title: Effect of the chain length on the thermal and analytical properties of laterally biforked nematogens.
abstract: Three laterally substituted liquid crystals were synthesized in order to investigate the effect of a lateral biforked chain on the thermal and analytical properties. The mesogenic molecules have the same core containing four aromatic rings connected by two ester and one diazo linkages, they differ by the length of one chain within the lateral biforked substituent. The phase transition temperatures were obtained by polarized light microscopy and differential scanning calorimetry (DSC). The clearing temperature and the nematic range decrease with increasing length of the lateral biforked chain. The stationary phases derived from these nematogens provide excellent resolution of various classes of compounds, including aromatic hydrocarbons (AH), substituted benzenes, polycyclic aromatic hydrocarbons (PAH), phenols and volatile organic compounds (VOC) present in the essential oils. The selectivities of the stationary phases were found to decrease according to the length of the side chain.
authors.affiliation: Laboratoire de Chromatographie, Faculté de Chimie, Université des Sciences et de la Technologie Houari Boumediène, B.P. 32, El-Alia, 16111 Bab-Ezzouar, Alger, Algeria.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Dahmane
authors.forename: Fatiha
authors.initials: F
authors.lastname: Athman
authors.forename: Saïd
authors.initials: S
authors.lastname: Sebih
authors.forename: Moulay-Hassane
authors.initials: MH
authors.lastname: Guermouche
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Bayle
authors.forename: Soulimane
authors.initials: S
authors.lastname: Boudah
mesh_terms: D001555:Benzene Derivatives / Q000737:chemistry; D002152:Calorimetry, Differential Scanning; D002849:Chromatography, Gas / Q000379:methods*; D006841:Hydrocarbons, Aromatic / Q000737:chemistry*; D008853:Microscopy; D008958:Models, Molecular; D009822:Oils, Volatile; D044367:Phase Transition; D010636:Phenols / Q000737:chemistry*; D013696:Temperature
chemical_list: D001555:Benzene Derivatives; D006841:Hydrocarbons, Aromatic; D009822:Oils, Volatile; D010636:Phenols