96288-40-3Relevant academic research and scientific papers
Dependence of molecular structure on mesomorphic behavior with special reference to central bridge
Patel, Brijesh H.,Doshi, Ankita A.,Doshi
, p. 38 - 46 (2015)
A novel homologous series of liquid crystalline 4-(4′-n-alkoxy cinnamoyloxy)-4″-methoxy benzyl cinnamates was synthesized and studied with a view to understand and establish the effects of molecular structure on liquid crystal behavior. The series consists of eleven members of the series. None of the homologue derivatives are either nonliquid crystal or smectogenic, i.e. all the eleven members of the novel homologous series are enantiotropcially nematogenic only. Transition and melting temperatures as well as textures of the nematic mesophase were determined on an optical polarizing microscope equipped with a heating stage. The transition curves of the phase diagram show phase behavior in a normal expected manner. An odd-even effect is observed for the nematic-isotropic transition curve. The textures of the nematic mesophase are threaded or Schlieren as determined a by miscibility method. Analytical and spectral data confirm the molecular structures of the homologues. The average thermal stability for nematic is 213.8°C. The isotropic temperatures vary between 190°C and 240°C. The nematogenic mesophase length varies from 17°C to 102°C. Thus, the novel homologous series is entirely nematogenic without the exhibition of smectogenic character. The liquid crystal (LC) properties of the present novel series are compared with structurally similar other known homologous series.
Study of mesomorphism and its relation to molecular structure with special reference to central bridges viz. -COO- and -CH=CH-COO- of the homologous series
Sharma,Solanki,Patel,Patel
, p. 137 - 145 (2016/03/01)
Two ester homologous series of mesogens, viz., Methyl-p-(p′-n-alkoxy benzoyloxy) cinnamates (X) and Methyl-p-(p′-n-alkoxy cinnamoyloxy) cinnamates (Y) being structurally similar are discussed. Both (X) and (Y) differ in respect of central bridges linking two phenyl rings. Only enantiotropic nematogenic character is observed without exhibition of any smectic character by all members of series (X) and (Y). Thermal stability of series (X) is relatively low as compared to (Y), but nematogenic mesophase lengths are of reverse order. Solid-nematic/solid-isotropic and nematic-isotropic transition curves in the phase diagrams behave in normal manner.
Study of a new homologous series of liquid crystals: Isopropyl-p-(p/-n-alkoxy cinnamoyloxy) cinnamates
Jain,Jadeja,Sharma,Patel
, p. 146 - 153 (2016/03/01)
A new homologous series: isopropyl-p-[p/-n-alkoxy cinnamoyloxy] cinnamates was synthesized and studied with a view to understanding and establishing the relation between liquid crystal property and molecular structure. Twelve homologues were synthesized. Methyl to butyl homologues are not liquid crystals, while pentyl, hexyl, heptyl, octyl, decyl, dodecyl, tetradecyl, and hexadecyl derivatives are enantiotropic liquid crystal in nature with nematogenic character. Smectogenic character is totally absent. A phase diagram is obtained by plotting a graph of transition temperatures versus number of carbon atoms is n-alkyl chain of left n-alkoxy terminal end group. Solid-isotropic or solid-nematic transition curve rises steeply from methyl to propyl derivatives and falls to pentyl homologue through butyl homologue, and follows a zigzag path of rising and falling values as the series is ascended. Nematic-isotropic transition curve shows descending tendency as series is ascended in a normal manner with exhibition of odd-even effect. Smectic mesophase does not appear even in the monotropic condition. Phase transition temperatures are determined by hot stage polarizing microscope. Analytical data support the structure of molecules. Texture of nematic mesophase is of threaded type. Mesomorphic properties are compared with structurally similar homologous series.
