Fluorescence of the diastereoisomers of 2,4-di(N-carbazolyl)pentane and the two excimers observed in poly(N-vinylcarbazole)
Fluorescence of the diastereoisomers of 2,4-di(N-carbazolyl)pentane and the two excimers observed in poly(N-vinylcarbazole)
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2,4-二(N-咔唑基)戊烷的非对映异构体和聚(N-乙烯基咔唑)中观察到的两种准分子的荧光
DOI：
10.1021/ma00230a040
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发表时间：
1982
期刊：
影响因子：
5.5
通讯作者：
N. Boens
中科院分区：
文献类型：
--
作者：
F. Schryver;J. Vandendriessche;S. Toppet;K. Demeyer;N. Boens
合成了2，4-二(ZV-咔唑)戊烷的两个非对映异构体，并用核磁共振进行了表征。它们在准分子区域的发射波长分别为420 nm和370 nm，这可能与聚(乙烯基咔唑)中观察到的两个准分子有关。最近发表的一篇文章1解释了聚(IV-乙烯基咔唑)在溶液中的准分子动力学，促使我们报道了2，4-二(AT-咔唑)戊烷的发射性质的初步结果。我们已经证明，经典的分子间络合物形成动力学方案不能推广到势垒阻碍快速构象平衡的体系。Morawetz还提出了构象平衡在分子内异构体形成中的作用。3正如Bovey指出的，4在聚苯乙烯等聚合物的情况下，应考虑构型方面。Monnerie5已经证明了2，4-二苯基戊烷的激发态性质对于中间体和外消旋的非对映异构体有很大的不同，特别是它们形成准分子的能力。在聚(2-乙烯基萘)6中分子间准分子形成的经典动力学方案的不正确性也可能与介观模型和外消旋模型体系的前态性质的不同有关。
The twodiastereoisomers of 2, 4-di (ZV-carbazolyl) pentane were synthesized and characterized by NMR. Their respective emission in the excimer region, at 420 nm for the meso isomer and 370 nm for the racemic isomer, can be related to the two excimers observed in poly (vinylcarbazole).A recent publication1 proposing an interpretation of the excimer kinetics of poly (iV-vinylcarbazole) in solution prompts us to report preliminary results on the emission properties of 2, 4-di (AT-carbazolyl) pentanes. Wehave already shown2 that the classical kinetic scheme for inter-molecular complex formation could not be extended to systems where substantial barriers prevent fast conformational equilibrium. The role of conformational equi-librium upon intramolecular excimerformation was also suggested by Morawetz. 3As was pointed out by Bovey, 4 one should, in the case of polymers such as polystyrene, consider configurational aspects. Monnerie5 has shown that the excited-state properties of 2, 4-diphenylpentane are substantially different for the meso and the racemic diastereoisomers, especially their capacity to form the excimer. 5b The nonvalidity of theclassical kinetic scheme of intermolecular excimer formation in poly (2-vinyl-naphthalene) 6 could also be related to differences in ex-cited-state properties of meso and racemic model sys-