最新热点
联系我们
张文彬课题组
地址:北京市海淀区成府路202号
北京大学化学与分子工程学院
邮编:100871
电话:010-62766876
电邮:wenbin@pku.edu.cn
请扫以上二维码关注我们课题组的公众号。
我们将定期推送组会每周精读和泛读文献介绍以及课题组的最近新闻!
--------------------------------------------
新闻中心
See http://pubs.rsc.org/EN/content/articlelanding/2017/ra/c6ra28147h#!divAbstract
Shao, Y.; Yin, G.-Z.; Ren, X.; Zhang, X.; Wang, J.; Guo, K.; Li, X.; Wesdemiotis, C.; Zhang, W.-B.; Zhu, M.;* Sun, B.* Engineering π-π Interactions for Enhanced Photoluminescent Properties: Unique Discrete Dimeric Packing of Perylene Diimides. RSC Adv. 2017, 7, 6530-6537.
Abstract
This article reports the enhanced photoluminescent properties observed in the crystals of a cube-plane-cube shape amphiphile composed of perylene diimide (PDI) tethered with polyhedral oligomeric silsesquioxanes (POSS) at the imide position via either rigid or flexible linkages (POSS-PDI-POSS). The fluorescence quantum yields (Φf) of the conjugates in crystal (∼0.48) are much higher than that of the more amorphous samples (∼0.17) and that of the reference compound without pendant POSS cage (∼0.12). The enhancement was understood in three ways. First, their self-assembly behaviors in gaseous phase were studied by tandem mass spectrometry coupled with traveling wave ion mobility separation; second, their self-assembly behaviors in solution were revealed by concentration- and solvent-dependent experiments using UV/vis absorption and fluorescence spectrometry; and third, the molecular packing in crystals was determined by wide angle X-ray diffraction and transmission electron microscope. The results demonstrate the conjugates' strong tendency toward dimer formation in solution and show a unique molecular packing of discrete dimeric motifs in the solid states. It suggests that the high Φf of these conjugates can be attributed to the discontinuous π–π stacking, which results in a weaker electron interaction between the dimers, and the relatively fixed position of the PDI, which prohibits the common structural relaxation of PDIs π-planes.
上一篇: Polymer 文章上线!