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A new Dy Na complex [DyIIINaI(CH3CO2)2(DMF)3(H6C8A)]·4DMF (1, DMF = N,N-dimethylformamide, H8C8A = p-tert-butylcalix[8]arene) was obtained and it was characterized by elemental analyses, IR spectroscopy, single-crystal X-ray diffraction analyses, PXRD and magnetic properties. In 1, one DyIII and one NaIII were linked by two O atoms from two CH3CO2− and the two metal ions were enclosed into a H8C8A. The remaining coordination sites of the DyIII and NaI ions were occupied by three O atoms from three DMF coordinated molecules. The DyIII ion in 1 adopts eight coordinate with a triangular dodecahedron. Magnetic property studies indicated complex 1 show slow magnetic relaxation behavior under 1000 Oe applied dc field. Additionally, the orientation of the anisotropy axis for the DyIII in 1 was estimated by Magellan program and the anisotropic axis is aligned along Dy1-O2 bond with an angle of 12.608°.

The photocatalytic hydrogen evolution on inorganic semiconductors has been studied for several decades. However, the conversion efficiency of solar energy is still poor caused by the recombination of photo-generated electron-hole pairs. Semiconductors - metal organic frameworks (MOFs) hybrid photocatalysts are being regarded as promising candidates due to large surface area and porosity. Here we reported the coordinative integration of a composite material with efficient capacity of H2 evolution driven by solar light, namely TiO2@ZIF-8, made up of titanium dioxide hollow nanospheres (TiO2 HNPs) externally decorated with zeolitic imidazolate framework-8 (ZIF-8) via a facile sonochemical route. The resulting composite demonstrates the high dispersion of ZIF-8 on the surface of TiO2 HNPs and this kind of close connection makes for an efficient photocatalyst through the synergistic effect. Up to 50.89% of apparent quantum efficiency (AQE), the hybrid double-shell HNPs exhibits 3.5 times higher H2 evolution rate (HER) than the bare TiO2 HNPs under solar light and shows good stability and recyclability. It is further proposed by photoluminescence spectra and optoelectronic measurement that the remarkably enhanced photocatalytic activity of TiO2@ZIF-8 is not only attributed to the efficient charge separation with electron injection from ZIF-8 to TiO2 HNPs, but also more active reaction sites provided by cavity structure of ZIF-8. Overall, this work exemplifies that surface engineering of semiconductors with MOFs is a great strategy to achieve advanced photocatalytic performance for solar energy conversion.

Porous CuO/Cu2O heterostructure was successfully synthesized through a metal organic frameworks (MOFs)-assisted template method. Tunable production of pure phase CuO and Cu2O could be achieved by regulating the coordination environment of copper. The copper oxides inherited the polyhedral morphology from the Cu MOFs and possessed higher surface area and larger pore volume. Compared with pure CuO and Cu2O, heterostructured CuO/Cu2O displayed remarkably enhanced NH3-SCR de-NOx activity and N2 selectivity in a low temperature range of 170–220 °C. Systematical in situ DRIFT characterization revealed that the NH3-SCR of NOx over CuO/Cu2O heterostructure followed Eley-Rideal (E-R) mechanism, which was greatly improved by the abundant Lewis acid sites, improved O2 adsorption and the synergistic effect between Cu+ and Cu2+. In addition, CuO/Cu2O heterostructure exhibited excellent H2O, SO2, alkali metals, and hydrocarbon durability, indicating its potential use in industrial NH3-SCR of NOx.

Six new transition metal phosphonates, [Cd(H2L)(H2O)]n (1), [Cd2(H2L)2(H2O)]n (2), [Cd4(H2bmt)2(H2O)]n (3), {[Cd2(H4bmt)2(2, 2′-bipy)2]·4H2O} (4), [Zn(H4bmt)(2, 2′-bipy)]n (5) and [Zn3(bmt)(4, 4′-bipy)2]n (6), H4L = (benzylazanediyl)bis(methylene)-diphosphonicacid,H6bmt = (benzene-1,3,5-triyltris(methylene))triphosphonic acid, have been synthesized by H4L or H6bmt as well as auxiliary ligands under hydrothermal conditions and characterized by elemental analysis, IR, XRD and single-crystal X-ray diffraction. Structural analysis indicates that complexes 1–6 feature 0D-3D structures. The introduction of auxiliary ligands including 4, 4′-Vinylenedipyridine, 4-Cyanopyridine, 4, 4′-bipy, 2, 2′-bipy and H6TTHA (1,3,5-triazine-2,4,6-triamine hexaacetic acid) increases the crystallinity and controls the dimensionality of the final complexes. The fluorescence emission properties of 1–6 and the free ligands were investigated in the solid state at room temperature. Moreover, the fluorescence lifetime (τ) and quantum yield (Φf) were measured to further characterize the fluorescence properties. The results are compared to illustrate the influence of the auxiliary ligands and structure difference on the fluorescence properties.

