• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >Resolution of three fluorescence components in the spectra of all-trans-1,6-diphenyl-1,3,5-hexatriene under isopolarizability conditions
【24h】

Resolution of three fluorescence components in the spectra of all-trans-1,6-diphenyl-1,3,5-hexatriene under isopolarizability conditions

机译：等极化性条件下全反式1,6-二苯基-1,3,5-己三烯光谱中三种荧光成分的拆分

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

all-trans-1,6-Diphenyl-1.3.5-hexatriene (DPH) fluorescence in solution consists of emissions from the S-1 (2(1)A(g)) and S-2(1(1)B(u)) states of the s-trans,s-trans conformer (s-t-DPH) and emission from the S-1 state of the s-cis,s- trans conformer (s-c-DPH). The contribution of s-c-DPH fluorescence increases upon excitation at longer wavelengths. and both minor emissions, s-c-DPH and 1(1)B(u), s-t-DPH fluorescence. contribute more at higher temperatures (Ts). Resolution of a spectrothermal matrix of DPH fluorescence spectra by principal component analysis with self-modeling (PCA-SM) is hampered by T-dependent changes in the spectra of the individual components. We avoided differential polarizability-dependent spectral shifts by measuring the spectra in n-alkanes (C-u, C-8 to C-16 with n even) at T values selected to keep the index of refraction constant, hence under isopolarizability conditions. Compensation of the spectra for T-induced broadening allowed resolution of the spectral matrix into its three components. The optimum van't Hoff plot gives DeltaH = 2.83 kcal/mol for s-c-DPH/s-t-DPH equilibration, somewhat smaller than the 3.4 kcal/mol calculated value. and the optimum Boltzmann distribution law plot gives DeltaE(ab) = 4.09 kcal/mol for 1(1)B(u)/2(1)A(g) equilibration. The 1(1)B(u) fluorescence spectrum bears mirror-image symmetry with the DPH absorption spectrum. and the energy gap. 14431 cm(-1), is consistent with the 1615 cm(-1) difference between the lowest energy bands in the 1(1)B(u) and 2(1)A(g) fluorescence spectra. The results Live V-ab = 198 +/- 12 cm(-1) for the vibronic matrix coupling element between the 2(1)A(g) and 1(1)B(u) states. Fluorescence quantum yields and lifetimes under isopolarizability conditions reveal an increase in the effective radiative rate constant of s-t-DPH with increasing T.
机译：溶液中的全反式1,6-二苯基-1.3.5-己三烯（DPH）荧光由S-1（2（1）A（g））和S-2（1（1）B（ u））s-反式，s-反式构象异构体（st-DPH）的状态，以及s-顺式，s-反式构象异构体（sc-DPH）的S-1态发射。 s-c-DPH荧光的贡献随着在更长波长下的激发而增加。以及次要发射，s-c-DPH和1（1）B（u），s-t-DPH荧光。在较高温度（Ts）下贡献更大。通过具有自建模的主成分分析（PCA-SM）来解析DPH荧光光谱的热光谱矩阵受到各个成分光谱中T依赖变化的阻碍。我们通过测量正构烷烃（C-u，C-8至C-16，n为偶数）中的光谱，选择T值以保持折射率恒定，从而避免了极化率依赖于差分偏振的变化，因此在等极化率条件下。 T引起的光谱的光谱补偿可以将光谱矩阵分解为三个分量。对于s-c-DPH / s-t-DPH平衡，最佳van't Hoff曲线给出DeltaH = 2.83 kcal / mol，比3.4 kcal / mol的计算值小一些。对于1（1）B（u）/ 2（1）A（g）平衡，最佳Boltzmann分布规律图给出DeltaE（ab）= 4.09 kcal / mol。 1（1）B（u）荧光光谱与DPH吸收光谱具有镜像对称性。和能隙。 14431 cm（-1）与1（1）B（u）和2（1）A（g）荧光光谱中最低能带之间的1615 cm（-1）差异一致。振动矩阵耦合元件在2（1）A（g）和1（1）B（u）状态之间的结果Live V-ab = 198 +/- 12 cm（-1）。等极化性条件下的荧光量子产率和寿命表明，随着T的增加，s-t-DPH的有效辐射速率常数增加。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号