Three different structural lead(II) polymers constructed from newly designed chlorophenyl-imidazole dicarboxylate ligands

A 1-D coordination polymer, {[Pb(o-ClPhH₂IDC)₂]·H₂O}_n (o-ClPhH₃IDC = 2-(2-chlorophenyl)-1H-imidazole-4,5-dicarboxylic acid) (1), a 2-D coordination polymer, [Pb₃(p-ClPhIDC)₂(H₂O)]_n (p-ClPhH₃IDC = 2-(4-chlorophenyl)-1H-imidazole-4,5-dicarboxylic acid) (2), and a 3-D polymer, [Pb(p-ClPhH₂IDC)₂]_n (3), have been obtained solvothermally and structurally characterized by elemental analyses, IR, and single-crystal X-ray diffraction. Although they were prepared with similar ligands and Pb²⁺, polymers 1–3 show distinct structures. The X-ray powder diffraction and thermal properties of the polymers have been investigated. The influence of the reaction conditions to the final products and coordination of the organic ligands are discussed.     

Syntheses,structures and properties of four metal-organic frameworks from chlorophenyl imidazole dicarboxylates

Four metal-organic frameworks, [Sr(o-ClPhHIDC)(H₂O)₂]_n (o-ClPhH₃IDC = 2-(o-chlorophenyl)-1H-imidazole-4,5-dicarboxylic acid) (1), [Mg(m-ClPhHIDC)(H₂O)₂]_n (2), [Sr(m-ClPhHIDC)(H₂O)]_n (3) and {[Co₃(m-ClPhIDC)₂(H₂O)₆]·2H₂O}_n (m-ClPhH₃IDC = 2-(m-chlorophenyl)-1H-imidazole-4,5-dicarboxylic acid) (4), have been solvothermally synthesized and structurally characterized. Single-crystal X-ray analyses reveal that 1–3 show 2-D architectures and 4 exhibits a 3-D structure. The o-ClPhH₃IDC and m-ClPhH₃IDC ligands in the polymers can be partly deprotonated and coordinate to metal ions by various modes. The metal ions of 1–4 are coordinated only to oxygens. The thermal and luminescence properties of the polymers have also been investigated.     

Synthesis,characterization, and magnetochemical properties of two Mn4 clusters derived from 2-pyridinecarboxaldehyde Schiff base ligands

Two tetranuclear manganese complexes, [Mn₄(L¹)₆](ClO₄)₂?2.75H₂O (1) [HL¹ = 4-methyl-2-((pyridin-2-ylmethylene)amino)phenol] and [Mn₄(L²)₄(NO₃)₃(OH)]?pz?3H₂O (2) [HL² = (1H-pyrazol-1-yl)(pyridin-2-yl)methanol, pz = pyrazole], have been synthesized and characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction, and magnetic measurements. The structural analysis revealed that the central manganese ion is linked with three apical manganese ions through six phenoxo-bridges creating a Mn₄O₆ core for 1; 2 has a cubane-like topology with the Mn(II) ions and the deprotonated oxygens from L² alternatively occupying vertices. The magnetic studies indicated a weak ferromagnetic coupling interaction (J = 0.48 ± 0.087 cm^?1, g = 2.00, θ = ?0.78 K) for 1 and a weak antiferromagnetic spin-exchange interaction (J₁ = ?0.50 ± 0.075 cm^?1, J₂ = ?0.13 ± 0.082 cm^?1, g = 1.98) between Mn(II) ions for 2. The magnetostructural correlations of the two Mn₄ clusters have been discussed tentatively.     

