Synthesis, Crystal Structure, and Thermal, Magnetic and Spectroscopic Properties of New Thiocyanato Transition Metal Coordination Polymers Based on Pyrimidine as Ligand

Controlling Noncollinear Ferromagnetism in van der Waals Metal-Organic Magnets

Van der Waals (vdW) magnets both allow exploration of fundamental 2D physics and offer a route toward exploiting magnetism in next generation information technology, but vdW magnets with complex, noncollinear spin textures are currently rare. We report here the syntheses, crystal structures, magnetic properties and magnetic ground states of four bulk vdW metal-organic magnets (MOMs): FeCl2(pym), FeCl2(btd), NiCl2(pym), and NiCl2(btd), pym = pyrimidine and btd = 2,1,3-benzothiadiazole. Using a combination of neutron diffraction and bulk magnetometry we show that these materials are noncollinear magnets. Although only NiCl2(btd) has a ferromagnetic ground state, we demonstrate that low-field hysteretic metamagnetic transitions produce states with net magnetization in zero-field and high coercivities for FeCl2(pym) and NiCl2(pym). By combining our bulk magnetic data with diffuse scattering analysis and broken-symmetry density-functional calculations, we probe the magnetic superexchange interactions, which when combined with symmetry analysis allow us to suggest design principles for future noncollinear vdW MOMs. These materials, if delaminated, would prove an interesting new family of 2D magnets.

Three pillared-layered inorganic–organic hybrid polymers with efficient luminescence

Three pillared-layered inorganic–organic hybrid polymers are synthesized via layer diffusion methods, which exhibit efficient luminescence.

Poly[bis-(μ(2)-pyrimidine-κN:N')bis-(seleno-cyanato-κN)zinc]

The asymmetric unit of the title compound, [Zn(NCSe)₂(C₄H₄N₂)₂]_n, consists of one Zn²⁺ cation located on a special position with site symmetry 2/m, one seleno­cyanate anion on a mirror plane and one pyrimidine ligand on a twofold rotation axis. The zinc cation is coordinated by six N atoms of four pyrimidine ligands and two N-bonded seleno­cyanate anions in mutually trans orientations within a slightly distorted octa­hedral coordination environment. The Zn atoms are μ-1,3-bridged via the pyrimidine ligands into a polymeric layer extending parallel to (100).

Polymeric potassium triformatocobalt(II)

In the crystal structure of the title compound, poly[tri-μ-formato-cobalt(II)potassium], [CoK(CHO(2))(3)](n) the Co(2+) cations are coordinated by six O-bonded formate anions in an octa-hedral coordination mode and the K(+) cations are eightfold coordinated by seven O-bonded formate anions within irregular polyhedra. The Co(2+) cations are connected by bridging formate anions into a three-dimensional coordination network in which the K(+) cations are embedded. The asymmetric unit consits of one Co(2+) cation located on a center of inversion, one K(+) cation located on a twofold axis and two crystallographically independent formato anions, of which one is located on a twofold axis and the other occupies a general position.

catena-Poly[(E)-4,4'-(ethene-1,2-di-yl)dipyridinium [[bis-(thio-cyanato-κN)ferrate(II)]-di-μ-thio-cyanato-κN:S;κS:N]]

In the title compound, {(C₁₂H₁₂N₂)[Fe(NCS)₄]}_n, each Fe^II cation is coordinated by four N-bonded and two S-bonded thio­cyanate anions in an octa­hedral coordination mode. The asymmetric unit consists of one Fe^II cation, located on a center of inversion, as well as one protonated (E)-4,4′-(ethene-1,2-di­yl)dipyridinium dication and two thio­cyanate anions in general positions. The crystal structure consists of Fe—(NCS)₂—Fe chains extending along the a axis, in which two further thio­cyanate anions are only terminally bonded via nitro­gen. Non-coordinating (E)-4,4′-(ethene-1,2-di­yl)dipyrid­inium cations are found between the chains.

Diaqua-bis-(seleno-cyanato-κN)bis-(pyrimidine-κN)manganese(II)

In the crystal structure of the title compound, [Mn(NCSe)(2)(C(4)H(4)N(2))(2)(H(2)O)(2)], the manganese(II) cation is coordinated by two N-bonded pyrimidine ligands, two N-bonded seleno-cyanate anions and two O-bonded water mol-ecules in a distorted octa-hedral coordination mode. The asymmetric unit consists of one manganese(II) cation, located on a centre of inversion, as well as one seleno-cyanate anion, one water mol-ecule and one pyrimidine ligand in general positions. The crystal structure consists of discrete building blocks of composition [Mn(NCSe)(2)(pyrimidine)(2)(H(2)O)(2)], which are connected into layers parallel to (101) by strong water-pyrimidine O-H⋯N hydrogen bonds.

Poly[[bis-(μ-4,4'-bipyridyl-κN:N')bis-(thio-cyanato-κN)manganese(II)] diethyl ether disolvate]

In the title compound, {[Mn(NCS)₂(C₁₀H₈N₂)₂]·2C₄H₁₀O}_n, the Mn^II ion is coordinated by four N-bonded 4,4′-bipyridine (bipy) ligands and two N-bonded thio­cyanate anions in a distorted octa­hedral coordination geometry. The asymmetric unit consists of one Mn^II ion and two bipy ligands each located on a twofold rotation axis, as well as one thio­cyanate anion and one diethyl ether mol­ecule in general positions. In the crystal structure, the metal centers with terminally bonded thicyanate anions are bridged by the bipy ligands into layers parallel to (001). The diethyl ether solvent mol­ecules occupy the voids of the structure.

Tetra-aqua-bis-(pyridine-κN)nickel(II) dinitrate

In the title compound, [Ni(C₅H₅N)₂(H₂O)₄](NO₃)₂, the Ni^II ion is coordinated by two N-bonded pyridine ligands and four water mol­ecules in an octa­hedral coordination mode. The asymmetric unit consists of one Ni^II ion located on an inversion center, as well as one pyridine ligand, one nitrate anion and two water mol­ecules in general positions. In the crystal structure, the discrete complex cations and nitrate anions are connected by O—H⋯O and C—H⋯O hydrogen bonds.

Poly[tetra-kis-(seleno-cyanato-κN)bis-(methanol-κO)tris-(μ-pyrimidine-κN:N')dicobalt(II)]

In the title compound, [Co(2)(NCSe)(4)(C(4)H(4)N(2))(3)(CH(3)OH)(2)](n), the Co(II) ion is coordinated by three N-bonded pyrimidine ligands, two N-bonded seleno-cyanate anions and one O-bonded methanol mol-ecule in an octa-hedral coordination mode. The asymmetric unit consists of one Co(II) ion, one pyrimidine ligand, two seleno-cyanate anions and one methanol mol-ecule in general positions as well as one pyrimidine ligand located around a twofold rotation axis. In the crystal structure, the pyrimidine ligands bridge [Co(CNSe)(2)(CH(3)OH)] units into zigzag-like chains, which are further connected by pyrimidine ligands into layers parallel to (010).