Water-soluble perylene diimides: Solution photophysics and layer-by-layer incorporation into polyelectrolyte films.
Water-soluble perylene diimides: Solution photophysics and layer-by-layer incorporation into polyelectrolyte films.
复制标题
水溶性苝二酰亚胺：溶液光物理学和逐层纳入聚电解质薄膜。
作者：
Tingji Tang;J. Qu;K. Müllen;S. Webber
最近，已经报道了水溶性荧光苝二酰亚胺的合成（Müllen, K.；等人 Angew. Chem., Int. Ed. 2004, 43, 1528；Chem.-Eur. J. 2004, 10, 5297）。我们表征了其中两种化合物（阴离子 n-PDI，CAS 注册号 694438-88-5 和阳离子 p-PDI，CAS 注册号 817207-4-7）在纯水、二甲基亚砜 (DMSO) 和 NaCl 水溶液中的光物理特性。这些研究在分子动力学模拟的支持下得出的结论是，这些化合物在纯水中形成弱相互作用的聚集物种。 n-PDI 和 p-PDI 已按照逐层 (LBL) 方法纳入聚苯乙烯磺酸盐 (PSS) 和聚二烯丙基二甲基氯化铵 (PDAC) 的聚电解质膜中。 PDI-LBL薄膜的光密度和荧光强度随着层数线性增长，并且PDI不会被随后的聚电解质沉积提取。这些薄膜中的 PDI 荧光量子产率大幅降低，我们将其解释为自猝灭效应，通过层间和层内能量转移而增强。对掺入的阳离子染料亮绿 (BG) 的能量转移研究表明，BG 与 p-PDI 位于同一富含 PSS 的区域，并且很大程度上被排除在含有 n-PDI（富含 PDAC）的区域之外。
Recently the synthesis of water-soluble and fluorescent perylene diimides has been reported (Müllen, K.; et al. Angew. Chem., Int. Ed. 2004, 43, 1528; Chem.-Eur. J. 2004, 10, 5297). We have characterized the photophysics of two of these compounds (anionic n-PDI, CAS Reg. No. 694438-88-5. and cationic p-PDI, CAS Reg. No. 817207-4-7) in pure water, dimethyl sulfoxide (DMSO), and aqueous NaCl. These studies, supported by molecular dynamics simulations, have led to the conclusion that these compounds form weakly interacting aggregated species in pure water. n-PDI and p-PDI have been incorporated in polyelectrolyte films of poly(styrene sulfonate) (PSS) and poly(diallyldimethylammonium chloride) (PDAC) following the layer-by-layer (LBL) methodology. The optical density and fluorescence intensity of the PDI-LBL films grew linearly with the number of layers, and the PDI was not extracted by subsequent polyelectrolyte deposition. The PDI fluorescence quantum yield was substantially diminished in these films, which we interpret as a self-quenching effect, enhanced by inter- and intralayer energy transfer. Energy-transfer studies to the incorporated cationic dye Brilliant Green (BG) has demonstrated that the BG resides in the same PSS-rich region as p-PDI and is largely excluded from the region that contains n-PDI (PDAC-rich).