Structure and vibrational spectra of the tetra(betaine) selenate crystal

Abstract

The crystal structure of tetra(betaine) selenate has been determined by X-ray diffraction as orthorhombic, space group Fddd, with a = 13.243(8), b = 19.077(9) and c = 21.96(2) Å, Z = 8. The crystal comprises selenate ions, SeO 4 2−, and the betaine dimers: two betaine moieties are joined by a very strong symmetric C 2) hydrogen bond with the O···O distance of 2.424(6) Å. Powder FTIR and FT-Raman spectra were measured and assignment of the observed bands to vibrations of the hydrogen bonds and internal vibrations of the betaine molecules and selenate ions is proposed.