In this work, a new series of triphenylamine-based diketo-pyrrolo-pyrrole (DPP) compounds (DPP-I, DPP-II, DPP-III) have been designed and synthesized by a concise route. Their one- and two-photon absorption properties have been investigated. It was found that DPP-based compounds are very weakly fluorescent in THF solution, but their intensities are increased by almost 29, 9, and 24 times in water/THF (v/v 90 %) mixtures, respectively, in which they exhibit a strongly enhanced red fluorescence. The result indicates that the intramolecular vibration and rotation of these dyes is considerably restricted in nano-aggregates formed in water/THF mixtures, which leads to significant increases in fluorescence. The two-photon absorption (2PA) cross-sections measured by the open aperture Z-scan technique were determined to be 188, 275 and 447 GM for DPP-I, DPP-II, and DPP-III, respectively; DPP-III with the symmetrical structure shows the highest value of 2PA cross-section. The excellent properties of aggregation-induced emission (AIE) and 2PA provide an attractive alternative for the biophotonic materials.
在这项工作中,采用简洁的路线设计并合成了一系列新的
三苯胺基二酮
吡咯(
DPP)化合物(
DPP-I、
DPP-II、
DPP-III)。研究了它们的单光子和双光子吸收特性。研究发现,基于
DPP 的化合物在 THF 溶液中的荧光很弱,但在
水/THF(v/v 90 %)混合物中,它们的荧光强度分别增加了近 29 倍、9 倍和 24 倍,其中红色荧光强烈增强。结果表明,在
水/THF 混合物中形成的纳米聚集体中,这些
染料的分子内振动和旋转受到很大限制,从而导致荧光显著增强。通过开孔 Z 扫描技术测定的
DPP-I、
DPP-II 和
DPP-III 的双光子吸收(2PA)截面分别为 188、275 和 447 GM,其中对称结构的
DPP-III 的 2PA 截面值最高。聚集诱导发射(AIE)和 2PA 的优异特性为
生物光子材料提供了一种极具吸引力的选择。