Structural diversity for three Zn(II) coordination polymers from 4-nitrobenzene-1,2-dicarboxylate and bispyridyl ligand

Three Zn(II) complexes, [Zn₂(bpp)₂(FNA)₂]·H₂O (1), [Zn(bpp)(FNA)]·H₂O (2), and Zn₂(bpp)₂(FNA)₂ (3) (bpp = 1,3-bi(4-pyridyl)propane, H₂FNA = 4-nitrobenzene-1,2-dicarboxylic acid), were synthesized and characterized by single-crystal and powder X-ray diffraction methods, IR spectroscopy, TG analyses, elemental analyses, and fluorescent analysis. In 1, the Zn(II) ions are linked by FNA anions and bpp into 2-D layers. The Zn(II) ions in 2 are bridged by FNA anions into chiral chains, which are interlinked by bpp into 3-D metal–organic framework with (6⁵·8) CdS topology. Complex 3 features 1-D zigzag chains, which are interconnected by bpp ligands to give a 3-D framework with (6·7⁴·8)(6⁴·7·8) topology. Complexes 2 and 3 exhibit significant ferroelectric behavior (for 2 remnant polarization Pr = 0.050 μC cm^?2, coercive field Ec = 1.13 kV cm^?1, saturation of the spontaneous polarization Ps = 0.239 μC cm^?2; for 3 Pr = 0.192 μC cm^?2, Ec = 4.64 kV cm^?1, Ps = 0.298 μC cm^?2).     

Mono-, di-, and trinuclear phosphonate oxygen-bridged copper(II) complexes: syntheses,structures, and properties

Reactions of copper salts, zoledronic acid, and 2,2′-bipyridine/1,10-phenanthroline in aqueous ethanolic solutions afforded four phosphonate oxygen-bridged copper complexes, Cu(bipy)(H₄zdn)(HSO₄) (1), [Cu₂(bipy)₂(H₂zdn)(H₂O)(Cl)]·4H₂O (2), [Cu₂(phen)₂(H₂zdn)(H₂O)(Cl)]·2.5H₂O (3), and [Cu₃(bipy)₃(H₄zdn)(H₂zdn)(SO₄)]·5H₂O (4) (H₅zdn = zoledronic acid, bipy = 2,2′-bipyridine, phen = 1,10-phenanthroline). The copper centers of 1–4 have square pyramidal coordination geometries. The Cu(II) ions are coordinated to bipy/phen, zoledronate, and HSO₄^?/Cl^? forming mononuclear units for 1, dinuclear for 2 and 3, and trinuclear for 4. These building units are further extended into 3-D supramolecular networks via multiple hydrogen bond interactions. Temperature-dependent magnetic properties of 2 and 4 suggest weak antiferromagnetic coupling (J = ?4.53(8) cm^?1 for 2, J = ?1.69(4) cm^?1 for 4). The antitumor activity of 2 was evaluated against the human lung cancer cell line and indicates effective time- and dose-dependent cytotoxic effects.     

Syntheses,structural diversity and properties of three coordination polymers built by chlorophenyl imidazole dicarboxylate

Two 2D coordiantion polymers, [Sr(p-ClPhHIDC)(H₂O)]_n (p-ClPhH₃IDC = 2-(4-chlorophenyl)-1H-imidazole-4,5-dicarboxylic acid) (1) and [Cd₃(p-ClPhH₂IDC)₂(p-ClPhHIDC)₂(H₂O)₂]_n (2) and one 3D polymer {[Co₃(p-ClPhHIDC)₃(H₂O)₃]·6H₂O}_n (3) have been prepared successfully under solvothermal conditions and structurally characterised by elemental analyses, IR and XRPD determinations, and have been further analysed by single-crystal X-ray diffraction. Polymer 1 exhibits a graceful 2D grid sheet structure. Polymer 2 can be regarded as a (3,3,4)-coordinated 2D network. Polymer 3 exhibits a 3D motif with 1D open channels and [Co₁₂(p-ClPhHIDC)₉] bihexagonal rings. The coordination features of the newly prepared imidazole dicarboxylate ligand, p-ClPhH₃IDC, have been discussed from both theoretical and experimental aspects. Furthermore, the solid-state photoluminescence and thermal properties of the polymers have also been investigated.     

