An isostructural series of transition metal-formate-chloride-hydrate compounds, M3(OOCH)5Cl(OH2) (M = Fe, Co, Ni), have been synthesized using a solvothermal method. These compounds crystallize in the chiral and polar space group P31 and are comprised of three different types of helical chains of edge-sharing M2+-centered octahedra. All three compounds undergo 3D ferrimagnetic ordering at low temperature, and the iron and cobalt analogues exhibit field-induced metamagnetic transitions. The magnetic structure was determined by neutron powder diffraction, revealing ferromagnetic intrachain coupling and antiferromagnetic interchain interactions, with the three chains arranged in a two-up/one-down triangular lattice. As all three chains contain one type of metal in the same spin state, these compounds are rare examples of homospin topological ferrimagnets.
A one-dimensional (1D) chain compound [Fe(en)3]3(FeSe2)4Cl2 (en = ethylenediamine), featuring tetrahedral FeSe2 chains separated by [Fe(en)3]2+ cations and Cl– anions, has been synthesized by a low temperature solvothermal method using simple starting materials. The degree of distortion in the Fe–Se backbone is similar to previously reported compounds with isolated 1D FeSe2 chains. 57Fe Mössbauer spectroscopy reveals the mixed-valent nature of [Fe(en)3]3(FeSe2)4Cl2 with Fe3+ centers in the [FeSe2]− chains and Fe2+ centers in the [Fe(en)3]2+ complexes. SQUID magnetometry indicates that [Fe(en)3]3(FeSe2)4Cl2 is paramagnetic with a reduced average effective magnetic moment, μeff = 9.51 μB per formula unit, and a negative Weiss constant, θ = −10.9(4) K, indicating antiferromagnetic (AFM) nearest neighbor interactions within the [FeSe2]− chains. Weak antiferromagnetic coupling between chains, combined with rather strong intrachain AFM coupling, leads to spin-glass behavior at low temperatures, as indicated by a frequency shift of the peak observed at 3 K in AC magnetic measurements. A combination of [Fe(en)3]2+ and Cl– ions is also capable of stabilizing mixed-valent 2D Fe–Se puckered layers in the crystal structure of [Fe(en)3]4(Fe14Se21)Cl2, where Fe14Se21 layers have a unique topology with large open pores. Property measurements of [Fe(en)3]4(Fe14Se21)Cl2 could not be performed due to the inability to either grow large crystals or synthesize this material in single-phase form.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.