Synthesis, Crystal Structures, and Spectroscopic Characterization of Bis-aldehyde Monomers and Their Electrically Conductive Pristine Polyazomethines

Abstract

Bis-aldehyde monomers 4-(4′-formyl-phenoxy)benzaldehyde (3a), 3-methoxy-4-(4′-formyl-phenoxy)benzaldehyde (3b), and 3-ethoxy-4-(4′-formyl-phenoxy)benzaldehyde (3c) were synthesized by etherification of 4-fluorobenzaldehyde (1) with 4-hydroxybenzaldehyde (2a), 3-methoxy-4-hydroxybenzaldehyde (2b), and 3-ethoxy-4-hydroxybenzaldehyde (2c), respectively. Each monomer was polymerized with p-phenylenediamine and 4,4′-diaminodiphenyl ether to yield six poly(azomethine)s. Single crystal X-ray diffraction structures of 3b and 3c were determined. The structural characterization of the monomers and poly(azomethine)s was performed by FT-IR and NMR spectroscopic techniques and elemental analysis. Physicochemical properties of polymers were investigated by powder X-ray diffraction, thermogravimetric analysis (TGA), viscometry, UV–vis, spectroscopy and photoluminescence. These polymers were subjected to electrical conductivity measurements by the four-probe method, and their conductivities were found to be in the range 4.0 × 10−5 to 6.4 × 10−5 Scm−1, which was significantly higher than the values reported so far.

Novel 2‐cyanoacrylamido‐4,5,6,7‐tetrahydrobenzo[b]thiophene derivatives as potent anticancer agents

“…However, a few studies have been performed on the use of bis ‐benzaldehydes as a starting material for the preparation of novel compounds with different applications such as redox flow battery, [ 25 ] biofunctional dynamic covalent polymer, [ 26 ] allosteric effectors of hemoglobin, [ 27 ] fluorescence‐based assay, [ 28 ] in Groebke–Blackburn–Bienayme/Ugi reactions, [ 29 ] electrical conductivity, [ 30 ] macrocyclization, [ 31 ] breaking and mending of the porphyrin, [ 32 ] and a broad spectrum of biological activities. [ 16,23 ]…”

The enhanced photocatalytic performance of CPAA doping with different concentrations of Titanium oxide nanocomposite against MB dyes under simulated sunlight irradiations

“…1 a displays the observed absorption bands in the resulting polymer and their assignments. There is an alteration to lower wavelengths compared to the monomer and the absence of the aliphatic peak CH 3 group at 2889 cm −1 in the IR range of CPAA; the CH=N (imine) bond can be seen at 1609 cm −1 , and the carbonyl carbon is at 1658 cm −1 indicating the polymer formation 32 , 36 – 38 . In addition, the existence of repeated monomer units causes a reduction in the wave number and intensity of the conjugated bonds in the polymer, leading to a semi-broad combined peak in the CPAA spectrum.…”

Polynaphthylimide–Azomethines Containing Triphenylamine or Carbazole Moieties with Tuned Optoelectronic Properties through Molecular Design

“…These have found a plethora of applications, such as electroluminescent materials in light-emitting devices, photonic memories or electrochromic materials, hole transporting materials in solar cells or active layers in organic field-effect transistors [8][9][10][11][12][13][14]. However, a challenge that still faces the development of polyazomethines is to obtain solution-processable, highly conducting or fluorescent materials in a neutral state [15][16][17]. In this regard, there is still a need to incorporate new functional groups in the main chains to attain both improved solubility and innovative physicochemical properties, so as to make them compatible with current optoelectronic devices.…”