A 3D supramolecular network constructed from {Ni9} cluster and benzotriazole

The solvothermal reaction of Hbta (Hbta = benzotriazole) and Ni(NO₃)₂·6H₂O yielded a blue block crystal, [Ni₉(bta)₁₂(NO₃)₆(DMA)₆]·3DMA (1), (DMA = N,N-dimethylacetamide), which has been characterized by various measurements including elemental analysis, thermogravimetric (TG) analysis, infrared (IR) spectrum, powder X-ray diffraction (PXRD), and X-ray single-crystal diffraction. In compound 1, three crystallographic independent Ni^2 + ions are connected by two types of Hbta ligands to generate a centrosymmetric nine-nuclear {Ni₉} cluster, which could further form a 3D supramolecular network through intra- and intermolecular hydrogen bonds. The TG curve of 1 exhibits a weight loss between 25 and 330 °C, being in accordance with the release of DMA. Furthermore, the variable-temperature magnetic susceptibility of 1 has studied, and the results indicate that antiferromagnetic interactions exist among Ni^2 + ions.     

A unique 3D Co(II)-MOF based on [Co6(μ3-OH)4]8 +n chains: Synthesis,crystal structure,and magnetic property

A novel metal-organic framework, [Co₆(μ₃-OH)₄(ndc)₄(bip)₂(H₂O)₂]_n (1)[H₂ ndc = 1,4-naphthalenedicarboxylic acid, bip = 1,5-bis(imidazole-1-yl)pentane], constructed from unique [Co₆(μ₃-OH)₄]^8 +_n chains containing alternate [Co₄(OH)₂]^6 + and [Co₂(OH)₂]^2 + subunits, was reported, which has a new (3,3,8,12)-connected or 12-connented fcu/cubic network and shows weak antiferromagnetic interaction between the adjacent Co(II) ions mediated through the carboxylate and hydroxyl groups.     

Two transition metal coordination polymers constructed from 1,4-naphthalenedicarboxylate and N/O-donor auxiliary ligands: Syntheses,structures and magnetic property

Two transition metal coordination polymers (CPs), namely, Cd(1,4-NDC)(py) (1), Co₂(1,4-NDC)₂(DMF)₂ (2) (1,4-NDCH₂ = 1,4-naphthalenedicarboxylic acid, py = pyridine, DMF = N,N-dimethylformamide) have been synthesized and characterized. Compound 1 contains one-dimensional chains, which are further linked by the NDC^2 − ligands to form a three-dimensional framework with a 5,5T2 topology network. There exist two types of left-hand helical chains interconnected to each other through the Cd(II) center in compound 1. Although compound 2 has been reported previously, in this work the synthetic method of 2 is modified to obtain high quality crystals. In addition, the magnetic property of compound 2 is investigated, which shows the metamagnetic behavior induced by the external field.     

Two open-framework zinc phosphites constructed from different secondary building units

Presented here are two new zinc phosphites, formulate as Zn₃(dabco)₂(HPO₃)₃ (1, dabco = 1,4-diazabicyclo[2·2·2]octane), and H₂pmdeta ⋅ Zn₃(HPO₃)₄ (2, pmdeta = N,N,N′,N″,N″-pentamethyldiethylenetriamine). Compound 1 has 12-membered-ring (12 MR) channels with a 5-connected bnn topology containing 4 = 1 secondary building units. Compound 2 has multidirectional 10 MR channels with a pcu topology constructed from 6*1 secondary building units. The gas adsorption and fluorescent properties of compound 1 were also investigated.     

Solvothermal in situ synthesis of (Schiff-base)-containing dinuclear cobalt compound

A new dinuclear cobalt compound, namely Co₂(L)(H₂O)Cl₂ (1, H₂L = N,N′-o-phenylenebis(salicylide-neimine) was obtained by one-pot solvothermal self-assembly of CoCl₂, 1,2-phenylenediamine, and salicylaldehyde in C₂H₅OH. The magnetic studies suggest weak antiferromagnetic behavior and the magnetic data were interpreted by means of a dinuclear cobalt model with the parameters of g = 2.12, J = ?1.25 cm^?1, θ = ?3.12 K.     

Copper–cobalt heterobimetallic ceramic oxide thin film deposition: Synthesis,characterization and application of precursor

Thin films of halide free Cu–Co mixed metal oxide have been prepared at 390 °C from the heterobimetallic complex Co₄(THF)₄(TFA)₈(μ-OH)₂Cu₂(dmae)₂ · 0.5C₇H₈ (1) [dmae = N,N-dimethylaminoethanol ((CH₃)₂NCH₂CH₂O⁻), TFA = triflouroacetate (CF₃COO⁻), THF = tetrahydrofurane (C₄H₈O)] which was prepared by the reaction of [Cu(dmae)Cl]₄ and Co(TFA)₂ · 4H₂O. The precursor was characterized for its melting point, elemental composition, FTIR and X-ray single crystal structure determination. Thin films grown on glass substrate by using AACVD out of complex 1 were characterized by XRD and SEM. TGA and AACVD experiments reveal it to be a suitable precursor for the deposition of halide free Cu–Co mixed-metal oxide thin films at relatively low temperatures.     

A layered cobalt phosphonate exhibiting ferrimagnetism and slow magnetic relaxation

Compound Co₃(hpyedpH)₂(H₂O)₄ · H₂O (1) (hpyedpH₄ = 1-hydroxy-2-(3-pyridyl)ethylidene-1,1-diphosphonic acid) has a layer structure where chains of {Co₃(hpyedpH)₂(H₂O)₄}_n are connected by {CPO₃} tetrahedra, generating a layer containing 4-, 8- and 16-membered rings. Magnetic measurements show that compound 1 is a ferrimagnet with T_c = 3.8 K. Slow magnetic relaxation is observed below 3.8 K, possibly due to the domain wall movement.     

Two new 3-D coordination polymers with 5-tert-butyl isophthalic acid and flexible N-donor co-ligands bearing linear trinuclear secondary building blocks

Two new 3-D coordination polymers bearing linear trinuclear secondary building blocks with mixed bridging ligands, {[Ni₃(tbip)₂(Htbip)₂(bib)₂]·4H₂O}_n (1) and {[Co₃(tbip)₂(Htbip)₂(btb)₂]·4H₂O}_n (2) (H₂tbip = 5-tert-butyl isophthalic acid, bib = 1,4-bis(imidazol-1-yl)butane, btb = 1,4-bis(1,2,4-triazol-1-yl)butane), were obtained and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, single-crystal X-ray crystallography and powder X-ray diffraction. Both complexes 1 and 2 display similar 3D 6-connected pcu networks containing the linear trinuclear [M₃(COO)₆] (M = Ni and Co) clusters as nodes.     

A 3D pillared-layer porous framework with rare magnetic corner-sharing ∆-chain and unprecedented pentadentate 5-(4-pyridyl)tetrazolate ligand

A 3D pillared-layer porous framework, {[Co₂(H₂O)(μ₃-OH)(ptz)(nip)]·2H₂O}_n (1) (ptz = 5-(4-pyridyl)tetrazolate, nip = 5-nitroisophthalate), was in situ hydrothermally synthesized and structurally and magnetically characterized. Interestingly, the layered substructure of 1 consists of scarcely observed corner-sharing Co₂(μ₃-OH) ?-chain and unprecedented pentadentate ptz ligand. More importantly, due to the mixed triple syn,syn-carboxylate-μ₃-OH-μ₄-tetrazolyl bridges as well as the triangular Co^II arrangement, 1 behaves as a typical antiferromagnetically coupled paramagnet with a slight spin frustration, which exhibits a low-dimensional antiferromagnetic ordering below 10 K (Neel Temperature).     

Synthesis,structure, and adsorption properties of a three-dimensional porous yttrium–organic coordination network

Deprotonation of 4,4′-biphenyldicarboxylic acid (H₂BPDC) with triethylamine followed by the copolymerization with Y(III) in N,N-dimethylformamide (DMF) at room temperature yields a new three-dimensional (3-D) porous metal–organic coordination network, [Y₂(BPDC)₃(DMF)₂(H₂O)₂]_n · (DMF)_n · (H₂O)_n (1). Compound 1 (C_24.50H₁₉N_1.50O₉Y) crystallizes in the triclinic P-1 space group (a = 8.220 (2), b = 13.998 (4), c = 14.212 (4) Å, α = 111.058 (5)°, β = 90.187 (5)°, γ = 94.318 (5)°, V = 1520.9 (7) ų, and Z = 2). X-ray crystallography reveals that 1 consists of a 3-D framework contained open 1-D channels with the dimension of 5 × 10 Å along the crystallographic a axis. The adsorption measurements show that compound 1 can adsorb N₂, Ar and CO₂ into its pores. The adsorption isotherms for MeOH and H₂O were also measured.     

First example of near-infrared (NIR) luminescent Yb4(Salen)4-containing metallopolymer through radical copolymerization with MMA (methyl methacrylate)

Through the radical copolymerization of MMA (methyl methacrylate) with a vinyl-containing complex monomer {[Yb₄(L)₂(HL)₂(μ₃-OH)₂(NO₃)₂]·(NO₃)₂} (1; H₂L = N,N′’-bis-(5-(3′-vinylphenyl)-3-methoxy-salicylidene)cyclohexane-1,2-diamine), the first example of PMMA-supported and Yb₄(Salen)₄-containing metallopolymer Poly(1-co-MMA) exhibits significantly improved physical properties besides relatively higher NIR quantum yields (Φ_Yb^Yb = 1.18% and Φ_L^Yb = 0.86%) than those (Φ_Yb^Yb = 1.02–1.04% and Φ_L^Yb = 0.73–0.75%) of complex monomer 1 in solution and 1@PMMA in solid state.     

A cyanide-bridged two-dimensional grid-like FeIII–CoII complex based on the pentacyanideferrite(III) building block

A cyanide-bridged Fe^III–Co^II heterometallic complex {[Fe(1-CH₃im)(CN)₅][Co(H₂O)₂]}n·3H₂O (1-CH₃im = 1-methylimadazole) (2) has been synthesized by the reaction of Co^II(ClO₄)₂·6H₂O with the pentacyanideferrite(III) building block (Ph₄P)₂[Fe^III(1-CH₃im)(CN)₅]·4.5H₂O (1). X-Ray single crystal diffraction analysis shows that complex 2 has a two-dimensional (2D) grid-like structure. Magnetic investigations show that complex 2 displays long-range antiferromagnetic ordering with T_N = 9.45 K. The typical metamagnetic behaviors were observed with the critical field of ca. 4000 Oe at 1.82 K.     

Synthesis,crystal structure and third-order non-linear optical properties of two-dimensional supramolecular polymer [Co2(μ2-4,4′- bipy)2(μ2-be)2(be)2]n

Two-dimensional (2D) metal-organic supramolecular polymer [Co₂(μ₂-4,4′-bipy)₂(μ₂-be)₂(be)₂]_n 1 (4,4′-bipy = 4,4′-bipyridine, be = benzoate) has been synthesized by low-temperature solid-state reaction and characterized by single-crystal X-ray diffraction, elemental analyses, TGA, IR spectra and UV–visible spectra. The 2D structure is built from the linkage of secondary building units of binuclear [Co₂(μ₂-4,4′-bipy)₂(μ₂-be)₂(be)₂] clusters by a mixed connector of 4,4′-bipyridine and benzoate. The third-order non-linear optical (NLO) properties of the 1 were also investigated and they exhibit the reverse saturable absorption and self-defocusing performance with modulus of the hyperpolarizability (γ) 8.30 × 10⁻³⁰ esu for 1 in a 2.70 × 10⁻⁴ mol dm⁻³ DMF solution.     

Two new carboxylate–oxygen bridged trinuclear M(II) (MMn and Co) compounds with zwitterionic dicarboxylate ligands: crystal structures and magnetism

Two new Mn(II) and Co(II) coordination polymers with azide and zwitterionic dicarboxylate ligands L¹ and L² (L¹ = [4-((1-carboxylatobenzyl)pyridimium-3-yl) benzoic acid] chloride, L² = [1,1′-bis(4-carboxylatobenzyl)-4,4′-bipyridinium] dichloride) were synthesized and structurally and magnetically characterized. They are formulated as [Mn₃(L¹)₄(N₃)(CH₃CH₂OH)(H₂O)]ClO₄·4H₂O (1) and [Co₃(L²)₄(N₃)₂(H₂O)₂]·4NO₃ (2). Compound 1 contains two different linear trinuclear [Mn₃(COO)₈(CH₃CH₂OH)₂]^2 − and [Mn₃(COO)₆(H₂O)₂(N₃)₂]^2 − units built from the mixed bridges of (μ-COO)₂(μ₂-O_carboxylate). The trinuclear units are alternately linked into 1D chains by L¹. Compound 2 contains linear trinuclear [Co₃(N₃)₂(COO)₄(H₂O)₂] units built from the mixed bridges (μ-COO)₂(μ-H₂O). Magnetic studies demonstrated that the mixed triple bridges are antiferromagnetic in compounds 1 and 2.     

A unique 2D framework containing rhombic tetrameric cobalt(II) of mixed Td and Oh geometries linked by two different rigid ligands: Synthesis,crystal structure and magnetic properties

A new 2D coordination polymer with the formula [Co₄(μ₃-OH)₂(H₂nip-2H)₂(H₂nip-H)₂(bpe)₂]_n (1) (H₂nip = 5-nitro-isophthalic acid, bpe = trans-1,2-bis(4-pyridyl)ethylene), has been hydrothermally synthesized and structurally characterized. The structure of 1 is built around uncommon, rhombic {Co₄} clusters with double T_d and double O_h Co(II) geometries, which are extended into 2D network by the rigid deprotonated H₂nip and bpe bridges. Magnetic property study indicates there is weak antiferromagnetic coupling interaction between Co(II) ions, which mainly arises from the antiferromagnetic coupling interaction in the tetramer, based on the nature of the μ₃-hydroxyl group and syn–syn carboxylate-bridged modes.     

Co-existence of heterometallic Zn2Er and ZnEr arrayed chromophores for the sensitization of near-infrared (NIR) luminescence

With the Zn-Schiff-base [ZnL(Py)] from the simple Salen-type Schiff-base ligand H₂L (H₂L = N,N′-bis(salicylidene)ethylene-1,2-diamine) as the precursor, two co-crystallized heterometallic (Zn₂Ln and ZnLn array) complexes [Zn₂Ln(L)₂(Py)₂(NO₃)₂]·[ZnLn(L)(Py)(NO₃)₃(H₂O)]·NO₃·mMeOH·nS (Ln = Er(1), S = CH₃CN, m = 2, n = 1 or Gd(2), S = H₂O, m = 1, n = 3) were obtained by the further reaction with Ln(NO₃)₃·6H₂O, respectively. The result of their photophysical properties shows the intramolecular effective energy transfer has been demonstrated in the Zn₂Er and ZnEr arrayed complex 1, and the co-existence of different chromophores should be a potentially new way to the fine-tuning properties of NIR luminescence from Er³⁺ ions.     

Three cobalt (II) complexes with triethylenetetraaminehexaacetic acid: From binuclear complex to 3d-4f coordination polymers

The cobalt(II)–lanthanide(III) heteronuclear complexes [Ln(H₂O)₄Co₂(TTHA)(SCN)₂]·H₃O⁺ (H₆TTHA = triethylenetetraaminehexaacetic acid, Ln = La(2), Ce(3)) have been synthesized based on a binuclear building block of [Co₂(H₂TTHA)(H₂O)₂] in [Co₂(H₂TTHA)(H₂O)₂]·4H₂O (1). Single-crystal structures show that complex 1 is a binuclear complex, containing the [Co₂(H₂TTHA)(H₂O)₂] unit as a useful building block. Adding the La^3 + and Ce^3 + ions to this synthesis system, two new 3d-4f mixed complexes 2 and 3 were obtained. Complexes 2 and 3 show 3D framework, comprising an infinite 1D (one-dimensional) chain based on heterometallic Ln₂Co₂ (Ln = La(2), Ce(3)). Further investigations such as IR spectra, UV–vis spectra, TGA, XRD and magnetic properties were studied.     

Synthesis,reactivity, and X-ray structural characterization of a vanadium(III) oxidation pre-catalyst, (CpPOEtCo)VCl2(DMF)

Vanadium complexes are extensively used in the chemical industry as oxidation catalysts. During the course of our investigations into vanadium oxidation catalysis, the rich reactivity of a vanadium(III) scorpionate analogue complex, (CpP^OEtCo)VCl₂(DMF) (1), was investigated. The octahedrally coordinated 1 was prepared by mixing vanadium(III) chloride with Na(CpP^OEtCo) in DMF. The crystal structure of 1 has been determined through X-ray diffraction. Complex 1, C₂₀H₄₂Cl₂CoNO₁₀P₃V, crystallizes in the monoclinic space group P2₁/c with a = 38.566(9) Å, b = 9.499(2) Å, c = 18.149(4) Å, and β = 100.485(4)° with Z = 8. Complex 1 was found to be an effective pre-catalyst for the oxidation of 3,5-di-tert-butylcatechol to 3,5-di-tert-butylquinone. The reactivity studies, oxidative catalytic ability, as well as X-ray structural characterization of (CpP^OEtCo)VCl₂(DMF) will be discussed. ((CpP^OEtCo) = [η⁵-cyclopentadienyltris(diethylphosphito-κ¹P) cobaltate(III)⁻; DMF = N,N-dimethylformamide).     

A polythreaded three-dimensional architecture of undulated layers originated by the contribution of different supramolecular interactions

The structure of compound [Cd₂(NDC)₂(L)₂(H₂O)]·0.5DMF (1) (NDC = 1,4-naphthalenedicarboxylate, L = pyrazino[2,3-f][1,10]phenanthroline and DMF = N,N′-dimethylformamide) is reported. Two independent Cd(II) atoms in a distorted [CdO₄N₂] octahedral environment and three unique NDC ligands showing different coordination modes give strongly undulated two-dimensional grid motifs. Dangling L ligands are chelated to every Cd(II) atom decorating both sides of the layers. Due to the marked undulation of the layers, the large open windows are threaded by the dangling ligands of other layers producing a three-dimensional polythreaded supramolecular array that can be also described as a single three-dimensional framework if the extended columnar face-to-face π–π interactions are considered.     

A 2D brickwall architecture from a double-T-shaped ligand and hybrid coordinatively unsaturated copper: Synthesis,structure, and framework dynamic

A double-T-shaped ligand (H₄BPTC) as the spacer has been first used to direct the assembly of a 2D coordination polymer with brickwall network topology, [Cu₂(BPTC)(Im)₄(H₂O)(DMF)]_n (1) (DMF = N,N-dimethylformamide, H₄BPTC = Biphenyl-3,3′,4,4′-tetracarboxylic acid, Im = imidazole), which exhibits an interesting framework dynamic upon de-/resolvation.