Towards Heterolytic Bond Dissociation of Dihydrogen: the Study of Hydrogen in Arsenolite under High Pressure

The discovery of arsenic(III) oxide hydrogen inclusion compound As4O6∙2H2 formed under high pressure is presented. Synchrotron X-ray diffraction experiments and DFT computations permit for a proposal of the compound’s structural model, whereas Raman scattering experiments reveal significant softening of H−H stretching mode. This is attributed to the onset of heterolytic H−H bond dissociation induced by hydrogen interactions with arsenic(III) lone electron pairs based on ICOOP and ICOHP computational study.