Chemical preparation, spectroscopic study and crystal structure of DL 2-ammoniumbutyric dihydrogenmonophosphate (CH3CH2CHCOOH)(H2PO4)-+NH3

Crystals of DL 2-ammoniumbutyric dihydrogenmonophosphate were obtained by evaporating an aqueous solution containing equimolar quantities of DL 2-amino butyric and orthophosphoric acids. IR and NMR spectrometry studies has been investigated and confirmed by X-ray single crystal diffraction results. The title compound is monoclinic, space group P2(1)/c, unit cell dimensions a = 10.5450(3) Angstrom, b 10.0486(3) Angstrom, c = 8.9526(4)Angstrom, beta = 111.769(5)degrees. Using 1,303 reflections with 1 > 3sigma(I) measured on CAD4 Mach 3 diffractometer the crystal structure was solved by direct methods and was refined by least squares full matrix procedures to R = 0.038. The main feature of this structure consists of an alternate stacking Of H2PO4 tetrahedral sheets and NH3C3H,COOH' cation layers. The H2PO4 groups are associated to form infinite chains [(H2PO4)n](n-). The crystal structure is stabilized by a three-dimensional network of strong hydrogen bonds.