Effects of the 3- and 4-Methoxy and Acetamide Substituents and Solvent Environment on the Electronic Properties of N-Substituted 1,8-Naphthalimide Derivatives
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- 作者：J. L. Gu. Coronado ; E. Martí ; n ; L. A. Montero ; J. L. G. Fierro ; J. M. Garcí ; a de la Vega
- 刊名：Journal of Physical Chemistry A
- 出版年：2007
- 出版时间：October 4, 2007
- 年：2007
- 卷：111
- 期：39
- 页码：9724 - 9732
- 全文大小：295K
- 年卷期：v.111,no.39(October 4, 2007)
- ISSN：1520-5215
文摘
The photophysical properties of polar molecules in solution with an intramolecular charge-transfer effect inthe excited state depend strongly on the polarity and proticity of the solvents. UV-visible spectra of 1,8-naphthalimide and some N-substituted derivatives in acetic acid, acetonitrile, dichloromethane, and p-dioxanewere carried out. Several molecular cluster geometries formed with N-substituted 1,8-naphthalimide derivativesand a large set of random positioning of some solvent molecules in their environment were optimized by asemiempirical method. It provided a complete screening of possible solute-solvent configurations and resultedin a multiple minima hypersurface of the supramolecular systems. With such local minima energies, the mainthermodynamic association functions were found. They also provided selected cluster geometries for calculationsof vertical electronic transitions with a time-dependent density functional theory (TD-DFT), if the lowestenergy structures were considered. Calculated vertical electronic transition energies at the TD-DFT levelwere compared with experimental data. The experimental absorption UV-visible spectra for the six compoundsin the four solvents were performed in our laboratory. Moreover, X-ray photoelectron spectroscospy of the1,8-naphthalimide was carried out in the ICP-CSIC laboratory. Thermodynamic function values show differentassociation energies between each solvent and the molecules, in correlation with the possibility of hydrogenbond formation and the polarity and dielectric constant of the solvents. The 3- and 4-acetamide1,8-naphthalimide derivatives have the highest conformer number and the most negative Gibbs free associationenergy values for a determined solvent. This indicates the importance of the entropic factors.