Three novel metal–organic frameworks (MOFs) photocatalysts with different structures [Cd(4-Hptz)2(H2O)2Cl2](4-Hptz = 4-(1H-tetrazol-5-yl)-pyridine) (1), [Cu(btx)2(ClO4)2]n(btx = 1,4-bis(triazol-1-ylmethyl)benzene) (2), and [Cu(btx)(ClO4)]n (3) have been synthesized by solvothermal reaction successfully. All samples were characterized by X-ray, FT-IR, XPS and UV–Vis diffuse reflectance spectra. The photocatalytic properties were investigated by degradation of methylene blue (MB) dye and reduction of Cr(VI) to Cr(III) in aqueous solution under UV light. Control experiments show that the pH value is vital for Cr(VI) reduction, and meanwhile, the use of hole scavenger of methanol promotes the photocatalytic reduction significantly. It has been also demonstrated that photocatalysts 1 and 2 are efficient for MB degradation. The cyclic experiments indicated three photocatalysts are stable and reusable, enabling them to be the potential candidate in environment governance.

A novel DyIII-NaI one-dimensional chain, namely [DyIIINaI(L)(CH3CO2)2]n·2CH3CN (1, H2L = N1,N3‑bis(3‑methoxysalicylidene)diethylenetriamine), was synthesized by treating H2L, di-2-pyridyl ketone (dpk), and NaHCO3 with Dy(CH3CO2)2·6H2O in acetonitrile. Complex 1 was characterized by elemental analyses, IR spectroscopy, single-crystal X-ray diffraction analyses and magnetic properties. Structural analyses revealed that 1 consists of a neutral one-dimensional (1D) chain. In each [DyNa] unit, one DyIII and one NaI ions are bridged by two phenoxido O atoms from one L2− ligand and one carboxyl O atom from one CH3CO2−. Moreover, the [DyNa] units were further connected by two carboxyl O atoms from another CH3CO2−. The magnetic studies revealed that 1 exhibits the field-induced single molecule magnet behavior with an effective energy of 13.21 K. The orientation of the anisotropy axes for the DyIII in 1 was estimated by Magellan program, indicating that the directionality of the anisotropic axes is almost collinear to the Dy1-O8 bond, with an angle of 3.085°.

Four new complexes of Robson-type macrocycles, [CuH(L1)]2(ClO4)2(H2O)2 (1), [CuH(L2)] ClO4 (2), [Cu H(L3)]2(ClO4)2 (3), [Cu H(L4)]2(ClO4)2(CH3CH2OH)2(CH3CN)2(4) and two reported Robson-type macrocycles polymers {[CuL5](H2O)2}n(5), {[MnL5](H2O)2}n (6) were obtained. The ligands (H2L1, H2L2, H2L3) are the products from the condensation between bata and N,N′-bis(3-formyl-5-X-salicylimine)-1,2-ethylenediimine (X = CH3, Cl, F), respectively. Ligands H2L4 and H2L5 are the products of N,N′-bis(3-formyl-5-methylsalicylimine)-1,2-propylenediimineand condensation with bafa and bapa, respectively. All the metal ions have unsaturated coordinated sites, which are available for NO binding. The binding of the complexes with NO molecules have been confirmed by UV–Vis spectrophotometry. The binding constants were calculated to be 1.28 × 103 M−1, 8.9 × 102 M−1, 7.7 × 103 M−1, 1.2 × 103 M−1, 1.2 × 103 M−1, 1.3 × 103 M−1 for 1, 2, 3, 4, 5 and 6, respectively. The control experiments revealed there was non-reversible binding of NO, which can be ascribed to specially coordination environment of the central ions. Moreover, the interactions of the complexes with calf thymus DNA (CT-DNA) have been measured by agarose gel electrophoresis, and unobvious DNA cleavage ability of complexes 1, 3 and 4 indicating no damage to DNA. The results reveal that complexes 1, 3 and 4 can be served as potential NO scavengers.

New magnesium phosphonates Mg(H 2 L) 3 1 (H 4 L = 2,5-dimethylbenzene-1,4 -diylbis(methylene)diphosphonic acid) and Ca(H 2 L)·2H 2 O 2 have been hydrothermally synthesized from H 4 L and the corresponding metal salts. Complex 1 and 2 have been characterized by IR, powder and single-crystal X-ray diffraction methods. Complex 1 crystallizes in trigonal space group R-3c and complex 2 belongs to the triclinic space group. The complexes both form two-dimensional (2D) network structure and show three-dimensional (3D) network through hydrogen bonds. Thermal stability of complex 1 and 2 have also been investigated. CCDC: 1534599 for 1 ; 1536423 for 2 .

