Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1234386 | Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2012 | 6 Pages |
The molecular structure of the sodium borate mineral ameghinite NaB3O3(OH)4 has been determined by the use of vibrational spectroscopy. The crystal structure consists of isolated [B3O3(OH)4]− units formed by one tetrahedron and two triangles. H bonds and Na atoms link these polyanions to form a three-dimensional framework. The Raman spectrum is dominated by an intense band at 1027 cm−1, attributed to BO stretching vibrations of both the trigonal and tetrahedral boron. A series of Raman bands at 1213, 1245 and 1281 cm−1 are ascribed to BOH in-plane bending modes. The infrared spectra are characterized by strong overlap of broad multiple bands. An intense Raman band found at 620 cm−1 is attributed to the bending modes of trigonal and tetrahedral boron. Multiple Raman bands in the OH stretching region are observed at 3206, 3249 and 3385 cm−1. Raman spectroscopy coupled with infrared spectroscopy has enabled aspects about the molecular structure of the borate mineral ameghinite to be assessed.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Ameghinite NaB3O3(OH)4 is a mineral found in borax deposits. ► We have used the Raman and infrared spectrum to determine the molecular structure of ameghinite. ► Multiple OH stretching Raman bands are observed.