Department of Chemistry, Indian Institute of Technology, Guwahati, Guwahati, India.
Photochem Photobiol Sci. 2012 Aug;11(8):1356-67. doi: 10.1039/c2pp25039j. Epub 2012 Jun 11.
The spectral characteristics of 2-(4'-N,N-dimethylaminophenyl)oxazolo[4,5-b]pyridine (DMAPOP) have been investigated in solvents of different polarity and hydrogen bonding capacity. Unlike its imidazole analogue, DMAPOP emits single emission in both aprotic and protic solvents and the hydrogen-bond induced TICT emission is not observed in any protic solvents. The solvent effect on both absorption and the emission spectral data are analyzed by multiple parametric regression analysis. The prototropic studies reveal that two kinds of monocations are formed by protonation of pyridine nitrogen (MC1) and the dimethylamino nitrogen (MC3) in both ground and excited states. However three kinds of dications are formed by protonation of pyridine and oxazole nitrogens (DC1), pyridine and dimethylamino nitrogens (DC2), and dimethylamino and oxazole nitrogens (DC3).
2-(4'-N,N-二甲基氨基苯基)噁唑并[4,5-b]吡啶（DMAPOP）的光谱特性在不同极性和氢键能力的溶剂中进行了研究。与咪唑类似物不同，DMAPOP 在质子溶剂和非质子溶剂中均发出单一的发射，并且在任何质子溶剂中都未观察到氢键诱导的 TICT 发射。通过多元参数回归分析对吸收和发射光谱数据的溶剂效应进行了分析。质子转移研究表明，在基态和激发态中，吡啶氮（MC1）和二甲氨基氮（MC3）的质子化分别形成两种单阳离子（MC1 和 MC3）。然而，通过吡啶和噁唑氮（DC1）、吡啶和二甲氨基氮（DC2）以及二甲氨基和噁唑氮（DC3）的质子化形成三种二阳离子（DC1、DC2 和 DC3）。