The synthesis, crystal structures, and magnetic properties of a nonanuclear dysprosium complex [Dy9(μ3-OH)8(μ4-OH)2(N3)8{(py)2C(OCH3)O}8](OH)·4H2O (1, (py)2C(OCH3)OH = the hemiacetal form of di-2-pyridyl ketone) and a tetranuclear dysprosium complex [Dy4(μ4-O)(μ-N3)2(μ-OCH3)2(L)4](OH)2·3.5CH3OH (2, HL = 2-(benzothiazol-2-yl-hydrazonomethyl)-6-methoxyphenol) have been prepared and structural characterization. Nine DyIII ions in 1 form a sandglass with the eight DyIII atoms at the apexes and one DyIII ion located at the center of a square antiprism formed by eight DyIII ions, while four DyIII ions in 2 form an irregular tetrahedron. Complexes 1 and 2 have been investigated by direct current (dc) and alternating current (ac) susceptibility measurements. The ac susceptibility studies revealed that complexes 1 and 2 exhibit slow magnetic relaxation. Moreover, complex 2 shows two-step thermal magnetic relaxation with their energy barriers of about 15 K and 2.68 K, respectively. The orientations of the magnetic anisotropy of DyIII ions in 1 and 2 were also estimated by electrostatic calculations.

The magnetic solid acid, Fe3O4@PEI@SO3H, was synthesized and used as a catalyst to transfer steroid saponins into diosgenin in an alcoholysis approach. The results showed that the magnetic solid acid greatly improved the alcoholysis efficiency for extraction diosgenin from steriod saponins. To optimize the parameters for alcoholysis, such as the mass of the solid acid, solvent volume, the reaction temperature and time, single factor experiments as well as response surface experiment have been performed. Under the optimal conditions, the diosgenin yield obtained by alcoholysis is higher than that of the traditional inorganic acid hydrolysis. And it worth to mention that no waste liquid is discharged. The catalyst is very stable and can be used for three times without obvious mass loss and activity decrease, indicating that the technology of extracting diosgenin from Dioscorea zingiberensis C.H. Wright tuber has a broad prospect in industrial application.

Since 1993, single molecule magnets (SMMs) have received a wide attention for their potential applications in high-density information storage device, quantum computer and spintronics. Particularly, since a CuII2TbII2 complex was found to possess slow magnetic relaxation behavior in 2004, 3d-4f heterometallic complexes are being investigated because they can provide the moderate magnetic couplings between 3d and 4f ions and can provide the significant single-ion magnetic anisotropies of 4f ions, which are in favor of improving SMM performance. Choosing an appropriate organic ligand with ligating atoms linked with 3d and 4f ions simultaneously is a key to synthesize 3d-4f complexes. However, synthesizing 3d-4f complexes by employing two kinds of non-carboxylate organic ligands has received little attention. We believe that the metal core topologies, the magnetic couplings, coordination geometries of 4f ions and the magnetic relaxation behavior of the 3d-4f complexes could be modulated by employing several types of non-carboxylate organic ligands due to the large steric effects between the non-carboxylate organic ligands. Based on the considerations, in recent years, we concentrated on the investigations of the 3d-4f complexes with several types of non-carboxylate organic ligands. In this review, we will present a summary of the 3d-4f complexes reported by us. The studies indicate that the metal core topologies and the magnetic couplings of the obtained 3d-4f complexes were indeed regulated, and most of the complexes possess SMM behavior. Finally, we provided some suggestions to further improve the SMM performance of the 3d-4f complexes.

Diosgenin is an important intermediate of steroid hormone drugs, green production of diosgenin with high yield is a key research issue. In this study, a convenient, efficient, and eco-friendly approach was developed to produce diosgenin from saponins in D. zingiberensis C. H. Wright (Curcuma longa L) using a magnetic solid acid. Fe3O4@SiO2-Pr-S-SO3H is a heterogeneous catalyst and was obtained by loading 3-(mercaptopropyl) trimethoxysilane on the surface of Fe3O4@SiO2, followed by sulfonation with chlorosulfonic acid. The magnetic solid acid catalyst was fully characterized by Fourier Transform-Infrared (FT-IR) spectra, thermo gravimetric analysis (TGA), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and X-ray photoelectron spectroscopy (XPS), scanning electron microscope(SEM), transmission electron microscope (TEM), NH3-TPD, elemental mapping analysis. The effects of single factors, such as the solid acid mass, alcoholysis temperature, extraction time, and solvent volume on the diosgenin yield were analyzed. The extraction parameters for diosgenin were optimized by response surface methodology (RSM). The optimized values for the solid acid mass, solvent volume, extraction time, and temperature were 0.22 g, 7.8 mL, 7.4 h, and 100 °C, respectively. Under the optimized conditions, the maximum yield of diosgenin was 19.15 %. The solid acid reported in this work exhibited higher catalytic activity at a smaller dosage than traditional sulfuric acid and other solid acids. The alcoholysis products were identified by high-performance liquid chromatography-mass spectrometry (HPLC-MS). Alcoholysis catalysed by an as-prepared magnetic solid acid is clearly superior in terms of catalytic activity, dosage, and reusability. It is a promising strategy for the green production of diosgenin.

