Synthesis, Characterization, Electrical Conductivity and Fluorescence Properties of Polyimine Bearing Phenylacetylene Units

Abstract

In this study, a Schiff base was synthesized by the condensation reaction of 4-bromobenzaldehyde and 4-aminophenol. Then, phenylacetylene substituted Schiff base monomer (IPA) was obtained by HBr elimination reaction of IPA with phenylacetylene through Sonogashira reaction. IPA was polymerized via chemical oxidative polycondensation reaction. FT-IR and NMR measurements were used for the structural analyses of the synthesized substances. Fluorescence and UV-Vis analyses were carried out for optical characterization. Electrochemical characteristics, electrical conductivities and thermal properties were determined using cyclic voltammetry (CV), four-point probe conductometer, TG-DTA and DSC methods. The main purpose of the present study was to investigate the effects of phenylacetylene bearing units on the properties of conjugated aromatic polyimines. The spectral analysis signified a green light emission behavior when irradiated at different wavelengths. Combined with fluorescent behavior and good thermal stability, the electrical conductivity was found to be very crucial for π-conjugated polymer.

Polymerization of Chrysoidine with chemical and enzymatic oxidative preference: Synthesis, characterization, and spectroscopic study

“…As a result of doping with iodine at room temperature in a vacuum, its conductivity almost 4‐fold increased to 9.88 × 10 −7 and 1.56 × 10 −7 S cm −1 in 24 hours and reached to a maximal value of 3.15 × 10 −6 and 1.56 × 10 −6 S cm −1 in 120 hours, respectively. The coordination of nitrogen atoms of azo linkage in the polymer structure and iodine results in the formation of iodine doped polymer . A lower band gap between the HOMO‐LUMO orbitals with higher conductivity value makes the electronic transition easier.…”

Synthesis, characterization, optical and electrochemical band gaps of green poly(azomethine-ester)s containing oxalyl and succinyl units

“…The HOMO, LUMO and E g values of the synthesized products were identified as in ref. [36], and the calculated results are summarized in table 3. The lowest E g values were observed in para substituted (PAZ-E)s (P-13 and P-14).…”

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

“…Polyazomethines, also known as poly(Schiff base)s or polyimines, with general structure (R–CH=N–R′), are a group of organic conducting polymers [4,5] exhibiting excellent thermal [6,7,8], and mechanical properties. Conjugated polyazomethines show interesting optical [9,10,11,12], optoelectronic [13,14,15], and electrical [6,16,17,18] properties.…”

“…On the other hand, synthesis of polyazomethines might be catalyzed with mineral or organic acids, and the product is purified by a simple precipitation method. The conjugated polyazomethines are widely used as a counterpart for currently employed conjugated structures in optoelectronic devices [28] such as photovoltaic cells [29,30] and electroluminescent [19] and electrochromic [1,16,31] devices. Still, there are some practical problems with their low conductivity.…”

“…Over the past few decades, halogens (such as Br, Cl, I) have been the most commonly used doping elements. The effects of protonating and doping on the properties of imine (–CH=N–) polymers have been investigated in numerous papers [8,16,33,34,35]. The mechanism of iodine oxidative doping has been reported in previous publications [3,36], as the process of removing an electron from the lone pair of nitrogen atom.…”