Zhen WANG, Tan LI, Yan-hao WEN, et al. Synthesis and properties of isothiocyanato pyrimidine acetylene liquid crystals[J]. Chinese journal of liquid crystals and displays, 2018, 33(9): 750-757.
DOI:
Zhen WANG, Tan LI, Yan-hao WEN, et al. Synthesis and properties of isothiocyanato pyrimidine acetylene liquid crystals[J]. Chinese journal of liquid crystals and displays, 2018, 33(9): 750-757. DOI: 10.3788/YJYXS20183309.0750.
Synthesis and properties of isothiocyanato pyrimidine acetylene liquid crystals
The pyrimidine ring outside of the rigid core ring of liquid crystal molecules used as a polar mesogenic group
can effectively increase the molecular dipole moment and intermolecular force
improve the dielectric anis-otropy of the compounds
reduce the driving voltage of the liquid crystal
and also favor to form some smec-tic phases. In this paper
where pyrimidine acetyleneisused as the central structural unit and isothiocyanide asthe end group
we could see that a series of liquid crystal compounds (nBTM-NCS) about five compounds were designed and synthesized. The molecular structure of all compounds were identified by IR
1
H-NMR
13
C-NMR and MS spectra
and their liquid crystal properties were measured by differential thermal analyzer (DSC) and polarizing microscope (POM).The experimental results show that all the compounds have the correct molecular structure and smectic phases. The melting point of the compounds is high and it shows a parity effect. Its optical anisotropy reaches about 0.45
and the dielectric constant is about 22 to 24. It can be used as the components for ferroelectric liquid crystals and polymer-dispersed liquid crystal materials.
PENG Z H, LIU Y G, YAO L S, et al . Synthesis and liquid crystal properties of isothiocyanate tolane compounds[J]. Chinese Journal of Liquid Crystals and Displays , 2011, 26(4):428-431. (in Chinese)
MCMANAMON P F, BOS P J, ESCUTI M J, et al . A review of phased array steering for narrow-band electrooptical systems[J]. Proceedings of the IEEE , 2009, 97(6):1078-1096.
PRAMANIKA, DAS M K, DAS B, et al . Preparation and study of the electro-optical properties of binary mixtures of orthoconic anti-ferroelectric esters and achiral phenyl pyrimidine liquid crystal[J]. Soft Materials , 2015, 13(4):201-209.
TIAN B. Synthesis and properties of new type pyrimidine liquid crystals[D]. Beijing: Tsinghua University, 2009. (in Chinese)
MONGELLI N, ANIMATI F, D'ALESSIO R, et al . 1-Fluorocycloalkanecarboxylic acids in the synthesis of 16-achiral 16-fluoro-9a-carbaprostacyclin derivatives[J]. Synthesis , 1988(4):310-313.
LIU G Z, XIA D L, HUANG Z Q, et al . Study of E-O characteristics of low-threshold voltage flexible PDLC films[J]. Materials Review , 2009, 23(1):1-5. (in Chinese)
KORNFIELD J, MICHAEL W, ZULEIKHA K. Ferroelectric liquid crystal (FLC) polymers: US, US2010220279 A1[P]. 2010-09-02.
TANB H. The novel of a new photoelectronic functional devices on PDLC[D]. Ningbo: Ningbo University, 2011. (in Chinese)
韩喆.浅析PDLC的显示原理及制作[J].现代显示, 2011, 22(4):31-32, 45.
HAN Z. Analysis of PDLC display principle and production[J]. Advanced Display , 2011, 22(4):31-32, 45. (in Chinese)
SRIVASTAVAA K, MA Y, GUO Q, et al . Polymer stabilized electrically suppressed helix ferroelectric liquid crystal cell: US, US2015138496A1[P]. 2015-05-21.
ZHAO J, YAN C L, DING Y, et al . Optical voltage sensor based on spiral deformation ferroelectric liquid crystal: CN, CN107782947A[P]. 2016-08-25. (in Chinese)
GAO H J, SHEN G Y. Application and research progress of liquid crystal in non-display area[J]. Fine and Specialty Chemicals , 2012, 20(3):1-4. (in Chinese)
BRADSHAW M J, RAYNES E P, FEDAK I. A correlation between short range smectic-like ordering and the elastic constants of nematic liquid crystals[J]. Journal of Physics , 1984, 45:157-162.
PETROV V F, TORGOVA S I, KARAMYSHEVA L A, et al . The trans-1, 4-cyclohexylene group as a structural fragment in liquid crystals[J]. Liquid Crystals , 1999, 26(8):1141-1162.
CSÁSZÁR A G, DEMAISON J, RUDOLPH H D. Equilibrium structures of three-, four-, five-, six-, and seven-membered unsaturated N-containing heterocycles[J]. The Journal of Physical Chemistry A , 2015, 119(9):1731-1746.
BURROW M P, GRAY G W, LACEY D, et al . The synthesis and liquid crystal properties of some 2, 5-disubstituted pyridines[J]. Liquid Crystals , 1988, 3(12):1643-1653.
PETROV V F, PAVLUCHENKO A I, SMIRNOVA N I. New liquid crystalline pyridine derivatives[J]. Molecular Crystals and Liquid Crystals , 1995, 265(1):47-53
SCHOENBERG A, BARTOLETTI I, HECK R F. Palladium-catalyzed carboalkoxylation of aryl, benzyl, and vinylic halides[J]. Journal of Organic Chemistry , 1974, 39(23):3318-3326.
DAI Z Q, ZHANG W W, ZHANG Z Y, et al . Iron-catalyzed cross-coupling reaction of alkyl halides with biphenyl grignard reagent[J]. Asian Journal of Chemistry , 2013, 25(11):6303-6305.
LIU X Q, REN X H, SHANG H Y, et al . Terminal isothiocyano liquid-crystal compound containing pyrimidine ring and preparation method thereof: CN, CN101580716A[P]. 2009-11-18. (in Chinese)
CATANESCU Q, CHIEN L C. High birefringence difluoroisothiocyanate biphenyl tolane liquid crystals[J]. Liquid Crystals , 2006, 33(1):115-120.
LIAO Y M, JANARTHANAN N, HSU C S, et al . Synthesis and mesomorphic properties of fluoro and isothiocyanato biphenyl tolane liquid crystals[J]. Liquid Crystals , 2006, 33(10):1199-1206.
FANTA P E, HEDMAN E A. 2-Substituted 5-nitropyrimidines by the condensation of sodium nitromalonaldehyde with amidines[J]. Journal of the American Chemical Society , 1956, 78(7):1434-1437.
MOL C, LI J, GUO Z Q, et al . Synthesis and properties of novel liquid crystal compounds containing pyridine ring[J]. Chinese Journal of Applied Chemistry , 2016, 33(5):542-548. (in Chinese)
DEJEU W H, EIDENSCHINK R. Smectic behavior and molecular structure:on the mesomorphism of a series of hydrocarbons[J]. Journal of Chemical Physics , 1983, 78(7):4637.
CAO Z L, XUAN L, HU L F, et al . Investigation of optical testing with a phase-only liquid crystal spatial light modulator[J]. Optics Express , 2005, 13(4):1059-1065.
GAUZA S, WEN C H, WU B J M, et al . High figure-of-merit nematic mixtures based on totally unsaturated isothiocyanate liquid crystals[J]. Liquid Crystals , 2006, 33(6):705-710.