College of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400044, China.
J Fluoresc. 2010 Jan;20(1):353-64. doi: 10.1007/s10895-009-0564-x. Epub 2009 Dec 2.
Suitable chemical strategy is a useful approach on the tuning color and photoluminescence of organic dyes. This paper presented tuning novel branched p-nitro-stilbene derivatives efficiently with a new chemical strategy through variation of chemical bridged bond. Linking bonds played significant effects on the absorption and fluorescence spectroscopy of the branched p-nitro-stilbene derivatives. A change from "D-pi-A" to "A-pi-A" chemical structural characteristics occurred for the branched p-nitro-stilbene derivatives as ester bond was attached. This led to not only large hypsochromic shift of the maximal absorption wavelength of the branched p-nitro-stilbene derivatives, but considerable reduction of the fluorescence intensity. While in contrast, the branched p-nitro-stilbene derivatives with ether bond exhibited longer wavelength absorption and much stronger fluorescence emission in modest polar solvent. The cyclic voltammograms of these branched p-nitro-stilbene derivatives were determined. Different electrochemistry processes were observed for the branched p-nitro-stilbene derivatives with various linking bonds. The energies of frontier orbital of the branched p-nitro-stilbene derivatives were estimated from their corresponding redox potentials. Molecular geometry optimization of the branched p-nitro-stilbene derivatives was performed, and the electron density distribution of frontier orbital was analyzed. Thermal stabilities of these branched nitro-stilbene derivatives were investigated via the analysis of the differential scanning calorimetry (DSC) and thermograving (TGA) curves. This paper presented strong evidences that the absorption and fluorescence spectroscopy of the branched stilbene derivatives could be mediated efficiently by chemical strategy.
合适的化学策略是调节有机染料颜色和光致发光的有效方法。本文通过改变化学桥键，提出了一种有效调节新型支化对硝基二苯乙烯衍生物的新化学策略。连接键对支化对硝基二苯乙烯衍生物的吸收和荧光光谱有显著影响。当酯键连接时，支化对硝基二苯乙烯衍生物的化学结构特征从“D-π-A”变为“A-π-A”，这不仅导致支化对硝基二苯乙烯衍生物的最大吸收波长发生显著红移，而且荧光强度显著降低。相比之下，支化对硝基二苯乙烯衍生物具有醚键，在中等极性溶剂中表现出更长的吸收波长和更强的荧光发射。这些支化对硝基二苯乙烯衍生物的循环伏安法被确定。具有不同连接键的支化对硝基二苯乙烯衍生物观察到不同的电化学过程。通过相应的氧化还原电位，估算了支化对硝基二苯乙烯衍生物的前沿轨道能。对支化对硝基二苯乙烯衍生物进行了分子几何优化，并分析了前线轨道的电子密度分布。通过差示扫描量热法（DSC）和热重（TGA）曲线分析研究了这些支化硝基二苯乙烯衍生物的热稳定性。本文提供了强有力的证据表明，通过化学策略可以有效地调节支化二苯乙烯衍生物的吸收和荧光光谱。
