Manganese(II)-Octacyanometallate(V) Bimetallic Ferrimagnets with T_c from 41 to 53 K Obtained in Acidic Media

Abstract

A series of three-dimensional (3D) octacyanometallate-based bimetallic magnets, {[Mn(H(2)O)][Mn(0.75)(HCOO)(0.5)(H(2)O)(0.5)][W(CN)(8)] x H(2)O}(4n) (1), {[Mn(2)(HCOO)(HCOOH)][M(CN)(8)] x H(2)O}(n) (M = W (2) and Mo (3)), and {[Mn(2)(HCOO)(HCOOH)][W(CN)(8)] x CH(3)OH}(n) (M = W (4) and Mo (5)), were synthesized by the reaction of octacyanometallates A(3)[M(CN)(8)] x nH(2)O (A = Na, Cs, and (C(4)H(9))(3)NH; M = W and Mo; and n = 2 or 4) with manganese salt (Mn(CH(3)COO)(2) x 4 H(2)O, Mn(ClO(4))(2) x 6 H(2)O, and MnCl(2) x 4 H(2)O) in aqueous or methanolic solution containing formic acid. All complexes crystallize in the tetragonal or orthorhombic system. Complex 1 shows an unexpected 3D network structure by connections of manganese ions and octacyanotangstate-manganese double layers via cyanide bridges, while other complexes have typical structure constructions similar to the reported complexes {[MnL](m)[M(CN)(8)]}(n) (L = CH(3)COO(-), Cl(-), and H(2)O), which the CN group of [W(V)(CN)(8)] coordinates to eight Mn(II) ions forming a -[W(CN)(8)]-Mn(4)-[W(CN)(8)]-Mn(4)- columnar chain, and then all chains share Mn(II) ions as the nodes interlocking with each other to form the 3D networks. Magnetic studies indicate that the cyanide group mediates the antiferromagnetic coupling between octacyanometallates and manganese ions in all complexes, and the ferrimagnetic phase transition temperatures are 53, 52, 42, 49, and 41 K for 1-5, respectively.

The Temperature Effect on the Structural Features of Bidentate Ligand‐Decorated Cyanide‐Bridged MnII‐MoV Compounds

“…Cyanide‐bridged molecule‐based magnetic materials has received intense attention in the past decades, and octacyanometalates [ M (CN) 8 ] 3– ( M = Mo, W) are flexible building blocks, which can adopt variable coordination configurations (e.g., square‐antiprism, dodecahedron, bicapped trigonal‐prism) depending on the surrounding arrangement . The assembly of [ M (CN) 8 ] 3– ions and the second central metal atoms has generated a great deal of diversified topological structures ranging from discrete entities to three‐dimensional (3D) extended networks, and the resulting materials exhibited interesting magnetisms such as high T c , single‐molecule/chain magnets,, as well as spin crossover,, etc. However, how to rationally control desired topologies with potential applications is still a great challenge.…”

Neutral Low-Dimensional Assemblies of a Mn(III) Schiff Base Complex and Octacyanotungstate(V): Synthesis, Characterization, and Magnetic Properties

“…Some of them are 1D polymers [53][54][55][56]; others possess layered [57][58][59][60][61][62][63] or 3D network structures [64][65][66][67][68]. The paramagnetic cyanotungstate(V) tectones have been used to build discrete molecules [69][70][71], chains [53][54][55][56], 2D [57] and 3D networks [64][65][66][67][68], and some of them have displayed variable magnetic properties such as high ordering temperatures [72], photo-induced magnetism [73,74], SMMs [75], and SCMs [17,54,55]. However, the assemblies of the paramagnetic [W(CN) 8 ] 3− precursor and manganese(III) Schiff base complex, [Mn(SB)] + , are fairly limited and poorly studied in comparison with the large family of bimetallic compounds comprised of the [Mn(SB)] + cation and the 3d metal hexacyanides that are extensively investigated both structurally and magnetically [76].…”

Neutral Low-Dimensional Assemblies of a Mn(III) Schiff Base Complex and Octacyanotungstate(V): Synthesis, Characterization and Magnetic Properties

“…Some of them are 1D polymers [53][54][55][56]; others possess layered [57][58][59][60][61][62][63] or 3D network structure [64][65][66][67][68]. The paramagnetic cyanotungstate(V) tectones have been used to build discrete molecules [69][70][71], chains [53][54][55][56], 2D [57] and 3D networks [64][65][66][67][68] and some of them have displayed variable magnetic properties such as high ordering temperatures [72], photo-induced magnetism [73,74], SMMs [75], and SCMs [17,54,55]. However, the assemblies of the paramagnetic [W(CN)8] 3− precursor and manganese(III) Schiff base complex, [Mn(SB)] + , are fairly limited and poorly studied in comparison with the large family of bimetallic compounds comprising of [Mn(SB)] + cation and the 3d metal hexacyanides that are extensively investigated both structurally and magnetically [76].…”