荧光标记磺酸基强聚电解质的合成

Syntheses of Pyrenyl and Dansyl Labeled Strong Polyelectrolytes with Sulfonate Groups

为了考察聚电解质溶剂化层的变化 ,合成了发色团分别为 5_(N ,N_二甲胺基 )_1_萘磺酰基 (dansyl)和芘 (pyrenyl)基的两种单体 .将它们分别与 2_丙烯酰胺基_2_甲基丙磺酸 (AMPS)、N ,N_二甲基丙烯酰胺 (DMAA)共聚 ,得到了dansyl单体摩尔分数为 0 .0 0 2或 pyrenyl单体摩尔分数为 0 .0 0 1、AMPS摩尔分数为 0 .0 3～ 0 .90的两个系列的荧光标记强聚电解质 .水溶液的荧光光谱表明 :dansyl标记大分子的荧光最大峰位置 λem为 533nm ,比dansyl单体蓝移约 9nm ;pyrenyl标记的聚电解质的第一发射峰与第三发射峰强度比I1/I3为 1.54,小于芘单体的 1.88.说明大分子疏水骨架的存在 。

Dansyl monomer N_[2_[[[5_(N,N_dimethylamino)_1_naphthalenyl]sulfonyl]amino]ethyl]_2_propenamide (DANSAEP) and pyrenyl monomer N_(1_pyrenylmethyl)methacrylamide (PyMA) were prepared as fluorescent labels. Labeled strong polyelectrolytes were synthesized by copolymerization of 2_acrylamido_2_methylpropane sulfonic acid (AMPS) and dimethyl acrylamide (DMAA) with DANSAEP of mole fraction of 0.002 in water or with PyMA of mole fraction of 0.001 in H 2O/DMSO (3/2 in volume), respectively. Mole fraction of AMPS monomer in copolymer varied from 0.03 to 0.90. The fluorescence spectra in aqueous solution showed a blue_shift of 9 nm for dansylated polyelectrolytes compared with DANSAEP and a decrease in the relative intensity I 1/I 3 of the first to third emission bands for pyrenyl polyelectrolytes to 1.54 from 1.88 for PyMA. These results indicate that the hydrophobicity of macromolecular backbone reduce the polarity surrounding the labeled chromophores even with strong polyelectrolytes.