One-dimensional square- and ladder-type architectures incorporating octacyanometallates of molybdenum(V) and tungsten(V)

Reactions of tptz complexes of Cu(II), Co(II), and Fe(III) with [MV(CN)8]3− (M = Mo, W) anions produced three new heterobimetallic chain compounds (2–4). The mer-capped building block [CuII(tptz)(CF3SO3)2(CH3OH)]·2H2O (1) (tptz = 2,4,6-tris(2-pyridyl)-1,3,5-triazine) was also isolated. The structures of 2, 3, and 4 consist of linked squares composed of alternating [MV(CN)8]3− and [M(tptz)]2+/3+ units bridged by cyanide ligands. Both {[CuII(tptz)MoV(CN)8]−·H3O+·CH3OH}∞ (2) and {[FeIII(tptz)WV(CN)8]·2CH3OH}∞ (4) exhibit an infinite ladder-type motif of edge-sharing squares, whereas {[CoII2(tptz)2(H2O)2W2V(CN)16CoII(H2O)4]·2H2O}∞ (3) is composed of molecular squares bridged by [Co(H2O)4]2+ cations. The magnetic behavior of 2 is dominated by ferromagnetic coupling between Cu(II) and Mo(V) spin centers. The isostructural compound 4 exhibits weak antiferromagnetic coupling between Fe(III) and W(V) spin centers. In the case of 3, magnetic studies indicate the presence of ferromagnetic interactions between Co(II) and W(V) centers and the ac data reveal a weak out-of-phase signal at low temperature which suggests single-chain magnet behavior.

Reactions of tptz complexes of CuII, CoII, and FeIII with [M(CN)8]3− (M = Mo, W) anions led to three new heterobimetallic magnetic materials based on a square motif that connects into infinite ladders and chains. The magnetic behavior of the CoII/WV compound exhibits a weak out-of-phase signal at low temperature in the ac magnetic data that suggests single-chain magnet behavior.Figure optionsDownload as PowerPoint slide