TDDFT Study of the Optical Properties of Cy5 and Its Derivatives
TDDFT Study of the Optical Properties of Cy5 and Its Derivatives
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DOI：
10.1021/jp908485z
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发表时间：
2010-03-18
影响因子：
2.9
通讯作者：
Leszczynski, Jerzy
中科院分区：
文献类型：
--
作者：
Bamgbelu, Anu;Wang, Jing;Leszczynski, Jerzy
具有很强的pi-pi*型电子吸收的菁氨酸染料作为光电子应用的活性成分受到了广泛的关注。本研究应用时间依赖密度泛函理论（TDDFT）方法对Cy5和Cy5-X （X = F, Cl, Br， I）的光学性质进行了理论探讨。所研究模型的基态几何在B3LYP/LanL2DZ和B3LYP/SDD理论水平上得到了充分优化。在优化基态结构的基础上，进行了TDDFT计算，计算了所研究物质的垂直单线态激发能和吸收光谱。与Cy5的光学性质相比，卤素离子降低了Cy5- x衍生物的垂直激发能，使其最大吸收波长发生了红移。采用极化连续介质模型（PCM）方法对所有的气相优化结构，考虑溶剂效应油对Cy5和Cy5- x在三种溶剂（乙醇、DMSO和水）中的光谱的影响。所得结果表明，溶剂可以降低Cy5的激发能。而Cy5-X在溶剂中的激发能比在气相中的激发能高。
Cyanine dyes which show a very strong pi-pi* type electronic absorption have attracted attention as active components for optoelectronic applications. In the present Study, the optical properties of Cy5 and Cy5-X (X = F, Cl, Br, and I) have been theoretically explored by applying the time-dependent density functional theory (TDDFT) method. The geometries of the ground state of the Studied models have been fully optimized at the B3LYP/LanL2DZ and B3LYP/SDD levels of theory. Based upon the optimized structures of the ground state, the TDDFT calculations were performed to compute the vertical singlet excitation energies and the absorption spectra of the Studied species. Compared with the optical properties of Cy5, halogen ions lower the vertical excitation energies and Cause the maximum absorption wavelength to be red-shifted for the Cy5-X derivatives. By employing the polarizable continuum model (PCM) approach For all the gas-phase-optimized Structures, the influence of solvent effects oil the spectra of Cy5 and Cy5-X was considered in three solvents (ethanol, DMSO, and water). The obtained results suggest that the solvents may lower the excitation energy of Cy5. However, for the Cy5-X species the excitation energies are higher in solvents than in the gas phase.