Three transition-metal polymers from imidazole dicarboxylates-bearing methoxyphenyl groups: syntheses,crystal structures and properties

Three coordination polymers, namely, {[Cu₂(HMOPhIDC)(4,4′-bipy)]}_n (H₃MOPhIDC = 2-(3-methoxyphenyl)-1H-imidazole-4,5-dicarboxylic acid) (1), [Co(HDMOPhIDC)(phen)]_n (H₃DMOPhIDC = 2-(3,4-dimethoxyphenyl)-1H-imidazole-4,5-dicarboxylic acid) (2) and [Ni₂(HDMOPhIDC)₂(H₂O)₄]_n (3) have been prepared under hydrothermal condition and characterised by elemental analyses, infrared spectroscopy and single-crystal X-ray diffraction. Each of the polymers 1–3 is a 1D column-like structure and displays a 3D supramolecular network via the π…π stacking or hydrogen bond interactions. Furthermore, fluorescence and UV–vis spectroscopic properties of the polymers have been studied.     

A new tetranuclear copper(II) complex containing decameric water clusters bridged by–OH–and pyridine-2,4, 6-tricarboxylate: synthesis and magnetic characterization

Using pyridine-2,4,6-tricarboxylic acid (H₃ptc) and 2,2-bipyridine (2,2-bipy), a tetranuclear copper(II) compound [Cu₄(2,2-bipy)₄(ptc)₂(H₂O)₂(OH)₂] · 12H₂O (1) has been isolated under hydrothermal conditions. Variable temperature magnetic susceptibility of 1 from 2–300 K indicates anti-ferromagnetic interactions. The magnetic exchange coupling constants of J = ?159.4 and J′ = ?18.66 cm^?1 for 1 can be obtained through fit of the magnetic data, corresponding to two kinds of bridges, hydroxyl anions (OH^?) and pyridine carboxylate oxygen of ptc^3?. Moreover, decameric water clusters can also be observed, which are located between these tetranuclear copper(II) entities, forming a series of intricate O-H ··· O hydrogen bonds and stabilizing the resulting three-dimensional (3-D) hydrogen-bonded framework structure.     

Syntheses,structures and luminescent properties of a series of ladder-shaped [Ln2Sr3] heterometal-organic frameworks

A series of Ln^III–Sr^II heterometallic coordination polymers formulated as [Ln₂Sr₃(pda)₆(H₂O)₁₈]·nH₂O (Ln = Pr-1, n = 14; Nd-2, n = 12; Sm-3, n = 11; Eu-4, n = 11; Gd-5, n = 16; Tb-6, n = 13; Dy-7, n = 13) were synthesized via assembly of Ln(NO₃)₃·6H₂O, SrCl₂·6H₂O, pyridine-2,6-dicarboxylic acid (H₂pda) and imidazole (im) in H₂O/C₂H₅OH solution. Single crystal X-ray diffraction revealed that they are isostructural. All of these complexes possess ladder-shaped 1-D chain structures. The luminescent properties of Sm-3, Eu-4, Gd-5, Tb-6 and Dy-7 have been investigated. The solid-state quantum yields and the lifetimes of Eu-4 and Tb-6 are also studied.     

Solvothermal syntheses,crystal structures and properties of four polymers built by p-methoxyphenyl imidazole dicarboxylates

By employing 2-(4-methoxyphenyl)-1H-imidazole-4,5-dicarboxylic acid (p-MOPhH₃IDC) to react with Cd(II), Zn(II) and Sr(II) ions, four polymers, [Cd(p-MOPhHIDC)(2,2′-bipy)]_n (2,2′-bipy = 2,2′-bipyridine) (1), [Zn_0.5(p-MOPhH₂IDC)·H₂O]_n (2), {[Cd₄(p-MOPhHIDC)₄(C₂H₅OH)₂(H₂O)₂]·4C₂H₅OH·2H₂O}_n (3) and {[Sr₂(H₂MOPhIDC)₂(C₈H₄O₄)(H₂O)₆]·6H₂O}_n (4) have been solvothermally synthesised and structurally characterised by single-crystal X-ray diffraction. Polymer 1 is a chain with 2,2′-bipy appending in the same side. Polymer 2 is a 2D rhombus grid structure. The π?π interactions between the aromatic groups supply the additional stabilisation for the solid-state structures of 1 and 2. Polymer 3 shows a 3D framework bearing 1D open channels. Polymer 4 exhibits a 2D latticed plane. The thermal and photoluminescence properties of 1–4 have been investigated as well.     

