Einfluß der Deuterierung auf die Excimerenkinetik des Pyrens

1976 ◽  
Vol 31 (8) ◽  
pp. 990-994
Author(s):  
Günther Heidt

AbstractThe effect of deuteration on all six photophysical and kinetic constants of pyrene excimer formation is investigated. The rate constants of monomer and excimer emission and the rate of dissociation of the excimer are not affected by deuteration. The increase of the radiationless deactivation of the monomer (anomalous effect) agrees with the theoretical expectation. The radiationless deactivation of the excimer at various temperatures shows no effect and therefore does not take place via the excimer triplet. The decrease of the excimer formation rate can be explained by the effect of deuteration on the partition function and hence on the entropy.

2016 ◽  
Vol 4 (14) ◽  
pp. 2784-2792 ◽  
Author(s):  
Jaehyun Lee ◽  
Hyocheol Jung ◽  
Hwangyu Shin ◽  
Joonghan Kim ◽  
Daisuke Yokoyama ◽  
...  

The wavelength of excimer formation and efficiency of an OLED device were controlled through the change of the center position of the triple-core chromophore.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1690
Author(s):  
Weize Yuan ◽  
Remi Casier ◽  
Jean Duhamel

The denaturation undergone by α–helical poly(L-glutamic acid) (PLGA) in N,N-dimethylformamide upon addition of guanidine hydrochloride (GdHCl) was characterized by comparing the fluorescence of a series of PLGA constructs randomly labeled with the dye pyrene (Py-PLGA) to that of a series of Py-PDLGA samples prepared from a racemic mixture of D,L-glutamic acid. The process of pyrene excimer formation (PEF) was taken advantage of to probe changes in the conformation of α–helical Py-PLGA. Fluorescence Blob Model (FBM) analysis of the fluorescence decays of the Py-PLGA and Py-PDLGA constructs yielded the average number (<Nblob>) of glutamic acids located inside a blob, which represented the volume probed by an excited pyrenyl label. <Nblob> remained constant for randomly coiled Py-PDLGA but decreased from ~20 to ~10 glutamic acids for the Py-PLGA samples as GdHCl was added to the solution. The decrease in <Nblob> reflected the decrease in the local density of PLGA as the α–helix unraveled in solution. The changes in <Nblob> with GdHCl concentration was used to determine the change in Gibbs energy required to denature the PLGA α–helix in DMF. The relationship between <Nblob> and the local density of macromolecules can now be applied to characterize the conformation of macromolecules in solution.


Energies ◽  
2015 ◽  
Vol 8 (1) ◽  
pp. 645-655 ◽  
Author(s):  
Jan Moestedt ◽  
Jonas Malmborg ◽  
Erik Nordell

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