Heterometallic SrII-MII(M=Co, Ni, Zn and Cu) Coordination Polymers: Synthesis, Temperature-Dependent Structural Transformation, and Luminescent and Magnetic Properties

Bis(4-aminophenylhydroxamato-κ2 O,O′)copper(II) methanol disolvate

In the title complex, [Cu(C7H7N2O2)2]·2CH3OH, the metal centre is coordinated by two 4-aminophenylhydroxamate bidentate ligands, in a distorted square-planar geometry. The asymmetric unit is completed by two methanol solvent molecules, which are involved in hydrogen bonding with N—H functionalities of the free hydroxamate groups. The crystal structure also features N—H...O bonds formed by the NH2 groups, and O—H...O hydrogen bonds with the methanol solvent molecules as donors.

Bis(4,6-di-tert-butyl-2-{N-[4-(diethylamino)phenyl]carboximidoyl}phenolato)cobalt(II)

In the title complex, [Co(C25H35N2O)2], the cobalt(II) atom has a distorted tetrahedral geometry provided by pairs of O and N atoms. The dihedral angles between the benzene rings of the same ligand are 52.39 (9) and 34.96 (9)°. The molecular structure is stabilized by weak intramolecular C—H...O hydrogen bonds. The crystal packing is stabilized mainly by van der Waals forces. The structure contains a solvent-accessible void of 276 Å3which was treated using the SQUEEZE routine fromPLATON[Spek (2015).Acta Cryst.C71, 9–18]. The methyl C atoms of thetert-butyl groups are rotationally disordered, with site occupancies of 0.802 (3) and 0.548 (9) for the major components and 0.198 (3) and 0.452 (9) for the minor components.

Bis{3,5-di-tert-butyl-N-[(4-dimethylamino)phenyl]salicylaldiminato}cobalt(II)

In the title complex [systematic name: bis(2,4-di-tert-butyl-6-{N-[4-(dimethylamino)phenyl]carboximidoyl}phenolato)cobalt(II)], [Co(C23H31N2O)2], the cobalt(II) atom is coordinated by pairs of O and N atoms in a distorted tetrahedral coordination geometry. The dihedral angles formed by the aromatic rings of the same ligand are 51.99 (11) and 36.58 (9)°. The molecular conformation features weak intramolecular C—H...O hydrogen bonds. In the crystal, inversion-related pairs of complex molecules are linked into dimers by weak C—H...π interactions. The methyl C atoms oftert-butyl groups have rotational disorder, with site occupancies of 0.647 (7) and 0.617 (6) for the major components and 0.353 (7) and 0.383 (6) for the minor components. One of the methyl C atoms of the dimethylamino groups is also disordered over two orientations, with an occupancy ratio of 0.75 (4):0.25 (4).

Facile synthesis of an ultra-stable metal–organic framework with excellent acid and base resistance

A novel ultra-stable metal–organic framework, MCIF-1, [Cu₂(DCI)₂](MeCN), based on dicyanoimidazole and Cu(i), has been synthesized at room temperature successfully. MCIF-1 shows excellent water stability and can retain crystallinity after soaking in water for about one week. In addition, MCIF-1 also shows exceptional resistance under both acidic and basic conditions within a large pH range from 0 to 13.5. What is more, after modifying the synthesis procedure slightly, we can produce this material in a large scale during a very short time. Mild synthesis conditions, excellent stability and ease of large scale production give MCIF-1 great potential for practical use.

Bis(μ-4-amino-N-oxidobenzamide)bis[(4-amino-N-oxidobenzamide)aquacobalt] dihydrate

The structure of the title compound, [Co2(C7H7N2O2)4(H2O)2]·2H2O, consists of a centrosymmetric binuclear [Co2(4-Apha)4(H2O)2] complex molecule (4-AphaH = 4-aminophenylhydroxamic acid), and two solvent water molecules. Each CoII cation is six coordinate, binding five oxygen atoms from three 4-Apha− ligands and a water molecule in a slightly distorted octahedral geometry. Two of the 4-Apha− ligands bridge two neighbouring CoII ions to form the binuclear complex. A three-dimensional network structure is generated by O—H...O, N—H...O, and N—H...N hydrogen bonds.

Temperature-induced single-crystal-to-single-crystal transformation of a binuclear Mn(ii) complex into a 1D chain polymer

The new binuclear Mn(ii) complex can transform into a new 1D chain structure in a SCSC transformation via dehydration.

The first three-dimensional Fe(III)-Sr(II) heterometallic coordination polymer: poly[[diaquatetrakis(μ3-pyridine-2,3-dicarboxylato)diiron(III)strontium(II)] dihydrate]

The title compound, poly[[diaqua-1κ(2)O-tetrakis(μ3-pyridine-2,3-dicarboxylato)-2:1:2'κ(10)N,O(2):O(2'),O(3):O(3');2:1:2'κ(8)O(3):O(3'):N,O(2)-diiron(III)strontium(II)] dihydrate], {[Fe2Sr(C7H3O4)4(H2O)2]·2H2O}n, which has triclinic (P-1) symmetry, was prepared by the reaction of pyridine-2,3-dicarboxylic acid, SrCl2·6H2O and Fe(OAc)2(OH) (OAc is acetate) in the presence of imidazole in water at 363 K. In the crystal structure, the pyridine-2,3-dicarboxylate (pydc(2-)) ligand exhibits μ3-η(1),η(1):η(1):η(1) and μ3-η(1),η(1):η(1),η(1):η(1) coordination modes, bridging two Fe(III) cations and one Sr(II) cation. The Sr(II) cation, which is located on an inversion centre, is eight-coordinated by six O atoms of four pydc(2-) ligands and two water molecules. The coordination geometry of the Sr(II) cation can be best described as distorted dodecahedral. The Fe(III) cation is six-coordinated by O and N atoms of four pydc(2-) ligands in a slightly distorted octahedral geometry. Each Fe(III) cation bridges two neighbouring Fe(III) cations to form a one-dimensional [Fe2(pydc)4]n chain. The chains are connected by Sr(II) cations to form a three-dimensional framework. The topology type of this framework is tfj. The structure displays O-H...O and C-H...O hydrogen bonding.

Crystal structure of poly[[hexaqua-1κ4O,2κ2O-bis(μ3-pyridine-2,4-dicarboxylato-1κO2:2κ2N,O2′;1′κO4)cobalt(II)strontium(II)] dihydrate]

In the title polymeric complex, {[CoSr(C₇H₃NO₄)₂(H₂O)₆]·2H₂O}_n, the Co^II ion, which is situated on a crystallographic centre of inversion, is six-coordinated by two O atoms and two N atoms from two pyridine-2,4-di­carboxyl­ate (pydc²⁻) ligands and two terminal water mol­ecules in a slightly distorted octa­hedral geometry, to form a trans-[Co(pydc)₂(H₂O)₂]²⁻ unit. The Sr^II ion, situated on a C₂ axis, is coordinated by four O atoms from four pydc²⁻ ligands and four water mol­ecules. The coordination geometry of the Sr^II atom can be best described as a distorted dodeca­hedron. Each Sr^II ion bridges four [Co(pydc)₂(H₂O)₂]²⁻ units by four COO⁻ groups of four pydc²⁻ ligands to form a three-dimensional network structure. Two additional solvent water mol­ecules are observed in the crystal structure and are connected to the three-dimensional coordination polymer by O—H⋯O hydrogen bonds. Further intra- and intermolecular O—H⋯O hydrogen bonds consolidate the overall structure.