Correlation between thermodynamic parameters (GLC) and structure of esters

1981 ◽  
Vol 59 (15) ◽  
pp. 2243-2246 ◽  
Author(s):  
F. Saura Calixto ◽  
P. M. Deyá
Keyword(s):  
Molecular Structure ◽  
Stationary Phase ◽  
Thermodynamic Parameters ◽  
Homologous Series ◽  
Phase Gazeuse ◽  
Carboxylic Group ◽  
Phase Stationnaire ◽  
De Formula ◽  
Branching Chains ◽  
Polar Stationary Phase

The ΔHs and [Formula: see text] values of some one hundred esters belonging to twenty different homologous series are determined experimentally in the polar stationary phase (Carbowax 1540) by gas–liquid chromatography.Correlations between thermodynamic values and the molecular structure of esters are studied. The influence of the number of carbon atoms in the acid and alcohol chains and the position of the carboxylic group and branching chains on the ΔHs and [Formula: see text] values is considered.Faisant appel à la chromatographie en phase gazeuse impliquant du Carbowax 1540 comme phase stationnaire on a déterminé expérimentalement les valeurs de ΔHs et de [Formula: see text] d'une centaine d'esters appartenant à 20 séries homologues différentes.

Chromatographic and column stability at pH 7 of a C18 dimethylurea polar stationary phase

2004 ◽  
Vol 1030 (1-2) ◽  
pp. 157-166 ◽  
Author(s):  
César Ricardo Silva ◽  
Carol H Collins ◽  
Isabel Cristina Sales Fontes Jardim ◽  
Claudio Airoldi
Keyword(s):  
Stationary Phase ◽  
Polar Stationary Phase

scholarly journals Study of Mesomorphism in Isomeric and Nonisomeric Linear and Nonlinear Chalconyl Series

2015 ◽  
Vol 60 ◽  
pp. 182-191 ◽  
Author(s):  
Vinay S. Sharma ◽  
R.B. Patel
Keyword(s):  
Molecular Structure ◽  
Homologous Series ◽  
Nematic Phase ◽  
Molecular Structures ◽  
Transition Curve ◽  
Geometrically Nonlinear ◽  
Group Efficiency ◽  
Normal Manner ◽  
Linear And Nonlinear ◽  
Transition Curves

A novel nonlinear chalconyl homologous series of ester: RO-C6H4-COO-C6H4 (m)-CO-CH:CH-C6H4-OC16H33(n) (para) have been synthesized and studied with a view to understand and establish the relation between thermotropic liquid Crystal (LC) properties and geometrically nonlinear shaped molecular structure. Homologous series consists of thirteen members ( C1 to C18) whose enantiotropic nematogenic mesomorphism commences from C6 homologue without exhibition of smectic property. C1 to C5 homologues are nonmesomorphic. Transition temperatures and textures of homologues were determined by an optical polarising microscopy equipped with a heating stage (POM). Transition curves of a phase diagrams (Cr-N/I and N-I) behaved in normal manner. N-I transition curve exhibited odd-even effect. Textures of a nematic phase are threaded or schlieren. Analytical and spectral data supported molecular structures of homologues. Thermal stability for nematic is 104.5°C whose degree of mesomorphism vary minimum of 13.0°C to maximum of 37.0°C. Group efficiency order for nematic is derived by comparing present novel series with structurally analogous other homologous series. Thus, homologous series of present investigation is nematogenic with absence of smectic property and of middle ordered melting type with considerable degree of mesomorphism.

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