Synthesis, Photophysical, and Electrochromic Characterization of Wholly Aromatic Polyamide Blue-Light-Emitting Materials

Abstract

A new carbazole-derived triphenylamine-containing aromatic dicarboxylic acid monomer, 4,4′dicarboxy-4′′-N-carbazolyltriphenylamine, with blue light (460 nm) fluorescence quantum yield of 40% was successfully synthesized by the cesium-fluoride-mediated condensation of N-(4-aminophenyl)carbazole with 4-fluorobenzonitrile, followed by alkaline hydrolysis of the dinitrile intermediate. A series of novel poly(amineamide)s with pendent N-phenylcarbazole units having inherent viscosities of 0.36-0.61 dL/g were prepared from the newly synthesized dicarboxylic acid monomer and various aromatic diamines by direct phosphorylation polycondensation. The obtained polymers were amorphous and could afford flexible, transparent, and tough films with good mechanical properties. They had useful levels of thermal stability associated with relatively high glasstransition temperatures (269-322 °C). These polymers exhibited strong UV-vis absorption maxima at 340-361 nm, and their photoluminescence showed emission peaks around 449-465 nm with quantum yields up to 46% in NMP solution. The hole-transporting and electrochromic properties were examined by electrochemical and spectroelectrochemical methods. Cyclic voltammograms of the poly(amine-amide) films prepared by casting polymer solution onto an indium-tin oxide (ITO)-coated glass substrate exhibited one reversible oxidative redox couples at potentials of 1.11-1.18 V vs Ag/AgCl in acetonitrile solution due to oxidation of main-chain triphenylamine unit. The polymer films revealed excellent stability of electrochromic characteristics for the radical cations generated, changing color from original yellowish to deep blue.

Determination of Enantiomeric Compositions of Analytes Using Novel Fluorescent Chiral Molecular Micelles and Steady State Fluorescence Measurements

“…Generally, it is expected that the fluorescence quantum yields and lifetimes of the FCMMs are likely to be different from the corresponding amino acid standard due to polymerization, aggregation, structure, cavity size, dynamic equilibrium, and hydrophobicity. Also, multiple fluorophores brought into close proximity because of polymerization have been reported to have increased quantum yields and different fluorescence lifetimes as compared to the corresponding monomer [31,32].…”

Effect of triphenylamine as electron-donor evenly spaced in 2, 4, 6 and 8 thiophene units of the main chain: synthesis and properties

“…4,4 0 -Bisdinitro-triphenylamine was synthesized according to Liou et al [30], then the dinitro compound was reduced using hydrazine and 10 % Pd/carbon as catalyst to obtain 4,4 0 -bis amino-triphenylamine, Fig. 1.…”

A new donor–acceptor double‐cable carbazole polymer with perylene bisimide pendant group: Synthesis, electrochemical, and photovoltaic properties

“…N,N 0 -Di(2-ethylhexyl)perylene-3,4,9,10-tetracarboxylicacid bisimide (3) and N-(2-ethylhexyl)-3,4,9,10-perylenetetracarboxylic acid 3,4-anhydride-9,10-imide (4) were prepared according to the previously published procedures. 22 Although the syntheses and characterizations of 9-(4-nitrophenyl)-9H-carbazole (1) and 4-(9H-carbazol-9-yl)aniline (2) were previously described by Liou et al, 23 the procedure followed for the synthesis in this work is slightly different.…”