6628-99-5Relevant academic research and scientific papers
THE EFFECT OF CARBONYL CONTAINING SUBSTITUENTS IN THE TERMINAL CHAINS ON MESOMORPHIC PROPERTIES IN AROMATIC ESTERS AND THIOESTERS, 2. ACYLOXY GROUPS ON THE PHENOLIC END
Neubert, Mary E.,Wildman, Patricia J.,Zawaski, Michael J.,Hanlon, Carol A.,Benyo, Theresa L.,Vries, Adriaan De
, p. 111 - 158 (2007/10/02)
The effect of replacing an alkoxy (Y=OR') with acyloxy (Y=OCOR') group on the phenolic end of the esters: on their mesomorphic properties has been studied.These esters were prepared by esterification of 4-acyloxyphenols with the appropriate acid chloride.The phenols were synthesized by acylation of 4-benzyloxyphenol with either an aliphatic acid or acid chloride followed by catalytic hydrogenolysis of the benzyl group.A comparison of the melting and clearing temperatures of these acyloxy esters with the corresponding known alkoxy ones showed small increases in both these temperatures for the acyloxy esters.The same types of mesophases (N, SA, SC, SB) were observed in both series, but the SB was more favored when Y=OCOR'.The SC phase was found to occur in the acyloxy series at chain lengths beyond which it disappeared in the alkoxy series.Comparisons were also made with the mesomorphic properties previously reported for the correponding alkyl and α-keto esters.Some correlation was observed between increasing dipole moments of these substituents and increasing transition temperatures but not in the types of mesophases observed.Fewer mesophases were found when the alkyl chain was attached to the benzene ring through a carbon atom than through an oxygen atom.
