Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1410826 | Journal of Molecular Structure | 2010 | 10 Pages |
Abstract
The application of near-infrared and infrared spectroscopy has been used for identification and distinction of basic Cu-sulphates that include devilline, chalcoalumite and caledonite. Near-infrared spectra of copper sulphate minerals confirm copper in divalent state. Jahn-Teller effect is more significant in chalcoalumite where 2B1g â 2B2g transition band shows a larger splitting (490 cmâ1) confirming more distorted octahedral coordination of Cu2+ ion. One symmetrical band at 5145 cmâ1 with shoulder band 5715 cmâ1 result from the absorbed molecular water in the copper complexes are the combinations of OH vibrations of H2O. One sharp band at around 3400 cmâ1 in IR common to the three complexes is evidenced by CuOH vibrations. The strong absorptions observed at 1685 and 1620 cmâ1 for water bending modes in two species confirm strong hydrogen bonding in devilline and chalcoalumite. The multiple bands in ν3 and ν4(SO4)2â stretching regions are attributed to the reduction of symmetry to the sulphate ion from Td to C2V. Chalcoalumite, the excellent IR absorber over the range 3800-500 cmâ1 is treated as most efficient heat insulator among the Cu-sulphate complexes.
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Physical Sciences and Engineering
Chemistry
Organic Chemistry
Authors
Ray L. Frost, B. Jagannadha Reddy, Eloise C. Keeffe,