A cubane-like [Ni4O4] cluster and a chloro-bridged dinuclear copper complex incorporating a hydroxyl-rich ligand: syntheses and crystal structures

A tetranuclear cubane-like cluster [Ni₄(HL)₄(DMSO)₂]?·?2DMSO?·?H₂O (1) and a dinuclear compound [Cu₂Cl₂(H₂L)₂]?·?1.5MeOH (2) (H₃L?=?3-(2-hydroxy-benzylideneamino)propane-1,2-diol) have been prepared and characterized by X-ray single crystal diffraction, IR, and elemental analysis. The X-ray diffraction analysis indicated that the four metals of 1 showed a Ni₄O₄ cubane arrangement, and two of the six faces of the Ni₄O₄ cubane were capped by DMSO. Complex 1 is the first reported DMSO capped Ni₄O₄ cubane cluster. Complex 2 contains a u ₂-Cl bridged dinuclear core with each Cu^II ion exhibiting pseudo square pyramidal geometry.     

Tetranuclear Zn(II) complexes with compartmental and dicyanamido ligands: synthesis,structure, and luminescent properties

New tetranuclear compounds have been obtained by reacting binuclear complexes, [Zn₂L ⁿ (μ-OH)(H₂O)₂](ClO₄)₂, with sodium dicyanamide (HL ⁿ are end-off bicompartmental ligands resulting from condensation between 2,6-diformyl-p-cresol with N,N-dimethyl-ethylenediamine or 2-aminomethyl-pyridine). The complexes, [{L¹(μ-OH)Zn₂}(μ _1,5-dca)₂{Zn₂(μ-OH)L¹}](ClO₄)₂ (1) and [{Zn₂L²(μ ₃-OH)(dca)}₂](ClO₄)₂?·?2H₂O (2), have been characterized by single-crystal X-ray diffraction. The angular nature of the bridging dicyanamido induces the “M” shape of the tetranuclear cationic unit in 1. The tetranuclear cation, because of its particular shape, acts as a receptor toward one perchlorate ion, which is hydrogen bonded to the hydroxo groups. This tetranuclear unit in 2 has a defective heterocubane structure. The luminescence properties of the new tetranuclear complexes have been investigated.     

Nuclease activity of redox/non-redox active binuclear transition metal mixed-polypyridine complexes: [M2(1,4-tpbd)(diimine)2(H2O)2]4+, M = Zn,Co, Ni,Cd, diimine = phen,bpy, dafo

Seven new transition metal complexes formulated as [M₂(1,4-tpbd)(diimine)₂(H₂O)₂]⁴⁺ [M = Zn, Co, Ni, Cd; 1,4-tpbd = N,N,N′,N′-tetrakis(2-pyridylmethyl)benzene-1,4-diamine; diimine is a N,N-donor heterocyclic base like 1,10-phenanthroline (phen), 2,2′-bipyridine (bpy), 4,5-diazafluoren-9-one (dafo)] have been synthesized and structurally characterized by X-ray crystallography: [Zn₂(1,4-tpbd)(phen)₂(H₂O)₂]⁴⁺ (1), [Zn₂(1,4-tpbd)(bpy)₂(H₂O)₂]⁴⁺ (2), [Co₂(1,4-tpbd)(phen)₂(H₂O)₂]⁴⁺ (3), [Ni₂(1,4-tpbd)(phen)₂(H₂O)₂]⁴⁺ (4), [Ni₂(1,4-tpbd)(bpy)₂(H₂O)₂]⁴⁺ (5), [Ni₂(1,4-tpbd)(dafo)₂(H₂O)₂]⁴⁺ (6) and [Cd₂(1,4-tpbd)(phen)₂(H₂O)₂]⁴⁺ (7). Single crystal diffraction reveals that the metals in the complexes are all in a distorted octahedral geometry. The interactions of the seven complexes with calf thymus DNA (CT-DNA) have been investigated by UV absorption, fluorescence, circular dichroism spectroscopy and viscosity measurements. The apparent binding constants (K_app) are calculated to be 5.2?×?10⁵ M^?1 for 1, 1.05?×?10⁵ M^?1 for 2, 5.76?×?10⁵ M^?1 for 3, 4.57?×?10⁵ M^?1 for 4, 1.29?×?10⁵ M^?1 for 5, 1.7?×?10⁵ M^?1 for 6, 2.53?×?10⁵ M^?1 for 7, the binding propensity to the calf thymus DNA in the order: 3 (Co-phen) > 1 (Zn-phen) > 4 (Ni-phen) > 7 (Cd-phen) > 6 (Ni-dafo) > 5 (Ni-bpy) > 2 (Zn-bpy). Furthermore, these complexes display efficient oxidative cleavage of supercoiled DNA; the Zn(II)/H₂O₂ and Cd(II)/H₂O₂ systems efficiently cleave DNA attributed to the peroxide ion coordinated to the Zn(II) and Cd(II), which enhanced their nucleophilicity, this is rare.     

