Efficient Anion Recognition Property of Three Dimensionally Clustered Amide Groups Organized on a Poly(phenylacetylene) Backbone
Efficient Anion Recognition Property of Three Dimensionally Clustered Amide Groups Organized on a Poly(phenylacetylene) Backbone
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DOI：
10.1021/ma8025892
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发表时间：
2009-03-10
期刊：
影响因子：
5.5
通讯作者：
Kakuchi, Toyoji
中科院分区：
文献类型：
--
作者：
Kakuchi, Ryohei;Nagata, Sachiko;Kakuchi, Toyoji
三维有序的酰胺基团已被证明对使用具有L-亮氨酸和酰胺官能团(聚-PA-亮氨酸)的聚苯乙炔的阴离子客体表现出高度的敏感性。以Rh+(2，5-norbornadiene)[(eta(6)-C6H5)B-(C6H5)(3)](Rh(NbD)BPh_4)为催化剂，N-(4-乙炔基苯乙酰)-L亮氨酸乙酯(PA-Leu)为原料合成了聚PA-Leu。圆二色谱(CD)中的Cotton效应证明了聚PA-Leu具有偏置的螺旋构象。添加的铵盐包括醋酸盐、氟化物、苯甲酸盐、叠氮化物和溴化物(CH3COO-，F-。C6H5COO-、N-3(-)和BR-)加入到聚PA-Leu溶液中，增强了聚PA-Leu的CD反应，表明酰胺基团的阴离子识别引发了聚乙炔螺旋度的变化。聚PA-Leu与CH3COO-发生了有效的阴离子结合，其表观结合常数为1.1×10(3)(mol(-1)·L)。另一方面，包括高氯酸盐(ClO4-)、硝酸盐(NO3-)、氯离子(Cl2-)和碘化物(I-)在内的阴离子对聚PA-Leu的CD和UV谱线基本没有影响。带有反阴离子的聚PA-Leu的CD谱中观察到的客体专一性与客体碱性明显相关。
Three-dimensionally organized amide groups have been demonstrated to show a high sensitivity toward anionic guests using poly(phenylacetylene)s with L-leucine and amide functionalities (poly-PA-Leu). The poly-PA-Leu was prepared from the N-(4-ethynylphenylcarbonyl)-L-leucine ethyl ester (PA-Leu) using Rh+(2,5-norbornadiene)[(eta(6)-C6H5)B-(C6H5)(3)] (Rh(nbd)BPh4) as a catalyst. The biased helical conformation of poly-PA-Leu was demonstrated through Cotton effects in the circular dichroism (CD) spectra. The addition of ammonium salts including acetate, fluoride, benzoate, azide, and bromide (CH3COO-, F-. C6H5COO-, N-3(-), and Br-, respectively) into the poly-PA-Leu solution intensified the CD responses of the poly-PA-Leu, indicative of the polyacetylene helicity changes triggered by anion recognition of the amide groups. The efficient anion binding was observed for poly-PA-Leu with CH3COO-, whose apparent binding constant was estimated to be 1.1 x 10(3) (mol(-1).L). On the other hand, the anions including perchlorate (ClO4-), nitrate (NO3-), chloride (Cl-), and iodide (I-) had essentially no effects on both the CD and UV profiles of poly-PA-Leu. The guest specificity observed in the CD spectra of poly-PA-Leu with counteranions clearly correlated with the guest-basicity.