Department of Chemistry, University of Alabama, 201 Chemistry Building, 901 14th Street South, Birmingham, Alabama 35294-1240, United States.
Inorg Chem. 2012 Feb 20;51(4):2016-30. doi: 10.1021/ic201309k. Epub 2012 Feb 9.
A series of bithiophene derivatives that are either symmetrically disubstituted with two Ph(2)(X)P groups (X = O, S, Se) or monosubstituted with one Ph(2)(X)P group (X = O, S, Se) and an organic functional group (H, CHO, CH(2)OH, CO(2)Me) have been synthesized. The X-ray crystal structures of Ph(2)(Se)P(C(4)H(2)S)(2)P(Se)Ph(2), Ph(2)(O)P(C(4)H(2)S)(2)H, Ph(2)(S)P(C(4)H(2)S)(2)H, and Ph(2)(O)P(C(4)H(2)S)(2)CH(2)OH exhibit very different solid-state structures depending on the type of intermolecular π-π interactions that occur. The compounds have been characterized by electronic absorption and fluorescence studies. Of particular interest is that the quantum yields of Ph(2)(O)P(C(4)H(2)S)(2)H, Ph(2)(O)P(C(4)H(2)S)(2)P(O)Ph(2), Ph(2)(O)P(C(4)H(2)S)(2)CO(2)Me, and Ph(2)(O)P(C(4)H(2)S)(2)CH(2)OH are significantly larger than that of bithiophene (factors of 13, 14, 14, and 22, respectively). This behavior is quite different from that of analogously substituted terthiophenes in which substitution results in only modest increases in the quantum yields over that of terthiophene (factors of 0.94, 2.7, 1.3, and 1.5, respectively). DFT studies of the emission process suggest that modifying the Ph(2)(X)P group affects both the fluorescence and nonradiative rate constants while modifications of the organic substituents primarily affect the nonradiative rate constants. The higher quantum yields of the substituted bithiophenes make them promising for application in organic light-emitting devices (OLED). The optical power limiting (OPL) performances of these Ph(2)(X)P-substituted bithiophenes were evaluated by nonlinear transmission measurements in the violet-blue spectral region (430-480 nm) with picosecond laser pulses. The OPL performances are enhanced by heavier X groups and when by higher solubilities. Saturated chloroform solutions of Ph(2)(O)P(C(4)H(2)S)(2)H and Ph(2)(S)P(C(4)H(2)S)(2)H exhibit significantly stronger nonlinear absorption than any previously reported compounds and are promising candidates for use in broadband optical power limiters.
一系列的噻吩衍生物，其要么是对称取代有两个 Ph(2)(X)P 基团（X = O，S，Se），要么是单取代有一个 Ph(2)(X)P 基团（X = O，S，Se）和一个有机官能团（H，CHO，CH(2)OH，CO(2)Me）。这些噻吩衍生物的 X 射线晶体结构为 Ph(2)(Se)P(C(4)H(2)S)(2)P(Se)Ph(2)，Ph(2)(O)P(C(4)H(2)S)(2)H，Ph(2)(S)P(C(4)H(2)S)(2)H 和 Ph(2)(O)P(C(4)H(2)S)(2)CH(2)OH，它们根据发生的分子间π-π相互作用的类型表现出非常不同的固态结构。这些化合物通过电子吸收和荧光研究进行了表征。特别值得注意的是，Ph(2)(O)P(C(4)H(2)S)(2)H，Ph(2)(O)P(C(4)H(2)S)(2)P(O)Ph(2)，Ph(2)(O)P(C(4)H(2)S)(2)CO(2)Me 和 Ph(2)(O)P(C(4)H(2)S)(2)CH(2)OH 的量子产率明显大于噻吩（分别为 13，14，14 和 22 倍）。这种行为与类似取代的三联噻吩明显不同，其中取代只会使量子产率相对于三联噻吩略有增加（分别为 0.94，2.7，1.3 和 1.5 倍）。发射过程的 DFT 研究表明，修饰 Ph(2)(X)P 基团会同时影响荧光和非辐射速率常数，而修饰有机取代基主要会影响非辐射速率常数。取代的噻吩的更高量子产率使它们有望在有机发光器件（OLED）中得到应用。通过皮秒激光脉冲在紫-蓝光谱区域（430-480nm）进行非线性传输测量，评估了这些 Ph(2)(X)P 取代的噻吩的光学限幅（OPL）性能。较重的 X 基团和更高的溶解度会增强 OPL 性能。饱和的 Ph(2)(O)P(C(4)H(2)S)(2)H 和 Ph(2)(S)P(C(4)H(2)S)(2)H 的氯仿溶液表现出比以前报道的任何化合物都要强的非线性吸收，是宽带光学限幅器的有前途的候选材料。
