Jia‐Jia Lin
2007
Citations
0
Influential Citations
0
Citations
Journal
Fine chemicals
Abstract
Six lateral difluorine substituted tolan-type liquid crystals were synthesized via Sonogashira cross-coupling of 4-alkylphenylacetylene and 4-iodo-2,3-difluoro-1-alkoxybenzene under the protection of argon.4-Iodo-2,3-difluoro-1-alkoxybenzene were obtained via double ortho-metalation reaction,etherification and oxidation by using ortho-difluorobenzene as starting material.The overall yield was 27.8%~41.9% with purity above 99%.Structures of the compounds were identified by IR and 1HNMR.Phase transitions of the compounds were tested by DSC and POM.It was found that nematic phase formed when the right terminal alkyl chain n=2 and the left terminal alkyl chain m≥5,and the left terminal alkyl chain m=5 and the right terminal alkyl chain n≥2.