72245-80-8Relevant academic research and scientific papers
Liquid crystal control of bimolecular thermal reactions. Highly regioselective pericycloaddition of fumarates to 2,6-dialkoxyanthracenes in liquid-crystalline media
Kansui,Hiraoka,Kunieda
, p. 5346 - 5352 (2007/10/03)
The ability of liquid crystalline solvent phases to control the stereochemical course of bimolecular thermal reactions of 2,6-dialkoxyanthracenes with a series of fumarates conducted at 130-180°C has been examined, primarily with respect to the structural compatibility of the solutes with the solvent mesogens. For the case of the model thermal [4 + 2] cycloadditions of 2,6-bis(decyloxy)anthracene to bis(trans-4-cyclohexylcyclohexyl) and cholesteryl trans-4-cyclohexylcyclohexyl fumarates at 130-150°C, cholesteryl 2,4-dichlorobenzoate (CDCB) and bis(4-pentyloxyphenyl) trans-1,4-cyclohexanedicarboxylate (BPCD) serve well as cholesteric and smectic liquid crystalline solvents and result in the preferential formation of syn-isomers with an extremely high level of regioselection (syn/anti ≥ 20/1). In contrast, the isotropic solvents with closely related structures give isomer ratios of only ≥ 3/1. Structural similarities between the solutes and the solvent mesogens appear to play a key and influential role in controlling the stereochemical course of the reaction. The temperature dependence for the isomer distribution affords an estimate of the differences of solvation enthalpy and entropy between syn and anti transition states in the anisotropic media.
Reentrant Phases in New Polar Cyclohexane Series
Tinh, Nguyen Huu
, p. 143 - 152 (2007/10/02)
A homologous series of 4'-alkoxyphenyl 4''-cyanophenyl, 1,4-cyclohexanedicarboxylates in which the alkoxy group is C1 -> C12 has been prepared.Interphase transitions between solid, mesomorphic and isotropic phases were studied by hot stage microscopy.The
