Synthesis And Characterization Of Liquid Crystal Compounds Based On A Variety Of Chiral Units

Chiral liquid crystals(CLC)have attracted much interest because of their unique optical and electrical properties which due to their helical structures.Star-shaped crystal is a new type of liquid crystal which is different from the traditional liquid crystal,It has theoretical significance and application value because of its unique spatial configuration and rheological properties.In this dissertation,seven liquid crystalline monomers have been successfully synthesized,which include 6-(4-((4-ethoxybenzoyl)oxy)phenoxy)-6-oxohexanoic acid(M1),10-oxo-10-((4’-((4-(trifluoromethyl)benzoyl)oxy)-[1,1’-biphenyl]-4-y1)oxy)decanoic acid(M2),Di { 6-(4-((4-ethoxybenzoyl)oxy)phenoxy)-6-oxohexanoic acid } Chenodeoxycholic acid ester(M3),Di { 10-oxo-10一((4’-((4-(trifluoromethyl)benzoyl)oxy)-[1,1’-biphenyl]-4-y1)oxy)decanoic acid }Chenodeoxycholic acid ester(M4),5-isopropyl-2-methylcyclohexyl 4’-((4-(allyloxy)benzoyl)oxy)-[1,1’-biphenyl]-4-carboxylate(M5),5-isopropy 1-2-methylcyclohexyl 4’((4-(trifluoromethyl)benzoyl)oxy)-[1,1’-biphenyl]-4-carboxylate(M6),4’-((4-(trifluoromethyl)benzoyl)oxy)-[1,1’-biphenyl]-4-carboxylic Cholesterol ester(M7).A series of liquid crystals(LCs)named YE have been successfully synthesized by using M3 as the liquid crystal unit and reacting with 4-hydroxyphenyl 4-ethoxybenzoate,4’-hydroxy-[1,1’-biphenyl]-4-y14-(trifluoromethyl)benzoate,Allyl alcohol,4’-Hydroxy-4-biphenyl carbonitrile,menthol,Cholesterol,Isosorbide,1,2-propanediol,4,4’-Biphenyldiol.They are Di { 6-(4-((4-ethoxybenzoyl)oxy)phenoxy)-6-oxohexanoicacid }-Mono { 4-hydroxyphenyl 4-ethoxybenzoate } Chenodeoxycholic acid ester(YEYD),Di { 6-(4-((4-ethoxybenzoyl)oxy)phenoxy)-6-oxohexanoicacid }—Mono { 4’-hydroxy-[1,1’-biphenyl]-4-y1 4-(trifluoromethyl)benzoate } Chenodeoxycholic acid ester(YEFD),Di { 6-(4-((4-ethoxybenzoyl)oxy)phenoxy)-6-oxohexanoicacid } Chenodeoxycholic acid Allyl alcohol ester(YEBX),Di{ 6-(4-((4-ethoxybenzoyl)oxy)phenoxy)-6-oxohexanoicacid }-Mono { 4’-Hydroxy-4-biphenyl carbonitrile } Chenodeoxycholic acid ester(YEDJ),Di { 6-(4-((4-ethoxybenzoyl)oxy)phenoxy)-6-oxohexanoicacid } Chenodeoxycholic acid menthol ester(YEBH),Di { 6-(4-((4-ethoxybenzoyl)oxy)phenoxy)-6-oxohexanoicacid } Chenodeoxycholic acid Cholesterol ester(YEDZ),Di { Di { 6-(4-((4-ethoxybenzoyl)oxy)phenoxy)-6-oxohexanoicacid } Chenodeoxycholic acid }Isosorbide ester(YEYS),Di { Di { 6-(4-((4-ethoxybenzoyl)oxy)phenoxy)-6-oxohexanoicacid } Chenodeoxycholic acid } 1,2-propanediol ester(YEBE),Di { Di { 6-(4-((4-ethoxybenzoyl)oxy)phenoxy)-6-oxohexanoicacid } Chenodeoxycholic acid } 4,4’-Biphenyldiol ester(YELB).A series of liquid crystals(LCs)named FE have been successfully synthesized by using Ma as the liquid crystal unit and reacting with 4’-hydroxy-[1,1’-biphenyl]-4-y1 4-(trifluoromethyl)benzoate,Allyl alcohol,4’-Hydroxy-4-biphenyl carbonitrile,menthol,Cholesterol,Isosorbide,1,2-propanediol,4,4’-Biphenyldiol.They