Spin Canting and Topological Ferrimagnetism in Two Manganese(II) Coordination Polymers Generated by In Situ Solvothermal Ligand Reactions

Discovery of an olivine-type lithium manganese thiophosphate, LiMnPS4, via a building block approach

An olivine-type orthothiophospate LiMnPS₄ has been synthesized for the first time through a building block approach by reacting preformed ternary lithium thiophospate with MnCl₂. Diffuse reflectance measurements show an optical band gap of 2.36 eV, which is further confirmed by DFT calculations. Irreversible weak ferromagnetic ordering and metamagnetism are verified through preliminary magnetic measurements.

Coexistence of Spin Canting and Metamagnetism in a One-Dimensional Mn(II) Compound Bridged by Alternating Double End-to-End and Double End-On Azido Ligands and the Analog Co(II) Compound

Two new compounds of general formula [M(N3)2(dmbpy)] in which dmbpy = 5,5′-dimethyl-2,2′-bipyridine, and M = Mn(II) or Co(II), have been solvothermally synthesized and characterized structurally and magnetically. The structures consist of zig-zag polymeric chains with alternating bis-µ(azide-N1)2M and bis-µ(azide-N1,N3)2M units in which the cis-octahedrally based coordination geometry is completed by the N,N’-chelating ligand dmbpy. The molecular structures are basically the same for each metal. The Mn(II) compound has a slightly different packing mode compared to the Co(II) compound, resulting from their different space groups. Interestingly, relatively weak interchain interactions are present in both compounds and this originates from π–π stacking between the dmbpy rings. The magnetic properties of both compounds have been investigated down to 2 K. The measurements indicate that the manganese compound shows spin-canted antiferromagnetic ordering with a Néel temperature of TN = 3.4 K and further, a field-induced magnetic transition of metamagnetism at temperatures below the TN. This finding affords the first example of an 1D Mn(II) compound with alternating double end-on (EO) and double end-to-end (EE) azido-bridged ligands, showing the coexistence of spin canting and metamagnetism. The cobalt compound shows a weak ferromagnetism resulting from a spin-canted antiferromagnetism and long-range magnetic ordering with a critical temperature, TC = 16.2 K.

A 2D rhomboidal system of manganese(ii) [Mn(3-MeC6H4COO)2(H2O)2]n with spin canting: rationalization of the magnetic exchange

The crystal structure of Mn(ii) carboxylate with 3-methylbenzoate as a bridging ligand [Mn(3-MeC₆H₄COO)₂(H₂O)₂]_n shows a rhomboidal layer, where each pair of neighbor Mn(ii) ions are bridged through only one carboxylate group with a syn-anti conformation. The magnetic exchange between neighbor ions is weakly antiferromagnetic (J = -0.52 cm^-1, g = 2.04), and at low temperature the system shows spin canting with T_B = 3.8 K. Computational studies, based on periodic calculations of the energies of the significant spin states on the magnetic cell and some higher supercells, corroborate the weak AF interaction between the adjacent Mn(ii) ions and preclude the negligible effect of frustration caused by very weak interactions between the non-adjacent ions in the magnetic response of the system. The results provide compelling evidence that the observed spin canting is due to the local coordination geometry of the manganese ions leading to two antiferromagnetically coupled subnets with different axial vectors.

Tetrazolate–azido–copper(ii) coordination polymers: tuned synthesis, structure, and magnetic properties

Two antiferrimagnetic tetrazolate–azido–copper(ii) coordination polymers, [Cu(tz)(N₃)]_n (1) and [Cu(tz)(N₃)(NH₃)₂]_n (2) with distinct topological structures were synthesized under different reaction conditions and structurally characterized.

4-Substituent pyridine directed cobalt(ii) azides: solvothermal synthesis, structure, and magnetic properties

Azido-bridged magnetic complexes: Different 4-substituent groups of pyridine co-ligands directed the linkages between azide and Co(ii) ions, to give three azide–Co(ii) complexes with different structures and magnetic properties.

Exploration of the slow relaxation behavior in the manganese phosphate network

Our endeavors are devoted to the explanation of the nature of the magnetic relaxation phenomena in the herein prepared [Mn(II)5(HPO4)2(PO4)2(H2O)4]n (1). The behavior investigation indicates the prominence of the half-occupied magnetic centers and the competence of the antiferromagnetic interactions and non-zero magnetic moments. The investigation suggests that the design and synthesis of unusual magnetic center materials with innate unquenched magnetic moments could provide a new route for the production of molecular magnets with magnetic relaxation.

catena-Poly[manganese(II)-(μ(2)-3,5-di-2-pyridyl-1,2,4-triazol-ato)-μ(2)-formato]

Owing to the presence of crystallographic twofold rotation axes (site symmetry 2, Wyckoff letters e and f), the asymmetric unit of the title compound, [Mn(C₁₂H₈N₅)(CHO₂)]_n, contains one-half of an Mn^II cation, one-half of a bpt anion (Hbpt is 3,5-di-2-pyridyl-4H-1,2,4-triazole) and one-half of a formate anion. The bpt and formate ligands occupy the same C₂ symmetry, while the Mn^II ion resides on another crystallographic twofold rotation axis. Each bpt ligand acts as a cis-bis-chelate to ligate two Mn^II ions into a one-dimensional chain running along the crystallographic 4₁ screw axis. Adjacent Mn^II ions are further bridged by a μ₂-formate ligand, completing the distorted octa­hedral coordination geometry of the cation.