Novel self-protective phosphorescence from crystalline nanoparticles assembled by 3-bromo- and 3-iodo-carbazoles based on halogen-halogen interaction in suspension solutions.
Novel self-protective phosphorescence from crystalline nanoparticles assembled by 3-bromo- and 3-iodo-carbazoles based on halogen-halogen interaction in suspension solutions.
复制标题
DOI：
10.1016/j.aca.2006.05.050
复制
发表时间：
2006-07
影响因子：
6.2
通讯作者：
W. Liang;Yu Wang;Feng Feng-Feng;W. Jin
中科院分区：
文献类型：
--
作者：
W. Liang;Yu Wang;Feng Feng-Feng;W. Jin
基于悬浮水溶液中卤素-卤素相互作用，3-溴-和3-碘-咔唑（3-BrC和3-IC）可以组装成晶体纳米颗粒。当胶体状悬浮液滴入薄膜时，颗粒进一步聚集成长3μm、宽1μm的棒状结构。单晶x射线数据很好地证明了卤素-卤素相互作用，数据表明每个溴原子与相邻的两个原子相互作用，每个碘原子与相邻的五个原子相互作用，并且I-I相互作用比Br-Br相互作用强。在338nm激发下，3-BrC和3-IC都能在480 ~ 800nm范围内发出新的自保护室温磷光（RTP）， 3-BrC在350 ~ 480nm范围内还表现出延迟的荧光发射，两者都具有卤化引起的电荷转移特征。RTP衰变具有双指数性质，3-BrC的RTP寿命分别为3.37、31.16ms（含乙醇）和1.52、30.83ms（含THF）， 3-IC的RTP寿命分别为3.53、14.95ms（含乙醇）和1.68ms、13.74ms（含THF），显示出“重原子”I，使得从s1到t1和t1到s1的系统间交叉速率更快。结果表明，3-BrC和3-IC的检出限分别可达2.4×10−7和9.0×10−8molL−1，与其他体系相比具有更宽的线性范围和更高的精度。
The crystalline nanoparticles can be assembled by 3-bromo- and 3-iodo-carbazole (3-BrC and 3-IC) based on the halogen–halogen interaction in suspension aqueous solutions. As the colloid-like suspension was dropped onto film the particles further aggregate as rod-like structures with size of 3μm in length and 1μm in width. The halogen–halogen interaction are well proved by single crystal X-ray data, and the data reveal that each bromine atom interacts with the neighboring two, and each iodine atom interacts with the neighboring five and I–I interaction is stronger than that of Br–Br. Both 3-BrC and 3-IC can emit novel self-protective room temperature phosphorescence (RTP) in the range of 480 to near 800nm at the excitation of 338nm, and 3-BrC shows additionally the delayed fluorescence emission from 350 to 480nm, both possessing the charge-transfer character caused by halogenations. RTP decay possesses the bi-exponential property and RTP lifetimes are 3.37, 31.16ms (with ethanol) and 1.52, 30.83ms (with THF) for 3-BrC or 3.53, 14.95ms (with ethanol) and 1.68ms, 13.74ms (with THF) for 3-IC, showing “ heavier atom ”, I, makes intersystem crossing rate kISCfrom both S1to T1and T1to S0faster. For the results, the detection limits of 3-BrC and 3-IC can reach 2.4×10−7and 9.0×10−8molL−1, respectively, with wider linear range and higher precision compared with other systems.