title: Structure, vibrational analysis, and insights into host-guest interactions in as-synthesized pure silica ITQ-12 zeolite by periodic B3LYP calculations.
abstract: As-made and calcined ITQ-12 zeolites are structurally characterized by means of the analysis of their vibrational modes. The experimental IR spectra made on high crystalline samples are compared with accurate B3LYP periodic calculations performed with the CRYSTAL06 code. The fair agreement between both sets of data allows us to make a reliable assignment of the IR modes. Thanks to the detailed information provided by the theoretical calculations, the analysis of the IR intensities, the Born dynamic charges, and the whole set of vibrational frequencies at Gamma-point shed light on several aspects of the host-guest interaction, structure-direction issues, including the role of fluoride anions in allowing the crystallization of silica structures with strained double-four rings, and the role played by the framework flexibility.
authors: Facultad de Ciencias, Universidad Autnóma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, 62209 Cuernavaca (Morelos), Mexico. claudio@servm.fc.uaem.mx
authors: Claudio Marcelo
authors: CM
authors: Zicovich-Wilson
authors: María Luisa
authors: ML
authors: San-Román
authors: Miguel Angel
authors: MA
authors: Camblor
authors: Fabien
authors: F
authors: Pascale
authors: José Sergio
authors: JS
authors: Durand-Niconoff