title: 6-Hydr-oxy-3-(hydroxy-imino)indolin-2-one.
abstract: In the title compound, C(8)H(6)N(2)O(3), the indol-2-one system is almost planar [maximum deviation = 0.010 (3) Å]. In the crystal structure, inter-molecular N-H⋯O, O-H⋯N and O-H⋯O hydrogen bonds link the mol-ecules into a three-dimensional network. π-π contacts between the indole ring systems [centroid-centroid distances = 3.494 (1), 3.731 (1) and 3.736 (1) Å] may further stabilize the structure.
authors.affiliation: Yibin Vocational & Technical College, Si chuan, People's Republic of China.
authors.forename: Hui-Ling
authors.initials: HL
authors.lastname: Yu