6953-40-8Relevant academic research and scientific papers
Dependence of mesomorphism on terminal polar group in novel azoester series
Kher, Seema N.,Prajapati,Makwana,Chandra, Raviprakash S.
, p. 44 - 53 (2019/10/14)
Novel homologous series 4-(4′-n-alkoxy benzoyloxy) napthyl azo 4″–bromo benzenes, consisted of 11 members of a series. All the 11 members (ethoxy to hexadecyloxy) except hexadecyloxy are only enantiotropically nematogenic without exhibition of any smectogenic character. Transition temperatures and the textures are determined by an optical polarizing microscopy equipped with a heating stage. Textures of a nematic phase are threaded or schlieren. Analytical and spectral data supported the molecular structure of homologs. Transition curves viz., solid-nematic and nematic-isotropic showing phase behavior of the mesophase in a phase diagram behave in normal manner. Alternation of transition temperatures is exhibited by N–I transition curve. Thus, novel series is entirely nematogenic and high ordered melting type. Thus, synthesis of a novel azoester homologous series is carried out with a view to understand and establish the effect of molecular structure on Liquid crystal (LC) behaviors of a substance.
Facile synthesis of 1-naphthol azo dyes with nano Sio2/Hio4 under solvent-free conditions
Bamoniri, Abdolhamid,Pourali, Ali Reza,Nazifi, S. Mohamad Reza
, p. 439 - 445 (2013/12/04)
Nano-silica supported periodic acid (nano-SPIA) has been utilized as a heterogeneous reagent for a highly efficient and one pot synthesis of azo dyes based on 1-naphthol under solvent-free conditions at room temperature. This method has some advantages, the reaction workup is very easy and the catalyst can be easily separated from the reaction mixture and one-pot procedure. The related products have been obtained in good to excellent yields, high purity and short reaction times. The structures of the products have been characterized by several techniques using UV-Vis, FT-IR, 1H NMR, 13C NMR and mass spectra.
BORON PHOTOCHEMISTRY. XV. DETERMINATION OF THE HAMMETT SUBSTITUENT CONSTANT FOR THE p-DIMESITYLBORYL GROUP
Glogowski, M. E.,Williams, J.L.R.
, p. 137 - 146 (2007/10/02)
Hammett signal values reflect relative strengths of the combined inductive and resonance effects of substituents.Using the ionization technique, as well as an independent neutralization method, we found the ?H value for the p-dimesitylboryl group to be 0.42 as compared to 0.78 for the p-nitro group.The value of ?uv,H=0.65 +/- 0.03 determined from pi-electron interaction processes, such as absorption spectra and pi complex formation, is felt to relate better to the p-dimesitylboryl-substituted dyes.A similar function reflecting the pi resonance interaction of substituent groups is the Tomasik-Krygowski ?uv,K value, for which 0.58 was found for the p-dimesitylboryl group compared to 0.66 for the p-nitro group.
