Ca[CO][CO] is a pyrocarbonate which can be formed at p, T-conditions prevalent in the Earth's transition zone.

Understanding the fate of subducted carbonates is a prerequisite for the elucidation of the Earth's deep carbon cycle. Here we show that the concomitant presence of Ca[CO] with CO in a subducting slab very likely results in the formation of an anhydrous mixed pyrocarbonate, , at moderate pressure ( ≈ 20 GPa) and temperature ( ≈ 1500 K) conditions. We show that at these conditions can be obtained by reacting Ca[CO] with CO in a laser-heated diamond anvil cell.

Synthesis and crystal structure of acentric anhydrous beryllium carbonate Be(CO).

The anhydrous alkaline earth metal carbonate Be(CO) was synthesized in a laser-heated diamond anvil cell at moderate pressures and temperatures (20(2) GPa and 1500(200) K) by a reaction of BeO with CO. It crystallizes in the acentric, trigonal space group 321 with = 3. The crystal structure was obtained from synchrotron single crystal X-ray diffraction data and confirmed by density functional theory-based calculations in combination with Raman spectroscopy.

Synthesis and crystal structure of silicon pernitride SiN at 140 GPa.

Silicon pernitride, SiN, 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 , No.

Stabilization of Guanidinate Anions [CN ] in Calcite-Type SbCN.

The stabilization of nitrogen-rich phases presents a significant chemical challenge due to the inherent stability of the dinitrogen molecule. This stabilization can be achieved by utilizing strong covalent bonds in complex anions with carbon, such as cyanide CN and NCN carbodiimide, while more nitrogen-rich carbonitrides are hitherto unknown. Following a rational chemical design approach, we synthesized antimony guanidinate SbCN at pressures of 32-38 GPa using various synthetic routes in laser-heated diamond anvil cells.

Stabilization Of The CN Anion In Recoverable High-pressure Ln O (CN ) (Ln=La, Eu, Gd, Tb, Ho, Yb) Oxoguanidinates.

A series of isostructural Ln O (CN ) (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 O (CN ) solids are composed of the hitherto unknown CN guanidinate anion-deprotonated guanidine.