FLUOROALKANE DERIVATIVE, GELATOR, LIQUID CRYSTALLINE COMPOUND AND GEL COMPOSITION
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Paragraph 0124-0125, (2017/01/05)
PROBLEM TO BE SOLVED: To provide a novel fluoroalkane derivative, a gelator comprising a compound thereof, a gel composition comprising the gelator, and a liquid crystalline compound comprising the novel fluoroalkane derivative. SOLUTION: The present invention provides a fluoroalkane derivative represented by general formula (1): R2-L1-Ar1-X1-R1 (where, Ar1 is a substituted or unsubstituted divalent aromatic group having 6 to 30 nuclear atoms, R1 is a saturated or unsaturated monovalent hydrocarbon group having a perfluoroalkyl group with 2 to 22 carbon atoms, X1 is an oxygen atom, a sulfur atom or a group represented by -SO2-, R2 is a specific monovalent group, L1 is a group represented by -COO- or a group represented by -OCO- depending on the type of R2). SELECTED DRAWING: None COPYRIGHT: (C)2017,JPOandINPIT
Mesomorphism Dependence on Terminally Substituted End Group
Marathe, Rajesh B.,Doshi
, p. 1 - 8 (2015/12/30)
A novel homologous series of liquid crystalline substances has been synthesized and studied with a view to understanding and establishing the relation between liquid crystal properties and molecular structure. The novel ester series consists of eleven enantiotropically smectogenic homologous without exhibition of nematogenic property. Transition temperatures were determined with an optical polarizing microscope equipped with a heating stage. Textures of smectic mesophase are focal conic fan shaped of smectic A or C type. Analytical and spectral data confirms the molecular structures of homologous. Transition curve, Cr-Sm behaved in normal manner. Transition curve Sm-I behaved in a normal manner up to the octyloxy (C8) homolog derivative and then behaved in the unusual manner for the C10, C12, C14, and C16 derivatives. An odd-even effect is observed for the Sm-I transition curve. The series entirely smectogenic with a middle-ordered melting type and a moderate mesophase length. The average thermal stability for smectic is 128.09°C and mesophase length ranges from 8.6°C to 73.2°C. The mesomorphic (LC) behavior of the novel series is compared with structurally similar known homologous series.
Mesomorphism and molecular structure: Novel homologous series 4-(4′-n-alkoxy cinnamoyloxy)-4″-methoxy benzyl benzoates
Patel, Brijesh H.,Doshi
, p. 78 - 86 (2015/03/14)
A novel homologous series consists of 11 homologues, studied with a view to understand and establish the relations between mesomorphism and molecular structure of novel substances. All the novel members of a series except methoxy and pentyloxy homologue derivatives are liquid crystalline [LC] in nature. Mesomorphism commences from a second member of a series ethoxy, propyloxy, butyloxy, and hexyloxy to hexadecyloxy homologue derivatives are nematogenic while decyloxy, dodecyloxy, and tetradecyloxy homologue derivatives are smectogenic, in addition to nematogenic. All mesogenic homologues of a series are enantiotropic mesomorphic. Phase transition curve for Smectic-Nematic behave in normal manner without exhibition of odd-even effect, whereas nematic-isotropic transition curve adopts serpentile shape as rising and falling nature with exhibition of very minor odd-even effect. Textures of nematic phase are threaded or schlieren and that of a smectic mesophase is a focal conic fan shaped of the type smectic A or C. Analytical and spectral data supported molecular structures of homologues. The mesomorphic behaviors of present series are compared with a structurally similar other known series. Smectic and nematic thermal stabilities are 182.6 and 246.0°C, respectively. Present series is partly smectogenic and predominantly nematogenic with considerable degree of mesomorphism (maximum 100 °C) and high melting type.
