Dimer liquid crystals with bent mesogenic units

Three series of dimer liquid crystals containing an aromatic and a cholesteryl mesogenic unit were synthesized and investigated The compounds within the series differ in the length of the spacer connecting the mesogenic groups. Two of the three series contain an aromatic mesogenic group that is connected to the spacer at a meta-position instead of the para-position. Due to the presence of this bent mesogenic group, the odd-even effect in the transitional properties that is normally observed for dimer liquid crystals is reversed as compared with that of the third series, which contains a para-substituted aromatic mesogenic group. The reversed odd-even effect is found for the isotropization temperatures, the associated enthalpy changes and also for the optical properties.

[1]  M. Laguerre,et al.  Dimesogenic compounds with an electron-attracting terminal group , 2000 .

[2]  Yoon-Sok Kang,et al.  Synthesis and liquid crystalline properties of T-shaped dimesogenic compounds , 1999 .

[3]  M. Laguerre,et al.  Dimesogenic compounds consisting of a cholesteryl moiety and an aromatic mesogen interconnected through a central pentamethylene spacer , 1999 .

[4]  Y. Takanishi,et al.  Structure and Switching in Bent-Shaped Molecular Liquid Crystal Systems with Two Mesogenic Groups Linked by Alkylene Spacer , 1999 .

[5]  G. Pelzl,et al.  Banana-Shaped Compounds—A New Field of Liquid Crystals , 1999 .

[6]  M. Laguerre,et al.  Influence of the molecular length on the occurrence of incommensurate low ordered smectic phases for non-symmetric dimesogenic compounds , 1999 .

[7]  W. H. Jeu,et al.  Side-Chain Liquid-Crystalline Polymers from the Alternating Copolymerization of Maleic Anhydride and 1-Olefins Carrying Biphenyl Mesogens , 1999 .

[8]  S. Lagerwall,et al.  A review of textures of the TGBA* phase under different anchoring geometries , 1999 .

[9]  C. Imrie.  Liquid Crystal Dimers , 1999 .

[10]  G. Pelzl,et al.  Designing banana-shaped liquid crystals without Schiff's base units: m-terphenyls, 2,6-diphenylpyridines and V-shaped tolane derivatives , 1999 .

[11]  J. Goodby.  Twist Grain Boundary (TGB) Phases , 1999 .

[12]  Jung‐Il Jin,et al.  H-shaped dimeric LC compounds: synthesis and thermotropic properties of alpha, omega -bis\[2,5-bis(4-ethoxyphenoxycarbonyl)phenoxy]alkanes , 1998 .

[13]  Y. Takanishi,et al.  Antiferroelectric Smectic Liquid Crystal Formed by Achiral Twin Dimer with Two Mesogenic Groups Linked by Alkylene Spacer , 1998 .

[14]  John W. Goodby,et al.  Handbook of liquid crystals , 1998 .

[15]  Jung‐Il Jin,et al.  Competition in low ordered smectics between incommensurate phases and two-dimensional modulated ones for dimesogenic compounds , 1998 .

[16]  C. Tschierske,et al.  Synthesis and thermotropic liquid crystalline properties of calamitic molecules with laterally attached hydrophilic groups : Y-shaped three-block molecules which can form smectic and columnar mesophases , 1998 .

[17]  Y. Takanishi,et al.  Origin of Helix in Achiral Banana-Shaped Molecular Systems , 1997 .

[18]  G. R. Luckhurst,et al.  Symmetric and non-symmetric liquid crystal dimers with branched terminal alkyl chains : racemic and chiral , 1997 .

[19]  E. Sudhölter,et al.  Odd-even effects in the optical properties of chiral triplet liquid crystals based on estradiol , 1996 .

[20]  E. Sudhölter,et al.  Influence of spacer lengths on the properties of chiral triplet liquid crystals based on estradiol. , 1996 .

[21]  S. Diele,et al.  Synthesis and liquid-crystalline properties of novel laterally connected twins: the influence of the connecting topology and the length of the rigid core , 1996 .

[22]  E. Sudhölter,et al.  Thermal and optical properties of chiral twin liquid crystalline bis(cholesteryl) alkanedioates. , 1996 .

[23]  J. Goodby,et al.  5-Bromo-2-iodopyrimidine: a novel, useful intermediate in selective palladium-catalysed cross-coupling reactions for efficient convergent syntheses , 1996 .

[24]  S. Okamoto,et al.  Thermodynamics and molecular ordering of carbonate‐type dimer liquid crystals with emphasis on the geometrical characteristics of the linking group , 1995 .

[25]  Jung‐Il Jin,et al.  From Incommensurability to Commensurability in Smectic Phases for a Series of Dimesogenic Liquid Crystals , 1995 .

[26]  E. Sudhölter,et al.  Odd-even effects in the thermotropic and optical properties of three series chiral twin liquid crystals. , 1995 .

[27]  E. Sudhölter,et al.  Odd-even effects in the thermotropic and optical properties of chiral triplet liquid crystals. , 1995 .

[28]  G. R. Luckhurst.  Liquid crystal dimers and oligomers: Experiment and theory , 1995 .

[29]  Jung‐Il Jin,et al.  Novel sequence with incommensurate SA phases in a new dimesogenic liquid crystal , 1994 .

[30]  E. Sudhölter,et al.  Odd-even effects in the optical properties of chiral twin liquid-crystalline cholestryl w-(cyanobiphenylyloxy)alkanoates. , 1994 .

[31]  G. R. Luckhurst,et al.  An enhanced odd-even effect of liquid crystal dimers Orientational order in the α,ω-bis(4′-cyanobiphenyl-4-yl)alkanes , 1993 .

[32]  G. R. Luckhurst,et al.  Smectogenic dimeric liquid crystals. The preparation and properties of the α,ω-bis(4-n-alkylanilinebenzylidine-4′-oxy)alkanes , 1992 .

[33]  T. Endo,et al.  Synthesis and radical copolymerization of new type pyridinum monomer and redox behavior of its polymers , 1990 .

[34]  S. Diele,et al.  From laterally branched mesogens to novel twin molecules , 1989 .

[35]  G. R. Luckhurst,et al.  Non-symmetric dimeric liquid crystals The preparation and properties of the α-(4-cyanobiphenyl-4′-yloxy)-ω-(4-n-alkylanilinebenzylidene-4′-oxy)alkanes , 1988 .

[36]  D. Demus,et al.  Liquid-crystalline compounds with lateral aromatic branches , 1988 .

[37]  V. Percec,et al.  Liquid crystalline polymers containing heterocycloalkane mesogens. 2. Side‐chain liquid crystalline polysiloxanes containing 2,5‐disubstituted‐1,3‐dioxane mesogens , 1987 .

[38]  Stewart E. Hazlet.  The Bromination of 4-Phenylphenylbenzenesulfonate , 1937 .

[39]  Stewart E. Hazlet.  Some New Sulfonic Acid Esters , 1937 .