Synthesis, characterization, investigation of mesomorphic properties and DFT studies of a new 2,5-(dimethoxy)-2-[[(4-(dodecyloxy)phenyl)imino]methyl]benzene): a material liquid crystal for optoelectronics

In this article, synthesis, characterization and mesomorphic properties of a new calamitic liquid crystal, 2,5-(dimethoxy)-2-[[(4-(dodecyloxy)phenyl)imino]methyl]benzene) (DDPIMB) are described. The phase transition temperatures of the DDPIMB mesomorphic compound have been carried out by differential scanning calorimetry and optical polarizing microscopy. Geometry optimization calculations have been made for the two possible isomers as cis and trans of DDPIMB using the DFT/B3LYP/6-311++G(d,p) level of theory. According to the theoretical calculation results, trans isomerism was found more stable than cis isomerism. Therefore, all theoretical calculations were made for the trans-isomer and compared to the observed results. Vibrational assignments of the observed infrared spectra of title compound were carried out based on the calculated potential energy distributions (PEDs). The electronic properties of the DDPIMB were shown on the TD-DFT/B3LYP level. The optical behavior of the liquid crystal DDPIMB was determined through basic optical parameters, nonlinear optics (NLO) properties and dipole moments. Moreover, frontier molecular orbitals and molecular electrostatic potential (MEP) were determined to define the chemical activity of the headline molecule. The obtained results showed that this liquid crystal is a candidate material that can be used in NLO, optics and optoelectronic technology

A new synthesis of limonene copolymer: experimental and theoretical analysis

A copolymer of limonene with 2-(4-methoxyphenylamino)-2-oxoethyl methacrylate (LIM-co-MPAEMA) which is thought to be a non-toxic and used generally as a dietary supplement was synthesized and characterized for the first time both experimentally and theoretically. The structure of synthesized limonene copolymer was chemically characterized by Fourier transform infrared and nuclear magnetic resonant (1H NMR) spectroscopic techniques and compared with the theoretical calculated results. Charge transfer that is important in the formation of chemically bonded adducts causing cancer is quantitatively calculated. It was found that this polymer can be used as a biomaterial. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature

Synthesis and mesomorphic properties of new side chain liquid crystalline oligomers containing salicylaldimine mesogenic groups

New liquid crystalline salicylaldimine-based homopolymers PLC1 and PLC2 have been synthesized from their corresponding monomers 5-(10-undecenyloxy)-2-[[(4-(hexyloxy)phenyl)imino]methyl]phenol (LC1) and 5-(10-undecenyloxy)-2-[[(4-(hexyl)phenyl)imino]methyl]phenol (LC 2) via free radical polymerization. The polymers were characterized by 1H-NMR, differential scanning calorimetry (DSC) and optical microscopy in polarized light (polarizing microscope). The synthesized polymers have low molecular weights, and so are in the oligomeric domain. The oligomers behave very similarly to their monomers that exhibit smectic mesophases. Replacing the hexyloxy chain by a hexyl chain of the mesogenic unit generates an additional SmC mesophase in the temperature range of both the monomer and oligomer. All the observations suggest that the oligomerization of the liquid crystalline salicylaldimine monomers gives rise to decreased transition temperatures whereas it has no influence on the type and stability of the mesophase formed. © 2013 Copyright Taylor and Francis Group, LLC.The work has been supported by Yildiz Technical University Scientific Research Projects Coordination Department under Project Number: 24–01-02–03. We also acknowledge Mrs. N. Coskun for the synthesis of PLC1 and PLC2

Synthesis, characterization and mesomorphic properties of side Chain liquid crystalline oligomer having schiff base type mesogenic group

A new liquid crystalline oligomer OLC was synthesized from its monomer having Schiff-base type mesogenic group MLC via free radical polymerization. The chemical structures of all compounds were confirmed using UV, FTIR, 1H NMR, 13C NMR and MS spectroscopy. Schiff-base type thermotropic system based on side chain oligomer containing long aliphatic branching was studied to determine the change in mesophase behaviour of the Schiff-base type mesogenic groups. A combination of differantial scanning calorimetry (DSC) and polarize optical microscopy (POM) demonstrated that the oligomer behaves similar to its monomer and both of them exhibit enantiotropic SmC and monotropic SmX mesophases. The oligomerization of the liquid crystal monomer gives rise to decreased transition temperatures whereas it has no influence on the type and stability of the mesophase formed. Namely, simply through oligomerization, we can greatly vary transition temperatures of the mesogenic groups. © 2014 VBRI press