Bao-Li Fei

Synthesis and crystal structure of a luminescent infinite 2D brick-wall network with two- and three-coordinate silver(I) atoms and ligand-unsupported silver–silver interactions

Assembly of a novel flexible tetradentate ligand 1,7-bis(4′-pyridyl)-2,6-diazaheptane (py-hep) with silver perchlorate hydrate provides an interesting two-dimensional (2D) brick-wall network: [Ag3(py-hep)2](ClO4)3·0.5CH3CN. The X-ray crystal structural analysis indicates that the framework consists of trigonal and linearly coordinated silver(I) atoms and ligand-unsupported metal–metal interactions. The complex shows photoluminescence in both the solid state and in acetonitrile solution.

Self-assembly of a snake-like blue photoluminescent coordination polymer from 4,4'-bis(imidazol-1-ylmethyl)biphenyl and zinc acetate

A novel snake-like zinc(II) coordination polymer with blue photoluminescence, {[Zn(bimb)(OAc)2]·6H2O}∞ [bimb = 4,4′-bis(imidazol-1-ylmethyl)biphenyl, OAc = acetate anion], was obtained by reaction of Zn(OAc)2·2H2O with the ligand bimb. The X-ray crystal structural analysis indicates that two independent single-stranded helical chains are interwoven like two entwined snakes and held together through hydrogen bonds and π-π interactions.

Effects of copper ions on DNA binding and cytotoxic activity of a chiral salicylidene Schiff base

A chiral Schiff base HL N-(5-bromo-salicylaldehyde)dehydroabietylamine (1) and its chiral dinuclear copper complex [Cu2L4]·4DMF (2) have been synthesized and fully characterized. The interactions of 1 and 2 with salmon sperm DNA have been investigated by viscosity measurements, UV, fluorescence and circular dichroism (CD) spectroscopic techniques. Absorption spectral (Kb=3.30 × 10(5)M(-)(1) (1), 6.63 × 10(5)M(-)(1)(2)), emission spectral (Ksv=7.58 × 10(3)M(-)(1) (1), 1.52 × 10(4)M(-)(1) (2)), and viscosity measurements reveal that 1 and 2 interact with DNA through intercalation and 2 exhibits a higher DNA binding ability. In addition, CD study indicates 2 cause a more evident perturbation on the base stacking and helicity of B-DNA upon binding to it. In fluorimetric studies, the enthalpy (ΔH>0) and entropy (ΔS>0) changes of the reactions between the compounds with DNA demonstrate hydrophobic interactions. 1 and 2 were also screened for their cytotoxic ability and 2 demonstrates higher growth inhibition of the selected cancer cells at concentration of 50 μM, this result is identical with their DNA binding ability order. All the experimental results show that the involvement of Cu (II) centers has some interesting effect on DNA binding ability and cytotoxicity of the chiral Schiff base.

The synthesis, crystal structure and spectroscopic properties of a new two-dimensional silver(I) coordination network

A flexible tetradentate ligand 1,6-bis(4%-pyridyl)-2,5-diazahexane (BPDH) reacts with tetrakis(acetonitrile)silver(I) tetrafluoroborate to form a novel two-dimensional network complex [Ag(BPDH)]BF4·CH3CN. The compound crystallizes in monoclinic, space group P21:n with a14.121(2), b7.0410(10), c19.803(3) A, , b 94.700(10)°, V 1962.3(5) A, 3 and Z 4. The solvate acetonitrile molecule and counter anions are incorporated in the channels formed between two adjacent sheets through CH···F, NH···F and NH···N hydrogen bonds. The spectroscopic properties of the complex as luminescent, thermogravimetric and electrospray mass spectrometry were also described.

A heteropoly blue as environmental friendly material: An excellent heterogeneous Fenton-like catalyst and flocculent

The first 3D heteropoly blue Ba2Na4[SiW4VW8VIO40]·19H2O (1) as heterogeneous Fenton-like catalyst and flocculent was hydrothermally synthesized and fully characterized by various methods 1 was an efficient Fenton-like catalyst for degradation of phenol with degradation rate of 92.1% (visible light irradiation), and 89.0% (no light) in 90min, respectively. The degradation efficiency of anionic dye methyl orange was 97.0% in 5min, when 1 was used as photo-Fenton-like catalyst under visible light. And 1 was a nice flocculent for cationic dyes methylene blue and rhodamine B, the removal rates were both above 95%. Moreover, 1 could degrade methyl orange and flocculate rhodamine B at the same time, but the degradation rate decreased from 100% to 77.5% in 60min, while the flocculation of RhB in 10min was not affected.

