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XAFS studies of Ni, Ta, and Nb chlorides in the ionic liquid 1-ethyl-3-methyl imidazolium chloride/aluminum chloride

Published online by Cambridge University Press:  05 March 2012

W. E. O’Grady*
Affiliation:
Naval Research Laboratory, Code 6130, Washington, District of Columbia 20375
D. F. Roeper
Affiliation:
Naval Research Laboratory, Code 6130, Washington, District of Columbia 20375 andEXCET, Inc., Springfield, Virginia
K. I. Pandya
Affiliation:
SAIC, Brookhaven National Laboratory, Upton, New York 11973
G. T. Cheek
Affiliation:
Chemistry Department, US Naval Academy, Annapolis, Maryland 21402
*
a)Author to whom correspondence should be addressed. Electronic mail: [email protected]

Abstract

The structures of anhydrous nickel, niobium, and tantalum chlorides have been investigated in situ in acidic and basic ionic liquids (ILs) of 1-methyl-3-ethylimidazolium chloride (EMIC)/AlCl3 with X-ray absorption spectroscopy (XAS). The coordination of NiCl2 changes from tetrahedral in basic solution to octahedral in acidic solution. The NiCl2 is a strong Lewis acid in that it can induce the AlCl3 to share its chlorides in the highly acidic IL, forming a structure with six near Cl− ions and eight further distant Al ions which share the chloride ions surrounding the Ni2+. When Nb2Cl10, a dimer, is added to the acidic or basic solution, the dimer breaks apart and forms two species. In the acid solution, two trigonal bipyramids are formed with five equal chloride distances, while in the basic solution, a square pyramid with four chlorides forming a square base and one shorter axial chloride bond. Ta2Cl10 is also a dimer and divides into half in the acidic solution and forms two trigonal bipyramids. In the basic solution, the dimer breaks apart but the species formed is sufficiently acidic that it attracts two additional chloride ions and forms a seven coordinated tantalum species.

Type
Technical Articles
Copyright
Copyright © Cambridge University Press 2011

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References

Gale, R. J., Gilbert, B., and Osteryoung, R. A. (1979). “Electrochemical and spectral investigations of nickel(II) ion equilibriums in room-temperature chloroaluminate solvents,” Inorg. Chem. INOCAJ 18, 27232725. 10.1021/ic50200a019CrossRefGoogle Scholar
Hand, L. N. (2006). “CVD superconducting RF cavities: Past, present, and future,” The International Workshop on Thin Films and New Ideas for Pushing the Limits of RF Superconductivity, Padua, Italy, 9–12 October.Google Scholar
Konings, R. J. M. and Booij, A. S. (1994). “Infrared spectra of NbCl5 and MoCl5 in the gas phase,” Vib. Spectrosc. VISPEK 6, 345349. 10.1016/0924-2031(93)E0067-CCrossRefGoogle Scholar
Koningsberger, D. C., Mojet, B. I., Van Dorssen, G. E., and Ramaker, D. E. (2000). “XAFS spectroscopy: Fundamental principles and data analysis,” Top. Catal. TOCAFI 10, 143155. 10.1023/A:1019105310221CrossRefGoogle Scholar
Pitner, W. R., Hussey, C. L., and Stafford, G. R. (1996). “Electrodeposition of nickel-aluminum alloys from the aluminum chloride-1-methyl-3-ethylimidazolium chloride room temperature molten salt,” J. Electrochem. Soc. JESOAN 143, 130138. 10.1149/1.1836397CrossRefGoogle Scholar
Roeper, D. F., Cheek, G. T., Pandya, K. I., and O’Grady, W. E. (2008). “An XAFS study of nickel chloride in the ionic liquid 1-ethyl-3-methyl imidazolium chloride/aluminum chloride,” ECS Trans. ECSTF8 11(23), 2936. 10.1149/1.2910230CrossRefGoogle Scholar
Roeper, D. F., Pandya, K. I., Cheek, G. T., and O’Grady, W. E. (2009). “An XAFS study of niobium chloride in the ionic liquid 1-ethyl-3-methyl imidazolium chloride/aluminum chloride,” ECS Trans. ECSTF8 16(49), 5360. 10.1149/1.3159307CrossRefGoogle Scholar
Roeper, D. F., Pandya, K. I., Cheek, G. T., and O’Grady, W. E. (2011). “The structure of nickel chloride in the ionic liquid 1-ethyl-3-methyl imidazolium chloride/aluminum chloride. X-ray absorption spectroscopy,” J. Electrochem. Soc. JESOAN 158, F21F28. 10.1149/1.3522762CrossRefGoogle Scholar
Sayers, D. E. and Bunker, B A. (1988). X-Ray Absorption: Principles, Applications, Techniques of EXAFS, SEXAFS, and XANES, Chemical Analysis: A Series of Monographs on Analytical Chemistry and Its Applications Vol. 92, edited by Koningsberger, D. C. and Prins, R. (Wiley, New York).Google Scholar
Skinner, H. A. and Sutton, L. E. (1940). “Studies of the structures of some inorganic pentahalide molecules in the vapour phase, by electron diffraction,” Trans. Faraday Soc. TFSOA4 35, 668680. 10.1039/tf9403500668CrossRefGoogle Scholar
Smith, G. P., Dworkin, A. S., Pagni, R. M., and Zingg, S. P. (1989). “Broensted superacidity of hydrochloric acid in a liquid chloroaluminate. Aluminum chloride-1-ethyl-3-methyl-1H-imidazolium chloride (55.O m/o AlCl3),” J. Am. Chem. Soc. JACSAT 111, 525530. 10.1021/ja00184a020CrossRefGoogle Scholar
Zalkin, A. and Sands, D. E. (1958). “The crystal structure of NbCl5,” Acta Crystallogr. ACSEBH 11, 615619. 10.1107/S0365110X58001651CrossRefGoogle Scholar