title: Mn(II) staircase structures stitched by water clusters to a 3D metal-organic open framework: X-ray structural and magnetic studies.
abstract: 4-Hydroxypyridine-2,6-dicarboxylic acid (chelidamic acid, cdaH2) reacts with Mn(OAc)2 x 4H2O to form a 1D staircase structure with dimeric Mn(II) units connected by water clusters to form a 3D framework, {[Mn2(cda)2 x 4H2O] x 4H2O}n, 1, in aqueous pyridine at room temperature. The compound crystallizes in the triclinic space group P1 with a = 9.495(3), b =10.733(5), c = 11.065(4) A, alpha = 87.42(5), beta = 74.14(5), gamma = 80.07(2) degrees, U = 1068.5(9) A3, Z = 2, rho(calcd) = 1.915 g cm(-3), T = 100 K, mu = 1.28 mm(-1), R1 = 0.0453 (I > 2sigma(I)), wR2 = 0.1046, GOOF = 1.282. Upon removal of the water molecules by heating, the 3D structure breaks down. Thermogravimetric analysis, infrared, X-ray powder diffraction studies, and X-ray crystallography were performed to characterize this compound. Since the coordination polymer has diaqua-bridged Mn(II) centers, it was subjected to variable-temperature magnetic studies.
authors.affiliation: Chemistry Department, Indian Institute of Technology Kanpur, Kanpur 208016, India.
authors.forename: Sujit K
authors.initials: SK
authors.lastname: Ghosh
authors.forename: Joan
authors.initials: J
authors.lastname: Ribas
authors.forename: M Salah
authors.initials: MS
authors.lastname: El Fallah
authors.forename: Parimal K
authors.initials: PK
authors.lastname: Bharadwaj