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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°.

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°.

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.

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.

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.

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.

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.

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.

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.