کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1234515 | 968829 | 2009 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Spin-forbidden transitions in flavone
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Spin-forbidden transitions in flavone Spin-forbidden transitions in flavone](/preview/png/1234515.png)
چکیده انگلیسی
According to the calculations the phenyl ring is twisted out of the benzopyrone plane by 28° in the electronic ground state whereas the nuclear frame is nearly planar in the lowest excited (nÏâ)1 (S1) state and is slightly V-shaped in the (ÏÏâ)3 (T1) and (ÏÏâ)1 (S2) states. The calculations clearly show that the T1 state has mainly ÏÏâ character. The large spin-orbit coupling of the S1 and T1 states and their small energy gap explain the high S1âT1 ISC rate for which a value of kISCâ3Ã1011 s is computed, in good agreement with experimental build-up times of the TnâT1 absorption. In the absence of collisions and other nonradiative processes, the T1 state of flavone is prediced to be long-lived with a pure phosphorescence lifetime of ÏPâ4 s, in qualitative agreement with low-temperature measurements. The much faster decay of triplet flavone observed in fluid solutions is ascribed to nonradiative processes.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy - Volume 73, Issue 1, July 2009, Pages 1-5
Journal: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy - Volume 73, Issue 1, July 2009, Pages 1-5
نویسندگان
Christel M. Marian,