Three extended three-dimensional (3D) magnetic metal-organic frameworks (MMOFs), {[Mn3(H2O)2(atz)4Cl2]·2CH3OH}n (1), {[Mn2(H2O)(atz)2(ip)]·C2H5OH}n (2) and {[Mn2(H2O)2(atz)(btc)]·3H2O·0.7CH3OH}n (3) (atz(-) = 5-aminotetrazolate, ip(2-) = isophthalate and btc(3-) = 1,3,5-benzenetricarboxylate), were respectively obtained by varying the coligands with different numbers of functionalities and molecular topology, and structurally and magnetically characterized. Complex 1 exhibits an eight-connected 3(6)·4(18)·5(3)·6 topological network with linear Mn(II)3 subunits periodically linked by ditopic atz(-) connectors. Complex 2 possesses a pillared-layer framework constructed from undulated {Mn2(atz)2} layers and bidirectional ip(2-) spacers. By contrast, 3 consists of bent one-dimensional (1D) {Mn(atz)} ribbons, which are crosslinked through the carboxylate groups of tripodal btc(3-) connectors to generate a 3D architecture. Structural analysis reveals that the interesting motifs of 1-3 and their diverse linkages are significantly dominated by the cooperate coordination of the mixed ligands to the octahedral Mn(II) ion. Magnetically, 1 displays ferrimagnetic behavior resulting from the periodic arrangement of the net moment in the Mn(II)3 subunit, which is scarcely observed in the homometallic azolate systems. Complex 2 features unusual coexistence of spin-canted antiferromagnetic behavior and field-induced spin-flop transition due to the asymmetric magnetic superexchange within the two-dimensional (2D) {Mn2(atz)2} sublayer. By contrast, only antiferromagnetic ordering is observed in the 1D {Mn(atz)} ribbon of 3. These interesting results suggest that the diverse structural motifs by the cooperate coordination of octahedral Mn(II) ion with the N-rich tetrazolyl group can more significantly direct the magnetic behaviors and could be hopefully utilized upon the construction of novel MMOFs.

No abstract

The MnII atom in the title coordination polymer, [MnCl2(C12H12N6)2]n, lies on a center of inversion in a six-coordinate octa­hedral environment comprising four N-atom donors from four N-heterocyclic ligands and two chloride atoms. Bridging by the ligands results in a layer structure of a 14.79 (5) × 14.79 (5) Å (4,4) rhombic net topology, with the MnII atoms all lying on a plane. The parallel layers stack in an ABCABC… manner through inter­layer C—H⋯N and C—H⋯Cl hydrogen bonds.

The title complex, [ZnBr2(C7H6N4)]n, was formed under hydro­thermal conditions using the ligand 4-(3-pyrid­yl)-4H-1,2,4-triazole (L). The unique ZnII ion is coordinated by one triazole N atom, one pyridine N atom and two Br atoms in a slightly distorted tetra­hedral coordination environment. Symmetry-related ZnII ions are connected by bridging L ligands into chains parallel to [001] in which the Zn⋯Zn separation is 8.643 (7) Å. In the crystal structure, weak inter­molecular C—H⋯Br hydrogen bonds link the chains into a three-dimensional network.

No abstract