N -(2-Bromophenyl)propionamide

The title compound, C9H10BrNO, posseses normal geom­etrical parameters. The crystal packing is influenced by an N—H⋯O hydrogen bond.

The title compound, C 9 H 10 BrNO, posseses normal geometrical parameters.The crystal packing is influenced by an N-HÁ Á ÁO hydrogen bond.

Comment
The title compound, (I) (Fig. 1), was prepared as part of our ongoing studies of acetanilide derivatives (Ronaldson et al., 2005).
All C-bound H atoms were placed in idealized positions (C-H = 0.95-0.99A ˚) and refined as riding on their carriers with the constraint U iso (H) = 1.2U eq (C) or U iso (H) = 1.5U eq (methyl C) applied.The methyl group was allowed to rotate about the C9-C8 bond as a rigid group.The N-bound H atom was located in a difference map and its position was freely refned with the constraint U iso (H) = 1.2U eq (N).
The bond angle sum about N1 in (I) is 360.0°,indicating that this atom is sp 2 hybridized.The C6-N1 distance of 1.416 (3) Å in (I) is almost identical to the equivalent distance [1.418 (4) Å] in (II).All the other geometrical parameters for (I) lie within their expected ranges (Allen et al., 1995).
The crystal packing in (I) is infludenced by an N-H•••O hydrogen bond (Table 1 and Fig. 2) that links the molecules into chains propagating in the [100] direction.There are no π-π interactions in (I).The unit-cell packing is shown in Fig. 3; (I) is essentially isostructural (same space group, similar unit-cell parameters) with (II), except that the unit cell for (I) is slightly expanded in the c axis direction to accommodate the more bulky terminal ethyl moiety.

Special details
Geometry.All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s.planes) are estimated using the full covariance matrix.The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry.An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s.planes.Refinement.Refinement of F 2 against ALL reflections.The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 .The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement.R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Figure 1
Figure 1View of (I), shown with 50% displacement ellipsoids.H atoms are drawn as small spheres of arbitrary radius.

Figure 2
Figure 2 Detail of (I), showing how N-HÁ Á ÁO hydrogen bonds (dashed lines) link molecules into a chain.The view direction is perpendicular to the mean plane of the benzene ring of the central molecule, showing that nostacking occurs.All H atoms except H1 have been omitted for clarity.[Symmetry codes: (i) x À 1, y, z; (ii) x + 1, y, z.]

Figure 3
Figure 3The packing in (I), viewed down [010], with all H atoms except H1 omitted for clarity.

Figure 1
Figure 1View of (I), shown with 50% displacement ellipsoids.H atoms are drawn as small spheres of arbitrary radius.

Figure 2
Figure 2 Detail of (I), showing how N-H•••O hydrogen bonds (dashed lines) link molecules into a chain.The view direction is perpendicular to the best plane of the benzene ring of the central molecule, showing that no π-π stacking occurs.All H atoms except H1 have been omitted for clarity.[Symmetry codes: (i) x − 1, y, z; (ii) x + 1, y, z.]

Figure 3
Figure 3Unit-cell packing in (I), viewed down [010], with all H atoms except H1 omitted for clarity.