激发态
离域电子
发色团
光化学
超快激光光谱学
化学
吸收(声学)
分子内力
双光子吸收
吸收光谱法
单体
香豆素
轨道能级差
光谱学
分子
材料科学
有机化学
原子物理学
聚合物
激光器
光学
物理
量子力学
复合材料
作者
Jidong Jia,Jie Liu,Tianwei Zhang,Yanzhen Lu,Song Ye
摘要
Intramolecular charge transfer (ICT) and π-electron delocalization are two key factors affecting the nonlinear optical absorption of organic molecules. To clarify the different influences of ICT and π-electron delocalization on two-photon absorption (TPA) and excited-state absorption (ESA), monomeric coumarin C1 and dimeric coumarin C2 are synthesized and studied. Transient absorption spectroscopy (TAS) analysis of these coumarin derivatives in solvents of varying polarities describes the polarity-dependent excited-state dynamics and reveals the ESA signals of the charge transfer state (CTS) and local excited state (LES) with different spectral features. Femtosecond broadband Z-scan experiments indicate that dimeric coumarin C2 has a more significant TPA response than monomeric coumarin C1 in the near-infrared region. Natural transition orbital (NTO) analysis further theoretically characterizes the electron transition feature induced by TPA. Our results reveal that the TPA of these coumarin derivatives can be significantly enhanced by expanding π-electron delocalization, but their ESA is mainly dominated by ICT performance. This study indicates that coumarin derivatives will exhibit extremely broad application prospects in the field of ultrafast optical limiting (OL) through reasonable molecular design.
科研通智能强力驱动
Strongly Powered by AbleSci AI