Department of Dyestuff Technology, Institute of Chemical Technology, Matunga, Mumbai 400 019, India.
Department of Dyestuff Technology, Institute of Chemical Technology, Matunga, Mumbai 400 019, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2018 Oct 5;203:244-257. doi: 10.1016/j.saa.2018.05.101. Epub 2018 May 29.
Donor-π-Acceptor (D-π-A) compounds comprising of benzo[b]thiophen-3(2H)-one 1,1-dioxide (BTD) as acceptor with dibenzofuran, carbazole, triphenylamine, and N-methyl diphenylamine moieties as donors were synthesized for aggregation, viscosity induced emission enhancement and nonlinear optical studies. Compounds 3a-3d exhibited solid state emission. The compounds 3a-3d are viscosity sensitive in a solution of MeOH: PEG-400 and showed 10, 23, 14, and 25 fold viscosity induced enhanced emission. The compounds 3a, 3c, and 3d are aggregation-induced emission enhancement (AIEE) active while 3b quenches the fluorescence on aggregation. The quantum yield of 3a, 3c, and 3d in acetonitrile are 0.041, 0.002 and 0.002 which are enhanced in the aggregate state to 0.31, 0.009, and 0.22 respectively. Solvent-dependent parameters like dipole moment (μ), static polarizability (α), and hyperpolarizability (β and γ) were determined spectroscopically and using Density Functional Theory (DFT) calculations. First and second order hyperpolarizability increase as donor strength increases and the trend is found as 3a < 3b < 3c < 3d. Two-photon absorption (2PA) cross sections were calculated by the spectroscopic method, and large 2PA was observed 484.39 GM for compound 3c.
包含苯并[b]噻吩-3(2H)-1,1-二氧化物（BTD）作为受体，二苯并呋喃、咔唑、三苯胺和 N-甲基二苯胺部分作为供体的给体-π-受体（D-π-A）化合物被合成用于聚集、粘度诱导发射增强和非线性光学研究。化合物 3a-3d 表现出固态发射。化合物 3a-3d 在 MeOH:PEG-400 溶液中对粘度敏感，并显示出 10、23、14 和 25 倍的粘度诱导增强发射。化合物 3a、3c 和 3d 是聚集诱导发射增强（AIEE）活性的，而 3b 在聚集时会猝灭荧光。化合物 3a、3c 和 3d 在乙腈中的量子产率分别为 0.041、0.002 和 0.002，在聚集态下分别增强到 0.31、0.009 和 0.22。通过光谱和密度泛函理论（DFT）计算确定了溶剂依赖性参数，如偶极矩（μ）、静态极化率（α）和超极化率（β 和 γ）。第一和二阶超极化率随着供体强度的增加而增加，趋势为 3a < 3b < 3c < 3d。通过光谱法计算了双光子吸收（2PA）截面，观察到化合物 3c 的 2PA 截面较大，为 484.39 GM。
