17804-15-8Relevant academic research and scientific papers
Effects of different terminal substituents on the mesomorphic behavior of some azo-Schiff base and azo-ester-based liquid crystals
Thaker,Kanojiya,Tandel
, p. 120 - 137 (2010)
In order to investigate the influence of the terminal substitution on mesomorphism, two new series of azo-Schiff base and azo-ester liquid crystals having the following structures have been synthesized. All the compounds possess mesomorphic properties. In series A compounds A1 and A3 exhibit only a nematic mesophase, whereas compounds A2, A4, A5, A6, A7, A8, A9, and A10 exhibit a smectic as well as a nematic phase. In series B compounds B1 to B9 exhibit only a nematic mesophase, and compounds B10 and B11 exhibit a smectic as well as a nematic phase, but compound B12 exhibits only a smectic phase. All these compounds were characterized by elemental analyses and spectroscopic techniques (Fourier transform infrared [FTIR], 1H nuclear magnetic resonance [NMR], and mass spectroscopy). Their mesomorphic properties were measured by optical polarized light microscopy and differential scanning calorimetry (DSC). Copyright Taylor & Francis Group, LLC.
Sterically enhanced 2-iminopyridylpalladium chlorides as recyclable ppm-palladium catalyst for Suzuki–Miyaura coupling in aqueous solution
Lin, Wenhua,Zhang, Liping,Ma, Yanping,Liang, Tongling,Sun, Wen-Hua
, (2021/10/20)
Sterically hindered 2-iminopyridine derivatives and their palladium chlorides complexes are designed and prepared, which efficiently promote the Suzuki–Miyaura coupling (SMC) reaction in aqueous solution. Besides the good to excellent yields and broad substrate scope, these catalysts can be reused for at least four new batches of the substrates. Spontaneous separation of coupling products in the aqueous reaction medium is the additional striking feature of this catalytic process. Furthermore, catalytic performance of palladium complexes bearing the azo-bridged phenyl groups was greatly influenced by the UV irradiation due to the cis/trans photoisomerization of azo unit of the catalysts. In conclusion, titled palladium complexes provide a green, sustainable, cost-effective, and convenient process to synthesize SMC products at multi-gram-scale reaction.
MECHANISM OF AZO COUPLING. III. ROLE OF CROWN ETHER IN AZO COUPLING
Stovpovoi, P. A.,Bagal, I. L.,El'tsov, A. V.
, p. 895 - 900 (2007/10/02)
The equilibrium constants for complexation of a diazonium cation with a crown ether, as determined from kinetic data on azo coupling with aromatic amines, increase with decreasing polarity of the solvent, indicating a predominant contribution of electrost
