A chloride of a substituted heterocyclic analogue of chrysene: C19H17N2O+.Cl−

Abstract

thermal parameters for the H atoms were fixed throughout all subsequent refinements. Least-squares refinement converged to final R = 0.044, wR = 0.048, S = 1.416. At this point all subsequent shifts were found to be < 0.001tr. A single prominent peak is evident on the difference electron density map measuring 0.67 e A -3 in the immediate vicinity of Br. Otherwise, all remaining difference peaks were found to be < 0.39 e A -3. Anomalous scattering of Br anti S atoms was employed for verification of the proper choice of enantiomeric configuration, following the statistical criterion proposed by Hamilton (1965). The opposite enantiomorph refined to final reliability indices of R = 0.051, wR = 0.057. Scattering factors for neutral atoms and anomalous-scattering parameters for Br and S atoms were taken from International Tables for X-ray Crystallography (1974, Vol. IV). All calculations were performed on a PDP 11/60 utilizing the SDP-Plus package (Frenz, 1978). Discussion. Refined positional parameters for all atoms and equivalent isotropic B values are supplied in Table 1. Atom numbering follows the scheme indicated in Fig. 1. Fig. 2 shows a stereo OR TEP (Johnson, 1976) representation of the molecule. Interatomic bonding distances and angles are supplied in Table 2.* Bond distances and angles are, generally, as expected. The one exception to this is * Lists of structure factors, complete bond distances and angles, and anisotropic thermal parameters have been deposited with the British Library Document Supply Centre as Supplementary Publication No. SUP 55634 (18 pp.). Copies may be obtained through The Technical Editor, International Union of Crystallography, 5 Abbey Square, Chester CH1 2HU, England. [CIF reference: CRI012]