5-Bromo-1H-pyrrolo[2,3-b]pyridine

In the title compound, C7H5BrN2, fused six-membered pyridine and five-membered pyrrole rings form the essentially planar azaindole skeleton (r.m.s. deviation = 0.017 Å). In the crystal, pairs of N—H⋯N hydrogen bonds connect the molecules into inversion dimers.

In the title compound, C 7 H 5 BrN 2 , fused six-membered pyridine and five-membered pyrrole rings form the essentially planar azaindole skeleton (r.m.s. deviation = 0.017 Å ). In the crystal, pairs of N-HÁ Á ÁN hydrogen bonds connect the molecules into inversion dimers.

Experimental
The title compound was employed as a starting compound of the syntheses of cis-[PtCl 2 (5BrHaza) 2 ] and [Pt(ox)  Elemental analysis (C, H, N) was performed on a Thermo Scientific Flash 2000 CHNO-S Analyzer. The 1 H, 13 C and 15 N NMR spectra of the DMF-d 7 solutions were collected at 300 K on a Varian 400 spectrometer at 400.00 MHz, 100.58 MHz and 40.53 MHz, respectively. 1 H and 13 C spectra were calibrated using tetramethylsilane (TMS) as a reference. The 15 N NMR spectrum was measured relative to the DMF signals.

Refinement
Hydrogen atoms were located in difference maps and refined using the riding model with C-H = 0.95 Å and N-H = 0.88 Å, and with U iso (H) = 1.2U eq (CH, NH). The maximum and minimum residual electron density peaks of 1.69 and -0.33 eÅ -3 , respectively, were located 1.72 Å and 1.25 Å from the H6 and C6 atoms, respectively.

Figure 1
The molecular structure of the title compound with the non-hydrogen atoms depicted as displacement ellipsoids at the 50% probability level and given with the atom numbering scheme.  A view of the title compound showing the mutual orientation of the six-membered pyridine (least-squares plane created through the C4, C5, C6, N7, C8 and C7 atoms; in blue) and five-membered pyrrole rings (least-squares plane created through the N1, C2, C3, C7 and C8 atoms; in green). The planes are nearly coplanar forming the dihedral angle of 2.09 (14)°.

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.