Electron acceptor–electron donor interactions. Part XXII. Charge-transfer interactions of some of the highest-valency halides, oxyhalides, and oxides with aromatic hydrocarbons and fluorocarbons. Ball–plane interactions. Some remaining elements

Abstract

Among the compounds examined, intermolecular charge-transfer spectra are demonstrated for π-donors with sulphuryl chloride, selenium hexafluoride, tellurium hexafluoride, perchloryl fluoride, iodine heptafluoride, iodine oxide pentafluoride, ruthenium tetroxide, and osmium tetroxide. Colours of many of the two-component mixtures vanish when frozen, and the selenium and tellurium hexafluorides in p-xylene (m.p. 13 °C) effervesce and expel the acceptor into the vapour phase. The spectra define extremely weak interactions in the solvents carbon tetrachloride or cyclohexane, although in some cases the systems are too reactive for convenient quantitative study, whereas the precision of measurement is low for the volatile hexafluorides. For the same molar concentrations, selenium and tellurium hexafluorides produce nearly identical spectra with respect to wavelength position and small absorptivity values. Both show broad structureless absorptions at the 220 nm region for solutions in cyclohexane which are not observed in carbon tetrachloride or perfluoromethylcyclohexane and these are ascribed to hydrocarbon to MF₆ intermolecular charge-transfer transitions.