Post-polymerization functionalization approach for highly water-soluble well-defined regioregular head-to-tall glycopolythiophenes
Post-polymerization functionalization approach for highly water-soluble well-defined regioregular head-to-tall glycopolythiophenes
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DOI：
10.1021/ma070927k
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发表时间：
2007-09-18
期刊：
影响因子：
5.5
通讯作者：
Liu, Haiying
中科院分区：
文献类型：
--
作者：
Xue, Cuihua;Luo, Fen-Tair;Liu, Haiying
以2,5-二溴-3-溴己基噻吩(2)和2,5-二溴-3-（1,1 -溴-3,6,9-三氧-1-十一氧基）噻吩(7)为原料，采用格氏复分解法制备了两个含溴区域规则型首尾聚噻吩（聚合物1和3）。采用聚合后功能化的方法，分别用1-巯基- α -d -甘露糖四乙酸酯（3a）或1-巯基- β -d -葡萄糖四乙酸酯（3b）在THF溶液中以基本条件处理含溴的聚噻吩，然后在室温下用含甲氧基钠的甲醇和二氯甲烷在Zemplen条件下进行顺序脱乙酰化，制备出具有良好定义的区域规则的头-尾聚噻吩。在聚合物骨架和碳水化合物残基之间以亲水性四（乙二醇）作为系留间隔剂的共聚噻吩（聚合物C和D）具有高水溶性，而以疏水性己基系留间隔剂的共聚噻吩（聚合物A和B）完全不溶于水。所有多噻吩均显示低荧光，荧光量子产率在0.4% ~ 3%之间。而水溶性聚合物C和D在0.1 M磷酸盐缓冲液（pH 7.2）中的荧光强度略高于其前体聚合物3在氯仿溶液中的荧光强度。A -甘露糖基共聚物噻吩（聚合物C）通过多价相互作用与豆豆蛋白A特异性结合，结合常数为2.15 x 10(5)。
Two bromide-bearing regioregular head-to-tail polythiophenes (polymers 1 and 3) were prepared by using Grignard metathesis method to polymerize 2,5-dibromo-3-bromohexylthiophene (2) and 2,5-dibromo3-(1 1-bromo-3,6,9-trioxa-1-undecoxy)thiophene (7), respectively. Well-defined regioregular head-to-tail glycopolythiophenes were prepared through post-polymerization functionalization approach by treating the bromide-bearing polythiophenes with 1-thiolethyl-alpha-D-mannose tetraacetate (3a) or 1-thiol-beta-D-glucose tetraacetrate (3b) in THF solution with a basic condition, respectively, and followed by sequential deacetylation under Zemplen conditions in methanol and methylene chloride containing sodium methoxide at room temperature. Glycopolythiophenes (polymers C and D) with hydrophilic tetra(ethylene glycol) as tethered spacers between the polymer backbone and carbohydrate residues are highly water-soluble while glycopolythiophenes (polymers A and B) with hydrophobic hexyl tethered spacers are completely insoluble in water. All polythiophenes display low fluorescence with fluorescent quantum yield ranging from 0.4% to 3%. However, water-soluble polymers C and D in 0.1 M phosphate buffer (pH 7.2) show a little higher fluorescent intensity than their precursor polymer 3 in chloroform solution. a-Mannose-bearing glycopolythiophene (polymer C) exhibits specific binding to Concanavalin A through multivalent interactions with a binding constant of 2.15 x 10(5).