A new 3D metal–organic framework based on a hexanuclear cobalt(II): Synthesis,structure, and magnetic property

A new 3D framework 1 based on {Co₆} cluster as node was successfully synthesized and fully characterized, which showed an 8-connected bcu topology with the Schläfli symbol of {4²⁴,6⁴}. Furthermore, the thermal stability and magnetic property reveal that 1 displays high thermal stability and antiferromagnetic interaction among the Co^II spin carries.     

One novel near-infrared ytterbium metal–organic framework based on an unprecedented [Yb6(μ2-OH)2(μ3-OH)6]10 + cluster

A novel ytterbium metal–organic framework based on an unprecedented [Yb₆(μ₂-OH)₂(μ₃-OH)₆]^10 + cluster has been obtained and characterized, which shows a rare (3,12)-connected {3².4}₂{3⁸.4²².5²⁴.6¹⁰.7²} topological net and strong near-infrared luminescent emission.     

A new eight-connected net with CsCl-type topology built on unique [Co2(μ3-OH)(μ2-OH2)(CO2)3]2 building blocks

A new metal-organic framework (MOF) [Co₂(μ₃-OH)(μ₂-OH₂)(oba)(Hoba)(pyz)]_n(1), (oba = 4,4’-oxybis(benzoate), pyz = pyrazine) has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction, infrared spectroscopy, thermal gravimetric analysis, elemental analysis, and magnetic techniques. The framework defines an eight-connected CsCl net with 4²⁴·6⁴ topology symbol. To the best of our knowledge, this is the first eight-connected CsCl-type net built on unique [Co₂(μ₃-OH)(μ₂-OH₂)(CO₂)₃]₂ molecular building blocks (MBBs).     

A novel 3D coordination polymer [Cd15(μ4-Mtta)12(μ3-Mtta)6(μ3-SO4)4(μ3-OH)4]: Synthesis,structure and solid properties

A 3D coordination polymer, {[Cd₁₅(μ₄-Mtta)₁₂(μ₃-Mtta)₆(μ₃-SO₄)₄(μ₃-OH)₄] · 6H₂O}_n (1) (Mtta = 5-methyl-tetrazolate), which shows the rare multifunction of in situ formed Mtta and bright photo-induced blue emission, was isolated from a hydrothermal reaction of CdSO₄ · 8/3H₂O, NaN₃ in acetonitrile and water.     

Synthesis,supramolecular structure,and energetic properties of the first metal–organic nitrotetrazolate, [Me3Sn(μ-OH)SnMe3(μ-OH)SnMe3(H2O)][NT] (NT = 5-nitrotetrazolate)

The first metal–organic 5-nitrotetrazolate, [Me₃Sn(μ-OH)SnMe₃(μ-OH)SnMe₃(H₂O)][NT] (2), has been prepared by a simple metathetical reaction between Me₃SnCl and sodium 5-nitrotetrazolate dihydrate (= NaNT, 1). A single-crystal X-ray diffraction study revealed the presence of the trinuclear [Me₃Sn(μ-OH)SnMe₃(μ-OH)SnMe₃(H₂O)]⁺ cation to which the 5-nitrotetrazolate anion is coordinated via a ring-N atom. The NT anion is further engaged in four different OH⋯N and OH⋯N hydrogen bonds involving the remaining three ring-nitrogen atoms and one oxygen of the nitro group, leading to an extensive supramolecular hydrogen-bonded network in the solid state. Despite its very low N content of only 10.65%, compound 2 is highly impact-sensitive (< 2.5 J) and can be classified as a primary explosive.     

First macrocyclic oxamide Cu(II)–Co(II) complex: synthesis,crystal structure and magnetic properties

A oxamido-bridged binuclear complex, [Cu(L)Co(bpy)₂](ClO₄)₂·0.5C₂H₅OH·H₂O has been synthesized, and structurally and magnetically characterized, where L = 1,4,8,11- tetraazacyclotradecanne-2,3-dione and bpy = 2,2^′-bipyridine. In the complex, the copper atom from the macrocyclic oxamido-copper(II) precursor in a square-planar and cobalt atoms in a distorted octahedral environment is bridged by the oxamidate group, Cu⋯Co separation of 5.359 Å. The metal–metal separations are consistent with the sequence of decrease of the ion radius of the metal ion. The magnetic properties of the complex have been investigated. The χ_MT versus T plots is typical of antiferromagnetically coupled Cu(II)–Co(II).     

