A TD-DFT study of the absorption spectra of mono-nitrated fluoranthenes

作者：Onchoke Kefa K^*

来源：Computational and Theoretical Chemistry, 2014, 1042: 23-34.

DOI：10.1016/j.comptc.2014.04.027

• Nitrated fluoranthenes
• Nitro group orientation
• Time-dependent density functional theory
• Singlet excited states
• HOMO-LUMO gaps
• Molecular electrostatic potential

The singlet electronic excited state properties of 1-, 2-, 3-, 7-, and 8-nitrofluoranthene (1-, 2-, 3-, 7-, 8-NF) were investigated using the time-dependent density functional method (TD-DFT) at the B3LYP/6-311+G(d,p)//TD-B3LYP/6-311(d,p) level of theory. The simulated and experimental UV/Vis spectra are in good agreement, thus enabling assignments and interpretation of the observed absorption bands. The influence of the nitro group upon electronic spectra, and structure-spectroscopic-mutagenicity correlations are made. The absorption lambda(max) (S-1 excitation energy) for the nitrated fluoranthenes are red-shifted by similar to 10-30 nm vis-a-vis fluoranthene: with wavelength shifts dependent on the planarity of the nitro group relative to the aryl moiety. The chemical hardness and HOMO-LUMO energy gaps for the nitro-fluoranthenes are predicted in the range 3.5-3.8 eV and follow the order: fluoranthene (3.99 eV) > 7-NF (3.81 eV) > 2-NF (3.72 eV) approximate to 8-NF (3.71 eV) > 1-NF (3.52 eV) > 3-NF (3.50 eV).

• 出版日期2014-8-15