Niobium oxychloride
| Niobium oxychloride | ||
|---|---|---|
 | ||
| IUPAC name Niobium (V) Oxychloride | ||
| Other names Niobium oxytrichloride | ||
| Identifiers | ||
| CAS number | 13597-20-1  | |
| Properties | ||
| Molecular formula | Cl3NbO | |
| Molar mass | 215.26 g mol−1 | |
| Appearance | white crystals | |
| Melting point | sublimes above 200 °C | |
(verify) (what is: / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa) | ||
| Infobox references | ||
Niobium oxychloride is the inorganic compound with the formula NbOCl3. It is a white, crystalline, diamagnetic solid. It is often found as an impurity in samples of niobium pentachloride, a common reagent in niobium chemistry.
Structure
The coordination sphere for niobium is a distorted octahedron. The Nb-O bonds and Nb-Cl bonds are unequal. This structure can be described as planar Nb2Cl6 core connected by O-Nb-O bridges. In this way, the compound is best described as a polymer, consisting of a double stranded chain.[1][2]
Synthesis
Niobium oxychloride is prepared by treating the pentachloride with oxygen:[3]
- NbCl5 + 1/2 O2 → NbOCl3 + Cl2
This reaction is conducted at about 200 °C. NbOCl3 also forms as a major side-product in the reaction of niobium pentoxide with various chlorinating agents such as carbon tetrachloride and thionyl chloride.[3][4]
- 2 Nb2O5 + 6 CCl4 → 4 NbOCl3 + 6 COCl2
References
- ↑ Markus Ströbele, Hans-Jürgen Meyer, "Neubestimmung der Kristallstruktur von NbOCl3" Zeitschrift für anorganische und allgemeine Chemie 2002, vol. 628, pp. 488–491. doi:10.1002/1521-3749(200202)628:2<488::AID-ZAAC488>3.0.CO;2-B
- ↑ Beck, Johannes; Bordinhão, Jairo (2005). "Polar [NbOCl3]2n and [NbOX4-]n (X = Cl, Br) Chains in the Structures of NbOCl3 and the Thallium-Halogenooxoniobates Tl[NbOCl4] and Tl[NbOBr4] - Synthesis, Crystal Structures and Optical Second Harmonic Generation". Zeitschrift für anorganische und allgemeine Chemie 631 (6–7): 1261–1266. doi:10.1002/zaac.200500041.
- ↑ 3.0 3.1 "Niobium Oxytrichloride" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 2. pp. 1307.
- ↑ Jena, P. K.; Brocchi, E. A.; Garcia, R. I. (1997). "Kinetics of chlorination of niobium pentoxide by carbon tetrachloride". Metallurgical and Materials Transactions B 28: 39–45. doi:10.1007/s11663-997-0125-0..
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