Syntheses,structures, and luminescence of two Zn(II) coordination polymers based on 5-(4-imidazol-1-yl-phenyl)-2H-tetrazole and carboxylates

Reactions of Zn(II) salts, 5-(4-(1H-imidazol-1-yl)phenyl)-1H-tetrazolate (HIPT) and 2-mercaptobenzoic acid or 2-propyl-1H-imidazole-4,5-dicarboxylic acid (H₃PrIDC), result in two mixed-ligand coordination polymers (CPs), [Zn₂(IPT)(DSDB)(OH)]_n (H₂DSDB = 2,2′-disulfanediyldibenzoic acid, 1) and [Zn₂(IPT)(PrIDC)(H₂O)]_n (H₃PrIDC = 2-propyl-1H-imidazole-4,5-dicarboxylic acid, 2). Compound 1 possesses a 2-D structure built by 1-D [Zn(IPT)]_n chains and DSDB^2? connectors, in which the DSDB^2? is generated via in situ reaction from 2-mercaptobenzoic acid. It displays a new intricate 4-nodal {3·4·6·7·8·9}{3·6·7·8·9·10}{3·8·9}{4·6·8} topology. Compound 2 displays a 3-D framework with new 3-connected topology with Schläfli symbol of (4·8·10) (8·12²), in which the 1-D Zn-carboxylate chains were bridged by 3-connected IPT^? ligands. The thermal stabilities and luminescence properties of 1 and 2 have also been studied. The compounds exhibit intense solid-state fluorescent emissions at room temperature.     

Synthesis,crystal structures,and magnetic properties of methoxido-bridged dinuclear MnIII complexes derived from tri-dentate chelating ligands

Two new doubly methoxido-bridged Mn^III dinuclear complexes, [Mn^III(mphp)(μ-OCH₃)(CH₃OH)]₂·2CH₃OH (1) and ([Mn^III(ahbz)(μ-OCH₃)(CH₃OH)]₂·2CH₃OH (2), have been synthesized by using the tridentate ligands H₂mphp (H₂mphp = 2-methyl-6-(pyrimidin-2-yl-hydrazonomethyl)-phenol) and H₂ahbz (H₂ahbz = N-(2-amino-propyl)-2-hydroxy-benzamide). The complexes have been characterized by single-crystal X-ray diffraction analysis and magnetic measurements. Complexes 1 and 2 have a similar dimeric molecular structure. Two [Mn(L)(CH₃OH)]⁺ moieties (L^2? = mphp^2? or ahbz^2?) are bridged by two μ-OCH₃^? groups in the axial-equatorial asymmetric manner. The coordination geometry of Mn^III is an axially elongated octahedron with two oxygens of a methanol ligand and a methoxido ligand situated at the axial positions. Magnetic measurements indicate that 1 and 2 exhibit antiferromagnetic behavior with the fitting parameter of J = ?1.49(3) cm^?1, D = ?1.3(1) cm^?1, g = 1.98(1) and zJ′ = ?0.18(4) cm^?1 for 1, and J = ?1.6(2) cm^?1, D = 4.5(3) cm^?1, g = 2.06(1) and zJ′ = 1.4(1) cm^?1 for 2 on the basis of the spin Hamiltonian ? = ?2J?_Mn1?_Mn2.     

