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
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Towards the understanding of the chromatic behaviour of triphenylmethane derivatives
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 2–3, 20 June 2007, Pages 177-186
نویسندگان
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