TY  - JOUR
AU  - Bayarjargal, Lkhamsuren
AU  - Spahr, Dominik
AU  - Milman, Victor
AU  - Giordano, Nico
AU  - Glazyrin, Konstantin
AU  - Winkler, Bjoern
TI  - Synthesis and Characterization of Ti <sup>4+</sup> Containing Carbonates Ti[CO<sub>4</sub>] and Ti<sub>2</sub> O<sub>3</sub> [CO <sub>3</sub>]
JO  - Inorganic chemistry
VL  - 64
IS  - 44
SN  - 0020-1669
CY  - Washington, DC
PB  - American Chemical Society
M1  - PUBDB-2026-00234
SP  - 21893 - 21902
PY  - 2025
N1  -  DFG (projectsBA4020, BY101/2-1, and WI1232) and the DFG-ResearchUnit FOR2125/CarboPaT. B
AB  - Two titanium carbonates, Ti[CO<sub>4</sub>] and Ti<sub>2</sub>O<sub>3</sub>[CO<sub>3</sub>], were synthesized by the reaction of TiO<sub>2</sub> with CO<sub>2</sub> at high pressures and temperatures in a laser heated diamond anvil cell. Their structures were solved by in situ single crystal X-ray diffraction at high pressures. At pressures above ≈33 GPa, Ti[CO<sub>4</sub>]-I4̅2d is stable. It transforms to Ti[CO<sub>4</sub>]-I4<sub>1</sub>/amd on pressure release. The distinguishing feature of the Ti[CO<sub>4</sub>]-structures is the presence of isolated [CO<sub>4</sub>]<sup>4−</sup>-groups, while Ti<sub>2</sub>O<sub>3</sub>[CO<sub>3</sub>] has isolated [CO<sub>3</sub>]<sub>2</sub>–-groups. Both structures contain 8-fold coordinated tetravalent Ti<sup>4+</sup>-cations. Full geometry optimizations based on DFT calculations reproduced the crystal structures. The DFT models were used to complement the experimental compression data and for the assignment of Raman modes. While carbonates are typically compressible compounds, Ti[CO<sub>4</sub>] is rather incompressible with a bulk modulus of K0 ≈ 200 GPa. As we observed the pressure-induced transformation of TiO<sub>2</sub>, we provide the Raman spectra of TiO<sub>2</sub>–OI, and TiO<sub>2</sub>–OII.
LB  - PUB:(DE-HGF)16
DO  - DOI:10.1021/acs.inorgchem.5c03033
UR  - https://bib-pubdb1.desy.de/record/643487
ER  -