title: Hexaaquazinc(II) dipicrate trihydrate.
abstract: In the crystal structure of the title compound, [Zn(H2O)6](C(6)H(2)N(3)O(7))2.3H2O, the zinc cation complexes and picrate anions are stacked separately, extending along the b axis. No picrate species ligate to the metal cation. This lack of picrate coordination is atypical among metal picrate salts. We speculate that the size of the metal-aqua complex as related to the intermolecular distance of the picrate anions in the pi stack can be a measure of the formation of such separated stacks in the crystal structures of divalent metal complexes with picrate anions. Picrate ions are linked to each other with short intermolecular C...C contacts of 3.223 (6) and 3.194 (6) A in the stack.
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan. kaz-honda@aist.go.jp
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Honda
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamawaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujihisa
authors.forename: Takehiro
authors.initials: T
authors.lastname: Matsunaga
authors.forename: Makoto
authors.initials: M
authors.lastname: Matsukawa