Tantalum(V) iodide is the inorganic compound with the formula Ta2I10. Its name comes from the compound's empirical formula, TaI5.[2] It is a diamagnetic, black solid that hydrolyses readily. The compound adopts an edge-shared bioctahedral structure, which means that two TaI5 units are joined by a pair of iodide bridges. There is no bond between the Ta centres.[3] Niobium(V) chloride, niobium(V) bromide, niobium(V) iodide, tantalum(V) chloride, and tantalum(V) bromide all share this structural motif.

Tantalum(V) iodide
Names
Other names
Tantalum pentaiodide
Identifiers
3D model (JSmol)
ChemSpider
EC Number
  • 238-742-4
  • InChI=1S/5HI.Ta/h5*1H;/q;;;;;+5/p-5
    Key: MISXNQITXACHNJ-UHFFFAOYSA-I
  • [I-].[I-].[I-].[I-].[I-].[Ta+5]
Properties
Ta2I10
Molar mass 1631
Appearance black solid
Density 5.8 g/cm3
Melting point 382[1] °C (720 °F; 655 K) sublimes
Hazards
GHS labelling:
GHS05: CorrosiveGHS06: Toxic
Danger
H314, H331
P260, P261, P264, P271, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P311, P321, P363, P403+P233, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Synthesis and structure

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Tantalum pentaiodide forms from the reaction of tantalum pentoxide with aluminium triiodide:[4]

3 Ta2O5 + 10 AlI3 → 6 TaI5 + 5 Al2O3

References

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  1. ^ McCarley, R. E.; Boatman, J.C. (1965). "The Equilibrium Phase Diagrams for the Tantalum-Tantalum Bromide and Tantalum-Tantalum Iodide Systems". Inorganic Chemistry. 4 (10): 1486–1491. doi:10.1021/ic50032a029. S2CID 67778953.
  2. ^ Greenwood, N. N.; & Earnshaw, A. (1997). Chemistry of the Elements (2nd Edn.), Oxford: Butterworth-Heinemann. ISBN 0-7506-3365-4.
  3. ^ Müller, U. (1979). "Die Kristallstruktur von Tantalpentajodid und ihre Fehlordnung". Acta Crystallographica Section B: Structural Crystallography and Crystal Chemistry. 35 (11): 2502–2509. Bibcode:1979AcCrB..35.2502M. doi:10.1107/S0567740879009778.
  4. ^ G. Braurer (1963). "Niobium(V) and Tantalum(V) Bromides". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. Vol. 1. NY, NY: Academic Press. p. 1311.