Formation of High-Spin States (<i>S</i> = 3/2 and 2) in Linear Oligo- and Polyarylamines

This article describes the study of a linear trimer and three polyarylamines <b>PB1–3</b> containing a 3,4′-biphenyl ferromagnetic coupler. The synthesis of the model compound (trimer) and the polymers has been presented. The formation of radical cations was studied using electrochemical and optical (UV–vis) methods. The chemical oxidation of these compounds leads to the creation of high-spin states, evidenced by pulsed EPR nutation spectroscopy. A quartet spin state is observed for the trimer model compound, and its <i>J</i> exchange coupling constant has been measured experimentally (<i>J</i>/<i>k</i> = 11.8 K) and compared quantitatively to DFT calculations. Most importantly, quartet and quintet spin states have been formed for <b>PB3</b> and <b>PB2</b>, respectively. These last two doped polymers thus exhibit the highest spin states observed to date for linear polyarylamine compounds

Highly Phosphorescent Cyclometalated Iridium(III) Complexes for Optoelectronic Applications: Fine Tuning of the Emission Wavelength through Ancillary Ligands

A series of novel, highly phosphorescent cyclometalated iridium­(III) complexes of type [(X₂C^N)₂Ir­(Q₂bpy)]⁺PF₆^– (where X₂C^N is 2-phenylpyridine or 2-(2,4-difluorophenyl)­pyridine anion and Q₂bpy are 4,4′-bifunctionalized 2,2′-bipyridines) is presented. The complexes were fully characterized by means of NMR spectroscopy, high-resolution mass spectrometry (HRMS), cyclic voltammetry, and UV–vis. For several compounds also the crystallographic structures were obtained. The cyclometalates exhibited efficient photoluminescence at 298 K both in solution and in the solid state with good intensity and color purity. The emission wavelength range covered almost the whole visible spectrum and was strongly correlated with the EWG/ERG character of the Q substituent in the ancillary ligand. For further insight into the electronic structure of the complexes, a comprehensive electrochemical support (CV) was introduced, and finally, it was confronted with theoretical background using a density functional theory approach together with time-dependent calculations of the excited states