27959-62-2Relevant academic research and scientific papers
Synthesis and study of a novel azoester mesogenic homologous series: 4-[4′-n-alkoxy benzoyloxy]-naphthylazo-4″-acetyl benzenes
Patel,Chauhan,Doshi
, p. 57 - 63 (2013/02/22)
The synthesis and mesomorphic properties of a novel azoester homologous series consisting of 12 members is reported. The methyl to butyl derivatives of the series are non-mesogenic, and the others are enantiotropically smectogenic and/or nematogenic. The nematic mesophase shows a threaded or Schlieren texture and smectic mesophase shows a focal conic fan-shaped texture of the SmA or the SmC. The smectic and nematic thermal stabilities are 137.4 and 166.6 respectively. Analytical data support the molecular structures. The transition temperatures of the homologues are determined using optical polarizing microscopy. An odd-even effect is observed for the nematic-isotropic transition curve and the series is equally smectogenic and nematogenic over a wide temperature range, and the melting points are in the middle order. The mesogenic properties of the present series are compared with a structurally similar homologous series. Copyright Taylor & Francis Group, LLC.
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.
