Impact of Ion-Pairing Effects on Linear and Nonlinear Photophysical Properties of Polymethine Dyes**
Impact of Ion-Pairing Effects on Linear and Nonlinear Photophysical Properties of Polymethine Dyes**
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DOI：
10.1002/cphc.202000731
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发表时间：
2020-11-19
期刊：
影响因子：
2.9
通讯作者：
Maury, Olivier
中科院分区：
文献类型：
--
作者：
Pascal, Simon;Chi, San-Hui;Maury, Olivier
首次比较了七甲川染料的双光子吸收（2PA）和电子偶极结构。理想离域花菁体系的经典特征是与其较低能量吸收带的电子振动分量相匹配的双光子跃迁。偶极物种是通过在非解离溶剂中与硬抗衡离子离子配对产生的，并且显示出光学性质的显著改变，包括吸收的显著减色位移、较弱的发射和与较低能量跃迁匹配的2PA，从而揭示了聚甲炔电子结构内的对称性破缺。
The two-photon absorption (2PA) and photophysics of heptamethine dyes featuring cyanine or dipolar electronic structures have been compared for the first time. The perfectly delocalized cyanine system is classically characterized by a two-photon transition matching the vibronic component of its lower energy absorption band. The dipolar species is generated by ion-pairing with a hard counterion in a non-dissociating solvent and displays significant modifications oft he optical properties, including a significant hypochromic shift of absorption, weaker emission and 2PA matching the lower energy transition, thus revealing symmetry breaking within the polymethine electronic structure.