A Raman spectroscopic study of a hydrated molybdate mineral ferrimolybdite, Fe2(MoO4)3·7-8H2O

Jiří Sejkora; Jiří Cejka; Radana Malíková; Andrés López; Yunfei Xi; Ray L Frost

doi:10.1016/j.saa.2014.03.112

A Raman spectroscopic study of a hydrated molybdate mineral ferrimolybdite, Fe2(MoO4)3·7-8H2O

Spectrochim Acta A Mol Biomol Spectrosc. 2014 Sep 15:130:83-9. doi: 10.1016/j.saa.2014.03.112. Epub 2014 Apr 8.

Authors

Jiří Sejkora¹, Jiří Cejka², Radana Malíková¹, Andrés López³, Yunfei Xi³, Ray L Frost⁴

Affiliations

¹ Department of Mineralogy and Petrology, National Museum, Cirkusová 1740, CZ-193 00 Praha 9, Czech Republic.
² Department of Mineralogy and Petrology, National Museum, Cirkusová 1740, CZ-193 00 Praha 9, Czech Republic; School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia.
³ School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia.
⁴ School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia. Electronic address: r.frost@qut.edu.au.

PMID: 24769361
DOI: 10.1016/j.saa.2014.03.112

Abstract

Raman spectra of two well-defined ferrimolybdite samples, Fe2(3+)(Mo6+O4)3·7-8H2O, from the Krupka deposit (northern Bohemia, Czech Republic) and Hůrky near Rakovník occurrence (central Bohemia, Czech Republic) were studied and tentatively interpreted. Observed bands were assigned to the stretching and bending vibrations of molybdate anions, Fe-O units and water molecules. Number of Raman and infrared bands assigned to (MoO4)(2-) units and water molecules proved that symmetrically (structurally) nonequivalent (MoO4)(2-) and H2O are present in the crystal structure of ferrimolybdite. Approximate O-H⋯O hydrogen bond lengths (2.80-2.73 Å) were inferred from the published infrared spectra.

Keywords: Ferrimolybdite; Molybdate; Raman spectroscopy; Water molecules.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Crystallization
Ferric Compounds / chemistry*
Hydrogen / chemistry
Hydrogen Bonding
Hydroxyl Radical
Ions
Iron / chemistry*
Minerals / chemistry
Molybdenum / chemistry*
Oxides / chemistry*
Oxygen / chemistry
Spectrophotometry, Infrared
Spectrum Analysis, Raman
Water / chemistry*
X-Ray Diffraction

Substances

Ferric Compounds
Ions
Minerals
Oxides
Water
Hydroxyl Radical
Hydrogen
Molybdenum
Iron
Oxygen