β-(2-Hydroxyphenyl)ethanolamine hydrochloride [2-amino-1-(2-hydroxyphenyl)ethanol hydrochloride

Abstract

CsH~2NO2+.C1 -, m.p. 441-449 K (from ethyl acetate), P212~2 l, a = 7.363 (2), b = 21.824 (6), c = 5.790 (2)/~, Z = 4, D x = 1.354, D m = 1.356 Mg m -3 (flotation: CC14-C6H6). The structure was solved by MULTAN. Full-matrix least-squares refinement converged to R = 0.057 for the R configuration and to R = 0.056 for the S configuration (P 3av. Three standard reflections remained constant [+l .02(1)a v] throughout the data collection. Intensity data were corrected for Lorentz and polarization effects. No absorption correction was applied (p = 0.373 mm-~). Starting with atomic positional parameters generated from the best electron density map produced by M U L T A N (Germain, Main & Woolfson, 1971), all non-hydrogen atoms were located after several cycles of structure factor calculations, Fourier syntheses and least-squares isotropic refinements (Busing, Martin & Levy, 1962). Full-matrix least-squares anisotropic refinement using a 1/a 2 weighting scheme, zero-valent scattering factors and corrections for secondary extinction and anomalous dispersion for C1 (International Tables for X-ray Crystallography, 1974) converged at R = 0.109 (R w = 0.135). The function minimized was: Y. w(IFol IF c I) 2. A difference Fourier map revealed one relatively strong peak approximately three times the intensity of each of a series of smaller peaks subsequently identified as H atoms. Initial isotropic temperature factors of 3.0 A 2 w e r e assigned to H atoms. Least-squares refinement (anisotropic for non-hydrogen atoms) caused the temperature factor of the atom assigned to the strong peak to go strongly negative but with a lower overall R factor. On the basis of the excellent agreement in the experimental and theoretical crystal densities and the intensity of the peak, the presence of solvent or chemical impurity was ruled out. Based on its location (Fig. 1), the peak was assigned to an O atom [O(1)'] related by partial occupancy to O(1). Occupancy factors were allowed to vary in the final cycles of refinement. Positional parameters for HI(N) and H3(N), which are hydrogen bonded to C1, failed to refine properly although the atoms were readily discernible in the difference Fourier maps. The parameters for these H atoms were fixed in the final cycles of refinement which converged at R = 0-056 (R w = 0.060).* Changing the signs of the atomic positional parameters resulted in convergence at R = 0.057 indicating that the S configuration described by the positional parameters in Table 1 is correct (P < 0.05) (Hamilton, 1965). Final parameter shifts were less than 0.2a. The final occupancy factors for O(1) and O(1)' are 0.776 (13) and 0.265 (13), respectively. There were no peaks in the final difference Fourier map greater than 0.2 e A-3. Discussion. Bond lengths and angles and pertinent interand intramolecular distances are shown in Fig. 2. With the exception of the C(2)-O(1) , C(2)-O(1) ' and C(2)-H(C2) bonds (Fig. 2) all bond lengths and angles are consistent with values reported for other phenylethanolamines (Hearn & Bugg, 1972; Paxton & Hamor, 1977; Carlstr6m & Bergin, 1967; Carlstr6m, * Lists of structure factors and thermal parameters have been deposited with the British Library Lending Division as Supplementary Publication No. SUP 34459 (7 pp.). Copies may be obtained through The Executive Secretary, International Union of Crystallography, 5 Abbey Square, Chester CH 1 2HU, England.