Frontier molecular orbital analysis of dual fluorescent dyes: predicting two-color emission in N-Aryl -1,8-naphthalimides
作者:Premchendar Nandhikonda、Michael P. Begaye、Zhi Cao、Michael D. Heagy
DOI:10.1039/c001912g
日期:——
A 3 × 3 matrix of disubstituted N-aryl-1,8-naphthalimides was synthesized for the evaluation and discovery of dual fluorescence (DF). The matrix elements included for this study were based on a predictive model that is proposed as a seesaw balanced photophysical model. This model serves as a guide to optimize the dual fluorescence emission from N-phenyl-1,8-naphthalimdes by appropriate placement of substituent groups at both the 4-position of the N-arene as well as the 4′-position of the naphthalene ring. Steady-state fluorescence studies under a variety of solvents indicate that four of the nine dyes in the matrix are dual fluorescent. To provide a more quantitative description of the model, cyclic voltammetry experiments were used to calculate HOMO/LUMO energies of the aromatic components that comprise these DF dyes and give evidence in support for potential mixing of S1 and S2 excited states. Given the difficulties in predicting excited state properties such as molecular fluorescence, this ratio of four out of nine “hits’ for discovering DF signifies proof of principle for this proposed model and should provide a rational basis for the synthesis of future DF 1,8-naphthalimide systems.
合成了双取代 N-芳基-1,8-萘酰亚胺的 3 × 3 基质,用于评估和发现双荧光 (DF)。本研究中包含的矩阵元素基于作为跷跷板平衡光物理模型提出的预测模型。该模型可作为优化 N-苯基-1,8-萘二甲酰亚胺双荧光发射的指导,通过在 N-芳烃的 4 位和萘的 4'-位适当放置取代基戒指。各种溶剂下的稳态荧光研究表明,基质中的九种染料中有四种具有双荧光。为了提供模型的更定量描述,使用循环伏安实验来计算构成这些 DF 染料的芳香族成分的 HOMO/LUMO 能量,并为支持 S1 和 S2 激发态的潜在混合提供证据。考虑到预测激发态性质(例如分子荧光)的困难,发现 DF 的九个“命中”中的四个比率意味着该模型的原理证明,并且应该为未来 DF 1,8- 的合成提供合理的基础萘二甲酰亚胺系统。