Gutiérrez Mario, García Eduardo, Monterde Cristina, Sánchez Félix, Douhal Abderrazzak
Departamento de Química Física, Facultad de Ciencias Ambientales y Bioquímica, and INAMOL, Universidad de Castilla-La Mancha, Avenida Carlos III, S. N., 45071 Toledo, Spain.
Instituto de Química Orgánica General, IQOG-CSIC, Juan de la Cierva, 3, 28006 Madrid, Spain.
Phys Chem Chem Phys. 2022 Mar 16;24(11):6828-6835. doi: 10.1039/d1cp05294b.
Molecules undergoing excited-state proton transfer (ESPT) reactions are among the most interesting systems from spectroscopic and photophysical viewpoints. These molecules can be further functionalized with electron donating or accepting groups, inducing intramolecular charge transfer (ICT) events, which might be coupled to the ESIPT ones, conferring them with different spectroscopic and photophysical properties, which can be essential to implement the related materials in many key scientific and technological fields. Here, we report new benzimidazole derivatives that are functionalized with a phenyl group, 2-(5,10-diphenyl-1-phenanthro[9,10-]imidazol-2-yl)phenol (DP-HPPI), and its methylated equivalent, 2-(2-methoxyphenyl)-5,10-diphenyl-1-phenanthro[9,10-]imidazole (DP-MPPI). The results prove that these molecules in solutions undergo an ultrafast ICT (400-700 fs) reaction. Additionally, DP-HPPI also undergoes a reversible ESIPT process in dichloromethane. However, this is precluded in acetonitrile due to the involvement of intermolecular H-bonds in this solvent. These results provide key insights into the development of proton-transfer materials with bespoke spectral and photodynamical properties.
从光谱学和光物理的角度来看，经历激发态质子转移（ESPT）反应的分子是最有趣的体系之一。这些分子可以进一步用供电子或吸电子基团进行功能化，引发分子内电荷转移（ICT）事件，这些事件可能与ESIPT事件耦合，赋予它们不同的光谱和光物理性质，这对于在许多关键科技领域应用相关材料至关重要。在此，我们报道了用苯基功能化的新型苯并咪唑衍生物，即2-(5,10-二苯基-1-菲并[9,10-]咪唑-2-基)苯酚（DP-HPPI）及其甲基化类似物2-(2-甲氧基苯基)-5,10-二苯基-1-菲并[9,10-]咪唑（DP-MPPI）。结果证明，这些分子在溶液中会发生超快ICT（400 - 700飞秒）反应。此外，DP-HPPI在二氯甲烷中还会经历一个可逆的ESIPT过程。然而，由于该溶剂中存在分子间氢键，在乙腈中这种情况被阻止。这些结果为开发具有定制光谱和光动力学性质的质子转移材料提供了关键见解。
