title: 3a,11b-Dihy-droxy-3a,11b-dihydro-1H-imidazo[4,5-f][1,10]phenanthroline-2(3H)-thione.
abstract: The title compound, C(13)H(10)N(4)O(2)S, was prepared through a cyclization reaction of 1,10-phenanthroline-5,6-dione and thio-urea. The dihedral angle between the pyridine rings is 8.22 (2)°. In the crystal, mol-ecules are connected by N-H⋯O, O-H⋯N, N-H⋯S and O-H⋯S hydrogen bonds, forming a three-dimensional network.
authors.affiliation: College of Chemistry and Materials Science, Heilongjiang University, Harbin 150080,  People's Republic of China.
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.forename: Peng
authors.initials: P
authors.lastname: Mei
authors.forename: Wen-Yi
authors.initials: WY
authors.lastname: Chu
authors.forename: Zhi-Zhong
authors.initials: ZZ
authors.lastname: Sun
authors.forename: Yan-Jun
authors.initials: YJ
authors.lastname: Hou