A novel 3D cyano-bridged mixed-valence Co^II/Co^IIIcanted antiferromagnet constructed from defective cubanes. Synthesis, X-ray structure and magnetic properties

Abstract

The hydrothermal reaction of 2-pyrimidine-carboxamide, CoCl2.6H(2)O and K3[Co(CN)6] affords a novel mixed-valence Co(II)/Co(III) 3D complex K[Co3(CN)6(ox)(H(2)O)2].H2O, which contains cyano-bridged Co(7) defective cubanes connected by oxalate and cyanide bridging groups and behaves as a canted antiferromagnet with Tc = 17.5 K.

[Co(μ‐ox)(Hpmtz)] – A New CoII Zig‐Zag Chain Complex with the In Situ Generated Oxalate Bridging and Hpmtz Chelating Ligands (Hpmtz = 5‐pyrimidyltetrazole) Exhibiting Spin‐Canted Antiferromagnetism

“…In this latter compound, oxalate is formed in situ from the total hydrolysis of 2‐cyanopyrimidine. A similar process has been shown to occur for pyrimidine‐2‐carboxamide‐oxime,7 5‐pyrimidyltetrazole8 and pyridine‐2‐carboxylic acid9 species, which react with metal ions under hydrothermal conditions to afford oxalate‐bridged polymeric complexes. Hpmtz is also generated in situ from the reaction between 2‐cyanopyrimidine and sodium azide 6.…”

Di-μ-cyanido-1:2κ2C:N,2:3κ2N:C-hexacyanido-1κ3C,3κ3C-tetrakis(1,10-phenanthroline)-1κ2N,N′;2κ4N,N′;3κ2N,N′-1,3-dicobalt(III)-2-iron(II) tetrahydrate

“…For background to cyanide-bridged complexes, see: Rodríguez-Dié guez et al (2007); Colacio et al (2003Colacio et al ( , 2005; Chen et al (2006); Ferlay et al (1995); Ferná ndez-Armas et al (2007); Goodwin et al (2008); He et al (2005); Kosaka et al (2009); Mao et al (2005); Overgaard et al (2004); Paredes-García et al (2006); Phillips et al (2008); Reguera Balmaseda, del Castillo et al (2008); Reguera, Balmaseda, Krap et al (2008); Rodriguez et al (2005); Xie et al (2007); Yu et al (2003). For related structures, see: Halbauer et al (2008); Guo et al (2007); Zhao et al (2008); Brewer et al (2007).…”

Synthesis, crystal structure and properties of the cyano-bridged heteropolynuclear [Cu(meso)]3[Co(CN)6]2•9.5H2O compound

“…The macrocyclic meso was prepared as published elsewhere. 19 6 6 ] dissolved in 10 mL of water was added dropwise. Upon standing overnight at room temperature, purple crystals were colleted by filtration, washed with cold water and dried under vacuum.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] These building blocks, combined with coordinatively unsaturared systems such as cationic Schiff-bases, produce 1D, 2D or 3D network structures. These assemblies, also called Prussian blue analogues, gained importance due to the innumerous possibilities to prepare novel bimetallic extended lattices.…”