Synthesis and crystal structure of silicon pernitride SiN2 at 140   GPa

Silicon pernitride, SiN2, was synthesized from the elements at 140   GPa in a laser-heated diamond anvil cell. Its crystal structure was solved and refined by means of synchrotron-based single-crystal X-ray diffraction data. The title compound crystallizes in the pyrite structure type (space group Pa\overline{3}, No. 205). The Si atom occupies a site with multiplicity 4 (Wyckoff letter b, site symmetry .\overline{3}.), while the N atom is located on a site with multiplicity 8 (Wyckoff letter c, site symmetry .3.). The crystal structure of SiN2 is comprised of slightly distorted [SiN6] octahedra interconnected with each other by sharing vertices. Crystal chemical analysis of bond lengths suggests that Si has a formal oxidation state of +IV, while nitrogen forms pernitride anions (N — N)4 – .

Source: Acta Crystallographica Section E - September 19, 2023 Category: Chemistry Authors: Jurzick, P.L. Krach, G. Br ü ning, L. Schnick, W. Bykov, M. Tags: nitrides pernitrides silicon nitrides high pressure crystal structure research communications Source Type: research