A ferroelectric liquid crystal dimer: Synthesis and properties

Marcos, Mercedes; Omenat, Ana; Serrano, José Luís; Sierra, Teresa; Ezcurra, A.

doi:10.1002/adma.19920040409

Cited by 181 publications

(56 citation statements)

References 13 publications

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“…Cr-I or Cr-Sm transition curve adopt a zigzag path of rising and falling with overall descending tendency and behaved in normal manner. Sm-I or vice versa transition curve initially rises from C 8 and passes through a maxima at the C 14 homologue and then start to descend at C 16 homologue, without exhibition of odd-even effect. Thus, both transitions curves behave in normal manner.…”

Section: Resultsmentioning

confidence: 98%

“…o Ortho substituted -Br group of novel series is smectogenic from C 8 to C 16 . Homologues C 1 to C 7 are nonliquid crystal.…”

Section: Discussionmentioning

confidence: 99%

“…i.e. smectogenic mesophase formation facilitated to appear under microscopic observation from C 8 to C 16 . The absence of nematic mesophase formation is attributed to the weaker end to end intermolecular attractions whose magnitudes are insufficient or below suitable magnitudes of anisotropic forces of intermolecular end to end attractions as required to maintain statistically parallel orientational order of molecule in floating condition.…”

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confidence: 99%

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Dependence of Liquid Crystalline Behaviors on Molecular Flexibility

Maheta

Bhola

Bhoya

2015

ILCPA

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A novel homologous series of thermotropic liquid crystal (LC) has been synthesized with a view to understand and establish the effect of molecular structure on liquid crystal behaviors of a series. The present LC series consist of twelve homologues (C 1 to C 16 ); whose mesomorphic properties commence from octyloxy (C 8 ) homologue of a series. C 8 , C 10 and C 12 members of a series are monotropic smectic and C 14 , C 16 members are enantiotropically smectogenic. C 1 to C 7 homologues are nonmesomorphic. Nematogenic property is totally absent. Transition and melting temperatures are determined by an optical polarizing microscopy equipped with a heating stage. Textures of smectic mesophases are focal conic three or two dimensional networking of the type A or C. Cr-I/Sm and Sm-I or I-Sm transition curves behaved in normal manner. Analytical and spectral data confirms the molecular structures of homologues. Thermal stability of smectogenic mesophase is 100.6 o C and mesomorphic phase length is very short (12.9 o C to 15.3 o C). LC properties of a present novel series are compared with the structurally similar homologous series. Present series is partly smectogenic and partly non mesomorphic with poor degree of mesomorphism and middle ordered melting type without exhibition of nematogenic behavior.

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Section: Resultsmentioning

confidence: 98%

“…o Ortho substituted -Br group of novel series is smectogenic from C 8 to C 16 . Homologues C 1 to C 7 are nonliquid crystal.…”

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

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Dependence of Liquid Crystalline Behaviors on Molecular Flexibility

Maheta

Bhola

Bhoya

2015

ILCPA

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“…Present investigation is planned with a view to understand and establish the effect of molecular structure on mesomorphic behaviour with reference to absence of one phenyl ring bonded through carboxy or vinyl carboxy central bridge, affecting molecular rigidity; in combine with molecular flexibility [2,3,4,5]. Reduction in molecular rigidity may lower transition temperatures which may be useful for LC devices [6,7] and the presence of chalconyl central bridge may act properly as antibacterial, antifungal, antimalarial and anticancer etc.…”

Section: Introductionmentioning

confidence: 99%

“…The molecules of series-1 consisted of two phenyl rings and one central bridge -CH=CH-CO-are more coplanar than the corresponding homologues of series-X, which results into early commencement of mesophase from C 2 homologue of series-1 and from later C 3 homologue of series-X for nematic and reversal of it for smectic i.e. C 6 and C 4 . The molecules of series-X consisted of three phenyl rings bonded through two central bridges are more rigid than the corresponding homologues of series-1 which have high resistivity towards exposed thermal vibrations ( higher ΔH) requires more energy to transact from one physical state to other physical state.…”

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confidence: 99%

Study of the Effects of Decreasing Molecular Rigidity on Mesomorphism

Sharma

Jain

Patel

2016

ILCPA

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A Chalconyl homologous series: RO-C6H4-CH=CH-CO-C6H4-OC14H29(n) (meta) is synthesized and studied with a view to understand and establish the effect of molecular structure on Liquid crystal behaviour by reducing molecular rigidity through diminishing of a phenyl ring and a central carboxy or vinyl carboxy group from a molecule. Novel series consists of thirteen homologues (C1to C18). First member (C1) homologue is nonliquid crystal and the rest of the homologues (C2to C18) are enantiotropically ( C2to C5) nematogenic or monotropically (C6to C18) nematogenic plus smectogenic of low mesophaselengths and low transition temperatures ( 38°C to 76°C). Transition temperatures were determined by an optical polarizing microscopy (POM) equipped with a heating stage. Cr-N/I, N-I, I-N, N-Sm transition curves behaved in normal manner in a phase diagram. N-I and I-Sm transition curves exhibited odd-even effect. Textures of nematic phase are threaded or schlieren and that of the smectic phase are of the type A or C. Analytical, spectral and thermal data supported molecular structure of homologues. Thermal stability ( N-I/ I-N) of series for nematic is 67.5°C and that of the smectic is very low. Group efficiency order derived on the basis of thermal stability is as under. –Cl with –C6H4.COO- > -OC14H29(n) without –C6H4.COO-with reference to central bridge –CH=CH-CO-.

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