Related Experiment Video
Updated: May 11, 2026

Facile Preparation of (2Z,4E)-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
Published on: June 21, 2017
[Theoretical study on geometrical structure and spectrum of 4-(2-nitrobenzylideneamino) phenyl ethanone Schiff base]
Xiao-Rui Liang1, Yan-Lan Jiang, Jing Zhang
1Department of Basic Sciences, Naval Aeronautical and Astronautical University, Yantai 264001, China. xiaoruiliang12@yahoo.com.cn
Abstract:
The UV absorption spectra, fluorescence emission spectra and fluorescence quantum yield of the title Schiff base were studied by experiment. The results showed that this compound displayed superior fluorescence properties. Geometrical optimization of the title compound was carried out by employing density functional theory (DFT) method at the B3LYP/6-311G(d) level. The calculation results indicated that the title compound has comparatively stronger aromaticity and larger conjugate system. For the optimal configuration, there is no imaginary frequency after vibrational analysis, which indicates that the structure is stable. Based on the optimized structure for the ground state time-dependent density functional theory (TD-DFT) calculations were carried out at the B3LYP/6-311G level to predict the absorption spectra. The single-excitation configuration interaction (CIS) method was used to optimize the structure of the first excited state, and then TD-DFT calculations were carried out to predict the emission spectra. The results indicated that the wavelengths of the absorption and emission spectra are consistent with the experimental data.
Related Concept Videos
Structure of Benzene: Molecular Orbital Model
Structure of Benzene: Kekulé Model
He proposed that benzene has a cyclic structure of six carbon atoms attached to one hydrogen atom each, with three alternating pi bonds.
UV–Vis Spectroscopy: Woodward–Fieser Rules
Structure of Amines
NMR Spectroscopy of Benzene Derivatives
Criteria for Aromaticity and the Hückel 4n + 2 Rule
For the first time, Eric Hückel, a German chemical physicist, derived a set of structural features for a compound to be classified as aromatic. This is now known as Hückel’s rule or the 4n + 2 rule.