Synthesis,structure and magnetic property of a Gd–Mn coordination polymer based on 2,3,5-pyrazinetricarboxylate

A new three-dimensional lanthanide–manganese metal–organic framework [Gd₂Mn₃(PZTC)₄(H₂O)₁₂]·5H₂O (PZTC = 2,3,5-Pyrazinetricarboxylate) has been synthesized under hydrothermal conditions and characterized by IR, elemental analyses, and X-ray diffraction. Single-crystal X-ray diffraction shows that Gd^3 + and Mn^2 + ions are linked together to form a porous 3D Gd–Mn MOF by the alternative arrangement of two kinds of PZTC^3 − ligands. Taking the Gd, Mn and PZTC as node, the Schläfli symbol of the topology can be expressed as {4;8²}₂{4²;6}₂{4²;8⁴}₂{4³;6;8⁴;10²}₂{8}. Magnetic study indicates the magnetic coupling between two Mn^2 + ions through double monatomic carboxylate–oxo bridges is weak antiferromagnetic, while that between Gd^3 + and Mn^2 + ions through the carboxylate group in syn–anti-bridging mode is negligible.     

Synthesis,crystal structure and magnetic properties of one-dimensional cyano-bridged bimetallic complex of [Mn(Me2-bipy)2]3[W(CN)8]2·9H2O

An octacyanotungstate(V)-manganese(II) bimetallic assembly [Mn(Me₂-bipy)₂]₃[W(CN)₈]₂·9H₂O (1) (Me₂-bipy = 4,4′-dimethyl-2,2′-bipyridine) was synthesized in methanol and characterized by X-ray crystallography. X-ray analysis shows that complex 1 is a neutral, one-dimensional (1D) infinite chain polymer. Magnetic data analysis demonstrates a long-range magnetic interaction and two different antiferromagnetic coupling constants obtained by fitting between Mn and W ions in 1.     

Synthesis and structure of the pentanuclear mixed-metal cluster [Co4MoCp(μ3-SBut)(μ3-S)(μ3-CO)(μ-CO)2(CO)6]

The pentanuclear mixed-metal cluster [Co₄MoCp(μ₃-SBu^t)(μ₃-S)(μ₃-CO)(μ-CO)₂(CO)₆] (1) has been synthesised by reaction of [CoMoCp(CO)₇] with Bu^tSSBu^t. X-ray structural analysis identified an asymmetric unit with three cobalt atoms and one molybdenum forming an irregular tetrahedron while one cobalt–molybdenum edge is bridged by a cobalt atom. Crystal data: space group P2(1)/n, a=10.162(2), b=13.722(3), c=17.69(5) Å, β=91.44(2)°, Z=4.     

A spin-frustrated (4, 12)-connected metal-organic framework with unusual {Co8(μ4-OH)6}10 + cubes

A novel (4, 12)-connected metal-organic framework, {(NH₄)₂·[Co₁₁(μ₄-OH)₆(CN)₆(trz)₁₂]}_n, was solvothermally constructed from unusual Co^II₈ cubes, octahedral Co^II₁ subunits, and μ₃-N1,N2,N4-triazolate (trz) connectors. Strong antiferromagnetic coupling between the neighboring Co^II ions results in an absence of long-range magnetic ordering, leading to a strong spin-frustration with f > 62.     

A 2D polymer constructed through bridging oxalato and 4,4′-bipyridine ligands: crystal structure and magnetic behavior of [Cu3(μ-ox)3(μ-4,4′-bpy)2(4,4′-bpy)2]n

The crystal structure of the compound [Cu₃(μ-ox)₃(μ-4,4^′-bpy)₂(4,4^′-bpy)₂]_n 1 (ox=oxalato, 4,4^′-bpy=4,4^′-bipyridine) is comprised of two-dimensional sheets in which copper(II)–oxalato chains are cross-linked by bridging bidentate 4,4^′-bpy ligands. Metal centers show a tetragonally elongated octahedral environment formed by four oxygen atoms from two asymmetrically coordinated oxalato ligands and two nitrogen atoms from two trans-coordinated 4,4^′-bpy molecules. The magnetic measurements show the occurrence of weak ferromagnetic couplings.     

