| Abstrakt: |
The dissociation of (Se6I2)(AsF6)2in SO2(1) has been investigated by 77Se NMR spectroscopy at –80 °C involving both a natural-abundance sample as well as that containing selenium enriched in the 77Se-isotope (enrichment 92 %). In addition to the previously characterized cations Se6I22+, SeI3+, 1,1,4,4-Se4I42+, Se102+, Se82+, and Se42+, the NMR spectra of the equilibrium solution exhibited additional resonances the assignment of which has been carried out by 77Se-77Se COSY, selective irradiation experiments, and spectral simulation. Combining this information with the trends in the chemical shifts as well as with iodine, selenium, and charge balances that were calculated from quantitative integrated intensities, the presence of cyclic cations Se7[+and 1,4-Se7I22+, as well as acyclic Se2I+, and 1,1,6,6-Se6I42+(two rotamers) could be inferred. Upon evaporation of the solvent only Se6I22+was found to be present in the solid state. |