are Di { 10-oxo-10-((4’-((4-(trifluoromethyl)benzoyl)oxy)-[1,1’-biphenyl]-4-yl)oxy)decanoic acid }-Mono { 4’-hydroxy-[1,1’-biphenyl]-4-yl 4-(trifluoromethyl)benzoate }Chenodeoxycholic acid ester(FEFD),Di { 10-oxo-10-((4’-((4-(trifluoromethyl)benzoyl)oxy)-[1,1’-biphenyl]-4-yl)oxy)decanoic acid } Chenodeoxycholic acid Allyl alcohol ester(FEBX),Di { 10-oxo-10-((4’-((4一(trifluoromethyl)benzoyl)oxy)-[1,1’~biphenyl]-4-yl)oxy)decanoic acid }-Mono { 4’-Hydroxy-4-biphenyl carbonitrile } Chenodeoxycholic acid ester(FEDJ),Di { 10-oxo-10-((4’-((4-(trifluoromethyl)benzoyl)oxy)-[1,1’-biphenyl]-4-yl)oxy)decanoic acid }Chenodeoxycholic acid menthol ester(FEBH),Di { 10-oxo-10-((4’-((4－(trifluoromethyl)benzoyl)oxy)-[1,1’-biphenyl]-4-yl)oxy)decanoic acid }Chenodeoxycholic acid Cholesterol ester(FEDZ),Di { Di(10-oxo-10-((4’-((4-(trifluoromethyl)benzoyl)oxy)-[1,1’-biphenyl]-4-yl)oxy)decanoic acid }Chenodeoxycholic acid } Isosorbide ester(FEYS),Di { Di { 10-oxo-10-((4’-((4-(trifluoromethyl)benzoyl)oxy)-[1,1’-biphenyl]-4-yl)oxy)decanoic acid }Chenodeoxycholic acid } 1,2-propanediol ester(FEBE),Di { Di { 10-oxo-10-((4’-((4-(trifluoromethyl)benzoyl)oxy)-[1,1’-biphenyl]-4-y1)oxy)decanoic acid }Chenodeoxycholic acid } 4,4’-Biphenyldiol ester(FELB).(DSC)and polarizing optical microscopy(POM),XRD.Their structure-property relationships were discussed in detail.The optical rotation of monomers M3,M4,M5,M6,M7 and the two series of chiral liquid crystal compounds were characterized by the W22-2S-2SS Polarimeter of Shanghai.All the synthesized LCs are all consistent with the molecular design and show liquid crystal properties.M,is nematic LCs;M2 is smectic A LCs;M3,M5 and M7 are cholesteric LCs,M4 is chiral smectic A LCs;M6 is chiral smectic B LCs.The series of multi-arms LCs synthesized by using M3 as the liquid crystal unit all display thermotropic and bivariant LC properties.YEYD,YEDZ and YELB are cholesteric LCs;YEBX,YEDJ,YEBH,YEYS,YEBE are nematic LCs.YEFD displays cholesteric and nematic LC properties in heating cycle and nematic LC properites in cooling cycle.The series of multi-arms LCs synthesized by using M4 as the liquid crystal unit all display thermotropic and bivariant LC properties.FEFD,FEBX,FEDJ,FEDZ are cholesteric LCs;FEBH,FEYS,FEBE,YELB are chiral smectic A LCs.The research results of YE and FE series show that the properties of liquid crystal unit which was introduced into the two hydroxyl of chenodeoxycholic acid played a great influence on the properties of the two series of multi-arms LCs(YE series and FEseries).The LCs are prone to exhibit nematic and cholesteric properties when M1(nematic LC)was introduced into chenodeoxycholic acid.The LCs are prone to exhibit chiral smectic A and cholesteric properties when M2(smectic A LC)was introduced into it.The substituent(-CF3)in M2 has strong polarity.It enhances the lateral forces between the molecules.The LCs are prone to exhibit smectic A.