In the current study, we evaluated the solubility of a number of organometallic species and showed that it is noticeably improved in diiodomethane when compared to other haloalkane solvents. The better solvation properties of CH I were associated with the substantially better σ-hole-donating ability of this solvent, which results in the formation of uniquely strong solvent-(metal complex) halogen bonding. The strength of the halogen bonding is attenuated by the introduction of additional halogen atoms in the organometallic species owing to the competitive formation of more favourable intermolecular complex-complex halogen bonding. The exceptional solvation properties of diiodomethane and its inertness towards organometallic species make this solvent a good candidate for NMR studies, in particular, for the acquisition of spectra of insensitive spins.

Oxygen surface exchange kinetics and diffusion have been studied by the isotope exchange method with gas phase equilibration using a static circulation experimental rig in the temperature range of 600-800 °C and oxygen pressure range of 0.13-2.5 kPa. A novel model which takes into account distributions of the dissociative adsorption and incorporation rates has been developed. The rates of the elementary stages have been calculated. The rate-determining stages for a La2NiO(4±δ) polycrystalline specimen have been discussed. The diffusion activation energies calculated using the gas phase equilibration method (1.4 eV) differ significantly from those calculated using isotope exchange depth profiling (0.5-0.8 eV), which was attributed to the influence of different oxygen diffusion pathways.

A new application for bis­(cyclometalated) iridium­(III) species containing ancillary acyclic diaminocarbene ligands, viz. for sensing of mercury­(II) ions, is disclosed. A family of bis­(cyclometalated) iridium­(III) species supported by both parent isocyanide and acyclic diaminocarbene ligands was prepared, and their electrochemical and photophysical properties were evaluated, revealing efficient blue-green phosphorescence in solution with quantum yields of up to 55%. We uncovered that the photophysical properties of these complexes are dramatically altered by the presence of metal ions and that the complex [Ir­(ppy)2(CN)­{C­(NH2)­(NHC6H4-4-X)}] with an ADC ligand reacts selectively with Hg2+ ions, enabling its use for sensing of mercury­(II) ions in solution. The limit of detection was as low as 2.63 × 10–7 M, and additional mechanistic studies indicated the formation of an unusual dinuclear iridium­(III) cyclometalated intermediate, bridged by a mercury dicyano fragment as a driving force of mercury sensing.

A family of the C,N-cyclometalated species [Pt­(ppy)­Cl­(PPh3)], [Pt­(ppy)­Cl­(CNCy)], [Pt­(ppy)­(CNCy)­(PPh3)]­(OTf), and [Pt­(ppy)­(CNCy)2]­(BF4) (ppy = 2-phenylpyridinato-C 2,N; Cy = cyclohexyl) was generated from [Pt­(ppy)­(μ-Cl)]2, CNCy, and PPh3. The obtained platinum­(II) complexes were characterized by high-resolution ESI+-MS, IR, and 1D (1H, 13C­{1H}, 195Pt­{1H}) and 2D (1H,1H-NOESY; 1H,13C-HSQC; 1H,13C-HMBC) NMR spectroscopy, and the latter three complexes were investigated by X-ray diffraction. All four platinum species were examined as hydrosilylation catalysts (c 10–4–10–3 M; 80–120 °C; [Pt­(ppy)­Cl­(PPh3)] exhibited the highest catalytic activity) for the cross-linking of vinyl-terminated polydimethylsiloxane and polymethylhydrosiloxane to achieve luminescent silicone rubbers. Each solid complex and the appropriate silicone rubber exhibited the same emission spectra in the green region and strong phosphorescence with a solid-state quantum yield of up to 12.5% (measured for the silicone elastomer obtained with the [Pt­(ppy)­(CNCy)2]­(BF4) catalyst). The resulting luminescent silicone rubbers can be potentially used for protective coatings (to facilitate the thickness control) and as a component for phosphor-converted white light-emitting diodes (to transform a UV part of the LED emission to the visible spectrum).