Synthesis and Characterization of New 2D Coordination Polymers based on Mn(NCS)2and Ni(NCS)2with 1, 2-Bis(4-pyridyl)-ethane as Co-Ligand

Strengthening the Magnetic Interactions in Pseudobinary First-Row Transition Metal Thiocyanates, M(NCS)2

Understanding the effect of chemical composition on the strength of magnetic interactions is key to the design of magnets with high operating temperatures. The magnetic divalent first-row transition metal (TM) thiocyanates are a class of chemically simple layered molecular frameworks. Here, we report two new members of the family, manganese(II) thiocyanate, Mn(NCS)₂, and iron(II) thiocyanate, Fe(NCS)₂. Using magnetic susceptibility measurements on these materials and on cobalt(II) thiocyanate and nickel(II) thiocyanate, Co(NCS)₂ and Ni(NCS)₂, respectively, we identify significantly stronger net antiferromagnetic interactions between the earlier TM ions-a decrease in the Weiss constant, θ, from 29 K for Ni(NCS)₂ to -115 K for Mn(NCS)₂-a consequence of more diffuse 3d orbitals, increased orbital overlap, and increasing numbers of unpaired t_2g electrons. We elucidate the magnetic structures of these materials: Mn(NCS)₂, Fe(NCS)₂, and Co(NCS)₂ order into the same antiferromagnetic commensurate ground state, while Ni(NCS)₂ adopts a ground state structure consisting of ferromagnetically ordered layers stacked antiferromagnetically. We show that significantly stronger exchange interactions can be realized in these thiocyanate frameworks by using earlier TMs.

Charge-assisted hydrogen bond and nitrile⋯nitrile interaction directed supramolecular associations in Cu(ii) and Mn(ii) coordination complexes: anticancer, hematotoxicity and theoretical studies

Charge-assisted H-bonds and nitrile⋯nitrile interactions directed assemblies in Cu(ii) and Mn(ii) complexes have been analyzed by MEP surface and NCI plot index. Anticancer activities and hematotoxictiy have been investigated.

3-Cyanopyridine as a bridging and terminal ligand in coordination polymers

Crystal structures of [M^IIBr₂(3-CNpy)_x]_(n) with M = Mn, Fe, Co, Ni and x = 1, 2, 4 were determined by powder diffraction. For x = 1, the 3-cyanopyridine ligand is bridging two metal atoms.

4-Cyanopyridine, a versatile mono- and bidentate ligand. Crystal structures of related coordination polymers determined by X-ray powder diffraction

4-Cyanopyridine (4-CNpy) as a monodentate ligand in single or double chains or as a bidentate ligand in two-dimensional networks.

Biphenyl-2,4,6,3',5'-pentacarboxylic acid as a tecton for six new Co(II) coordination polymers: pH and N-donor ligand-dependent assemblies, structure diversities and magnetic properties

Six new Co(ii)-based mixed-ligand coordination polymers, namely, [Co2(H3bppc)2(2,2'-bpy)4]·H2O (), [Co2(Hbppc)(2,2'-bpy)2(H2O)]·H2O (), [Co(H2bppc)(H-bpp)]·2H2O (), [Co3(μ3-OH)(bppc)(dps)(CH3CH2OH)]·4H2O (), [Co2(bppc)(bib)(H2O)4]·(H2-bib)0.5·(H2O)3 (), and [Co2(Hbppc)(bix)2]·2H2O (), (H5bppc = biphenyl-2,4,6,3',5'-pentacarboxylic acid, 2,2'-bpy = 2,2'-bipyridine, bpp = 1,3-bis(4-pyridyl)propane, dps = 4,4'-sulfanediyldipyridine, bib = 1,4-bis(imidazol-1-yl)benzene, bix = 1,4-bis(imidazol-1-ylmethyl)benzene), have been obtained under solvothermal conditions. exhibits a 3D supramolecular framework based on a [Co2(H3bppc)2(2,2'-bpy)4] unit. has a (3,4)-connected dmc net with a (4·8(2))(4·8(5)) topology containing alternate binuclear metal clusters and single metal centres. shows a 3D supramolecular architecture constructed from ladder-like arrays decorated with H-bpp. exhibits a binodal (5,7)-connected 3D network based on trinuclear [Co3(μ3-OH)](5+) units with an unusual (3·4(6)·5(2)·6)(3(2)·4(6)·5(7)·6(5)·7) topology. features a (4,6)-connected 3D fsc open framework with binuclear [Co2(H2O)(COO)](3+) units as nodes, and H2-bib and water molecules located in the voids of its framework by hydrogen bonds. possesses a 3D net containing unusual 2D polyrotaxane sheets. Topological analysis reveals that has a (3,4,4)-connected 3D network with a (4·6·7(4))(4·6·7)(6·7(2)·10(2)·11) topology. The structural difference of and is due to the different pH values of the reaction system. Though complexes were synthesised under similar reaction conditions, the carboxylic groups of H5bppc were partially deprotonated in , and and fully deprotonated in and . Complexes display diverse structures depending on different N-donor ligands and the coordination modes of the multicarboxylate ligand. Variable-temperature magnetic susceptibility measurements reveal that complexes show antiferromagnetic interactions.