Stabilization Of The CN<sub>3</sub><sup>5−</sup> Anion In Recoverable High‐pressure Ln<sub>3</sub>O<sub>2</sub>(CN<sub>3</sub>) (Ln=La, Eu, Gd, Tb, Ho, Yb) Oxoguanidinates
Andrey Aslandukov, Pascal L. Jurzick, Maxim Bykov, Alena Aslandukovа, Artem Chanyshev, Dominique Laniel, Yuqing Yin, Fariia Iasmin Akbar, Saiana Khandarkhaeva, Timofey Fedotenko, Konstantin Glazyrin, Stella Chariton, Vitali B. Prakapenka, F. Wilhelm, Andreï Rogalev, Davide Comboni, Michael Hanfland, Natalia Dubrovinskaia, Leonid Dubrovinsky
Abstract
Abstract A series of isostructural Ln 3 O 2 (CN 3 ) (Ln=La, Eu, Gd, Tb, Ho, Yb) oxoguanidinates was synthesized under high‐pressure (25–54 GPa) high‐temperature (2000–3000 K) conditions in laser‐heated diamond anvil cells. The crystal structure of this novel class of compounds was determined via synchrotron single‐crystal X‐ray diffraction (SCXRD) as well as corroborated by X‐ray absorption near edge structure (XANES) measurements and density functional theory (DFT) calculations. The Ln 3 O 2 (CN 3 ) solids are composed of the hitherto unknown CN 3 5− guanidinate anion—deprotonated guanidine. Changes in unit cell volumes and compressibility of Ln 3 O 2 (CN 3 ) (Ln=La, Eu, Gd, Tb, Ho, Yb) compounds are found to be dictated by the lanthanide contraction phenomenon. Decompression experiments show that Ln 3 O 2 (CN 3 ) compounds are recoverable to ambient conditions. The stabilization of the CN 3 5− guanidinate anion at ambient conditions provides new opportunities in inorganic and organic synthetic chemistry.