A loop system was used to investigate the effect of flow velocity on corrosion behavior of AZ91D magnesium alloy at an elbow of loop system based on array electrode technology by polarization, computational fluid dynamics (CFD) simulation and surface analysis. The experimental results showed that the corrosion rate increased with increasing flow velocity, and a critical flow velocity could exist in the corrosion of AZ91D magnesium alloy. When flow velocity exceeded the critical flow velocity, fluid hydrodynamics was dominant in the corrosion of AZ91D magnesium alloy. On the contrary, the electrochemical factors were dominant.

Two new coordination polymers of Robson-type macrocycles, {[CuL1]n (1) and {[CuL2]n (2), were obtained by the condensation between bapa and N,N′-bis(3-formyl-5-R-salicylimine)-1,2-propylenediimine in the presence of Cu(II). These polymers have the common feature that the 3-methylaminopyridine group in one ligand coordinates to the metal ion in the neighboring coordination unit, leading to the formation of one-dimensional infinite chain. The formation of NO complexes has been confirmed by UV/Vis spectrophotometry. The binding constants were calculated to be 8.18 × 102 M− 1, 1.2 × 103 M− 1 for 1 and 2, respectively. The control experiments revealed there was non-reversible binding of NO, which can be ascribed to specially coordination environment of the central Cu(II) ions. Moreover, the interactions of the complexes with calf thymus DNA (CT-DNA) have been measured by agarose gel electrophoresis, and the results showed that they can not cleavage the CT-DNA. These two complexes can be served as potential NO scavengers. Graphical abstract Two new coordination polymers of Robson-type macrocycles, {[CuL1]n (1) and {[CuL2]n (2), were obtained by the condensation between bapa and N,N′-bis(3-formyl-5-R-salicylimine)-1,2-propylenediimine in the presence of Cu(II). The NO absorption experiments revealed a moderate binding to NO and control experiments showed the non-reversibility of the binding NO to these two macrocyclic metal Cu(II) complexes.

A one-dimensional (1D) chain [Cu3(HL)2(N3)(Mtta)]n.0.5CH3CN (1, H3L = 2-((2-hydroxybenzylidene)amino)propane-1,3-diol and Mtta = 5-methyl tetrazolate) and a Cu4Dy2 complex [Cu4Dy2{(py)2CO2}2{(py)2C(OH)O}2(CH3COO)4(N3)4].3CH3CN (2, (py)2C(OH)2 = the gem-diol form of di-2-pyridyl ketone) were obtained by the assemblies of the H3L ligand and Dy(NO3)3·5H2O with copper nitrate or with copper acetate and di-2-pyridyl ketone under the MeCN solution containing triethylamine or containing NaOH. In 1, three CuII ions were linked into a trinuclear Cu unit by three neighboring N atoms of Mtta ligand and two alkoxido-type O atoms from two HL2− ligands, then these units were further linked into a one-dimensional (1D) chain by two phenoxido O atoms from two HL2− ligands. In 2, two CuII and two DyIII ions formed a butterfly-type topology, which was further linked another two CuII by the O atoms from (py)2CO22– or from acetate ligands. Magnetic studies indicated that, in 1, the magnetic coupling through the paths of Cu N N Cu and Cu-Oalkoxido-Cu is antiferromagnetic (J1 = −14.81 cm−1), and its value was first determined in the polynuclear Cu complexes containing Mtta ligand. However, the magnetic coupling through the path of Cu-Ophenoxido-Cu is ferromagnetic (J2 = 24.61 cm−1). Magnetic studies revealed that 1 exhibits slow magnetic relaxation behavior, with an energy barrier Ueff of 6.06 K. The orientations of the easy magnetization axes of DyIII ions in 2 was estimated by Magellan program, indicating that the easy axes of DyIII in 2 are roughly aligned along alkoxido-type O atoms (O3 and O3a), which is slightly longer than other Dy-O distances.

