Nitrosonium nitrate (NO+NO3−) structure solution using in situ single-crystal X-ray diffraction in a diamond anvil cell
Dominique Laniel,
Bjoern Winkler,
Egor Koemets,
Timofey Fedotenko,
Stella Chariton,
Victor Milman,
Konstantin Glazyrin,
Vitali Prakapenka,
Leonid Dubrovinsky,
Natalia Dubrovinskaia
Affiliations
Dominique Laniel
Material Physics and Technology at Extreme Conditions, Laboratory of Crystallography, University of Bayreuth, Bayreuth, 95440, Germany
Bjoern Winkler
Institut für Geowissenschaften, Abteilung Kristallographie, Johann Wolfgang Goethe-Universität Frankfurt, Altenhöferallee 1, Frankfurt am Main, D-60438, Germany
Egor Koemets
Bayerisches Geoinstitut, University of Bayreuth, Bayreuth, 95440, Germany
Timofey Fedotenko
Material Physics and Technology at Extreme Conditions, Laboratory of Crystallography, University of Bayreuth, Bayreuth, 95440, Germany
Stella Chariton
Center for Advanced Radiation Sources, University of Chicago, Chicago, Illinois 60637, USA
Victor Milman
Dassault Systèmes BIOVIA, Cambridge, Cambridgeshire CB4 0WN, United Kingdom
At high pressures, autoionization – along with polymerization and metallization – is one of the responses of simple molecular systems to a rise in electron density. Nitrosonium nitrate (NO+NO3−), known for this property, has attracted a large interest in recent decades and was reported to be synthesized at high pressure and high temperature from a variety of nitrogen–oxygen precursors, such as N2O4, N2O and N2–O2 mixtures. However, its structure has not been determined unambiguously. Here, we present the first structure solution and refinement for nitrosonium nitrate on the basis of single-crystal X-ray diffraction at 7.0 and 37.0 GPa. The structure model (P21/m space group) contains the triple-bonded NO+ cation and the NO3− sp2-trigonal planar anion. Remarkably, crystal-chemical considerations and accompanying density-functional-theory calculations show that the oxygen atom of the NO+ unit is positively charged – a rare occurrence when in the presence of a less-electronegative element.
