The absorption and fluorescence study of 1,4,5,8-naphthalenetetracarboxy diimides in their low-energy 1 and 1 electronic states. The Franck–Condon analysis in terms of CASSCF method

Electronic structure and circular dichroism spectroscopy of naphthalenediimide nanotubes

“…Application to multi-coloured NDI chromophores with different core substituents would be possible but would require parametrization of the chromophore for substituents extending or changing the p-system. Sterzel et al 9 have shown that aliphatic substituents on the nitrogens do not affect the lowenergy states of NDI (hence the transfer of these results to the studied structures). However, Wu¨rther et al 7 have studied NDIs with electron-donating substituents on the naphthalene core and observed bathochromic shifts of up to 200 nm in the absorbance spectrum.…”

“…8 Sterzel et al have studied the NDI monomer using CASSCF/CASPT2 calculations to determine Franck-Condon parameters for the 1 1 B 3u and 1 1 B 2u states. 9 The absorption and emission spectra could be reproduced and the substituents of two N-substituted derivatives showed little effect on the low-energy states of the chromophore. The latter finding allows one to transfer results obtained for the optical properties of the NDI monomer to derivatives of the chromophore such as 1.…”

Vibronic Effects in the 11Bu(11B2) Excited Singlet States of Oligothiophenes. Fluorescence Study of the 11Ag(11A1) ← 11Bu(11B2) Transition in Terms of DFT, TDDFT, and CASSCF Methods

“…In the framework of that analysis, the geometry differences are projected onto the normal coordinates of the ground state. ,, The results of these projections, i.e., FC parameters, enter the vibrational overlap integrals which mediate in the intensity of an electronic transition and give rise to Poisson-like vibrational progressions in the absorption/emission spectra. Such a simple approach was successfully employed to elucidate the vibronic structures observed in the UV−Vis absorption and emission, the magnetic circular dichroism (MCD), and the resonance Raman spectra of the small, medium, and large size molecules.…”

Absorption, resonance, and near‐resonance Raman studies of the tetracyanoquinodimethane neutral and its monoanion in terms of density functional theory and complete active space self‐consistent field methods

“…Under resonance with a single dipole‐allowed nondegenerate state, not involved in vibronic coupling, the intensities in the RR spectra are controlled by the FC effect 1, which reflects the differences in the nuclear equilibrium configurations of the electronic states involved in the absorption‐emission processes. Hence, at least in principle, the theoretical analysis of the absorption and resonance Raman experiments should be quite simple, provided that the ground and excited state(s) geometries and vibrational frequencies are known with sufficient accuracy from the quantum chemical computations 7–10.…”