37065-54-6Relevant academic research and scientific papers
Mesomorphism dependence on molecular rigidity and substitution of same functional group on lateral or terminal position of tailed phenyl ring
Sharma, Vinay S.,Patel
, p. 178 - 187 (2017)
Novel liquid crystal materials (LCs) of low temperature range (53°C to 75°C) have been synthesized through a series of chalconyl derivatives consisting of two phenyl rings bonded through a –CH?CH?CO? central bridge to study the effect of molecular structure on LC properties in general and with a focus on molecular rigidity. The novel homologues series (C1 to C18) consists of thirteen homologues with general formula RO?C6H4?CH?CH?CO?C6H4?OC10H21(n) (meta). The C1, C2, C3 homologues are nonliquid crystals (NLC) and the rest of the homologues (C4 to C18) are either monotropic or enantiotropic liquid crystals. C4 to C6 homologues are enantiotropicnematic and the rest of the mesomorphic homologues are (C7 to C18) monotropicsmectic in addition to monotropicnematic character. Transition and melting temperatures including textures of homologues were determined by an optical polarizing (POM) microscopy equipped with a heating stage. Textures of a nematic phase are threaded or Schlieren, and that of the smectic phase are of the type Smectic A or C as judged directly from the heating top of the microscope. Thermal stability for smectic is very poor and of the nematic is (N-I) 69.3°C whose, total mesophase length ranges between 07.0 to 14.0°C at C8 and C4 homologues respectively.
Reactivity in micelles - Are we really able to design micellar catalysts?
Jurok, Radek,Svobodova, Eva,Cibulka, Radek,Hampl, Frantisek
, p. 127 - 146 (2008/12/21)
Coordination of lipophilic alkyl pyridin-2-yl ketoximes 1 to Ni 2+ ions, reduction of lipophilic 3-alkoxyacetophenones 2 with sodium borohydride, and alkaline hydrolysis of 4-nitrophenyl diphenyl phosphate (PNPDPP) were employed as probes in the investigation which factors may influence the reactivity of organic compounds in micellar systems. In all these reactions, a lipophilic substrate solubilized in micellar core was attacked by a hydrophilic reagent from the bulk aqueous phase. To evaluate the contribution of electrostatic interactions between the micellar surface charge and the reagent to the observed reactivity, we combined reactions involving the reagents with opposite polarity (Ni2+ cations and borohydride or hydroxide anions) with positively charged micelles of hexadecyltrimethyl-ammonium chloride (CTAC) or bromide (CTAB) and negatively charged micelles of sodium dodecyl sulfate (SDS). Non-ionic micelles (Triton X-100 or Brij 35) served as a reference. The results of the kinetic studies give evidence that each of the investigated systems has unique properties going in particular aspects beyond the scope of the generally accepted concepts of reactivity in micelles.
Mesomorphic properties of 1-(4'-dodecylbiphenyl-4-yl)-3-(2 or 3-alkoxyphenyl)propane-1,3-diones: the influence of alkoxysubstituent position
Sadashiva, Bukkinakere K.,Prasad, Veena
, p. 755 - 760 (2007/10/03)
Two homologous series of β-diketones, viz. 1-(4'-dodecylbiphenyl-4-yl)-3-(2-alkoxyphenyl)propane-1,3-diones and 1-(4'-dodecylbiphenyl-4-yl)-3-(3-alkoxyphenyl)propane-1,3-diones have been synthesised.The mesomorphic behaviour of all the compounds has been investigated using optical polarising microscopy and differential scanning colorimetry.The enthalpies associated with the transitions of all the liquid crystalline materials have also been determined.The mesophases exhibited by these compounds are explained on the basis of the structural features associated with such compounds.
