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

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.