title: DFT/TDDFT study on the electronic structure and spectral properties of diphenyl azafluoranthene derivative.
abstract: Paper reports the DFT/TDDFT study on the electronic structure and spectral properties of the five-membered annulated diphenyl azafluoranthene derivative 1,3-diphenyl-3H-indeno[1,2,3-de]pyrazolo[3,4-b]quinoline (DPIPQ) by means of polarizable continuum model (PCM) and Onsager reaction field approaches at the B3LYP/6-31+G(d,p) level of theory. The results of calculations are compared with the optical absorption and fluorescence spectra as well as with the cyclic voltammetry data. The DFT/TDDFT/PCM approaches exhibit rather good quantitative agreement regarding the spectral position of the first absorption band; the discrepancy between the experiment and theory is less than 0.06 eV (linear response approach) or 0.25 eV (state specific approach). As for the fluorescence emission the TDDFT/PCM calculations underestimate the transition energy on about of 0.7-0.8 eV. Such discrepancy should be attributed to insufficient quality of the TDDFT/PCM optimization in the excited state. Ignoring the geometrical relaxation in the excited state provides considerably better agreement between the experiment and theory; discrepancy is less than 0.1-0.22 eV depending on a solvent polarity. The dominant influence on the fluorescence emission results mainly from the solvent reorganization in the excited state whereas the solute relaxation is indeed weak and may be ignored.
authors.affiliation: Faculty of Electrical Engineering, Czȩstochowa University of Technology, Al. Armii Krajowej 17, 42-200, Czestochowa, Poland.
authors.forename: P
authors.initials: P
authors.lastname: Gasiorski
authors.forename: K S
authors.initials: KS
authors.lastname: Danel
authors.forename: M
authors.initials: M
authors.lastname: Matusiewicz
authors.forename: T
authors.initials: T
authors.lastname: Uchacz
authors.forename: W
authors.initials: W
authors.lastname: Kuźnik
authors.forename: A V
authors.initials: AV
authors.lastname: Kityk
mesh_terms: D004563:Electrochemistry; D004583:Electrons; D008958:Models, Molecular; D008968:Molecular Conformation; D011720:Pyrazoles / Q000737:chemistry*; D011789:Quantum Theory; D011804:Quinolines / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013057:Spectrum Analysis
chemical_list: C571951:1,3-diphenyl-3H-indeno(1,2,3-de)pyrazolo(3,4-b)quinoline; D011720:Pyrazoles; D011804:Quinolines; D012997:Solvents; C037219:quinoline