Syntheses,structures, and properties of three MOFs based on tertbutylphenyl imidazole dicarboxylate

By hydrothermal reactions of a newly designed ligand, 2-(p-tert-butylphenyl)-1H-imidazole-4,5-dicarboxylic acid (H₃BuPhIDC) with Cd(II) or Zn(II), three metal-organic frameworks, [Cd(μ₃-HBuPhIDC)(H₂O)]·2H₂O (1), [Cd(μ₃-HBuPhIDC)(4,4′-bipy)_0.5] (4,4′-bipy = 4,4′-bipyridine) (2), and [Zn₂(μ₃-HBuPhIDC)₂(CH₃OH)₂] (3), have been obtained and characterized by elemental analyses, IR spectroscopy, and single-crystal X-ray diffraction. In 1, small countless diamond grids form a mesh structure and then are bridged through μ₃-HBuPhIDC^2? linkers building a 3-D framework. Compared with 1, 4,4′-bipy participates in the construction of a 3-D structure of 2. Polymer 3 shows an interesting 3-D open architecture, which contains infinite 1-D octagonal channels built by left- and right-handed helical chains. Thermal and solid-state photoluminescence properties of the polymers have been investigated.     

New polynuclear compounds based on N-benzyliminodipropionic acid: solution studies,synthesis, and X-ray crystal structures

Three new polynuclear compounds based on a dicarboxylic acid ligand are reported. In particular, two Cu(II) coordination compounds, [Cu₂(H₂O)₆(Hbzlidp)₂](CF₃SO₃)₂·2H₂O (1) and [Cu(NO₃)(Hbzlidp)]_∞ (2) (bzlidp^2? = N-benzyliminodipropionate anion), and a Ni(II) dinuclear compound, [Ni₂(H₂O)₄(bzlidp)₂] (3), were synthesized and characterized by IR spectroscopy, elemental analysis and single crystal X-ray diffraction. Different structures were obtained depending on the reaction conditions. The structural analyses reveal that 1 was formed by dinuclear [Cu₂(H₂O)₆(Hbzlidp)₂]²⁺ units built by two copper(II) ions joined through two Hbzlidp^? ligands, while 2 was formed by pairs of Cu(II) centers bridged by four syn,syn carboxylate groups to generate “paddle wheel” units. The dinuclear copper units are arranged in a rhombus type grid, in a 2-D layer structure. In both cases, the N was protonated and not coordinated to the metal center. Compound 3 was formed by [Ni₂(H₂O)₄(bzlidp)₂] neutral dinuclear units, with octahedral Ni(II) centers. Solution studies of the ligand–M(II) systems (M(II) = Mn, Co, Ni, Cu, Zn, Cd, and Pb) were also carried out.     

Ca(II) and Ba(II) methyl carbazate energetic complexes: syntheses,crystal structures,and properties

