کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9591486 | 1507003 | 2005 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
A TDDFT study of the low-lying excitation energies of polycyclic cinnolines and their carbocyclic analogues
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: A TDDFT study of the low-lying excitation energies of polycyclic cinnolines and their carbocyclic analogues A TDDFT study of the low-lying excitation energies of polycyclic cinnolines and their carbocyclic analogues](/preview/png/9591486.png)
چکیده انگلیسی
The low-lying excited states of 21 compounds of polycyclic cinnoline, monoaza-hydrocarbon and their corresponding polycyclic aromatic hydrocarbon (PAH) analogues have been investigated in the framework of time-dependent density functional theory (TDDFT). The gradient corrected BLYP, hybrid B3LYP and B3P86 functionals together with 6-31G (d) basis set have been used. The hybrid-type B3LYP and B3P86 systematically overestimate the excitation energies for states with dominating ionic character (corresponding to group III band), with a mean absolute deviation (MAD) of 0.33 eV (B3LYP) and 0.34 eV (B3P86), respectively. However, they can accurately predict the excitation energies for states with covalent character (corresponding to group II and I bands). The MAD for group II (B3LYP: 0.05 eV; B3P86: 0.05 eV) and I bands (B3LYP: 0.12 eV; B3P86: 0.12 eV) are significantly smaller. The BLYP outperforms B3LYP and B3P86 for group III band (MAD: 0.09 eV), but has a worse performance for group II (MAD: 0.15 eV) and I (MAD: 0.13 eV) bands. Comparison of the lowest-lying excited states for polycyclic cinnolines with those of the corresponding PAH analogues, the first excited states of polycyclic cinnolines mainly result from nâÏ0* transitions. Therefore, in non-polar solvents, the spectra of some polycyclic cinnolines exhibit an additional absorption band at longer wavelengths.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure: THEOCHEM - Volume 732, Issues 1â3, 1 November 2005, Pages 21-32
Journal: Journal of Molecular Structure: THEOCHEM - Volume 732, Issues 1â3, 1 November 2005, Pages 21-32
نویسندگان
Wei Li, Xuan Cai, Yaogai Hu, Yong Ye, Mingdao Luo, Jiming Hu,