Structure, Vibrational Spectra and (11)B-NMR Chemical Shift of Na8[AlSiO4]6(B(OH)4)2: Comparison of Theory and Experiment.
Density functional theory (DFT) calculations at generalized gradient approximation (GGA) level were performed to interpret experimental IR and Raman vibrational spectra, to assign (11)B-NMR chemical shifts, and to calculate the structure of the tetrahydroxyborate sodalite Na8[AlSiO4]6(B(OH)4)2. Full optimization of the intercalated compound gave the following structural parameters of B(OH)4(-): B-O-B (105.3-115.3°) and B-O-H (111.5-115.4°) angles, B-O (1.476 Å, 1.491 Å) and O-H (0.98 Å) distances. The calculated normal modes were assigned to experimental IR and Raman spectra. In general, close agreement between theory and experiment was obtained. The mean absolute deviation (MAD) is below 11 cm(-1). We also calculate the thermodynamical stability of Na8[AlSiO4]6(B(OH)4)2 with respect to Na8[AlSiO4]6(BH4)2 in the context of the tetrahydroborate hydration reaction.
Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich- Wilhelms- Universität Bonn , Beringstraße 4-6, D-53115 Bonn, Germany.
Alexander G
AG
Schneider
Institut für Mineralogie, Leibniz Universität Hannover , Callinstraße 3, D-30167 Hannover, Germany.
Lars
L
Schomborg
Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich- Wilhelms- Universität Bonn , Beringstraße 4-6, D-53115 Bonn, Germany.
Anna C
AC
Ulpe
Institut für Mineralogie, Leibniz Universität Hannover , Callinstraße 3, D-30167 Hannover, Germany.
Claus H
CH
Rüscher
Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich- Wilhelms- Universität Bonn , Beringstraße 4-6, D-53115 Bonn, Germany.
Thomas
T
Bredow