van Hattem Andries, de Geus Laurent, Sacristán Ana, Dankelman Robert, Couweleers Sebastian, Hennig Christoph, Griveau Jean-Christophe, Colineau Eric, Dardenne Kathy, Rothe Jörg, Pruessmann Tim, Konings Rudy J M, Smith Anna L
Radiation Science & Technology Department, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, Delft 2629JB, The Netherlands.
ESRF, the European Synchrotron, 71 Avenue des Martyrs, Grenoble Cedex 9, CS40220, 38043, France.
Inorg Chem. 2025 Jan 13;64(1):674-681. doi: 10.1021/acs.inorgchem.4c03617. Epub 2025 Jan 1.
The detailed crystal structure as well as the heat capacity at low temperature and standard entropy of BaMoO are reported for the first time. High-resolution X-ray and neutron diffraction were employed to reveal the structural features of this compound. BaMoO has a six-coordinated Mo and a strongly negative excess volume with respect to the binary oxides. X-ray absorption near edge structure (XANES) spectroscopy at the Mo K-edge shows Mo to be in the oxidation state 6+. The pre-edge peak in the XANES spectrum indicates a distorted octahedral environment, in line with the results from diffraction studies and FDMNES calculations. The standard entropy and heat capacity of BaMoO at 298.15 K, determined with a thermal-relaxation technique, are calculated to be respectively 223.2 ± 7 and 184.7 ± 5 J·K·mol. The obtained thermodynamic properties are discussed in the context of the literature reports on molybdate compounds.
首次报道了BaMoO的详细晶体结构以及低温热容和标准熵。采用高分辨率X射线和中子衍射来揭示该化合物的结构特征。BaMoO具有六配位的Mo，相对于二元氧化物具有强烈的负过量体积。Mo K边的X射线吸收近边结构（XANES）光谱显示Mo处于氧化态6+。XANES光谱中的预边峰表明八面体环境发生了畸变，这与衍射研究和FDMNES计算的结果一致。采用热弛豫技术测定的BaMoO在298.15 K时的标准熵和热容分别计算为223.2±7和184.7±5 J·K·mol。结合钼酸盐化合物的文献报道对所获得的热力学性质进行了讨论。
