Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10557498 | Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2005 | 6 Pages |
Abstract
Raman spectroscopy at 298 and 77 K has been used to study the structure of likasite, a naturally occurring basic copper(II) nitrate of formula Cu3NO3(OH)5·2H2O. An intense sharp band is observed at 3522 cmâ1 at 298 K which splits into two bands at 3522 and 3505 cmâ1 at 77 K and is assigned to the OH stretching mode. The two OH stretching bands at 3522 and 3505 provide estimates of the hydrogen bond distances of these units as 2.9315 and 2.9028 Ã
. The significance of this result is that equivalent OH units in the 298Â K spectrum become two non-equivalent OH units at 77Â K suggesting a structural change by cooling to liquid nitrogen temperature. A number of broad bands are observed in the 298Â K spectrum at 3452, 3338, 3281 and 3040Â cmâ1 assigned to H2O stretching vibrations with estimates of the hydrogen bond distances of 2.8231, 2.7639, 2.7358 and 2.6436Â Ã
. Three sharp bands are observed at 77 K at 1052, 1050 and 1048 cmâ1 attributed to the ν1 symmetric stretching mode of the NO3 units. Only a single band at 1050 cmâ1 is observed at 298 K, suggesting the non-equivalence of the NO3 units at 77 K, confirming structural changes in likasite by cooling to 77 K.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Ray L. Frost, Kristy L. Erickson, Matt L. Weier, Peter Leverett, Peter A. Williams,