35620-05-4Relevant academic research and scientific papers
Nematic phases of bent-core mesogens
Keith, Christina,Lehmann, Anne,Baumeister, Ute,Prehm, Marko,Tschierske, Carsten
body text, p. 1704 - 1721 (2011/10/19)
Bent-core mesogens derived from 4-cyanoresorcinol with terminal alkyl chains have been synthesized and investigated by polarizing microscopy, XRD and electro-optical methods. Short chain compounds have exclusively nematic phases which can be cooled to ambient temperature. These nematic phases are similar to ordinary nematic phases with only nearest neighbour correlation (N) whereas long chain compounds form SmC-type cybotactic clusters and these cybotactic nematic phases (NcybC) can be regarded as strongly fragmented SmC phases. The chain length dependent as well as temperature dependent structural transition from N to NcybC is continuous and associated with a change of the position and intensity of the small angle scattering in the XRD patterns. Moreover, a temperature dependent stepwise transition from cybotactic nematic phases to different types of non-polar and tilted smectic phases (SmC (I) and SmC(II)) is observed with a mesophase composed of elongated, but not yet fused cybotactic clusters (CybC) as an intermediate state of this transition. This improves the understanding of the nature and special properties of the nematic phases formed by bent-core molecules as well as their transition to smectic phases and it paves the way to new materials with spontaneous or field-induced biaxial nematic phases at ambient temperatures.
Oxidation of aldehydes by sodium chlorite
Bayle, J. P.,Perez, F.,Courtieu, J.
, p. 565 - 567 (2007/10/02)
Oxidation of aldehydes by sodium chlorite.Sodium chlorite is an efficient reagent for the oxidation of aldehydes to the corresponding acids.The reactions were carried out at room temperature in dichloromethane-acetic acid solution for all aldehydes except salicylaldehydes.We show that these compounds can be oxidized using a DMSO-sodium methanolate solution.Yields are good, even in the case of aromatic aldehydes with electron donating groups.