In the present work, a 3D metal–organic frameworks (MOFs) of {[Mn2(BPDC)2]⋅DMF}n was successfully synthesized via solvothermal method based on 2,2′-biisonicotinic acid (H2BPDC) as ligand. The synthesized complex was characterized by single-crystal X-ray diffraction, thermogravimetric analyzer (TGA), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), X-ray Photoelectron Spectroscopy (XPS) and UV–vis diffuse reflectance spectroscopy(DRS). 4-Nitrophenol (4-NP) and Methyl Orange (MO) contaminants were selected as model contaminants to investigate the photocatalytic properties of the complex. In order to further evaluate the photocatalytic activity, the effects of the pH value and the catalyst dosage have been investigated. Under the optimized conditions, 97.72% of the photocatalytic degradation efficiency for MO was obtained. Moreover, only in 5 mins, the reduction efficiency for 4-NP reached 99.92% under the UV light irradiation. Accordingly, the results indicated that the superoxide radicals were main active substance in the process of photocatalytic degradation. It is worth mentioning that the complex could be recycled five times without noticeable loss of activity.

Four new Zn(II) and Cu(II) coordinated polymers ([ZnL2N3]ClO4 (1), [Cu2L2(CH3CN)]Cl4 (2) [CuL](NO3)2 (3), [Cu(H2O)L](SO4) (4) L = 2-((4-phenyl-2H-1,2,3-triazol-2-yl)methyl) pyridine (ptmp)) have been reported. All the compounds have been characterized by IR spectrum, elemental analyses and X-ray crystallography diffraction. Single-crystal X-ray diffraction analyses show that one-dimensional polymers are formed in these four complexes. Chain-like structures are formed in complex 1, 2 and 3, which are connected by azide, chloride and nitrate anions, respectively. In complex 4, one-dimensional left-handed polymer is formed by a μ2-SO4 bridge. The fluorescent and electrochemical properties of these four complexes were investigated. It was found that these three Cu(II) complexes displayed a quenching of fluorescence, while Zn(II) complex exhibited a clear enhanced fluorescence.

Effect of direct current electric field (DCEF) on corrosion behaviour of copper printed circuit board (PCB-Cu), Cl− ion migration behaviour, dendrites growth under thin electrolyte layer was investigated using potentiodynamic polarization and scanning electron microscopy (SEM) with energy dispersive spectrometer (EDS). Results indicate that DCEF decreases the corrosion of PCB-Cu; Cl− ions directionally migrate from the negative pole to the positive pole, and enrich on the surface of the positive pole, which causes serious localized corrosion; dendrites grow on the surface of the negative pole, and the rate and scale of dendrite growth become faster and greater with the increase of external voltage and exposure time, respectively.

The effect of an alternating electric field (AEF) on the atmospheric corrosion behaviour of copper under a thin electrolyte layer (TEL) was investigated by potentiodynamic polarization and SEM/EDS analyses. Results indicate that the corrosion rate of copper increases with increased AEF amplitude and frequency. Furthermore, copper corrosion is more severe under a square-wave AEF than under a sinusoidal AEF. The increase in copper corrosion can be due to the damage inflicted by AEF to the oxide film on the copper surface. With the AEF, copper corrosion under a TEL significantly differs from that in bulk solution.

Two new dinuclear Ni(II) complexes, [Ni 2 L 1 (OAc) 2 ]ClO 4 ( 1 ) and [Ni 2 L 2 (OAc) 2 ] Br·0.5H 2 O ( 2 ) (where HL is the condensation product of 2,6-diformyl-4-X-phenol (X = CH 3 , Br) and N 1 -(2-aminoethyl)-N 2 -(4-nitrobenzyl)ethane-1,2-diamine), were synthesized and characterized. The coordination polyhedron of each metal ion in the complexes can be approximately described as a distorted octahedron. The Ni–Ni distances in 1 and 2 are 3.306 A and 3.369 A, respectively. The phosphate hydrolysis promoted by the complexes was examined using 4-nitrophenyl phosphate disodium salt hexahydrate (pNPP) as the substrate. The catalytic rate constants ( k cat ) are 1.29 × 10 −5 s −1 for 1 and 0.47 × 10 −5 s −1 for 2 at 25 °C in physiological pH condition. The binding activities of the complexes toward calf thymus (CT-DNA) were analyzed by spectroscopic and voltammetric methods, and the corresponding binding constants are 7.75 × 10 5 and 6.51 × 10 4 M −1 for 1 and 8.59 × 10 5 and 9.18 × 10 4 M −1 for 2 , respectively. The linear Stern–Volmer quenching constants obtained in the fluorescent spectroscopic study of 1 and 2 are 0.7 × 10 3 and 1.5 × 10 3 M −1 , respectively.

