A vibrational spectroscopic study of kanemite

In this paper, the vibrational spectra of kanemite are measured. The fact that infrared and Raman spectral bands are not coincident indicates that kanemite belongs to a space group with a center of symmetry. The observation of an IR band at 1167 cm(-1) in kanemite suggests the existence of Si-O-Si linkages with a bond angle of approximately 180 degrees. The strong Raman band at 465 cm(-1) in the kanemite spectrum is associated with the six-membered rings of [SiO4] tetrahedra. The strong Raman band at 1060 cm(-1) is consistent with the stretching vibrations of Q(3) species (nu SiO-). The broad band centered at 1015 cm(-1) is assigned to the Q(3) units involved in strong hydrogen bonding. Hydrogen bonding occurring in kanemite is also evident from a broad OH stretching band (3463 cm(-1)) observed in the IR spectrum. However, not all hydroxyl groups are involved in hydrogen bonding since a sharp OH stretching signal is observed at 3582 cm(-1) in IR spectrum. (C) 1998 Elsevier Science B.V. All rights reserved.