A Raman spectroscopic study of the structural aspects of K$sub 2$MgCl$sub 4$ and Cs$sub 2$MgCl$sub 4$ as solid single crystals and molten salts
Journal Article
·
· J. Chem. Phys., v. 63, no. 7, pp. 3054-3061
OSTI ID:4184798
Polarized Raman spectra have been obtained for oriented single crystals of K$sub 2$MgCl$sub 4$ and Cs$sub 2$MgCl$sub 4$ at 77 and 298 K. The data are in excellent agreement with factor group analyses based on the space groups I$sub 4$/ mmm (D$sup 17$$sub 4$/subh/) and Pnma (D$sup 16$$sub 2$/subh/) for the K$sub 2$MgCl$sub 4$ and Cs$sub 2$MgCl$sub 4$ crystals. In K$sub 2$MgCl$sub 4$ the magnesium is surrounded by six chloride ions in a distorted octahedral arrangement with a network structure such that neighboring octahedra share corners. In Cs$sub 2$MgCl$sub 4$ a discrete tetrahedral MgCl$sub 4$$sup 2-$ species is present. The $sup 35$Cl--$sup 37$Cl isotopic splitting of the symmetric stetching mode of the tetrahedral MgCl$sub 4$$sup 2-$ species has been resolved at 77 K and is similar to that observed for CCl$sub 4$. Raman spectra for the high temperature solids and molten salts suggest that the coordination number of magnesium changes from six in solid K$sub 2$MgCl$sub 4$ to four in the melt, whereas Cs$sub 2$MgCl$sub 4$ melts with retention of the MgCl$sub 4$$sup 2- $ tetrahedral complex. Additional evidence is presented to support previous reports that the MgCl$sub 4$$sup 2-$ tetrahedral species is the principal complex ion in the melts, although a fraction of the magnesium appears to be present in a polynuclear complex, perhaps Mg$sub 2$Cl$sub 6$$sup 2-$.
- Research Organization:
- Department of Chemistry, Memorial University of Newfoundland, St. John's, Newfoundland, Canada A1C 5S7
- NSA Number:
- NSA-33-002609
- OSTI ID:
- 4184798
- Journal Information:
- J. Chem. Phys., v. 63, no. 7, pp. 3054-3061, Journal Name: J. Chem. Phys., v. 63, no. 7, pp. 3054-3061; ISSN JCPSA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Raman spectroscopic study of molten salt electrolysis of light metals
Ionization of TiCl{sub 4} and MgCl{sub 2} during the formation of a high-activity {alpha}-Olefin polymerization catalyst. Crystal structures of [cis-(C{sub 2}H{sub 4}(CO{sub 2}Et){sub 2}){sub 2}Cl{sub 2}Ti][SbCl{sub 6}]{sub 2}{center_dot}CH{sub 2}Cl{sub 2} and [Mg(C{sub 2}H{sub 4}(CO{sub 2}Et){sub 2}){sub 3}][MgCl{sub 4}]{center_dot}2CH{sub 2}Cl{sub 2}
Technical Report
·
Mon Dec 31 23:00:00 EST 1984
·
OSTI ID:5334374
Ionization of TiCl{sub 4} and MgCl{sub 2} during the formation of a high-activity {alpha}-Olefin polymerization catalyst. Crystal structures of [cis-(C{sub 2}H{sub 4}(CO{sub 2}Et){sub 2}){sub 2}Cl{sub 2}Ti][SbCl{sub 6}]{sub 2}{center_dot}CH{sub 2}Cl{sub 2} and [Mg(C{sub 2}H{sub 4}(CO{sub 2}Et){sub 2}){sub 3}][MgCl{sub 4}]{center_dot}2CH{sub 2}Cl{sub 2}
Journal Article
·
Tue Mar 26 23:00:00 EST 1996
· Inorganic Chemistry
·
OSTI ID:263746