A novel 3D heteropoly blue type photo-Fenton-like catalyst and its ability to remove dye pollution

A environment-friendly 3D inorganic heteropoly blue (HPB) Ba2Na2 [HPWV4WVI8O40]·26H2O was directly synthesized by hydrothermal method and characterized by means of ICP, IR, XPS, X-ray single crystal and X-ray powder diffraction. It was an efficient heterogeneous photo-Fenton-like catalyst to degrade anionic dye methyl orange under visible light irradiation. It removed cationic dyes methylene blue in neutral environment and rhodamine B in acidic condition via flocculation. The removal efficiency of methylene blue and rhodamine B by flocculation was more than 95%. Moreover, it could degrade methyl orange and flocculate rhodamine B at the same time. For MO and MO-RhB solutions, the degradation rates of MO in 60 min were 85.5% and 49.1%, respectively. Furthermore, the possible pathways for the production of active species in the MO degradation reaction were discussed. This is the first HPB constructed with 4e-reduced phosphotungstate, Ba and Na ions, having the properties of photo-Fenton-like catalyst and flocculant.

Enantiopure copper(II) complex of natural product rosin derivative: DNA binding, DNA cleavage and cytotoxicity.

To develop chiral anticancer drug candidates for molecular target DNA, the synthesis and characterization of a novel enantiomerically pure copper(II) complex [Cu1Cl2] (2) of an optically pure ligand N-(pyridin-2-ylmethylene) dehydroabietylamine (1) was carried out. The coordination geometry of the copper center is a distorted square-planar arrangement. The interactions of 1 and 2 with salmon sperm DNA were investigated by viscosity measurements, UV, fluorescence and circular dichroism (CD) spectroscopic techniques. All the results reveal that 1 and 2 interacted with DNA through intercalation and 2 exhibited a higher DNA binding ability. Further, 1 and 2 could cleave supercoiled pBR322 DNA by single strand and 2 displayed stronger cleavage ability in the presence of ascorbic acid. In vitro cytotoxicity of 1 and 2 against HeLa, SiHa, HepG-2 and A431 cancer cell lines was studied using CCK-8 assay. The results indicate that 2 had a superior cytotoxicity than 1 and the widely used drug cisplatin under identical conditions. Flow cytometry analysis demonstrates 2 produced death of HeLa cancer cells through an apoptotic pathway. Cell cycle analysis shows that 2 mainly arrested HeLa cells at the S phase.Graphical abstractA novel enantiomerically pure copper(II) complex [Cu1Cl2] (2) of an optically pure ligand N-(pyridin-2-ylmethylene) dehydroabietylamine (1), based on natural product rosin has been synthesized. 2 has the potential to act as effective anticancer drug.

Construction of co-ordination networks of 1,6-bis(4′-pyridyl)-2,5-diazahexane with silver(I) and copper(I). Structural diversity through change in metal ions and counter ions

A novel flexible tetradentate ligand 1,6-bis(4′-pyridyl)-2,5-diazahexane (BPDH) was synthesized, and its coordination networks with silver(I) and copper(I) salts chracterized by X-ray single-crystal structure analysis and electrospray mass spectrometry (ES-MS). The network topologies are found to depend greatly on the counter anions and metal ions employed during the reaction and crystallization. The structure of [Ag(BPDH)]NO31 is a one-dimensional infinite hinged cationic chain in which the counter anions link two adjacent chains through N–H⋯O and C–H⋯O hydrogen bonds. The complex [Ag(BPDH)]ClO4·CH3CN 2 is a two-dimensional infinite cationic network; the solvate acetonitrile molecule and counter anions are incorporated in the channels of two adjacent sheets through C–H⋯O, N–H⋯O and N–H⋯N hydrogen bonds. The structure of [Cu(BPDH)]ClO43 is an infinite two-dimensional cationic grid; the counter anions are located in the voids of two layers through a single C–H⋯O hydrogen bond. The structures of the three co-ordination polymers are stabilized by face-to-face or edge-to-face π–π interactions. The results demonstrate that counter ions and transition metal ions play important roles in the formation of supramolecular frameworks.

Synthesis and crystal structure of 4,4′-bis(4-pyridylethyl)biphenyl, noncovalently hydrogen bonded two-dimensional networks

A new pyridine containing compound, 4,4′-bis(4-pyridylethyl)biphenyl 1, was synthesized and its structure was determined by X-ray crystallography. Two kinds of two-dimensional networks linked by hydrogen bonds were obtained with different crystal solvents: 1·2H2O, monoclinic, space group P21/n with a = 8.3280(10), b = 5.5990(10), c = 24.054(4) Å, β = 98.79(2)°, V = 1108.4(3) Å3, Z = 2, Dc = 1.200 g cm−3, R1 = 0.0558; 1·CH3OH·2H2O, triclinic, space group P-1 with a = 8.3310(10), b = 12.861(2), c = 13.111(2) Å, α = 64.110(10), β = 75.000(10), γ = 83.750(10)°, V = 1220.7(3) Å3, Z = 2, Dc = 1.177 g cm−3, R1 = 0.0529. It is interesting that in the hydrate the host molecule of 1 contains an essentially flat biphenyl section, while in the methanol complex the host molecule of 1 contains a substantial twist in the center of the biphenyl section. The compounds were also characterized by NMR and FTIR spectroscopies. The 1H and 13C NMR assignments for 1 were carried out by 2D NMR spectral measurements in acetonitrile-d3.