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[en] Highlights: • New chalcogen-halogen diatomics. • Reliable characterization of excited electronic states including spin-orbit effects. • Should help plan and guide future experimental investigations. • Transition moments, transition probabilities, radiative lifetimes. A new species, selenium monoiodide (SeI), was investigated for the first time at a high level of theoretical approach, SA-CASSCF/MRCI. The overall picture of all doublet and quartet (Λ + S) states correlating with the three lowest dissociation channels and the associated Ω states provide reliable results to help understand the lack of experimental data on its transitions and to plan the investigation and determination of spectroscopic parameters. Transition probabilities were computed for the transitions X₂ – X₁, A₁ – X₁, A₂ – X₁, and A₂ – X₂, originated from the spin-forbidden 1 ⁴Σ⁻ - X ²Π system, and the corresponding radiative lifetimes evaluated.

[en] Luminescence is observed in three novel macropolyhedral nineteen- and eighteen-vertex chalcogenaboranes: Se${}_2$B${}_{17}$H${}_{17}$ (1), SeB${}_{17}$H${}_{19}$ (3) and SeB${}_{18}$H${}_{20}$ (4). This led us to the recognition that previously published macropolyhedral heteroborane species might also exhibit luminescence. Thus, the known nineteen- and eighteen-vertex dithiaboranes S${}_2$B${}_{17}$H${}_{17}$ (2), n-S${}_2$B${}_{16}$H${}_{16}$ (5) and i-S${}_2$B${}_{16}$H${}_{16}$ (6) were synthesised and also found to exhibit a range of luminescent properties. These macropolyhedral species are very different from the previously unique fluorescent binary borane B${}_{18}$H${}_{22}$ in terms of their structural architectures, by the presence of borane cluster hetero atoms, and, as in the cases of 5 and 6, that their synthetic origins are not derived simply through the modification of B${}_{18}$H${}_{22}$ itself. They consequently greatly expand the possibilities of finding new luminescent inorganic borane species. (© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH)

[en] The synthesis of various [⁷⁵Se]selenonium compounds of biological interest is described. [⁷⁵Se]Trimethylselenonium iodide (Sp. Ac. 32 mCi/mmol), prepared from commercially available [⁷⁵Se]selenocystine was decomposed thermally, in a stream of nitrogen, to give [⁷⁵Se]dimethyl selenide, which was trapped in nitromethane at -18⁰C. [⁷⁵Se]Dimethyl selenide was reacted, in nitromethane solution, with various alkyl halides to give dimethylselenonium compounds of the type (CH₃)₂Se⁺-R, where R = -CH₂CO₂H, -CH₂CO₂C₂H₅, -(CH₂)₂CO₂H and -(CH₂)₂CO₂C₂H₅. [⁷⁵Se]Methyl-selenomethionine-selenonium iodide was synthesized from [⁷⁵Se]selenomethionine and methyl iodide in a mixture of formic and acetic acids at 25⁰C. [⁷⁵Se]Selenocystine was reduced and methylated to give [⁷⁵Se]-methylselenocysteine, which was slowly converted to [⁷⁵Se]dimethyl-selenocysteineselenonium iodide by the same reaction. (author)

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[en] The research in the area of graphene derivatives containing chalcogen elements is currently an exclusive domain of oxygen- and sulfur-containing functional groups. Here we report an effective introduction of selenium-based organic functional groups and propose a mechanism of their attachment to graphene and graphene-related materials. Fluorographene can be effectively functionalized by selenium-containing group, forming C-Se bonds without undesired formation of elemental selenium, using selenourea. A similar reaction on graphene oxide is accompanied by the formation of elemental selenium due to oxidation of selenourea by oxygen-containing functional groups of graphene oxide. The formation of C-Se bonds was confirmed by several spectroscopic methods. The selenium covalently-modified graphene represents the first example of graphene-selenium compound with potential application in gas sensing. (paper)

[en] The formation of a new, metastable phase c.f.c. with a =5.65 A, in polycrystalline and orientated form films, in the Ag-Se system, is reported. The appearance of this phase is strictly connected with a high temperature of substrate (>220degC) and an excess of Se, during the evaporation. On the KBr(100) faces, maintained at 230degC, large grains of cubic c.f.c. phase orientated with (100) plane parallel to the substrate, are present. (author)

[en] A solution containing selenomethionine - ⁷⁵Se is provided with a thiol as a stabilisor, characterised in that the solution contains a thiol with a methyl group or a glutamyl group. (G.C.)

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