title: Methylpyrazole-capped two-dimensional supramolecular M(II) (M = Mn, Ni, Co) assemblies constructed by covalent and noncovalent interactions: uncommon coordination modes of methylpyrazoles and magnetic properties.
abstract: Two mononuclear complexes [Mn(5-methylpyrazole)4(N3)2] (1) and [Ni(5-methylpyrazole)4(N3)2] (2), as well as a novel one-dimensional coordination polymer [Co(3-methylpyrazole)2(5-methylpyrazole)2(tp)]n (3) (tp = terephthalate), were characterized. The isostructural complexes, 1 and 2, display two-dimensional supramolecular networks formed by hydrogen bonds between the N-H groups of 5-methylpyrazoles and the end N atoms of the azide ligands and additional face-to-face pi-pi interactions of the 5-methylpyrazoles. For 3, tp-bridged one-dimensional chains assisted by intrachain hydrogen bonds among the N-H groups of methylpyrazoles and carboxylate oxygens are connected with the help of interchain C-H...O hydrogen bonds, leading to a two-dimensional structure. The intra- and interchain hydrogen bonds account for the coexistence of two unique coordination forms (5-methylpyrazole and 3-methylpyrazole) of methylpyrazoles in the same coordination sphere. Weak antiferromagnetic interactions coupled with the spin-orbit coupling effect are operative in 3 through the tp ligands.
authors.affiliation: Department of Chemistry and Center for Electro- and Photo-Responsive Molecules, Korea University, Seoul 136-701, Korea.
authors.forename: Da Hye
authors.initials: DH
authors.lastname: Choi
authors.forename: Jung Hee
authors.initials: JH
authors.lastname: Yoon
authors.forename: Jeong Hak
authors.initials: JH
authors.lastname: Lim
authors.forename: Hyoung Chan
authors.initials: HC
authors.lastname: Kim
authors.forename: Chang Seop
authors.initials: CS
authors.lastname: Hong