56240-75-6Relevant academic research and scientific papers
Binary systems of non-mesogens with naphthalene derivatives
Yao, Yong fang,Patel,Prajapati, Ashish Kumar,Sangani, Chetan B.,Duan, Yong-Tao
, p. 31 - 42 (2021/04/14)
Binary mixtures with both the components are non-mesogenic becomes an interesting and enlighten feature when they exhibit mesomorphism at ambient temperature. In the present study, we report five binary systems where two non-mesogenes exhibit smectic and/or nematic mesophases at ambient temperature over a certain range of concentration. All the binary systems contain one non-mesogenic naphthalene derivative. The study provides many binary systems of non-mesogens which exhibit mesophases at ambient temperatures. The terminal nitro chain is found to be responsible for the induction of both the nematogenic and smectogenic tendency in the present investigation of binary systems with two ‘compatible' component.
Synthesis and mesomorphic properties of novel Schiff base liquid crystalline EDOT derivatives
Gowda, Ashwathanarayana,Roy, Arun,Kumar, Sandeep
, p. 840 - 847 (2016/12/30)
Herein, we reported novel banana liquid crystals derived from ethylenedioxythiophene (EDOT) central unit encompass with Schiff base. Structural charecterization of these compounds was carried out from their spectral and elemental analysis. Physical properties of all the newly synthesized compounds were investigated by polarising optical microscopy, differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction and Raman spectroscopy. EDOT bearing three-ring Schiff base bent-core compounds are non-mesomorphic but all the Schiff bases containing five-rings exhibit enantiotropic mesophase behaviour. The higher homologues show long range nematic phase along with a smectic C phase at lower temperature. While the lower homologues exhibit only N phase. The bent-angle in these compounds is in between of calamitic LCs and banana LCs; therefore, the molecules escape from the polar order packing observed in typical bent core LCs. Detailed XRD investigation endorses the presence of the N phase in lower homologues and Sm C phase in higher homologues.
Study of mixed mesomorphism in binary systems of azo-ester mesogens with structurally dissimilar nonmesogenic as well as mesogenic ester homologues
Bhatt, Himanshu S.,Patel, Purvang D.,Dave, Jayrang S.
, p. 80 - 91 (2014/01/06)
We have studied mixed mesomorphism in four binary systems comprising two azo-ester mesogens, viz. 4-(4′-n-alkoxybenzoyloxy)3-methylphenyl azo-2″ and 4″-dimethylbenzenes (where n-alkoxy is n-butoxy or n-hexyloxy), and two ester nonmesogenic and mesogenic components, viz. 4-nitrophenyl-4′-n-alkoxybenzoates (where n-alkoxy is n-butoxy or n-hexyloxy). All the four binary systems are mesogenic in nature, showing nematic phase with threaded/marble texture. The phase diagrams of the binary systems are plotted and eutectic transition temperatures and maximum mesophase ranges of the nematic mesophase in all the systems are determined.
Phase characterization and study of molecular order of a three-ring mesogen by 13C NMR in smectic C and nematic phases
Kalaivani,Narasimhaswamy,Das, Bibhuti B.,Lobo, Nitin P.,Ramanathan
, p. 11554 - 11565 (2011/12/15)
Molecules exhibiting a thermotropic liquid-crystalline property have acquired significant importance due to their sensitivity to external stimuli such as temperature, mechanical forces, and electric and magnetic fields. As a result, several novel mesogens have been synthesized by the introduction of various functional groups in the vicinity of the aromatic core as well as in the side chains and their properties have been studied. In the present study, we report three-ring mesogens with hydroxyl groups at one terminal. These mesogens were synthesized by a multistep route, and structural characterization was accomplished by spectral techniques. The mesophase properties were studied by hot-stage optical polarizing microscopy, differential scanning calorimetry, and small-angle X-ray scattering. An enantiotropic nematic phase was noticed for lower homologues, while an additional smectic C phase was found for higher homologues. Solid-state high-resolution natural abundance 13C NMR studies of a typical mesogen in the solid phase and in the mesophases have been carried out. The 13C NMR spectrum of the mesogen in the smectic C and nematic phases indicated spontaneous alignment of the molecule in the magnetic field. By utilizing the two-dimensional separated local field (SLF) NMR experiment known as SAMPI4, 13C-1H dipolar couplings have been obtained, which were utilized to determine the orientational order parameters of the mesogen. ? 2011 American Chemical Society.
Exhibition of induced mesophases in the binary systems where both the components are non-mesogenic
Prajapati,Pandya, Himanshu M.
, p. 43 - 54 (2007/10/03)
Binary systems of two non-mesogens exhibiting mesomorphism are rare. In the present study few binary systems of non-mesogens exhibiting smectic and/or nematic mesophases are reported. One of the components is Schiff base having terminal isopropyl group and the other component contains an ester linkage. The binary systems of non-mesogens with terminal isopropyl group having identical structures (homologues) also exhibit induced mesomorphism. Some of the binary compositions exhibit smectic phase at ambient temperature. The phase diagrams of the present study are discussed in detail and the common features emerging from the overall study are outlined.
