title: 3-Iodo-1H-pyrazolo-[3,4-b]pyridine.
abstract: The title compound, C6H4IN3, is essentially planar, with a dihedral angle of 0.82 (3)° between the planes of the pyridine and pyrazole rings. In the crystal, pairs of mol-ecules are connected into inversion dimers through N-H⋯N hydrogen bonds. C-I⋯N halogen bonds link the dimers into zigzag chains parallel to the b-axis direction. The packing also features π-π stacking inter-actions along (110) with inter-planar distances of 3.292 (1) and 3.343 (1) Å, and centroid-centroid distances of 3.308 (1) and 3.430 (1) Å.
authors.affiliation: Cardinal Tien College of Healthcare & Management, Taipei, 231, Taiwan.
authors.forename: Ping-Hsin
authors.initials: PH
authors.lastname: Huang
authors.affiliation: Institute of Chemistry, Academia Sinica, Nankang, Taipei, Taiwan.
authors.forename: Yuh-Sheng
authors.initials: YS
authors.lastname: Wen
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei, Taiwan.
authors.forename: Jiun-Yi
authors.initials: JY
authors.lastname: Shen