Vibrational spectra and structures of zinc carboxylates I. Zinc acetate dihydrate

The crystal structure of zinc acetate dihydrate was re-refined by X-ray diffraction analysis of the single crystal. The monoclinic cell dimensions were revised as a = 14.394 (3), b = 5.330 (2), c = 10.962 (3) Angstrom and beta = 99.8 (2)degrees with Z = 4. The bond distances and bond angles were also refined. Based on the structure, a normal mode analysis was made and the valence force constants were determined. Precise spectral assignments were made. Based on the assignments and the structure, the relation between the coordination forms and the vibrational frequencies of the carboxylate antisymmetric stretch and the symmetric stretch were discussed. In order to identify the coordination form of the carboxylate group from the vibrational frequencies, we propose the importance of other carboxylate modes other than the stretches. (C) 1998 Elsevier Science B.V. All rights reserved.