Portal de Periódicos da CAPES

Five New Manganese−μ-Azido 2D Compounds Synthesized in Aqueous Hydrazoic Acid from Pyrazine Derivatives

2005; American Chemical Society; Volume: 45; Issue: 2 Linguagem: Inglês

10.1021/ic051258z

1520-510X

Brigitte Bitschnau, Andreas Egger, Albert Escuer, Franz A. Mautner, B. Sodin, Ramón Vicente,

Lanthanide and Transition Metal Complexes

The syntheses, structural characterization, and magnetic behavior of five new 2D manganese(II) complexes with empirical formulas [Mn(N3)2(2,6-DiMepyz)(H2O)]n (1), [Mn(N3)2(Etpyz)(H2O)]n (2), [Mn(N3)2(H2O)2]n(2,3-DiMepyz)n (3), [Mn(N3)2(Clpyz)2]n (4), and [Mn(N3)2(Ipyz)2]n (5) (pyz = pyrazine (1,4-diazine)) are reported. 1 crystallizes in the monoclinic system, space group P21/c, with unit cell parameters a = 7.513(4) Å, b = 17.438(7) Å, c = 8.404(4) Å, β = 94.53(4)°, and Z = 4. 2 crystallizes in the triclinic system, space group P1̄, with unit cell parameters a = 7.386(2) Å, b = 8.434(2) Å, c = 9.442(3) Å, α = 71.82(2)°, β = 72.08(2)°, γ = 88.54(2)°, and Z = 2. 3 crystallizes in the monoclinic system, space group C2/c, with unit cell parameters a = 20.438(7) Å, b = 7.711(2) Å, c = 7.457(2) Å, β = 93.76(3)°, and Z = 4. 4 crystallizes in the orthorhombic system, space group Pbca, with unit cell parameters a = 8.600(2) Å, b = 13.440(4) Å, c = 24.083(7) Å, and Z = 8. 5 crystallizes in the orthorhombic system, space group Pbca, with unit cell parameters a = 8.521(2) Å, b = 13.787(3) Å, c = 26.237(5) Å, and Z = 8. The compounds 1−5 have only azido bridging ligands. In 1−3 each manganese atom is linked to the four nearest neighbors by only end-to-end azido bridges, forming square layers. 4 and 5 show alternating end-to-end and end-on azido bridges between manganese atoms. The magnetic properties of 1−5 are reported. At high temperatures the plots of χM or χMT vs T for the 1−3 compounds can be fitted as homogeneous 2D systems with J = −4.9, −4.4, and −3.9 cm-1 for 1−3, respectively. For 1, 3, and 5 magnetic ordering and spontaneous magnetizations is achieved below Tc = 35, 29, and 22 K, respectively, whereas 2 and 4 do not show spontaneous magnetization up to 2 K.