A class of pyrazole derivatives is described for use in treating p38 kinase medicated disorders. Compounds of particular interest are defined by Formula IA
wherein R
1
, R
2
, R
3
and R
4
are as described in the specification.
Azobenzene-decorated cellulose nanocrystals as photo-switchable chiral solutes in nematic liquid crystals
作者:Barış Sezgin、Torsten Hegmann
DOI:10.1039/d2tc04444g
日期:——
validate that cellulosenanocrystals (CNCs), surface-functionalized with pro-mesogenic azobenzene pendants, can act as photoswitchable chiral solutes in a nematic liquid crystal (N-LC). Upon UV illumination, the helical pitch and thus the helical twisting power (βw) can be altered based on the trans–cis photoisomerization of the azobenzene pendants. This approach shows that CNCs—biorenewable chiral additives
Cyclotriphosphazene and cyclotetraphosphazene derivatives with mesogenic 4-N-(4-alkoxyphenyl)iminomethyl)phenoxy and 4-(4'-alkoxy) biphenoxy moieties were synthesized. Schiff base moiety has higher mesomorphic stability than that in biphenyl moiety both in cyclotriphosphazene and cyclotetraphosphazene. Cyclotriphosphazenes possess higher thermal stability in the mesomorphic phase than the cyclotetraphosphazenes, suggesting the difference in the molecular structure.
Studies of Calamitic Liquid Crystalline Compounds Involving Ester-Azo Central Linkages with a Biphenyl Moiety
作者:B. T. Thaker、Y. T. Dhimmar、B. S. Patel、D. B. Solanki、N. B. Patel、N. J. Chothani、J. B. Kanojiya
DOI:10.1080/15421406.2011.591677
日期:2011.10.14
Two mesogenic homologous series involving ester-azo central linkages with a biphenyl moiety have been synthesized, such as 4 '-[(4-n-alkoxyphenyl)diazenyl]biphenyl-4-ol (series I) and 4 '-[(4-n-alkoxyphenyl) diazenyl]-4-butoxy phenyl biphenyl-4-carboxylate (series II). Azobiphenyl of series I having a free hydroxyl group with strong hydrogen bonding exhibits a high-temperature enantiotropic smectic phase. Whereas in series II, compounds containing C-1-C-8 carbon atoms exhibit only a monotropic smectic phase and compounds with C-10, C-12, C-14, and C-16 atoms show an enantiotropic smectic phase. These compounds were characterized by elemental analysis, FT-IR, H-1-NMR, and mass spectral studies. The phase transition and mesogenicity of these substances were studied by polarizing optical microscopic and differential scanning calorimetric techniques. Their thermal stabilities and other characteristics are discussed.
Synthesis and mesomorphic properties of 2,4-bis(4′-n-pentyloxybenzoyloxy)- benzylidine-4″- n-alkoxyaniline
作者:Wali M. Hamad、Hashim J. Azeez、Ammar H. Al-Dujaili
DOI:10.1080/15421406.2017.1357426
日期:2017.7.24
The synthesis andmesomorphic properties of a new series of 2,4-bis(4'-n-pentyloxybenzoyloxy)- benzylidine-4 ''-n-alkoxyaniline (DC5An) are reported. The molecular structure of compounds was confirmed by FTIR, H-1-NMR, C-13-NMR, mass spectroscopy and elemental analysis. The mesomorphic properties were studied by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM) measurements. All compounds of the series exhibit nematic (N) and smectic C (SmC) phases. The first four homologues (DC5A1-DC5A4) display a N mesophase, whereas the highest homologues (DC5A5-DC5A10) exhibit an enantiotropic dimorphism N and SmC phases. The mesomorphic properties of the present series are compared and discussed with other structurally related series.