The crystal structure, vibrational spectra and DSC measurements of mono-beta-alaninium nitrate

An X-ray structural analysis of mono-beta-alaninium nitrate has been carrie d out. The substance crystallizes in an orthorhombic system in the space gr oup Pca2(t), a = 14.8135(11) Angstrom, b = 7.3338(5) Angstrom, c = 11.9121( 12) Angstrom, V= 1294.12(18) Angstrom(3), Z = 8, R = 0.0361 for 1299 observ ed reflections. The asymmetric unit contains two beta-alaninium cations (NH 3+CH2CH2COOH) and two nitrate anions (NO3-). The whole crystal structure is formed by beta-alaninium dimers (linked by two intermediate asymmetrical h ydrogen bonds of length 2.64 Angstrom) and nitrate anions connected by a sy stem of hydrogen bonds, in which all the hydrogen atoms of the NH3+ groups participate. Fourier transform infrared (FTIR) and FT Raman spectra of natu ral and deuterated crystals were recorded and interpreted. The FTIR spectra were studied down to a temperature of 90 K. Differential scanning calorime try (DSC) measurements were carried out in the temperature range 95-370 K. No phase transition was found in this temperature range by DSC and FTIR. (C ) 1999 Elsevier Science B.V. All rights reserved.