Toward poly(aminophthalimide), structures of dimers and trimers

Effect of N-phenyl substituent on thermal, optical, electrochemical and luminescence properties of 3-aminophthalimide derivatives

The seven N-phthalimide derivatives substituted with the amine group at the 3-C position in the phenylene ring were synthesized. The effect of N-substituent chemical structure was investigated. The thermal, electrochemical and optical studies were performed and supported by the density functional theory calculations (DFT). The electrochemical investigations of the synthesized low-molecular phthalimides revealed the one oxidation and reduction process with the HOMO energy level under - 5.81 eV and energy-band gap below 3 eV. The N-phthalimide derivatives were emitted light in a blue spectral region in solutions (in polar and non-polar) with the quantum yield between 2 and 68%, dependent on the substituent at the nitrogen atom, solvent and concentration. The N-phthalimide derivatives were emissive also in a solid state as a thin film and powder. They were tested as a component of the active layer with PVK:PBD matrix and as an independent active layer in the organic light-emitting diodes. The registered electroluminescence spectra exhibited the maximum emission band in the 469-505 nm range, confirming the possibility of using N-phthalimides with PVK:PBD matrix as the blue emitters.

Synthesis and helical structures of poly(ω-alkynamide)s having chiral side chains: effect of solvent on their screw-sense inversion

New ω-alkynamides, (S)-HC≡CCH2CONHCH2CH(CH3)CH2CH3 (1) and (S)-HC≡CCH2CH2CONHCH(CH3)CH2CH2CH2CH2CH3 (2) were synthesized and polymerized with a rhodium catalyst in CHCl3 to obtain cis-stereoregular poly(ω-alkynamide)s (poly(1) and poly(2)). Polarimetric, CD, and IR spectroscopic studies revealed that in solution the polymers adopted predominantly one-handed helical structures stabilized by intramolecular hydrogen bonds between the pendent amide groups. This behavior was similar to that of the corresponding poly(N-alkynylamide) counterparts (poly(3) and poly(4)) reported previously, whereas the helical senses were opposite to each other. The helical structures of the poly(ω-alkynamide)s were stable upon heating similar to those of the poly(N-alkynylamide)s, but the solvent response was completely different. An increase in MeOH content in CHCl3/MeOH resulted in inversion of the predominant screw-sense for poly(1) and poly(2). Conversely, poly(3) was transformed into a random coil, and poly(4) maintained the predominant screw-sense irrespective of MeOH content. The solvent dependence of predominant screw-sense for poly(1) and poly(2) was reasonably explained by molecular orbital studies using the conductor-like screening model (COSMO).

Supramolecular chemistry with ureido-benzoic acids

A novel, complementary quadruple hydrogen-bonding motif is presented that shows very strong dimerization and is switchable with pH.

Biaryl phosphane ligands in palladium-catalyzed amination

Palladium-catalyzed amination reactions of aryl halides have undergone rapid development in the last 12 years, largely driven by the implementation of new classes of ligands. Biaryl phosphanes have proven to provide especially active catalysts in this context. This Review discusses the application of these catalysts in C-N cross-coupling reactions in the synthesis of heterocycles and pharmaceuticals, in materials science, and in natural product synthesis.