Browsing by Author "Win, Yip Foo"

Now showing 1 - 2 of 2

New mesogenic Schiff base esters comprising benzothiazole moiety: Synthesis and mesomorphic properties
(2009-09-01)
Ha, Sie Tiong
;
Koh, Teck Ming
;
Yeap, Guan Yeow
;
Lin, Hong Cheu
;
Beh, Jun Kit
A homologous series of Schiff base esters, 6-methoxy-2-(2-hydroxy-4-alkanoyloxybenzylidenamino)benzothiazoles, comprising a benzothiazole moiety as the core was synthesized. All the members of this series exhibited an enantiotropic nematic phase. The azomethine linkage along with the lateral hydroxyl and terminal methoxyl groups were found to exert an effect on the mesomorphic properties. (C) 2009 Sie Tiong Ha. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
Synthesis and mesomorphic properties of Schiff base esters possessing terminal chloro substituent
(2010-06-01)
Ha, Sie Tiong
;
Ong, Lay Khoon
;
Lee, Siew Ling
;
Lin, Hong Cheu
;
Win, Yip Foo
A homologous series of Schiff base esters, 4-chlorobenzylidene-4'-n-alkanoyloxyanilines, containing even number of carbons at the end groups of the molecules (C(n-1)H(2n-1)COO-, n = 4, 6, 8, 10, 12, 14, 16) were synthesized. The mesomorphic properties were investigated by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). It was found that the end groups of the molecules had an effect on the mesomorphic properties. n-Butanoyloxy was found non-mesogenic, whilst n-hexanoyloxy exhibited monotropic smectic phase. The higher members in this homologous series were enantiotropic smectogens. (C) 2010 Sie Tiong Ha. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.