Study of the effect of molecular structure on mesomorphic properties through a novel homologous series α-3-[4′-n-alkoxy cinnamoyloxy] phenyl-β-4″-nitro benzoyl ethylenes
Suthar,Doshi
, p. 76 - 83 (2013/08/24)
Eleven members of a novel homologous series α-3-[4′-n-Alkoxy Cinnamoyloxy] phenyl-β-4″-nitro benzoyl ethylene are synthesized and evaluated for their mesomorphic properties. Seven members of the series are enantiotropically nematogenic without exhibition of smectogenic character, and the other four members are non-mesomorphic in character. Mesomorphic behavior from a phase diagram for solid to nematic and for nematic to isotropic transitions shows the normal behavior. The nematic to isotropic transition curve shows an odd-even effect. Analytical data support the structures of molecules. Nematogenic phase length ranges from 30°C to 62°C. Nematic-isotropic thermal stability is 175.7°C. The mesomorphic properties of the series are compared with the structurally similar isomeric series. Thus, the series is predominantly mesomorphic (nematogenic) and partly non-mesomorphic with middle-order melting points. Transition temperatures and other liquid crystal properties were determined by optical polarizing microscopy with a heating stage.
Synthesis and mesomorphic properties of novel ethylene derivatives
Chaudhari,Patel,Doshi
, p. 95 - 102 (2013/08/23)
A novel homologous series, α-4-[-4′-n-alkoxy cinnamoyloxy] benzoyl-β-4″-methoxy phenyl ethylenes, has been synthesized, which consists of 12 homologues. The pentyl to tetradecyl homologues are enantiotropically mesomorphic, and the rest of the homologues are nonmesomorphic. The pentyl to octyl derivatives exhibit smectogenic character in addition to nematogenic character, but the decyl to tetradecyl homologues exhibit only nematogenic character without the exhibition of a smectic phase. A phase diagram of three transition curves shows a normal phase behavior. Analytical and spectral data confirm the molecular structure of the homologues. The optical microscopic textures are threaded or Schlieren for the nematic phase and the normal smectic A type, respectively. Liquid crystal properties and transition temperatures were determined using a hot stage polarizing microscope. The smectic and nematic thermal stabilities are 159.7°C and 174.1°C, respectively. Thus, the present novel series is predominantly nematogenic and partly smectogenic in nature and is compared with other structurally similar homologous series.
Synthesis and evaluation of a novel liquid crystalline homologous series: α-4-[4′-n-alkoxy cinnamoyloxy] benzoyl-β-3′,4′- dimethoxy phenyl ethylenes
Suthar,Doshi,Doshi
, p. 51 - 58 (2013/08/23)
The synthesis and evaluation of a novel series of 12 homologues is presented. Enantiotropic nematogenic mesomorphism is exhibited from the pentyl to hexadecyl homologues. The other homologues are not liquid crystalline. Smectic mesomorphism is absent in all homologues. Transition temperatures were determined using an optical polarizing microscope equipped with a heating stage. The transition curves of a phase diagram behave in a normal manner. An odd-even effect is observed for the N-I transition curve. The textures of the nematic phase are of the threaded or Schlieren type. Mesomorphic-isotropic transition temperatures range from 152°C to 178°C. The nematogenic phase length varies between 24°C and 51°C. The nematic thermal stability is 163.1°C. Thus, the novel homologous series is entirely nematogenic without the exhibition of smectogenic character, and is of a middle ordered melting type. Analytical and spectral data support the molecular structures. Liquid crystal (LC) properties of the novel series are compared with structurally similar homologous series.
Synthesis and mesomorphism of novel liquid-crystalline isobutyl-p-(p-n- Alkoxy Cinnamoyloxy) cinnamates
Patel,Patel,Doshi
, p. 3 - 9 (2012/05/19)
A new homologous series viz. Isobutyl-p-(p-n-alkoxy cinnamoyloxy) cinnamates consisting of 11 homologs has been synthesized with an isobutyl cinnamate end group and a further cinnamate moiety as a linking group. The methyl to butyl homologs are nonmesomorphic, and the pentyl to hexadecyl derivatives are enantiotropic nematogens without exhibition of any smectic phases. The average thermal stability for the nematic phase is 138.1C with a middle ordered melting point. The structures of the novel materials were confirmed by spectroscopic techniques. The liquid crystal phase type was determined by optical polarizing microscopy and all textures are of the threaded type. The mesomorphic behavior of the series is compared with a structurally similar homologous series.
