Accession Number : AD0617474

Title :   NMR STUDIES OF HYDRATED SODIUM TETRABORATE MINERALS. I. BORON-OXYGEN POLYION IN BORAX AND TINCALCONITE,

Corporate Author : MCMASTER UNIV HAMILTON (ONTARIO) DEPT OF METALLURGY AND METALLURGICAL ENGINEERING

Personal Author(s) : Cuthbert,J. D. ; Petch,H. E.

Report Date : 27 DEC 1962

Pagination or Media Count : 9

Abstract : The quadrupolar splittings of the B11 nuclear magnetic resonance (NMR) signals in single crystals of borax, Na2B4O7.10H2O, and tincalconite, Na2B4O7.5H2O, were investigated. The electric quadrupole coupling constants and asymmetry parameters of the electric field gradient tensors at the two unique B11 sites in the two crystals were determined. The orientations of the principal axes of the electric field gradient were also determined. The picture of the boron-oxygen polyion in borax as given by NMR is in complete agreement with the x-ray results as to numbers and coordinations of boron atoms, symmetry of the polyion and orientation of the planes of the triangularly coordinated boron atoms. The NMR results also indicate that the same boron-oxygen polyion occurs in tincalconite as in borax. (Author)

Descriptors :   (*SODIUM COMPOUNDS, BORATES), (*BORATES, NUCLEAR MAGNETIC RESONANCE), (*NUCLEAR MAGNETIC RESONANCE, BORATES), HYDRATES, IONS, BORON, OXYGEN, SINGLE CRYSTALS, QUADRUPOLE MOMENT, SYMMETRY(CRYSTALLOGRAPHY), MOLECULAR STRUCTURE, MINERALS, CANADA

Distribution Statement : APPROVED FOR PUBLIC RELEASE