Mixed alkali metal/transition metal coordination polymers with the mellitic acid hexaanion: 2-dimensional hexagonal magnetic nets
Autor: | Simon M. Humphrey, Richard A. Mole, Richard I. Thompson, Paul T. Wood |
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Rok vydání: | 2010 |
Předmět: |
chemistry.chemical_classification
Chemistry Metal ions in aqueous solution Inorganic chemistry Polymer Alkali metal Magnetic susceptibility Hydrothermal circulation Inorganic Chemistry chemistry.chemical_compound Crystallography Transition metal Mellitic acid Physical and Theoretical Chemistry Isostructural |
Zdroj: | Inorganic chemistry. 49(7) |
ISSN: | 1520-510X |
Popis: | The hexaanion of mellitic acid, mel = (C(6)(CO(2))(6))(6-), links metal ions into extensively connected magnetic coordination polymers. Reaction of alkali metal mellitate salts, M(6)(mel) (M = K, Rb), with M'Cl(2) precursors (M' = Mn, Co, Ni) under mild (473 K) hydrothermal conditions yields an extensive family of isostructural 3-dimensional mixed alkali metal/transition metal polymers of general formula M(2)[M'(2)(mel)(OH(2))(2)] (M/M' = K/Mn (1a); K/Co (1b); K/Ni (1c); Rb/Mn (2a); Rb/Co (2b); Rb/Ni (2c)). These materials incorporate distorted 2-dimensional magnetic hexagonal nets with a honeycomb topology that are exclusively based on metal-carboxylate-metal bridging interactions. A further isostructural alkali metal-free Co(2+) material with NH(4)(+) cations, (NH(4))(2)[Co(2)(mel)(OH(2))(2)] (3), produced by reaction of H(6)mel with [Co(NH(3))(6)]Cl(3) is also presented. The magnetic susceptibility data for 1a-c, 2a-c, and 3 are presented. The susceptibility data for the Mn(II)- and Ni(II)-containing phases have been analyzed using a simple Mean Field Theory approach, and have been modeled using a high temperature series expansion. The comparative magnetism of the Co(II) phases is also presented, and is more complicated because of significant spin-orbit coupling effects. |
Databáze: | OpenAIRE |
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