Amine-Templated One-Dimensional Metal Sulfates Includinga Mixed- Valent Fe Compound with a Half-Kagome Structure

Abstract

Organically templated metal sulfates are relatively new. Six aminetemplated transition-metal sulfates with different types of chain structures, including a novel iron sulfate with a chain structure corresponding to one half of the kagome structure, were synthesized by hydro/solvothermal methods. Amongst the one-dimensional metal sulfates, $[C_{10}N_2H_{10}][Zn(SO_4)Cl_2]$ (1) is the simplest, being formed by corner-linked $ZnO_2Cl_2$ and $SO_4$ tetrahedra.$[C_6N_2H_{18}][Mn(SO_4)_2(H_2O)_2]$ (2) and $[C_2N_2H_{10}][Ni(SO_4)_2(H_2O)_2]$ (3) have ladder structures comprising fourmembered rings formed by $SO_4$ tetrahedra and metal–oxygen octahedra, just as in the mineral krohnkite. $[C_4N_2H_{12}][V^{III}(OH)(SO_4)_2]·H_2O$ (4) and $[C_4N_2H_{12}][VF_3(SO_4)]$ (5) exhibit chain topologies of the minerals tancoite and butlerite, respectively. The structure of $[C_4N_2H_{12}][H_3O][Fe^ {III}Fe^{II} F_6(SO_4)]$ (6) is noteworthy in that it corresponds to half of the hexagonal kagome structure. It exhibits ferrimagnetic properties at low temperatures and the absence of frustration, unlike the mixedvalent iron sulfate with the full kagome structure.