title: Crystal structure of tetra-aqua-bis(3,5-di-amino-4H-1,2,4-triazol-1-ium)cobalt(II) bis-[bis-(pyridine-2,6-di-carboxyl-ato)cobaltate(II)] dihydrate.
abstract: The asymmetric unit of the title compound, [Co(C2H6N5)2(H2O)4][Co(C7H3NO4)2]2·2H2O, features 1.5 Co(II) ions (one anionic complex and one half cationic complex) and one water mol-ecule. In the cationic complex, the Co(II) atom is located on an inversion centre and is coordinated by two triazolium cations and four water mol-ecules, adopting an octa-hedral geometry where the N atoms of the two triazolium cations occupy the axial positions and the O atoms of the four water mol-ecules the equatorial positions. The two triazole ligands are parallel offset (with a distance of 1.38 Å between their planes). In the anionic complex, the Co(II) ion is six-coordinated by two N and four O atoms of the two pyridine-2,6-di-carboxyl-ate anions, exhibiting a slightly distorted octa-hedral coordination geometry in which the mean plane of the two pyridine-2,6-di-carboxyl-ate anions are almost perpendicular to each other, making a dihedral angle of 85.87 (2)°. In the crystal, mol-ecules are linked into a three-dimensional network via C-H⋯O, C-H⋯N, O-H⋯O and N-H⋯O hydrogen bonds.
authors.affiliation: H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75720, Pakistan ; Department of Chemistry, University of Uyo, P.M.B. 1017, Uyo, Akwa Ibom State, Nigeria.
authors.forename: Atim
authors.initials: A
authors.lastname: Johnson
authors.affiliation: Department of Chemistry, Federal University of Petroleum Recourses Effurun, Delta State, Nigeria.
authors.forename: Justina
authors.initials: J
authors.lastname: Mbonu
authors.affiliation: H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75720, Pakistan ; Department of Chemistry, Karakoram International University, Gilgit, Baltistan, Pakistan.
authors.forename: Zahid
authors.initials: Z
authors.lastname: Hussain
authors.affiliation: X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia.
authors.forename: Wan-Sin
authors.initials: WS
authors.lastname: Loh
authors.affiliation: Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, PO Box 2457, Riaydh 11451, Saudi Arabia ; X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia.
authors.forename: Hoong-Kun
authors.initials: HK
authors.lastname: Fun
keywords: CoII complex; crystal structure; hydrogen bonding; pyridine-2,6-di­carboxyl­ate; triazolium