Related Experiment Video
Updated: Aug 24, 2026
![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)
Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Study on the second-order optical behavior of 4-(substituted-benzylidene)-2-phenyl-4H-oxazol-5-one
Hua-Can Song1, Huan Wen, Wei-Ming Li
1Department of Chemistry, Zhongshan University, Guangzhou 510275, China. songhuacan@hotmail.com
Abstract:
The maximum absorption wavelengths (lambda(a-max)), absorption coefficient (epsilon), maximum emission wavelengths (lambda(e-max)) of 4-benzo[1,3]dioxol-5-ylmethylene-2-phenyl-4H-oxazol-5-one (1), 4-(3,4-dimethoxybenzylidene)-2-phenyl-4H-oxazol-5-one (2) and 4-(3,4,5-trimethoxy-benzylidene)-2-phenyl-4H-oxazol-5-one (3) were measured, their second-order nonlinear polarization values (beta(xxx)) were determined by solvatochromic method. Although the spectral nature (lambda(a-max), epsilon, lambda(e-max)) and beta(xxx) values of 1, 2 and 3 were close to each other in the same solvent, the second-order harmonic generation (SHG) value of sample 1 is higher obviously than that of sample 2 or 3 in solid state. The crystal structures of 1 and 2 characterized by single crystal X-ray diffraction technique indicated the reason why the SHG value of 1 is higher.
Related Concept Videos
Reactions at the Benzylic Position: Oxidation and Reduction
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.
NMR Spectroscopy of Benzene Derivatives
Nomenclature of Aromatic Compounds with Multiple Substituents
For disubstituted benzene derivatives, with two groups attached to the benzene ring, three constitutional isomers are possible. For example, consider dimethyl benzene, often called xylene, where the second methyl group can be substituted at the second, third, or fourth carbon. The relative position of the substituents is represented by prefixes ortho, meta, or...
Directing and Steric Effects in Disubstituted Benzene Derivatives
Structure of Benzene: Molecular Orbital Model
