کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5402371 | 1392732 | 2010 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Photoinduced electron transfer within a novel synthesized short-chain dyad
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Photoinduced electron transfer within a novel synthesized short-chain dyad Photoinduced electron transfer within a novel synthesized short-chain dyad](/preview/png/5402371.png)
چکیده انگلیسی
The investigations were made by using electrochemical, steady state and time resolved spectroscopic (time correlated single photon counting and laser flash photolysis) techniques on a novel synthesized dyad, 1-(4-chloro-phenyl)-3-(4-methoxy-naphthalen-1-yl)-propenone (MNCA) where the donor 1-methoxy-naphthalene (MNT) is connected with the acceptor p-chloroacetophenone (PCA) by an unsaturated olefinic bond. This dyad possesses mainly extended (E-type) conformation both in the ground and excited state. The unchanged conformational geometry of this dyad even after photoexcitation makes it different from the previously studied benzothiophene-p-chloroacetophenone dyads, though both the donors present are isosteric molecules. In the cases of the latter dyads though E-type isomeric structure dominates in the ground state, considerable amount of Z-type (folded) species are produced in the excited state. It is hinted that the proximity effect of methoxy functionality in donor moiety, may be the reason for the formation of mostly E-isomeric species in the case of the present dyad MNCA system. The observed unchanged values of charge recombination and ion-pair lifetime, estimated from the analysis of transient absorption spectra of the dyad in presence of βCD and without it, confirm the proposition about the maintenance of the extended conformation even upon photoexcitation. From the transient absorption measurements it appears that due to increase of delay times between the exciting and probe pulses, higher triplet Tn of the donor being generated gets involved in PET reactions with the surrounding medium ACN. From the present findings, MNCA in aqueous medium seems to be better candidate to build light energy conversion devices than the previously studied benzothiophene dyads where artificial devices like βCD were used to make elongated geometry. This geometry would help to prevent charge recombination processes within the redox components due to minimal overlapping between them.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Luminescence - Volume 130, Issue 7, July 2010, Pages 1238-1247
Journal: Journal of Luminescence - Volume 130, Issue 7, July 2010, Pages 1238-1247
نویسندگان
Sudeshna Bhattacharya, Munmun Bardhan, Avijit Kumar De, Asish De, Tapan Ganguly,