کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5376541 | 1504323 | 2007 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Towards the understanding of the chromatic behaviour of triphenylmethane derivatives
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
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چکیده انگلیسی
The absorption spectra of a large panel of substituted arylcarbonium dyes have been simulated with the PCM-TD-DFT theoretical scheme. For most compounds, there are at least two allowed excited-states showing a strong molar absorption coefficient in the UV/Vis region. Both involve a charge transfer from the para-NMe2 to the central carbonium. It turns out that B3LYP, combined with the 6-31G(d,p) basis set for the ground-state optimization, and with the 6-311G(d,p) basis set for the TD-PBE0 calculations, yields reliable auxochromic shifts when the solvation effects are included in the model. Indeed, a statistical treatment of the raw TD-DFT results allows a prediction of the λmax with a small average standard deviation: 26 nm. The accuracy required for the design of new molecules is globally reached: the mean average error is only 19 nm, in spite of the charge-transfer nature of the excitations. Moreover, linear correlations have been established between: (i) the ring-N average bond length and the experimental λmax(1-2), (ii) vibrational frequency of the chromophore and the λmax(2).
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemical Physics - Volume 335, Issues 2â3, 20 June 2007, Pages 177-186
Journal: Chemical Physics - Volume 335, Issues 2â3, 20 June 2007, Pages 177-186
نویسندگان
Julien Preat, Denis Jacquemin, Valérie Wathelet, Jean-Marie André, Eric A. Perpète,