New energetic materials, [Ca(MCZ)₃(H₂O)₂](ClO₄)₂ and {[Ba₂(MCZ)₄(H₂O)₂(μ₁-ClO₄)₂(μ₂-ClO₄)₂]_0.5}_n, are synthesized and tried as alternatives to common primary explosives. Both the crystal structures were determined by single-crystal X-ray diffraction. The crystal of [Ca(MCZ)₃(H₂O)₂](ClO₄)₂ belongs to the monoclinic, P2₁/c space group, a = 14.168(3) Å, b = 8.5938(18) Å, c = 18.889(4) Å, β = 111.234(2)°, V = 2143.8(8) Å³, ρ = 1.6893 g cm^?3, and {[Ba₂(MCZ)₄(H₂O)₂(μ₁-ClO₄)₂(μ₂-ClO₄)₂]_0.5}_n belongs to the triclinic, P-1 space group, a = 7.166(2) Å, b = 10.461(2) Å, c = 11.738(4) Å, α = 110.563(5)°, β = 93.799(2)°, γ = 96.864(3)°, V = 812.4(4) Å³, ρ = 2.185 g cm^?3. Their thermal stabilities were investigated by differential scanning calorimetry (DSC), and exothermic peak temperatures with a heating rate of 10 °C min^?1 are 249.7 and 181.7 °C, respectively. Non-isothermal reaction kinetics parameters were calculated via both Kissinger’s method and Ozawa-Doyle’s method to work out E_K = 124.6 kJ mol^?1, lgA_K = 10.38, E_O = 126.7 kJ mol^?1 for the calcium complex and E_K = 100.3 kJ mol^?1, lgA_K = 9.50, E_O = 102.6 kJ mol^?1 for the barium complex. Additionally, the critical temperatures of thermal explosion, ΔS^≠, ΔH^≠, and ΔG^≠ were calculated as ?231.2 J K^?1 mol^?1, 120.417 kJ mol^?1, 236.728 kJ mol^?1 for the calcium complex and ?230.6 J K^?1 mol^?1, 96.723 kJ mol^?1, 195.938 kJ mol^?1 for the barium complex. As for their explosive nature, sensitivities toward impact and friction were tested. Both [Ca(MCZ)₃(H₂O)₂](ClO₄)₂ and {[Ba₂(MCZ)₄(H₂O)₂(μ₁-ClO₄)₂(μ₂-ClO₄)₂]_0.5}_n are insensitive to friction (>360 N); their impact sensitivities are acceptable (20 and 13 J). Both compounds are energetic complexes.     

Extending the Structures of the p-Sulfonatothiacalix[4]arene Dimers Through Second-sphere Coordination and π…π Stacking Interactions

Reactions of cobalt(II) nitrate or zinc(II) nitrate, tetrasodium p-sulfonatothiacalix[4]arene (Na₄H₄TCAS), and methylviologen dihexafluorophosphate (MV(PF₆)₂) afforded two isomorphous complexes, {[M(H₂O)₆]^2 + [MV]^2 + [(MV)₂M₂(H₂O)₄(H₂TCAS)₂]^4 ? }·14H₂O (M = Co, 1; Zn, 2). In these two complexes, each two thiacalixarenes form a dimer with C _i symmetry through the coordination of sulfonate groups, and the above dimers further extend their structures through second-sphere coordination and π…π stacking interactions into three-dimension nets.     

Crystal structures and in vitro anticancer studies on new unsymmetrical copper(II) Schiff base complexes derived from meso-1,2-diphenyl-1,2-ethylenediamine: a comparison with related symmetrical ones

Two new unsymmetrical copper(II) Schiff base complexes, [CuLⁿ(py)]ClO₄ (n = 1, 2) in which Lⁿ represents a tridentate N₂O type Schiff base ligand, were synthesized. Lⁿs were derived from monocondensation of meso-1,2-diphenyl-1,2-ethylenediamine with salicylaldehyde or 3-methoxysalicylaldehyde. The reaction between [CuLⁿ(py)]ClO₄ and other salicylaldehyde derivatives resulted in new N₂O₂ unsymmetrical tetradentate Cu^II complexes, CuL^3–6. Crystal structures of [CuL¹(py)]ClO₄, CuL⁴, and CuL⁵ were obtained. These new complexes as well as a series of related symmetrical ones (i.e. CuL^7–12) were tested for their in vitro anticancer activity against human liver cancer cell line (Hep-G2) by MTT and apoptosis assay. All of the complexes showed considerable cytotoxic activity against tumor cell lines (IC₅₀ = 5.13–16.24 μg mL^?1). The symmetrical CuL⁷ was the most potent anticancer derivative (IC₅₀ = 5.13 μg mL^?1) compared to the control drug 5-FU (IC₅₀ = 5.4 μg mL^-1, p < 0.05). Flow cytometry experiments showed that the copper derivatives especially [CuL²(py)]ClO₄ and CuL⁷ induced more apoptosis on Hep-G2 tumor cell lines compared to 5-FU.