92966-92-2Relevant academic research and scientific papers
Liquid crystal behavior of Ag(I) complexes based on a series of mesogenic 1,3,4-thiadiazole ligands
Tomi, Ivan Hameed R.,Al-Karawi, Ahmed Jasim M.,OmarAli, Al-Ameen Bariz,Al- Heetimi, Dhafir T. A.
, p. 8 - 26 (2021/07/02)
2-(4-Alkoxyphenyl)-5-(p-tolyl)-1,3,4-thiadiazoles (alkoxy: O(CH2) n H, n = 1–8) (6a–h) (as a series of 1,3,4-thiadiazole derivatives) and their silver(I) complexes: bis(2-(4-alkoxyphenyl)-5-(p-tolyl)-1,3,4-thiadiazole)-silver(I) complexes (alkoxy: O(CH2) n H, n = 1–8) (7a–h) were prepared and characterized with different techniques: microelemental analysis, FTIR, UV–Vis, 1H NMR, 13C NMR and mass (for the organic compounds) spectra, in addition to the molar conductivity measurements (for Ag(I) complexes). Liquid crystal behavior of the two series of compounds was evaluated using polarized light optical microscopy (POM). The study revealed that both series are enantiotropic liquid crystalline materials (exhibiting wide mesomorpic temperature ranges) with different behavior and properties. 6a–f displayed only nematic mesophase upon heating and cooling, while 6g and 6h exhibited both of SmC and nematic mesophases upon heating and cooling. Upon complexation of 1,3,4-thiadiazoles (6a–h) to silver(I), the liquid crystal behavior and properties are significantly changed (different mesophases, and lower mesophase and clearing temperatures). However, 7b–h exhibited SmA mesophase upon heating and cooling, while 7a shows no mesomorphic properties (simply melted to isotropic liquid).
Columnar self-assembly, gelation and electrochemical behavior of cone-shaped luminescent supramolecular calix[4]arene LCs based on oxadiazole and thiadiazole derivatives
Sharma, Vinay S.,Shah, Akshara P.,Sharma, Anuj S.,Athar, Mohd
supporting information, p. 1910 - 1925 (2019/01/28)
A new class of blue light-emitting supramolecular liquid crystalline cone or bowl-shaped compounds were synthesized from substituted 1,3,4-oxadiazoles and 1,3,4-thiadiazoles inbuilt with ester groups containing substituted alkoxy side chains (-OC4H9,-OC8H17) at the lower rim of calix[4]arene. These supramolecular compounds were investigated by polarizing optical microscopy (POM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), high-temperature X-ray diffraction (XRD), cyclic voltammetry (CV) and photophysical behavior studies. It was observed that the 1,3,4-thiadizole calix[4]arene-based derivatives are more capable of stabilizing the hexagonal columnar phase over a broad thermal range compared to the 1,3,4-oxadiazole calix[4]arene derivatives. The cone-shaped calixarene-based LCs with terminally substituted alkyl chains are packed into columns with enhanced intermolecular interactions. Moreover, the 1,3,4-oxadiazole calix[4]arene derivatives show deeper blue emissions compared to the 1,3,4-thidiazole calix[4]arene derivatives in solution as well as in thin films. The thermal and photophysical behaviors of the synthesized bowl-shaped supramolecular derivatives are extremely dependent on the terminal substituted alkoxy chains on the lower rim of calix[4]arene. Due to their hexagonal columnar phases and the emissive nature of their supramolecular liquid crystal and xerogel states, these molecules are favourable for application in emissive electronic displays. The 1,3,4-thiadiazole calix[4]arene derivatives display lower band gaps than the 1,3,4-oxadiazole calix[4]arene derivatives and are considered to be promising entities for applications in organic light emitting diodes (OLEDs).
Synthesis, characterization of new carboxylic acid derivatives bearing 1,3,4-thiadiazole moiety and study their liquid crystalline behaviors
Jaffer, Hamed J.,Aldhaif, Yasmeen A.,Tomi, Ivan H. R.
, p. 199 - 215 (2017/03/08)
Thirteen carboxylic acid derivatives containing 1,3,4-thiadiazole ring in their core and swinging alkoxy terminal were synthesized. They were characterized by 1H, 13C NMR spectroscopy, FTIR, and mass spectrometry. Their liquid crystalline behaviors have been studied by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The 1,3,4-thiadiazole compounds in this study were 2,5 di-substituted asymmetrical, alkoxy, and carboxy linkages. The compounds with alkoxy of long carbon chains (n > 7) displayed Smectic C phase. The liquid crystal properties were found to be affected by the length of alkoxy chain attached to the phenyl moiety and the two types of the dimeric form were resulted from the hydrogen bonding interaction between carboxylic acid molecules.
17O NMR studies of substituted 1,3,4-oxadiazoles
Gierczyk, Blazej,Zalas, MacIej,Kazmierczak, Marcin,Grajewski, Jakub,Pankiewicz, Radoslaw,Wyrzykiewicz, Bozena
experimental part, p. 648 - 654 (2012/01/06)
Three series of substituted 1,3,4-oxadiazoles were studied by 17O NMR spectroscopy. Chemical shifts values were correlated with empirical Hammett parameters as well as calculated bond lengths and chemical shielding values.
Facile synthesis and stracture of novel 2,5-disubstituted 1,3,4-selenadiazoles
Hua, Guoxiong,Li, Yang,Fuller, Amy L.,Slawin, Alexandra M.Z.,Woollins, J. Derek
experimental part, p. 1612 - 1618 (2009/08/09)
The reaction of hydrazide with carbony] chloride in the presence of sodium carbonates leads to the corresponding 1,2- diacylhydrazines [1a-t, R 1C(O)NHNHC(O)R2, R1 = aryl, R2 = aryl or alkyl] in moderate to excellent yield (57-90%). The latter reacts with 2,4-diphenyl-l,3-diselenadiphosphetane- 2,4-diselenide (Woollins' reagent, WR) in refluxing toluene to give a series of new 2,5-disubstituted 1,3,4-selenadiazoles (2a-t, 51-99% yield). All compounds were characterized spectroscopically and six compounds were characterized crystalloqraphically. Wiley-VCH Verlag GmbH & Co. KGaA.