Two new macrocyclic dinuclear copper(II) complexes, [Cu2L1(MeOH)2]·(ClO4)2 (1) and [Cu2L2(EtOH)2]·(ClO4)2 (2) have been synthesized and characterized by ES-MS spectra and X-ray crystallography determination. The coordination polyhedron of Cu(II) ions in each complex can be described as approximately square pyramind, where the apical position is occupied by a labile coordinated alcoholic molecule. The reactions of complexes with nitric oxide (NO) cause an immediate color change, and the formation of NO complexes has been further confirmed by UV/Vis spectrophotometry. The binding constants are calculated to be 1.71 × 103 M− 1 and 2.0 × 103 M− 1 in 0.2 M anaerobic phosphate buffer solution (PBS), respectively. The control experiments reveal that the binding of NO to complexes is reversible. Moreover, the interactions of the complexes with calf thymus DNA (CT-DNA) have been measured by UV/Vis, cyclic voltammetry and viscosity study. The moderate binding ability and unobvious DNA cleavage ability account for their low toxicity towards DNA. Overall, the results reveal that these two complexes can be served as potential NO regulators.

A new hetero-tetranuclear complex [Mn III 2 Ni II 2 (HL) 2 L 2 (OAc) 2 (CH 3 OH) 2 ]CH 3 OH ( 1 ) has been synthesized and fully characterized, where H 2 L is N-(2-hydroxy-5-fluro-methylphenyl)-3-imine-2-propanol. The X-ray diffraction analysis of 1 shows that four metal ions as well as coordinated O atoms in one molecular unit exhibit a dicubane-like core with two missing vertexes. The extension of the magnetic exchange in 1 has been evaluated by means of a spin Hamiltonian, yielding the parameters of J 1 = − 11.85 cm − 1 , J 2 = − 6.44 cm − 1 and J 3 = 0.34 cm − 1 , D = 2.26 cm − 1 and g = 2.12, assumed under same anisotropy D and g. And the DNA cleavage ability of 1 was also investigated.

Three dinickel(II) macrocyclic complexes [Ni 2 L(μ-OAc)]ClO 4 •X (L = L 1 , L 2 and L 3 ) with two 2-thiophenoethyl pendant arms, have been synthesized by cyclocondensation between N , N -bis(3-aminopropyl)-2-thiophenoethylamine and 2,6-diformyl-4-R-phenol (where R = Me, Cl and F and X = MeOH, 2MeCN and H 2 O, respectively), in the presence of nickel(II) ions. The complexes were characterized by elemental analysis, spectroscopic methods and X-ray diffraction techniques. The geometry around both of the Ni(II) ions in each molecule is a slightly distorted octahedral and the thiopheno groups do not coordinate to the Ni(II) ions, resulting that the complexes display contorted saddle-form configurations. The distances between the Ni⋯Ni centers for the complexes are 3.145, 3.171 and 3.155 A, respectively. The influences of the substituted groups R in the benzene rings of the macrocyclic units on the structure, electrochemistry, magnetism, cleavage and antibacterial property to DNA have been investigated. The ES-MS results of the complexes confirm that [Ni 2 L] 2+ species in methanol solution are very stable because all the peaks in ES-MS spectra contain this kind of units. The reduction potentials of the complexes shift towards anode upon increasing the drawing electronic ability of substituted groups. Magnetic measurements in the 2–300 K range indicate weak antiferromagnetism for the dinuclear Ni(II) complexes and the magnetic exchange interactions enhance with the decrease of the Ni–Ni distances. These complexes exhibit cleavage activities towards plasmid pBR322 DNA and antibacterial activities.

Two new isomorphous tetranuclear complexes [Cu4L2(4,4′-bipy)2]·(ClO4)4·2CH3CN·2H2O (1) and [Zn4L2(4,4′-bipy)2]·(ClO4)3·CH3O·4H2O (2) have been obtained and fully characterized (where bipy = bipyridine, H2L = macrocycle is the [2+2] condensation product of 2,6-diformyl-4-fluoro-phenol and 1,4-diaminobutane). They exhibit wheel-like configuration in which two 4,4′-bipy molecules connect two dinuclear [M2L]2+ units. The interactions of the complexes with calf thymus DNA were studied by UV–Vis and CD spectroscopic techniques. The binding constants of 1 and 2 are 2.27 × 106 and 3.89 × 105 M−1, respectively. The magnetic measurement of 1 reveals that there are strong antiferromagnetic coupling (J = –272.6 cm−1) between two Cu(II) ions in the macrocyclic unit and ferromagnetic interaction (j′ = 41.7) between the Cu(II) ions in two adjacent macrocyclic units. Furthermore, the cyclic voltammogram of 1 shows that it undergoes two quasi-reversible processes with the half wave potentials –0.232 and –0.606 V, respectively.

