title: Diaquabis-[3-(hydroxy-imino-)butanoato]nickel(II): a triclinic polymorph.
abstract: The title centrosymmetric mononuclear complex, [Ni(C(4)H(6)NO(3))(2)(H(2)O)(2)], is a polymorph of the previously reported complex [Dudarenko et al. (2010 ▶). Acta Cryst. E66, m277-m278]. The Ni(II) atom, lying on an inversion center, is six-coordinated by two carboxyl-ate O atoms and two oxime N atoms from two trans-disposed chelating 3-hydroxy-imino-butanoate ligands and two axial water mol-ecules in a distorted octa-hedral geometry. The hydr-oxy group forms an intra-molecular hydrogen bond with the coordinated carboxyl-ate O atom. The complex mol-ecules are linked in stacks along [010] by a hydrogen bond between the water O atom and the carboxyl-ate O atom of a neighboring mol-ecule. The stacks are further linked by O-H⋯O hydrogen bonds into a layer parallel to (001).
authors.forename: Valentina A
authors.initials: VA
authors.lastname: Kalibabchuk
authors.forename: Nikolay M
authors.initials: NM
authors.lastname: Dudarenko
authors.forename: Turganbay S
authors.initials: TS
authors.lastname: Iskenderov
authors.forename: Maria L
authors.initials: ML
authors.lastname: Malysheva
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Gumienna-Kontecka