Novel UV-sensitive bis-chalcone derivatives: synthesis and photocrosslinking properties in solution and solid PMMA film
作者:Zheng Kai Si、Qing Zhang、Min Zhao Xue、Qiao Rong Sheng、Yan Gang Liu
DOI:10.1007/s11164-010-0236-0
日期:2011.7
A series of chalcone derivatives in which two chalcone groups are attached by alkyldioxy chains were synthesized and characterized by 1H NMR, UV–Vis, and Fourier transform infrared (FTIR) spectral analysis. Upon the irradiation of 365-nm UV light, the chalcone groups in the molecules underwent [2π + 2π] photodimerization. The photocrosslinking properties were investigated both in solution and in polymethyl methacrylate (PMMA) solid films on quartz plate. It has been found that the photocrosslinking rates of the compounds depended on the different flexibility of the functional groups, which was determined by the length of the spacer chain between the two chalcone moieties. The longest soft chain containing derivatives has a faster photocrosslinking rate both in solution and in solid film. Irradiated by polarized ultraviolet light (PUV), all of the films doped with bis-chalcone derivatives showed an anisotropic absorption property, which may give a promising application as LC-alignment materials.
Synthesis of novel bis(nicotinecarbonitrile) derivatives
作者:Ali M. S. Hebishy、Ismail A. Abdelhamid、Ahmed H. M. Elwahy
DOI:10.24820/ark.5550190.p010.367
日期:——
A series of bis(nicotinecarbonitriles) were prepared via the reaction of bis arylidenemalononitriles with acetophenone in ethanolic potassium hydroxide solution. The isomeric bis(nicotinecarbonitriles) could also be obtained by the reaction of arylidenemalononitriles with bis acetophenone under similar conditions.The reaction was assumed to take place via Michael addition followed by cyclization due