Synthesis, optical and electrochemical properties of new hyperbranched poly(triphenylamine amide)s

Direct synthesis of triphenylamine-containing polyarylsulfones from commercially available aniline

A novel triphenylamine-containing polyarylsulfone (PAS-TPA) was synthesized from commercially available aniline and 1,1′-sulfonylbis(4-fluorobenzene) via two-step N–C coupling reaction under nucleophilic substitution polycondensation condition. Subsequently, a new series of polysulfones with different TPA contents (PSU-TPAs) was developed by the same method. Both PAS-TPA and PSU-TPAs not only exhibited good thermal stability and solubility but also exhibited intense ultraviolet absorption and fluorescence and high fluorescence quantum yield (approximately 16–42%). Their ideal highest occupied molecular orbital level (approximately −5.5 to −5.6) indicated the potential application of these polymers in organic photoelectronic fields.

Low-band gap and fluorescent poly(triphenylamine-thiazolo[5,4-d]thiazole) copolymer dye

The synthesis, characterization and spectroscopy of a new fluorescent poly(triphenylamine-thiazolo[5,4-d]thiazole) dye with low band gap energy have been reported.

C–N cross-coupling reaction catalysed by reusable CuCr2O4 nanoparticles under ligand-free conditions: a highly efficient synthesis of triarylamines

A convenient, efficient and ligand-free method for the C–N coupling reaction of anilines and aryl iodides was performed using CuCr₂O₄ nanoparticles.

Synthesis and properties of poly(p-phenylene vinylene) derivatives with hyperbranched structure and containing a nitro substituent

Abstract

In order to improve efficiency, processability, and stability, two groups of novel poly(p-phenylene vinylene) (PPV) derivatives (P₁–P₃ and P₄–P₆) with hyperbranched structure and containing a nitro substituent were synthesized via a Gilch reaction in different monomer ratios. The properties of the polymers were investigated by using UV–Vis absorption, fluorescence spectroscopy, cyclic voltammetry, and thermogravimetric analysis. The result shows that the band gaps of the PPV derivatives with a nitro substituent were decreased and the polymers had higher molecular weights (10⁶), excellent solubility in common organic solvents, good film-forming ability, and better thermal stability. The polymers can be used as an efficient acceptor material in polymeric solar cells.

Graphical abstract

Hole transport in triphenylamine based OLED devices: from theoretical modeling to properties prediction

For the series of para-substituted triphenylamines, optimized geometries, HOMO and LUMO energy levels, ionization potentials Ip, reorganization energies for hole transport λ(+), and frontier orbital contours have been calculated by means of ab initio computations. Relationships between them and the Hammett parameter are presented. According to calculations, electron releasing substituents increase the HOMO and LUMO energies of TPA, while electron withdrawing ones decrease it. This behavior is reflected in subsequent decreasing and increasing of ionization potentials of substituted TPAs. Calculations show that there exists also a strong substituent effect on the reorganization energy λ(+), which is a dominating factor of hole mobility. It is concluded that proper tuning of the HOMO and LUMO levels (and, as a result, ionization potential, Ip) and reorganization energy λ(+) (consequently, hole mobility) of the triphenylamine can be done by alteration of the TPA electronic structure by an appropriate substitution. It is demonstrated that the proper adjustment of the HOMO levels of HTM facilitates the reduction of an energy barrier at the interface of ITO/HTL and HTL/EL and ensure the high hole injection and hole transport rate. On the other hand, appropriate adjustment of the LUMO level prevents an electron leak from the EL into the HTM layer. Results of these calculations can be useful in the process of designing new HTM materials of desired properties (high efficiency, stability, and durability).