YanGang Liu

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Name: 刘燕刚; YanGang Liu

Organization: Shanghai Jiaotong University

Department: School of Pharmacy

Title: Professor

Chemicals
References

Highly enantioselective hydrogenation of N-unprotected indoles using (S)-C10–BridgePHOS as the chiral ligand

Co-reporter:Chao Li, Jianzhong Chen, Guanghong Fu, Delong Liu, Yangang Liu, Wanbin Zhang

Tetrahedron 2013 69(33) pp: 6839-6844

Publication Date(Web):

DOI:10.1016/j.tet.2013.06.016

Synthesis of novel chalcone derivatives and their stabilization effect of spiropyran in PMMA films

Co-reporter:Zheng Kai Si, Qing Zhang, Min Zhao Xue, Yuan Yuan Zhu, Liang Ming, Qiao Rong Sheng, Yan Gang Liu

Chinese Chemical Letters 2011 Volume 22(Issue 9) pp:1025-1028

Publication Date(Web):September 2011

DOI:10.1016/j.cclet.2011.04.001

Three novel bis-chalcone derivatives with different alkyldioxy spacers were synthesized and dispersed into polymethyl methacrylate (PMMA) chloroform solution with 6-nitro-1′-ethyl-3′,3′-dimethylspiro-2H-1-benzopyran-2,2′-indoline (ESP) to prepare photochromic PMMA films in a facile way. After irradiation with 365 nm UV light, the photocrosslinking reaction between chalcone units was proved to retard the decolorization of merocyanine form of the photochromic spiropyran effectively, as results of the steric hindrance produced by photocycloaddition of chalcone groups. It has been found that the bis-chalcone molecule with the shortest spacer has the most effective stabilizing effect on retardation of decoloration of spiropyran.

Novel UV-sensitive bis-chalcone derivatives: synthesis and photocrosslinking properties in solution and solid PMMA film

Co-reporter:Zheng Kai Si;Qing Zhang;Min Zhao Xue

Research on Chemical Intermediates 2011 Volume 37( Issue 6) pp:635-646

Publication Date(Web):2011 July

DOI:10.1007/s11164-010-0236-0

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.

Fluorescent photoswitchable nanohybrids based on photochromism

Co-reporter:Zhenkun Hu, Qing Zhang, Minzhao Xue, Qiaorong Sheng, Yan-gang Liu

Journal of Physics and Chemistry of Solids 2008 Volume 69(Issue 1) pp:206-210

Publication Date(Web):January 2008

DOI:10.1016/j.jpcs.2007.08.063

A new type of fluorescent photoswitchable nanohybrids based on photochromism has been assembled, in which hydrophobic diarylethene and matched fluorescent dye are assembled in the nanoscale crosslinked polymeric matrix via a modified miniemulsion polymerization process and a seeded polymerization technique. The nanohybrids exhibited excellent fluorescent photoswitchable action owing to efficient photoinduced energy transfer whether the nanohybrids as nanoparticles dispersed in water or in a polymer film, and the improved photo-thermal stability of both essential components could be readily achieved. Importantly, our assembling approach is much simpler than the covalent chemical synthesis, and is a general method for other hydrophobic photochromic compounds.

Controlled preparation of nanocolorants via a modified miniemulsion polymerization process

Co-reporter:Z. K. Hu;M. Z. Xue;Q. Zhang;Q. R. Sheng;Y. G. Liu

Journal of Applied Polymer Science 2007 Volume 104(Issue 5) pp:3036-3041

Publication Date(Web):5 MAR 2007

DOI:10.1002/app.25353

Nanocolorants were successfully prepared via a modified miniemulsion polymerization process into which styrene, a polar monomer, crosslinkers, a highly hydrophobic solvent, dyes, and so forth were introduced. The obtained nanocolorants were nanocomposite entities in which a fraction of dye molecules attached to the crosslinked macromolecular chains and more dye molecules formed clustering because of the phase separation between the dye and polymer during the polymerization process and were further embedded in the interior of the crosslinked polymer because of the high hydrophobicity of the dyes. The effects of the polar monomers, the amounts of the dyes dissolved in styrene, and the polymer crosslinking, as well as the effects of the water-soluble and oil-soluble initiator, the amount of the surfactant, and the ultrasonic homogenization time, on the preserving fastness of the dyes in the polymeric matrix and the morphology and particle size distribution of the nanocolorants were studied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007