Two new tetranuclear copper (II) macrocyclic complexes, [Cu4L(OAc)2(OH)2](ClO4)2·2MeCN 1 and [Cu4L (OAc)2(OH)2](PF6)2(H2O)2 2, have been obtained via condensation of 2,6-diformyl-4-methylphenolate with N,N′-bis(3-aminopropyl)-2-thiophenoethylamine in the presence of copper (II) ions. The complexes were characterized by IR, ES-MS and X-ray diffraction techniques. It shows the similar chair-shaped Cu4O4 core structure for these two macrocyclic complexes, which is composed of two kinds of crystallographically independent Cu(II) ions. The coordination spheres of the Cu(II) ions are distorted square pyramid and approximate square-planar configuration, respectively. In addition, it was found that the crystal structures are stabilized by abundant hydrogen bonds between perchlorate anions and adjacent macrocyclic units for complex 1. The network structure of 2 was maintained by π–π stacking of thiopheno groups and C H···F hydrogen bond interactions between adjacent macrocycles. The variable temperature magnetic susceptibility of complex 1 was measured in the temperature range of 2–300 K. The best fitting with a quasi-butterfly magneto-structural model gave the magnetic exchange parameters of Jbb = −197.6 cm−1, Jwb1 = −60 cm−1 and Jwb2 = 103.5 cm−1.

Two new coordination polymers of Robson-type macrocycles, [Cu2L1(μ-ClO4)2]∞ (1) and [Cu2L2(μ-ClO4)2]∞ (2) (where H2L1and H2L2 are the [2+2] condensation products of 2,6-diformyl-4-flurophenol with 1,3-diaminopropane and 2-hydroxy-1,3-diaminopropane, respectively), have been synthesized and characterized. The intriguing feature is that intermolecular perchlorato bridges occur between adjacent copper(II) centers. The cyclic voltammograms of the complexes show that each complex undergoes two pseudo-reversible processes with the half wave potentials, −0.361 V and −0.729 V for 1, and −0.372 V and −0.744 V for 2, respectively. Magnetic susceptibility was measured for 1 and 2 over a temperature range of 2–300 K. The optimized magnetic data were J = −359.6 cm−1, j′ = −30 cm−1 and R = 6.8 × 10−8 for 1 and J = −411 cm−1, j′ = −26 cm−1 and R = 2.4 × 10−7 for 2, respectively. The data reveal antiferromagnetic couplings between the copper(II) ions of intra- and intermolecular units.

A new unsymmetrical bis-furan pendant-armed macrocyclic heterodinuclear Cu(II)Zn(II) complex, [CuZnL(OAc)](ClO4)·3MeCN·H2O(1) (H2L was derived from the condensation between 1,6-bis(2-furyl)-2,5-bis(2-hydroxy-3-formyl-5-bromobenzyl)-2, 5-diazahexane and 1,3-diaminopropane), has been synthesized and characterized by EDS (energy dispersive spectroscopy) and X-ray crystallography determination. The interaction between the complex and calf thymus (CT) DNA was investigated by UV–vis absorption, viscosity experiment, fluorescent and CD spectroscopy. The mechanism of the cleavage of supercoiled DNA (pBR 322DNA) process was also studied. It is proposed that DNA cleavage promoted by the complex occurrence via oxidative mechanism.

The title compound (13,27-dimethyl-3,6,9,17,20,23-hexaazatricyclo-[23.3.1.1 11,15 ]-triaconta-1(29),2,9,11,13,15(30),16,23,25,27- decaene-29,30-diol-N 3 , N 6 , N 9 , O 29 , O 30 )-bis (nitrato-O,O')-europium (III) nitrate hydrate ([EuL(NO 3 ) 2 ](NO 3 )·H 2 O, L denotes the macrocyclic ligand) was prepared and characterized by elemental analysis, infrared spectra, and electrospray mass spectra. Its crystal and molecular structure was determined by X-ray diffraction. The crystal crystallized in the monoclinic system, space group C 2/ c with a =2.3757 (4) nm, b =1.4302(3) nm, c =1.9584(3) nm, β =91.654(5)°, M =818.60, V =6.651(2) nm 3 , Z =8, D =1.635 g/cm, F (000)=3312, R =0.0542, w R =0.1045. The central ion Eu 3+ was nine-coordinated in the coordinaton geometry of a distorted tricapped trigonal prism. The macrocycle was coordinated through two oxygen and three nitrogen atoms. Two nitrate are chelate in the opposite positions of the macrocycle, the third nitrate being ionic. At room temperature, excitation of the title complex gave rise to the characteristic emissions of the Eu 3+ ion.

A novel binuclear manganese Mn(II) macrocyclic complex with two pyridylmethyl pendant arms, [Mn2II(H2L)(μ-OAc)2](ClO4)2 · H2O, has been synthesized and characterized crystallographically and magnetically. The crystal structure of the complex shows that two manganese ions locate in the same head of the macrocycle, leaving an uncoordinating cavity to catch protons through oxide of phenolate and the nearby imine groups in another head. The electrochemical study demonstrates that the complex gives two couples of redox peaks with E1/2 of 0.3775 V and 0.8409 V, respectively. The variable temperature magnetic susceptibility measurement on the sample displays weak antiferromagnetic interaction between two manganese (II) with the J = −3.733(7) cm−1. This complex exhibits a moderate activity for catalyzing disproportionation of H2O2 to O2.

