Synthesis and ¹³C CPMAS NMR Characterization of Novel Thiophene-Based Nematogens

Abstract

The synthesis and characterization of novel thermotropic liquid crystals based on thiophene are reported. In these molecules, a thiophene ring, 1−4 disubstituted phenyl rings, and ester and azomethine linking units form the core fragment, and an alkoxy unit serves as the terminal group. All compounds exhibited an enantiotropic nematic phase, as confirmed by hot-stage polarizing microscope analysis and differential scanning calorimetry. Isotropic 13C chemical shift values measured from CPMAS experiments on crystalline solid and nematic phases were compared to the values obtained from the static nematic phase. These experiments demonstrate the alignment of molecules in the magnetic field. Lower melting and clearing values are observed when two phenyl rings are part of the mesogen, while the addition of a third phenyl ring increases these values.

Meso- and microporous soft templated hydrothermal carbons for dye removal from water

“…39 The change in the surface charge of the carbon materials was studied by determining the pH IEP . The intensity of the peak related to sp 3 carbons was found weaker, whilst the peak related to the aromatic structure at δ= 124.8 ppm proved more intense in FruLi+TCA compared to FruLi.…”

2-Octyl thiophene based three ring mesogens: solid state 13C NMR and XRD investigations

“…[3][4][5][6][7][8][9][10][11][12][13][14][15][16][17].0° in the measured temperature range (Table 5). By using the relationship S zz (II)/S zz (T) = P 2 (cosθ), 67 the angle θ between thiophene and phenyl ring is calculated to be 14.…”

“…[4][5][6] The replacement of phenyl ring with thiophene unit in a mesogenic core imparts dramatic change in property characteristics despite their common aromatic character. [9][10][11][12] Also, thiophene can change the lateral dipole moment of the mesogen and expand the mesophase range too. [9][10][11][12] Also, thiophene can change the lateral dipole moment of the mesogen and expand the mesophase range too.…”

Synthesis, Mesogenic and Spectroscopic Properties of 2,5‐Disubstituted Thiophene Derivatives.

“…[1][2][3] Moreover, thiophene is a well-known structural fragment of conjugated polymers which have gained importance for their potential applications to nonlinear optical materials, 4 organic light emitting diodes, 5-8 thin film transistors, 9 and molecular switches. [1][2][3] Moreover, thiophene is a well-known structural fragment of conjugated polymers which have gained importance for their potential applications to nonlinear optical materials, 4 organic light emitting diodes, 5-8 thin film transistors, 9 and molecular switches.…”