Chiral stimuli-responsive gels: Helicity induction in poly(phenylacetylene) gels bearing a carboxyl group with chiral amines
Chiral stimuli-responsive gels: Helicity induction in poly(phenylacetylene) gels bearing a carboxyl group with chiral amines
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DOI：
10.1021/ja029036c
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发表时间：
2003-03-05
影响因子：
15
通讯作者：
Yashima, E
中科院分区：
文献类型：
--
作者：
Goto, H;Zhang, HQ;Yashima, E
聚苯乙炔凝胶带有羧基侧基的凝胶（凝胶-1-H和凝胶-2-H）通过以下物质的共聚来合成：（4-羧基苯基）乙炔（凝胶-1-H）与双（苯乙炔）衍生物作为交联剂，使用铑络合物（[Rh（cod）（2）] BF 4：cod = 1，5-环辛烯）作为催化剂或通过聚[（4-羧基苯基）乙炔]与二胺的交联（凝胶-2-H）。发现所得凝胶在DMSO中溶胀，并在光学活性胺的存在下在主链的长吸收区中表现出诱导圆二色性（ICD）。这些结果表明，一个主要的单手螺旋可以通过手性酸-碱相互作用在凝胶的聚合物网络中诱导。凝胶的溶胀性能和Cotton效应强度取决于交联率和手性胺。分别由凝胶-1-H和凝胶-2-H制备的凝胶-1-Na和凝胶-2-Na在水中也显著溶胀，并显示手性氨基醇和游离氨基酸在水中的ICD特征。
Poly(phenylacetylene) gels (gel-1-H and gel-2-H) bearing a carboxy pendant were synthesized either by the copolymerization of (4-carboxyphenyl)acetylene (gel-1-H) with a bis(phenylacetylene) derivative as the cross-linking reagent using a rhodium complex ([Rh(cod)(2)]BF4: cod = 1,5-cyclooctadiene) as the catalyst or by the cross-linking of poly[(4-carboxyphenyl)acetylene] with diamines (gel-2-H). The obtained gels were found to swell in DMSO and exhibited an induced circular dichroism (ICD) in the long absorption region of the main chain in the presence of optically active amines. These results indicate that a predominantly one-handed helix can be induced in the polymer network of the gels through chiral acid-base interactions. The swelling properties and the Cotton effect intensities of the gels depend on the cross-linking ratio and the chiral amines. Gel-1-Na and gel-2-Na prepared from gel-1-H and gel-2-H, respectively, also significantly swelled in water and showed ICDs characteristic of chiral amino alcohols and free amino acids in water.