title: Vibrational spectroscopic study of the sulphate mineral glaucocerinite (Zn,Cu)(10)Al(6)(SO(4))(3)(OH)(32)⋅18H(2)O - a natural layered double hydroxide.
abstract: We have studied the molecular structure of the mineral glaucocerinite (Zn,Cu)(5)Al(3)(SO(4))1.5(OH)16⋅9(H2O) using a combination of Raman and infrared spectroscopy. The mineral is one of the hydrotalcite supergroup of natural layered double hydroxides. The Raman spectrum is characterised by an intense Raman band at 982cm(-1) with a low intensity band at 1083cm(-1). These bands are attributed to the sulphate symmetric and antisymmetric stretching mode. The infrared spectrum is quite broad with a peak at 1020cm(-1). A series of Raman bands at 546, 584, 602, 625 and 651cm(-1) are assigned to the ν4 (SO4)(2)(-) bending modes. The observation of multiple bands provides evidence for the reduction in symmetry of the sulphate anion from Td to C2v or even lower symmetry. The Raman band at 762cm(-1) is attributed to a hydroxyl deformation mode associated with AlOH units. Vibrational spectroscopy enables aspects of the molecular structure of glaucocerinite to be determined.
authors.affiliation: 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.
authors.forename: Ray L
authors.initials: RL
authors.lastname: Frost
authors.affiliation: School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia.
authors.forename: Frederick L
authors.initials: FL
authors.lastname: Theiss
authors.affiliation: School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia.
authors.forename: Andrés
authors.initials: A
authors.lastname: López
authors.affiliation: Geology Department, School of Mines, Federal University of Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto, MG 35400-00, Brazil.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Scholz
mesh_terms: D006878:Hydroxides / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D008903:Minerals / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013059:Spectrum Analysis, Raman; D013431:Sulfates / Q000737:chemistry*
chemical_list: D006878:Hydroxides; D008670:Metals; D008903:Minerals; D013431:Sulfates
keywords: Glaucocerinite; Infrared spectroscopy; Raman spectroscopy; Sulphate