title: trans-Tetra-aqua-bis-[bis-(pyridin-3-yl)methanone-κN]manganese(II) bis-(perchlorate).
abstract: In the title complex, [Mn(C(11)H(8)N(2)O)(2)(H(2)O)(4)](ClO(4))(2), the Mn(2+) ion is located on an inversion center with the slightly distorted N(2)O(4) octa-hedral coordination sphere comprising N-atom donors from two monodentate trans-related bis-(pyridin-3-yl)methanone ligands and four water ligands. The two perchlorate anions are linked to the mononuclear complex mol-ecule through water O-H⋯O hydrogen bonds while inter-complex water O-H⋯N(pyridine) inter-actions form an infinite chain structure extending along the b axis. The perchlorate anions also function as inter-unit links through water O-H⋯O hydrogen bonds which, together with water O-H⋯O(carbon-yl) inter-actions, give a three-dimensional framework structure.
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing 100048,  People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang