A series of novel 1D coordination polymers constructed from metal–quinolone complex fragments linked by aromatic dicarboxylate ligands

Self-assembly of quinolones with metal salts in the presence of aromatic dicarboxylate ligands affords a series of novel 1D metal–quinolone complexes, namely [Mn(Hppa)(oba)]·3H₂O (1), [Co(Hppa)(oba)]·3.25H₂O (2), [Zn(Hppa)(sdba)]·1.5H₂O (3), [Mn(Hcf)(bpda)(H₂O)]·2H₂O (4), [Mn(Hppa)₂(bpdc)] (5) and [Mn(Hlome)₂(bpdc)]·4H₂O (6) (Hppa = Pipemidic acid, Hcf = ciprofloxacin, Hlome = lomefloxacin). The structures of compounds 1–3 consist of novel polymeric chains spanning two different directions, which display an intriguing 1D → 3D inclined polycatenation of supramolecular ladders. Compound 4 exhibits a chain compound formed from the interconnection of [Mn₂(Hcf)₂(μ-CO₂)₂] dimers with bpda ligands. Compounds 5 and 6 are similar chain compounds constructed from [Mn(Hppa)₂] (or [Mn(Hlome)₂]) fragments linked by bpdc ligands. The magnetic properties of 4 have been studied, which indicate the existence of antiferromagnetic interactions. Furthermore, the luminescent properties of compound 3 are discussed.     

Silver(I)-organic networks constructed with flexible silver-ethynide supramolecular synthon o-, m-, p-Cl–C6H5OCH2CC⊃Agn (n = 4, 5)

A series of five silver coordination polymers [(AgL1)·(AgCF₃COO)₅·(H₂O)₃] (1), [(AgL1)₂·(AgCF₃COO)₁₁·(H₂O)₆] (2), [(AgL2)·(AgCF₃COO)₃·(H₂O)] (3), [(AgL3)·(AgCF₃COO)₄·(CH₃CN)₂] (4), and [(AgL3)·(AgCF₃COO)₇·(CH₃CN)₂·(H₂O)₂] (5) have been constructed from three flexible anionic ligands HL1, HL2, and HL3 (HL1 = 1-chloro-2-(prop-2-ynyloxy)benzene, HL2 = 1-chloro-3-(prop-2-ynyloxy)benzene, HL3 = 1-chloro-4-(prop-2-ynyloxy)benzene). In these compounds, the invariable appearance of the μ₄- and μ₅-ligation modes of the ethynide moiety affirms the general utility of the flexible silver-ethynide supramolecular synthon o-, m-, p-Cl?C₆H₅OCH₂CC?Ag_n (n = 4, 5) in coordination network assembly. Among them, Ag?Cl interaction plays a vital role in assembling the supramolecular structures in complexes 1?3.     

Solvent-free synthesis of new metal phosphites with double-layered,pillared-layered,and framework structures

Three new metal phosphites, formulated as (H₃O)₂·Mn₂(HPO₃)₃ (1), Co(bpy) (H₂O) (HPO₃) (2), and H₂tmpda·Zn₃(HPO₃)₄ (3), have been synthesized under solvent-free conditions, where bpy = 4,4′-bipyridine, and tmpda = N,N,N′,N′-tetramethyl-1,3-propanediamine. Compound 1 has a double-layered structure with a thickness of 5.68 Å. Compound 2 has an inorganic-organic hybrid framework with cobalt phosphite layers pillared by bpy ligands. Compound 3 has a three-dimensional open-framework structure containing 8-ring channels. The temperature dependence of the magnetic susceptibility of compounds 1 and 2 were also investigated.     

Four novel linear trinuclear assemblies containing bridging triazole ligands. Crystal structure,magnetic, semiconducting and fluorescent properties

Four homotrinuclear linear coordination compounds with bridging ligand of (m-phenol)-1,2,4-triazole, [Mn₃(L)₆(H₂O)₆](ClO₄)₆ (1), [Ni₃(L)₆(H₂O)₆](BF₄)₆·4DMF (2), [Cd₃(L)₆(H₂O)₆](ClO₄)₆· 2H₂O·2DMF·2EtOH (3), [Zn₃(L)₈(H₂O)₄](BF₄)₄(SiF₆)·2EtOH·12H₂O (4), have been synthesized and structurally determined. The structures consist of three metal ions in linear arrangements, linked to each other by two pairs of three N1, N2 bridging triazole ligands. The negative value of J suggests that antiferromagnetic interaction exists in 1. Green fluorescence of 2 and 4 with emissions at 518 nm for 2 and 524 for 4 is possibly assigned to LMCT. The energy gaps of the compounds 2 and 4 are 1.82 and 1.97 eV, respectively, which suggests that the two materials behave as semiconductors.     

The crystal chemistry of four thorium sulfates

Four thorium sulfate compounds have been synthesized and characterized. [Th(SO₄)₂(H₂O)₇]·2H₂O (ThS1) crystallizes in space group P2₁/m, a=7.2488(4), b=12.1798(7), c=8.0625(5) Å, β=98.245(1)^o; Na₁₀[Th₂(SO₄)₉(H₂O)₂]·3H₂O (ThS2), Pna2₁, a=17.842(2), b=6.9317(8), c=27.550(3) Å; Na₂[Th₂(SO₄)₅(H₂O)₃]·H₂O (ThS3), C2/c, a=16.639(2), b=9.081(1), c=25.078(3) Å, β= 95.322(2)^o; [Th₄(SO₄)₇(OH)₂(H₂O)₆]·2H₂O (ThS4), Pnma, a=18.2127(9), b=11.1669(5), c=14.4705(7) Å. In all cases the Th cations are coordinated by nine O atoms corresponding to SO₄ tetrahedra, OH groups, and H₂O groups. The structural unit of ThS1 is an isolated cluster consisting of a single Th polyhedron with two monodentate SO₄ tetrahedra and seven H₂O groups. A double-wide Th sulfate chain is the basis of ThS2. The structures of ThS3 and ThS4 are frameworks of Th polyhedra and sulfate tetrahedra, and each contains channels that extend through the framework. One of the Th cations in ThS3 is coordinated by a bidentate SO₄ tetrahedron, and ThS4 is unusual in the presence of a pair of Th cations that share a polyhedral face.     

Two zincophosphite frameworks templated by 1,4-diaminobenzene: syntheses and structures of C6N2H10·Zn(HPO3)2 and (C6N2H8)0.5·ZnHPO3

The solution-mediated syntheses and single crystal structures of C₆N₂H₁₀·Zn(HPO₃)₂ (I) and (C₆N₂H₈)_0.5·ZnHPO₃ (II) are reported. Slight variation of the synthesis conditions led to two quite different phases. I contains infinite chains of ZnO₄ and HPO₃ groups with the protonated organic moiety acting as a template and interacting with the chains by NH⋯O hydrogen bonds and possible CH⋯O interactions. In II, the neutral 1,4-diamino benzene molecule bonds to Zn (as a ligand) and an unusual composite, “pillared”, structure results, with the organic species bridging 6³ polyhedral sheets, although NH⋯O bonds are also present. Similarities and differences to other zinc phosphites and phosphates are briefly discussed for I and II. Crystal data: C₆N₂H₁₀·Zn(HPO₃)₂, M_r=335.48, monoclinic, C2/c (No. 15), a=17.2471 (14) Å, b=9.0720 (8) Å, c=7.6529 (6) Å, β=103.752 (2)°, V=1163.09 (7) Å³, Z=4, R(F)=0.038, wR(F²)=0.084. (C₆N₂H₈)_0.5·ZnHPO₃, M_r=199.42, orthorhombic, Pbca (No. 61), a=8.0314 (16) Å, b=8.1299 (16) Å, c=18.830 (4) Å, V=1229.5 (4) Å³, Z=8, R(F)=0.026, wR(F²)=0.055.     

Synthesis,crystal structures and properties of three glutarato and adipato bridged manganese(II) coordination polymers under ambient conditions

Three Mn(II) polymers Mn(H₂O)₄(C₅H₆O₄) 1, [Mn(H₂O)₂(C₅H₆O₄)]·H₂O 2 and Mn(H₂O)(C₆H₈O₄) 3 were synthesized (H₂(C₅H₆O₄) = glutaric acid, H₂(C₆H₈O₄) = adipic acid) under mild ambient conditions. The [Mn(H₂O)₂]²⁺ units in 2 are interlinked by the glutarate anions with a η⁴μ₃ bridging mode to form 2D (4·8²) topological networks, which are stacked via interlayer hydrogen bonds into a 3D (4³·6⁵·8²)(4⁷·6³) topological net. Compound 3 crystallizes in the acentric space group P2₁ and exhibits significant ferroelectricity (remnant polarization Pr = 0.371 nC cm⁻², coercive field Ec = 0.028 kV cm⁻¹, saturation of the spontaneous polarization Ps = 0.972 nC cm⁻²). The adjacent MnO₆ octahedrons in 3 are one atom-shared to generate the Mn₂O₁₁ bi-octahedron, leading into 1D metal oxide chains. The resulting chains are interconnected by the η⁵μ₅ adipate anions to form new 2D (4⁸·6²) networks, which are held together via strong interlayer hydrogen bonds into 3D α-Po topological supra-molecular architecture. The temperature-dependent magnetic susceptibility data of 1–3 shows overall anti-ferromagnetic interactions between the metal ions bridged by the carboxylate groups.     

Two distinct manganese molybdenum(V) phosphates directed by different organic amines

By employing different organic amines as structure-directing agents, two new distinct 3D porous inorganic frameworks based on molybdenum(V) phosphates and Mn^II, (H₂en)₂{[Mn(H₂O)]₂[MnMo₁₂O₂₄(OH)₆(H₂PO₄)₂(HPO₄)₄(PO₄)₂]}·7H₂O (en = ethylenediamine) (1) and (H₃dien)₂{[Mn(H₃O)₂][Mn₃Mo₁₂O₂₄(OH)₆(HPO₄)₂(PO₄)₆]}·5H₂O (dien = diethylenetriamine) (2), have been hydrothermally synthesized, and characterized by routine physical methods. In compound 1, Mn^II all adopt octahedral coordination mode and each sandwich cluster Mn[Mo₆P₄O₃₁]₂ (abbreviated as Mn[Mo₆P₄]₂) acts as an octa-dentate ligand linking eight Mn^II, which result in a 3D inorganic (4, 8)-connected framework with the (4⁶)(4¹⁰·6¹²·8⁶) topology. Compound 2 shows a 3D (4, 10)-connected framework with the (3¹·4⁴·6¹)(3⁴·4⁹·5⁷·6¹⁷·7⁴·8⁴) topology, in which Mn^II ions exhibit both tetrahedral and octahedral coordination modes, and each Mn[Mo₆P₄]₂ links ten Mn^II. Interestingly, there exist channels along the a and b axes in 1, while along the a and c axes in 2. The differences between the two compounds should be ascribed to the distinctions of the organic amines. Primary de-/rehydration behaviors and electrochemistry properties have also been studied for the two compounds.     

Preparation and surface photoelectric properties of Fe(II/III) complexes

Four Fe(II/III) supramolecules, {[Fe(Hpdc)₂(H₂O)₂]·2H₂O} (1), [Fe(HImbc)₂(H₂O)₂] (2), [Fe(phen)₂(CN)₂]·CH₃CH₂OH·2H₂O (3), K[Fe(tp)₂]·SO₄ (4) (H₂pdc = 2,5-Pyridinedicarboxylic acid, H₂Imbc = 4,5-Imidazoledicarboxylic acid, phen = 1,10-phenanthroline, tp⁻ = poly(pyrazolyl)borate), were synthesized by hydrothermal and room temperature stirring methods. They were characterized by single crystal X-ray diffraction, surface photovoltage spectroscopy (SPS), field-induced surface photovoltage spectroscopy (FISPS), electron paramagnetic resonance (EPR), UV–Vis absorption spectra (UV–Vis), infrared spectra (IR) and element analysis. The structural analyses indicate that complex (1) is a supramolecule with 2D structure connected by hydrogen bonds. Complex (2) is a supramolecule with hydrogen-bonded 3D structure. Complexes (3) and (4) are both 1D supramolecules connected by hydrogen bonds. The electronic state of central metal Fe(II) ions in complexes (1) and (2) is d⁶ with FeN₂O₄ coordination mode, lying in weaker distorted octahedral field. The electronic state of Fe(II) ion in complex (3) is d⁶ with Fe(CN)₂N₄ mode in the strong distorted octahedral field. The electronic state of Fe(III) ion in complex (4) is d⁵ with FeN₆ mode, lying in the strong octahedral field. The micro-environment of Fe(II/III) ions in the four complexes is further investigated by EPR. The SPS of four complexes all exhibit photovoltage responses in the range of 300–700 nm. This indicates that they all possess certain photoelectric conversion capability. The effects of component, structure, type of ligands of the complexes, valence state and coordination micro-environment of the central metal ions on the SPS were discussed. Furthermore, the SPS and UV–Vis absorption spectra were interrelated.     

Supramolecular aspects of iron(II) crown-dipyridyl spin-crossover compounds

The synthesis, structures and magnetism of the complexes [Fe^II(3-bpp)₂][bpmdcK](SeCN)_1.7(ClO₄)_1.3·MeOH·H₂O (1), [Fe^II(3-bpp)₂]₄[bpmdcH₂(H₂O)₂](ClO₄)₁₀·7H₂O·3MeOH (2) and cis-[Fe^II₂(NCSe)₂((3,5-Me₂pz)₃CH)₂(μ-bpmdc)]·2MeCN (3) (where 3-bpp = 2,6-di(pyrazole-3yl)pyridine, bpmdc = N,N′-bis(4-pyridyl-methyl)diaza-18-crown-6) and (3,5-Me₂pz)₃CH = tris(3,5-dimethylpyrazole)methane, are presented. These compounds form a study of the supramolecular influence of host–guest/crown-ether interactions and cation-to-crown hydrogen-bonding effects upon d⁶ spin transitions, the latter occurring above, or near to, room temperature in 1 and 2. Desolvation effects also influence the T_1/2 values. The dinuclear compound 3 contains covalent pyridyl (crown) N to Fe bridge bonding and remains high spin.     

New derivatives of an enneanuclear Mn SMM

The reaction of the neutral triangular species [Mn₃O(O₂CR)₆L₃] (R = Me, Ph, CMe₃; L = py) with the tripodal ligands H₃tmp (1, 1, 1-tris(hydroxymethyl)propane) and H₄peol (pentaerythritol) affords the enneanuclear complexes [Mn₉O₇(O₂CMe)₁₁(tmp)(py)₃(H₂O)₂] (2); [Mn₉O₇(O₂CMe)₁₁(Hpeol)(py)₃(H₂O)₂] (3); [Mn₉O₇(O₂CCMe₃)₁₁(Hpeol)(py)₃(H₂O)₂] (4); and [Mn₉O₇(O₂CPh)₁₁(Hpeol)(py)₃(H₂O)₂] (5). Complexes 2–5 are characterized by spin ground states of S = 17/2 with axial zero-field splitting parameters in the range D = −0.26–0.30 cm⁻¹. Sweep-rate and temperature dependent hysteresis loops diagnostic of SMM behaviour are observed below 1.2 K featuring steps at regular intervals of field.     

Syntheses,structures and single-molecule magnetic behaviors of two dicubane Mn4 complexes

The reaction of MnX₂ · 4H₂O (X = Cl or Br) with 2,6-bis(hydroxymethyl)-4-methylphenol (H₃L) and NaOH in methanol solution yielded two tetranuclear manganese complexes, [Mn₄(HL)₄(MeOH)₄Cl₂] (1) and [Mn₄(HL)₄(MeOH)₄Br₂] (2). Both compounds crystallize in the monoclinic space group C₂/c with cell parameters: a = 26.0945(19) Å, b = 11.4999(8) Å, c = 21.2188(16) Å, β = 121.050(1)° and z = 4 for 1 · 2Et₂O; a = 25.8145(3) Å, b = 11.6734(2) Å, c = 21.3956(3) Å, β = 120.1277(6)° and z = 4 for 2 · 2Et₂O. Both complexes consist of a mixed-valence dicubane structure, which comprises two Mn^II and two Mn^III ions. Magnetic susceptibilities and magnetization of complexes 1 and 2 in the solid state indicate that two clusters have an S = 9 ground state. Frequency-dependent out-of-phase signals of alternating current magnetic susceptibilities were observed in the low temperature range (<3 K) for both complexes indicating a slow magnetic relaxation.     

Syntheses and structures of two new M6Li8(N3)a6 cluster-unit based compounds: Cs4Re6S8(N3)6·H2O and Na2Mo6Br8(N3)6·2H2O

The two new cluster compounds, Cs₄Re₆S₈(N₃)₆·H₂O (1) and Na₂Mo₆Br₈(N₃)₆·2H₂O (2), have been prepared via solution chemistry route, starting from the Cs₄Re₆S₈Br₆CsBr and Mo₆Br₁₂ precursors synthesized by solid state chemistry techniques, and structurally characterized (crystal data: Cs₄Re₆S₈(N₃)₆·H₂O (1): Orthorhombic, space group Pnam, a=10.0651(1) Å, b=15.8856(2) Å, c=20.1714(3) Å, V=3225.2(7) Å³, Z=4, d_calc=4.48 g cm⁻³, μ=27.43 mm⁻¹; Na₂Mo₆Br₈(N₃)₆·2H₂O (2): Orthorhombic, space group Ibam, a=11.5643(3) Å, b=14.3959(5) Å, c=17.0340(7) Å, V=2835.8(2) ų, Z=4, d_calc=3.63 g cm⁻³, μ=13.91 mm⁻¹). Their structures revealed that in both cases, the M₆Lⁱ₈ cluster core remains unchanged in the starting and final compounds whereas the bromine apical ligands (Br^a) are substituted by N₃ azide groups leading to M₆Lⁱ₈(N₃)^a₆ cluster unit. The new Cs₄Re₆S₈(N₃)₆·H₂O is the first example of a compound containing an octahedral rhenium cluster coordinated to azide groups.     

A unique 2-D hollow sheet structure and magnetic behavior of a cyanide- and triamine-bridged MnIICrIII ferrimagnet

A 2-D cyanide- and triamine-bridged Mn^IICr^III ferrimagnet, [Mn₃(dien)₂(H₂O)₂][Cr(CN)₆]₂ · 4H₂O (1), has been prepared by the combination of Mn²⁺, diethylenetriamine (dien) co-ligand and [Cr(CN)₆]³⁻. This compound forms a unique 2-D hollow sheet structure constructed by 1-D ribbon networks on the basis of triamine (dien)-bridged trinuclear Mn^II units. Compound 1 readily looses all lattice water molecules and irreversibly changes to a dehydrated form, [Mn₃(dien)₂(H₂O)₂][Cr(CN)₆]₂ (1a), in the air. Cryomagnetic studies of 1 and 1a reveal an antiferromagnetic interaction between Cr^III and Mn^II ions, and an unusual long-range ferrimagnetic ordering below 30 K (1) and 40 K (1a) with multiple magnetic phase changes below T_C. MCD spectra of 1a show a strong Faraday ellipticity associated with the LMCT band of the Cr–CN below 300 nm. Faraday ellipticity is remarkably enhanced below T_C in line with the characteristics long-range ferrimagnetic ordering.     

Fast tunneling Jahn–Teller isomer of the [Mn12O12(O2CC6H4-2-CH3)16(H2O)4] · S single-molecule magnet

The single-crystal X-ray structure of the single-molecule magnet [Mn₁₂O₁₂(O₂CC₆H₄-2-CH₃)₁₆(H₂O)₄] · CH₂Cl₂ · 2H₂O (complex 1) is reported. Complex 1 is a new example of a “Jahn–Teller isomer”, since it has two Mn(III) ions with abnormally oriented Jahn–Teller elongation axes. Complex 1 has a lower activation energy (U_eff = 29 K) for magnetization reversal relative to other reported [Mn₁₂O₁₂] type molecules (e.g., U_eff = 70 K for Mn₁₂Ac). Single-crystal low temperature magnetization measurements are reported that confirm that complex 1 is a single-molecule magnet. High-field electron paramagnetic resonance measurements were performed on a single crystal to give the spin Hamiltonian parameters.     

Synthesis,characterization and property study of new coordination polymers constructed from flexible dicarboxylates and bidentate nitrogen mixed ligands

Five new coordination polymers, [Cd(1,2′-cy)_0.5(bix)H₂O]_n (1), [Cd₂(1,2′-cy)₂(1,10′-phen)₂(H₂O)₂] (2), {[Co(1,2-cy)(2,2′-bipy)(H₂O)₂]·2H₂O}_n (3) {[Cd(succ)(1,10′-phen)H₂O]·H₂O}_n (4), and {[Cd(succ)(2,2′-bipy)H₂O]·2H₂O}_n (5) (1,2-cy = 4-cyclohexene-1,2-dicarboxylate, succ = succinic acid, bix = 1,4-bis(imidazol-1-ylmethyl)benzene, 1,10′-phen = 1,10-phenanthroline, 2,2′-bipy = 2,2′-bipyridine), have been synthesized and characterized by single-crystallographic X-ray diffraction. Complex 1 shows a two-dimensional covalent layer structure. Complex 2 exhibits a two-dimensional supramolecular layer network composed from discrete fundamental units. Complex 3 exhibits a one-dimensional covalent chain-like structure, which further extends to a two-dimensional supramolecular structure with hydrogen bonding and π-π interactions respectively. Complexes 4 and 5 show three-dimensional supramolecular networks composed from one-dimensional chain-like covalent structures. Furthermore, the magnetic property of complex 3 and fluorescent properties of complexes 1, 2, 4 and 5 have also been studied.     

Synthesis,structures and magnetic properties of two hexanuclear complexes

The reaction of salicylaldoxime (H₂salox) with Mn(ClO₄)₂ · 6H₂O, NaN(CN)₂ and NEt₃ in MeOH affords a Mn^III₆ hexanuclear complex of [Mn₆O₂(salox)₆(MeOH)₆(NCNCONH₂)₂] (1), while reaction of H₂salox with MnCl₂ · 4H₂O and NEt₄OH in EtOH affords a Mn^III₆ hexanuclear complex of [Mn₆O₂(salox)₆(EtOH)₄(H₂O)₂Cl₂] (2). Both complexes 1 and 2 contain a [Mn^III₆(μ₃-O)₂]¹⁴⁺ core, which is a known structural type in the family of Mn₆ complexes. Variable temperature magnetic susceptibilities and magnetization measurement of complexes 1 and 2 have been carried out. Exchange interactions of metal centers for complexes 1 and 2 are fitted by a full diagonalization matrix method. The fitting results indicate that both complexes 1 and 2 have the ground-state spin value of S = 4, and the ground state of complex 1 has the much closer energy to low-lying spin states than that of complex 2. Magnetization measurements at 2.0–4.0 K and 10–70 kG confirm that the ground state is S = 4, with significant magnetoanisotropy as gauged by the D value of ?0.82 cm^?1 and ?1.18 cm^?1, for 1 and 2, respectively. The frequency dependence of the out-of-phase component in alternating current magnetic susceptibilities for both complexes 1 and 2 indicates the slow magnetic relaxation of superparamagnetic behaviour with a U_eff of 27.0(1) K and τ₀ = 3.8(2) × 10^?9 s for complex 1, and U_eff of 25.1(6) K and τ₀ = 4.6(1) × 10^?8 s for complex 2.     

Three d10 coordination polymers assembled from 3,5-bis(imidazole-1-yl)pyridine and different polycarboxylates: Syntheses,structures and luminescence properties

Three novel Zn(II)/Cd(II) coordination polymers, [Cd₂(bip)₂(m-bdc)₂(H₂O)₂·3H₂O]_n (1), [Zn₂(bip)₂(p-bdc)₂·2.5H₂O]_n (2) and [Zn(bip) (p-bdc)·3H₂O]_n (3), where bip = 3,5-bis(imidazole-1-yl)pyridine, m-H₂bdc = 1,3-benzenedicarboxylic acid, p-H₂bdc = 1,4-benzenedicarboxylic acid, have been successfully synthesized under solvothermal conditions. The linkage of different ligands with Cd(II) ions in compound 1 affords a (3,5)-connected layer. Furthermore, 2D→3D parallel polycatenation occurs wherein the layers are polycatenated with the adjacent two parallel layers to form a 3D framework. In 2 and 3, the polycarboxylates act as pillars to combine the metal-bip chains, yielding the layered structures. These 2D networks are extended to the final 3D supramolecular architectures by π-π stacking interactions. The results show that bip can act as a versatile building block for the construction of various coordination polymers. Moreover, the fluorescent properties of 1–3 in the solid state at room temperature have been investigated.     

Syntheses and study on nickel and copper complexes with 1,3,5-benzenetricarboxylic acid. Crystal and molecular structure of [Cu3(mdpta)3(btc)](ClO4)3 · 4H2O

Nickel and copper complexes containing 1,3,5-benzenetricarboxylic acid, with a combination of selected N-donor ligands and Schiff bases, of the composition Ni₃(bimz)₆(btc)₂ · 12H₂O (1), Ni₃(btz)₉(btc)₂ · 12H₂O (2), Ni₂(L₁)(btc) · 7H₂O (3), Ni₃(L₂)₂(Hbtc) · 9H₂O (4), Ni₂(L₃)(btc) · 4H₂O (5), Cu₂(L₄)(btc) · 7H₂O (6), [Cu₃(pmdien)₃(btc)](ClO₄)₃ · 6H₂O (7) and [Cu₃(mdpta)₃(btc)](ClO₄)₃ · 4H₂O (8); H₃btc = 1,3,5-benzenetricarboxylic acid, bimz = benzimidazole, btz = 1,2,3-benztriazole, L₁ = 2-[(phenylimino)methyl]phenol, L₂ = N,N′-bis-(salicylidene)propylenediamine, L₃ = 2-{[(2-nitrophenyl)methylene]amino}phenol, L₄ = 2-[(4-methoxy-phenylimino)methyl]phenol, pmdien = N,N,N′,N″,N″-pentamethyldiethylenetriamine, mdpta = N,N-bis-(3-aminopropyl)methylamine, have been synthesized. The complexes have been studied by elemental analysis, IR, UV–Vis spectroscopies, magnetochemical and conductivity measurements and selected compounds also by thermal analysis. The crystal and molecular structure of complex 8 was solved. The complex is trinuclear with btc³⁻-bridge. The coordination polyhedron around each copper atom can be described as a distorted square with a CuON₃ chromophore formed by one oxygen atom of carboxylate and three nitrogen atoms of mdpta. The magnetic properties of 8 have been studied in the 1.8–300 K temperature range revealing a very weak antiferromagnetic exchange interaction with J = −0.56 cm⁻¹ for g = 2.13(9). The antimicrobial activities against selected strains of bacteria were evaluated. It was found that only complex 5 is able to inhibit the growth of Staphylococcus strains.     

Syntheses,structures, and properties of transition metal coordination polymers based on a long semirigid tetracarboxylic acid and multidentate N-donor ligands

Six transition metal coordination polymers based on a semirigid tetracarboxylic acid and the multidentate N-donor ligands have been synthesized by the hydrothermal method, namely, {[Co(H₂obda) (μ₂-H₂O) (H₂O)₂]·2H₂O}_n (1), {[Co(obda)_0.5(bpe) (H₂O)₂]·3H₂O}_n (2), {[Zn(H₂obda) (H₂O)₄]·H₄obda·6H₂O}_n (3), {[Zn(bpy) (H₂O)₄]·H₂obda}_n (4), {[Ni(bpy) (H₂O)₄]·H₂obda}_n (5) and {[Cu(H₂obda) (bpy)₂]}_n (6) (H₄obda = 1,4-bis(4-oxy-1,2-benzene dicarboxylic acid)benzene, bpe = 1,2-Bis(4-pyridyl)ethylene), bpy = 4,4′-bipyridine). Compounds 1–6 were structurally characterized by the elemental analyses, infrared spectra, and single crystal X-ray diffractions. Compounds 1–2 exhibit the 2D quadrilateral and polygonal layered grid structures, respectively; a 3D supramolecular structure of 2 has been build via π···π and hydrogen bonds interactions. Compounds 3–6 reveal the 1D zigzag and linear chains structures, respectively; furthermore, 3–5 display the diverse 3D supramolecular structures via hydrogen bonds, respectively. The 1-D infinite water chain in 3 has been found between the lattice water molecules. In addition, the thermogravimetric analyses of 1–6, magnetic property of 1, and photoluminescence of 3–4 have been investigated, respectively.