\psi}=3.5{\times}10^{-4}1/sec$</TEX>) of the dephosphorylation by a factor ca. 39, when compared with reaction (<TEX>$k_{\psi}=1.0{\times}10^{-5}1/sec$</TEX>) in water solution(without BI).