Three dimetallic complexes of the unsymmetrical macrocycle (L)2−, [M1M2L]2+ (M1M2 = NiNi, CuZn, CuCd), have been synthesized by cyclocondensation between N,N′-bis(3-formyl-4-n-butylsalicylidene)ethylenediimine and 1,3-diaminopropane in the presence of M 1 2 + and M 2 2 + .The crystal structure of the complex [Ni2L4(H2O)2](ClO4)2 · 0.5CH3OH was determined by X-ray diffraction techniques.The asymmetric unit contains two complete macrocyclic complexes which are nevertheless quite similar to one another.The nickel–nickel separations, bridged by the two phenoxides, are 2.977 A and 2.982 A.In each molecule, the Ni(II) located in the ethylene chain linked site has a square planar geometry whereas the Ni(II) located in the propylene chain linked site has an octahedral environment.The results of ES-MS and cycle voltammograms confirm that Cu–Zn, Ni–Ni form stable complexes with the macrocyclic ligand L, however the complex composed of Cu–Cd was unstable, and easily lost Cd2+ from the complex in methanol solution.The cyclic voltammograms of the complexes show that each complex undergoes a stepwise reduction process, e.g.[Ni2L]2+ with E 1 / 2 1 = - 0.862 V and E 1 / 2 2 = - 1.20 V .Magnetic measurements in the 2–300 K range indicate weak antiferromagnetism for the dinuclear nickel(II) complex with the exchange constantJ = −0.90 cm−1.

Two symmetric dinuclear copper (II) macrocyclic complexes ([Cu2L](ClO4)2 and [Cu2L′](ClO4)2) were unexpectedly obtained by the cyclocondensation between N,N′-bis(3-formyl-5-n-butylsalicylidene)ethylenediimine and 1,3-diaminopropane in the presence of copper (II) perchlorate and characterized by some physical methods. Both complexes were determined by X-ray diffraction techniques. DFT theoretical calculation was used to discuss the structure and to assign the IR spectra of the cation of the complex ([Cu2L](ClO4)2, the complete vibration spectral analysis was performed. A good agreement is obtained between DFT theoretical calculation results and the experimental data for the complex ([Cu2L](ClO4)2.

A novel saddle-form macrocyclic barium complex was synthesized by cyclo-condensation of diformylpyridine with [BaL1(ClO4)2]·3H2O. In the complex crystal [BaL2(ClO4)2(H2O)]·MeOH·1.5H2O, two perchlorate anions are cis-coordinated to barium(II), and the coordinated water molecule is located on the opposite side to the perchlorate anion. 1H NMR and ES MS spectra were used to characterize its structure in methanol solution. The mechanism of the reaction was discussed.

A novel water-soluble octaazamacrocyclic dinuclear copper(II) complex with tetra-pendant arms, [Cu 2 L] Cl 2 ∙ 5H 2 O, was synthesized by [2+2] condensation between 2, 6-diformyl-4-chlorophenol and N, N, N', N'-tetrakis(2'-aminoethyl)-1, 2-diaminopropane in the presence of Cu(OAc) 2 ·H 2 O. Single-crystal X-ray structural analysis reveals that every copper(II) adopts a trigonal bipyramid coordination configuration. Macrocyclic units are joined together by strong π – π stacking interaction with centroid–centroid distance of 3.658 A. Water pentamers with O–O distances of 2.099–2.841 A are observed in the complex. The activity of superoxide dismutase of the complex has been investigated by the nitro blue tetrazolium method.

Three alkaline earth metal cryptates (Barium(II), Strontium(II), Calcium(II)) were synthesized by (2+3) template condensation of tris(3-aminopropyl)amine with 2,6-diformylpyridine and characterized by some physical methods. The solution structure of [BaL]2+ (L=cryptand) was studied by electrospray mass spectrometry, 1H-13C NMR and molecular dynamics method based on analysis of 1H NMR NOE spectrum. The crystal structure presents a tricapped trigonal prism structure in which barium(II) is enclosed within the macrobicycle and is nine-coordinated by six imino nitrogen atoms and three pyridyl nitrogen atoms.

The copper(II) complex of a new bis-N4O-hexdentate Schiff-base, in which two N,N′-dimethyl-N-(3-(2′-aminoethylimine)-5-(chlorosalicylamine))-N′-(3-imine-5-chlorosalicylamine) units are connected by an ethylene, was synthesized and structurally characterized in the solid state as a form of pentanuclear single helicate based on the square-planar coordination geometries.