Thermotropic Liquid Crystalline and Photochemical Phase Transition Behavior of Octa[8-{4-(4'-cyanophenylazo)phenoxy}]octyl and Octa[8-{4-(4'-cyanophenylazo) phenoxycarbonyl}]heptanoated Disaccharides

Synthesis and Reactivity of 4′-Deoxypentenosyl Disaccharides

4-Deoxypentenosides (4-DPs) are versatile synthons for rare or higher-order pyranosides, and they provide an entry for structural diversification at the C5 position. Previous studies have shown that 4-DPs undergo stereocontrolled DMDO oxidation; subsequent epoxide ring-openings with various nucleophiles can proceed with both anti or syn selectivity. Here, we report the synthesis of α- and β-lin...

Liquid Crystalline Polymorphism of Methyl and Ethyl trans-4-{[4′-(alkanoyloxy)phenyl]diazenyl}benzoates

Authors present two new homologous series of liquid-crystalline compounds, methyl and ethyl 4-{[4-(alkanoyloxy)phenyl]diazenyl}benzoates, synthesis and investigation of their mesogenic properties. In the methyl series only nematic phase was detected and in the ethyl series nematic and smectic mesophases. In uence of the alkyl chain length on the phase transition temperatures and their entropic ...

Basic and Clinical Neuroscience, Volume 4, Number 4, Full Text

Synthesis of 1-(isopentyloxy)-4-nitrobenzene under ultrasound assisted liquid-liquid phase-transfer catalysis

In this paper, we report the reaction of isoamyl alcohol and 1-chloro-4-nitrobenzene was carried out in a batch reactor under aqueous-organic biphasic conditions using the techniques like phase transfer catalysis and ultrasound irradiation. Tetrabutylammonium bromide (TBAB) was employed as the phase transfer catalyst. The reaction is greatly enhanced by adding a small quantity of phase-transfer...

Probing the Texture of the Calamitic Liquid Crystalline Dimer of 4-(4-Pentenyloxy)benzoic Acid

The liquid crystalline dimer of 4-(4-pentenyloxy)benzoic acid, a member of the n-alkoxybenzoic acid homologous series, was synthesized using potassium carbonate supported on alumina as catalyst. The acid dimer complex exhibited three mesophases; identified as nematic, smectic X1 and smectic X2. Phase transition temperatures and the corresponding enthalpies were recorded using differential scann...