Crystal structure and novel magnetic property of a three-dimensional manganese(II)-μ-1,3-azido system

The synthesis, and crystal structure at room temperature of the three-dimensional manganese(II) complex with bridging 4,4′-bipyridine [Mn(4,4′-bipy) (N₃)₂]_n, in which the coordination mode of the azido ligand is end-to-end, are presented. The magnetic behavior for this compound is studied to show a weak antiferromagnetism to ferromagnetism transition at about 50 K, and is attributed to a canting phenomenon.     

A 3D cadmium coordination polymer with 2-fold interpenetration structure and helical chains based on biphenyl-4-hydroxyl-3,3′-bicarboxylic acid: Synthesis and crystal structure and properties

One cadmium coordination polymer with 2-Fold parallel Interpenetration Structure and Helical Chains based on biphenyl-4-hydroxyl-3,3′-bicarboxylic acid (H₂L) and μ-4,4′-bipyridine (bpy) {[Cd(L) (bpy)_1/2(H₂O)]₂}_n (1), has been obtained by hydrothermal synthesis and characterized by elemental analysis, powder X-ray diffraction (PXRD), IR spectra, thermal gravimetric analyses (TGA) and also by single-crystal X-ray diffraction. It crystallizes in the monoclinic, space group P2₁/c. The L^2 − anions of complex 1, as a bridging ligand, connect Cd(II) ions to form two-dimensional (Cd₂(L)₂)_n layer in which the 1D (Cd–L)_n helical chains are alternately arranged in a right- and left-handed sequence. These layers are further linked to build a three-dimensional network by the bpy ligands. In addition, the photochemical property of compound 1 has also been investigated.     

Synthesis,characterization and weak ferromagnetic coupling in [Cu2(μ3-CO3)(SCN)2(py)4]n

The crystal structure of a novel [Cu₂(μ₃-CO₃)(SCN)₂(py)₄]_n complex has been determined. It comprises of [CuCO₃Cu]_n infinite chains, running along the a-axis, and is in this aspect similar to the previously described [Cu(CO₃)(4-aminopyridine)₂]·H₂O complex. The FTIR spectrum of [Cu₂(μ₃-CO₃)(SCN)₂(py)₄]_n has been recorded and analyzed. A CuCO₃Cu intrachain coupling between Cu(II) atoms has been found to be responsible for the weak ferromagnetic properties of [Cu₂(μ₃-CO₃)(SCN)₂(py)₄]_n.     

Synthesis,crystal structure and magnetic properties of a new 2D cyanide-bridged heterobimetallic Cr(I)–Mn(III) complex

A new two-dimensional cyanide-bridged Cr(I)–Mn(III) coordination polymer {K[Mn(L)]₂[Cr(CN)₅NO]}·CH₃CN (1) (L = N,N-ethylene-bis(3-methoxysalicylideneiminate)) has been successfully synthesized by the reaction of K₃[Cr(CN)₅NO] with [Mn(L)(H₂O)₂]ClO₄ and characterized by elemental analysis, FT-IR and X-ray structure determination. Investigation systematic over magnetic susceptibility of the complex reveals the overall antiferromagnetic interaction between the cyanide-bridged Cr(I) ion and Mn(III) ion and its 3D antiferromagnetic ordering behavior with typical metamagnetic character below 12.5 K.     

A spin-crossover catecholato–iron(III) system: Synthesis,crystal structure and magnetic properties

A new mononuclear Fe(III)–catecholate complex, which exhibits an incomplete spin transition without hysteresis, had been synthesized and structurally characterized. Analyzed from the structural characteristics, the tripodal ligand must play the important role in affecting the spin crossover (SCO) behavior. The larger steric strain effect and weak cooperativity existed in the crystal lattice are inclined to favor the incomplete transition.     

A predesigned 1D chain of alternating di-μ1,1-azido bridged dinuclear Ni(II) and pyrazine: Synthesis,structure and magnetic properties

A new Ni(II) complex, [Ni₂(L)₂(μ_1,1-N₃)₂(pyz)]_n (1) (where pyz = pyrazine) has been synthesized using a dinuclear di-μ_1,1-azido bridged Ni₂ molecular building block derived from a tridentate NNO donor Schiff base ligand, HL (2-[(3-methylamino-propylimino)-methyl]-phenol) along with pyrazine as spacer. Single crystal X-ray analysis shows that complex 1 is a 1D chain in which dimeric Ni₂ units [Ni₂L₂(N₃)₂] are linked to each other by the bridging pyrazine ligand. Variable-temperature magnetic susceptibility studies indicate the presence of moderate ferromagnetic exchange coupling in complex 1 with J value of 53.54 cm^− 1.