A Pattern for Increasing the First Hyperpolarizability of a Push−Pull Polyene Dye as Indicated from DFT Calculations

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• 作者：Andrew P. Chafin ; Geoffrey A. Lindsay
• 刊名：Journal of Physical Chemistry C
• 出版年：2008
• 出版时间：May 29, 2008
• 年：2008
• 卷：112
• 期：21
• 页码：7829 - 7835
• 全文大小：582K
• 年卷期：v.112,no.21(May 29, 2008)
• ISSN：1932-7455

文摘

Density functional theory (DFT) calculations were performed on a polyene dye scaffold, keeping the end groups and bridge length the same but varying the pattern of electron-donating (D) and electron-withdrawing (W) substituents along the polyene bridge. The basic pattern that increased the first hyperpolarizability was to place W substituents on even-numbered (e) methine carbons, and D substituents on odd-numbered (o) methines (called the {eWoD} pattern). The numbering scheme used herein for the dye scaffold has the #1 methine at the W-terminus of the dye. The {eWoD} pattern polarizes the π bonds along the polyene in the opposite direction that the termini of the dye polarize the dye. By placing cyano and fluorine groups in the {eWoD} pattern along the polyene, a sixfold higher first hyperpolarizability was predicted compared to placing them in the opposite substitution pattern ({oWeD}). A superimposed but weaker gradient pattern was also observed.