STRUCTURE AND POLARIZED IR AND RAMAN-SPECTRA OF THE SOLID COMPLEX OF BIS(BETAINE)-SULFURIC ACID

The crystal structure of bis(betaine)-sulphuric acid has been determin ed by X-ray diffraction as orthorhombic, space group Pbca, with a = 11 .442(2), b = 22.710(5), c = 11.941(2)Angstrom and Z = 8. The crystal c omprises bisulphate ions, HSO4-, and two distinct betaine molecules, w hich are held in a complex by short hydrogen bonds. One of the betaine molecules is present as the zwitterion form (CH3N+-CH2-COO- and the s econd occurs as the protonated form (CH3N+-CH2-COOH. Powder FTIR and p olarized infrared and Raman spectra of the single crystal were measure d. An assignment of the observed bands to vibrations of the hydrogen b onds and internal vibrations of the bisulphate ion and the betaine mol ecules is proposed.