Department of Chemistry & Biochemistry, Laurentian University, Sudbury, ON P3E 2C6, Canada.
J Org Chem. 2010 Sep 17;75(18):6096-103. doi: 10.1021/jo100722v.
Polythiophenes bearing a specific chiral center such as L-leucine have been prepared via the electrochemical oxidation of a series of L-leucine functionalized oligothiophenes (monothiophenes and terthiophenes). These oligothiophenes have been prepared through the condensation of L-leucine methyl ester and the corresponding thiophene monomers in the presence of hydroxybenzotriazole (HOBt) and N,N'-dicyclohexylcarbodiimide (DCC) followed by hydrolysis of the esters. The electroactive polymers are electrochemically stable and exhibit excellent adhesive properties on electrode surfaces (platinum, gold, and glassy carbon) as well as interesting optical properties in both doped and undoped states. Hydrogen bonds between a free amino acid (L-leucine, D-leucine, L-alanine, D-alanine, and D/L-alanine) and the L-leucine based polythiophenes (chiral conducting surface) were probed using cyclic voltammetry. Preliminary results show that the capacitive current of a modified L-leucine-polythiophene electrode decreases as a result of the formation of a hydrogen bond barrier on the surface of the chiral conducting surface accompanied with a shift of the oxidation potential. Cyclic voltammetry responses resulting from the interaction of the chiral conducting surface with L and Dfree amino acid isomers are similar. The formation of hydrogen bonds between the chiral conducting surfaces and the free amino acids was characterized by (1)H NMR. A chemical shift was observed for the N-H group in monomer 6 as a result of the hydrogen bond formation between the L-leucine methyl ester (D-leucine methyl ester, D/L-leucine methyl ester) and monomer 6.
具有特定手性中心（如 L-亮氨酸）的聚噻吩已通过一系列 L-亮氨酸功能化寡噻吩（单噻吩和三噻吩）的电化学氧化来制备。这些寡噻吩是通过 L-亮氨酸甲酯与相应的噻吩单体在羟基苯并三唑（HOBt）和 N,N'-二环己基碳二亚胺（DCC）存在下缩合，然后酯水解制得。电活性聚合物具有电化学稳定性，在电极表面（铂、金和玻碳）具有优异的粘附性能，以及在掺杂和未掺杂状态下具有有趣的光学性质。使用循环伏安法探测了游离氨基酸（L-亮氨酸、D-亮氨酸、L-丙氨酸、D-丙氨酸和 D/L-丙氨酸）与基于 L-亮氨酸的聚噻吩（手性导电表面）之间的氢键。初步结果表明，由于手性导电表面表面形成氢键障碍，以及氧化电位的移动，修饰后的 L-亮氨酸-聚噻吩电极的电容电流减小。手性导电表面与 L 和 D 游离氨基酸异构体相互作用产生的循环伏安响应相似。通过（1）H NMR 对手性导电表面与游离氨基酸之间形成的氢键进行了表征。单体 6 中的 N-H 基团由于 L-亮氨酸甲酯（D-亮氨酸甲酯，D/L-亮氨酸甲酯）与单体 6 之间形成氢键而发生化学位移。
