Synthesis, structure and characterization of 4,4′-bipyridine directed isolated cluster and 1D chain of iron sulfates

Two 4,4′-bipyridine directed iron sulfates have been synthesized and characterized by single-crystal X-ray diffraction, infrared spectrum, powder X-ray diffraction, CHN elemental analysis, thermal gravimetric analysis and magnetic analysis. [C10N2H10]2[Fe4O2(SO4)6(H2O)4]·6H2O, I, and [C10N2H10][Fe(SO4)2(OH)]·H2O, II, both crystallize in triclinic space group P1¯ (No. 2). Crystal data: for I, a = 9.2064(8) Å, b = 11.5548(11) Å, c = 11.8130(11) Å, α = 117.3070(10)°, β = 94.650(2)°, γ = 96.493(2)°, V = 1096.79(17) Å3, Z = 1; for II, a = 7.0382(9) Å, b = 9.0625(12) Å, c = 11.8903(16) Å, α = 100.145(3)°, β = 98.701(2)°, γ = 91.047(3)°, V = 737.17(17) Å3, Z = 2. Compound I exhibits a rare discrete sulfated tetra-nuclear iron oxo cluster with a butterfly-type arrangement, and II possesses 1D tancoite-type chains. Magnetic properties analysis of I reveals a transformation from ferromagnetism to antiferromagnetism at about 14 K.