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Jiang L.,Nankai University | Jiang L.,Key Laboratory of Advanced Energy Materials Chemistry MOE | Jiang L.,Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry | Liu B.,Leibniz University of Hanover | And 12 more authors.
CrystEngComm | Year: 2017

The employment of a reduced Schiff-base ligand, 1,3-bis(3-methoxy-salicylamino)-2-propanol (H3L), with the assistance of acetate anions led to the isolation of eight heptanuclear heterometallic complexes containing [Cu5Ln2] cores. Single-crystal X-ray diffraction analyses have been performed for all the complexes and show that they all have dicationic [Cu5Ln2] cores with two nitrate or hexafluorophosphate anions to compensate the charge. The dicationic parts in 1-8 display centrosymmetric hexagonal-like arrangements in which one CuII ion sits on the inversion centre with six peripheral metal ions (two LnIII and four CuII) around it. The magnetic susceptibilities of all the complexes have been studied by dc magnetic measurements. The temperature dependent magnetic susceptibility data for the CuII-GdIII complex have been processed using PHI software. The results reveal that the magnetic exchange interactions between CuII and CuII ions are antiferromagnetic while those between CuII and GdIII ions are ferromagnetic. The magnetostructural correlations reveal that the bridging angles of Cu-O-Cu and Cu-O-Gd greatly influence the magnetic coupling of CuII-CuII and CuII-GdIII, respectively. Further, ac susceptibility studies have been carried out for DyIII and TbIII complexes and HoIII derivatives. The complexes CuII-HoIII and CuII-TbIII show slow magnetization relaxation behaviour of an SMM. © The Royal Society of Chemistry.


Qi K.,Key Laboratory of Advanced Energy Materials Chemistry MOE | Qi K.,Shenyang Normal University | Li D.,Key Laboratory of Advanced Energy Materials Chemistry MOE | Fu J.,Peking University | And 5 more authors.
Journal of Physical Chemistry C | Year: 2014

Using ionic liquids as controlling agents is known to effectively affect the morphologies of TiO2 crystals. To obtain a profound understanding of this observation, density functional theory calculations with inclusion of Grimme treatment of the dispersion forces (DFT+D) have been performed to study a typical ionic liquid 1-ethyl-3-methylimidazolium bromide ([Emim]Br) adsorption on the low-index TiO2 facets, and the equilibrium crystal shape of TiO2 has been predicted using Wulff'S rule. [Emim]Br is found to adsorb most strongly on (110) for rutile and (100) for anatase. The gap of surface energy shows an obvious increase after [Emim]Br adsorption, especially, between (101) and (001) for anatase and also between (110) and (001) for rutile. This gap variation results in increasing the (100) facet exposure of anatase, and an increase in the length-to-diameter ratio of rutile nanocrystals, which is verified by our experiments. This study is meaningful to gain further understanding of how ionic liquids achieve shape-controlled nanocrystals synthesis by turning surface chemistry, which will push a valuable step toward the ultimate goal, controlling synthesis of inorganic nanomaterials. © 2014 American Chemical Society.


Zhao P.,Nankai University | Zhao P.,Key Laboratory of Advanced Energy Materials Chemistry MOE | Han Y.,Tianjin Normal University | Dong X.,Nankai University | And 5 more authors.
ECS Journal of Solid State Science and Technology | Year: 2015

Nowadays, waste tires bring the world increasing environmental and economic issues. Although pyrolysis seems to be a feasible process, a proper application of generated residues needs to be solved urgently. In this work, activated carbons (ACs) derived from the industrial pyrolytic tire char were first evaluated as potential electrode materials for supercapacitor. The obtained ACs display good eletrochemical properties, with initial specific capacitance of about 200 F g-1 at 1 A g-1, long cycling life, low equivalent series resistance and relaxation time, which indicate the ACs are suitable for supercapacitor. © 2015 The Electrochemical Society.


Li J.-L.,Nankai University | Li J.-L.,Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry | Jiang L.,Nankai University | Jiang L.,Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry | And 14 more authors.
Journal of Inorganic Biochemistry | Year: 2015

Three new Co(II) complexes, [Co4(L)2(μ3-CrO4)2](ClO4)2 · 2CH3CN (1), [Co2(L)(μ2-na)(H2O)](ClO4)2 (2) and [Co2(L)(μ2-ba)](ClO4)2 · 0.5CH3CN (3) (Hna = nicotinic acid, Hba = benzoic acid, HL = N,N,N′,N′-tetrakis (2-quinolylmethyl)-1,3-diaminopropan-2-ol), have been synthesized and characterized by various physicochemical techniques. The Co(II) centers are connected by endogenous alkoxy bridge from L- and various extrinsic auxiliary linkers, some of which display coordination number asymmetry (5, 6-coordinated for 1 and 2; 5, 5-coordinated for 3). It is worth mentioning that complex 1 contains two rare reported μ3-η1, η1, η1-CrO4 2- moieties. Susceptibility data of three complexes indicated intramolecular antiferromagnetic coupling of high-spin Co(II) atoms with exchange integral values (J) - 14.94 cm- 1, - 11.26 cm- 1 and - 13.66 cm- 1 for 1, 2 and 3, respectively. Interaction of compounds with calf thymus DNA (CT-DNA) have been investigated by absorption spectral titration, ethidium bromide (EB) displacement assay and viscosity measurement, which revealed that compounds bound to CT-DNA with a moderate intercalative mode, accompanied the affinities order: 1 > 2 ≈ 3. Three complexes exhibit oxidative cleavage of pBR322 plasmid DNA including a reliance on H2O2 as the activator. Compound 1 demonstrates an increased DNA cleavage activity as compared with 2 and 3, which could degrade super coiled DNA (SC DNA) into nicked coiled DNA (NC DNA) in lower concentration (5 μM). Moreover, all compounds could quench the intrinsic fluorescence of bovine serum albumin (BSA) in a static quenching process. Complex 1 also shows higher anticancer activity than cisplatin with lower IC50 value of incubation for both 24 h and 48 h. © 2014 Elsevier Inc. All rights reserved.


Zhao P.,Nankai University | Zhao P.,Key Laboratory of Advanced Energy Materials Chemistry MOE | Liu S.,Nankai University | Liu S.,Key Laboratory of Advanced Energy Materials Chemistry MOE | And 3 more authors.
ECS Electrochemistry Letters | Year: 2015

Nitrogen-doped hierarchical porous carbons were synthesized by direct pyrolysis of a double metal organic salt, the disodium zinc tetrahydrate of ethylenediamine tetraacetic acid (EDTA) at 600-700°C. The carbon obtained at 700°C has the highest surface area (2818 m2 g-1), pore volume (2.851 cm3 g-1), and abundant nitrogen-containing functional groups as well as oxygen function groups and exhibits high specific capacitance (∼258 F g-1 at 1 A g-1 in 6 mol L-1 KOH aqueous electrolyte), excellent rate capability, and long cycle life. © 2015 The Electrochemical Society.


Sun Q.,Nankai University | Sun Q.,Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry | Sun Q.,Key Laboratory of Advanced Energy Materials Chemistry MOE | Lu J.,Nankai University | And 20 more authors.
Applied Organometallic Chemistry | Year: 2014

Three new mononuclear cobalt(II) complexes containing ligands with extended planar quinoxaline moieties, {dipyrido[3,2-a:2′,3′-c]phenazine (dppz) or dipyrido[3,2-d:2′,3′-f]quinoxaline (dpq)}, viz. [Co(dppz)(acac)2] · CH3OH (1), [Co(dpq)(tfnb) 2] (2) and [Co(dpq)(dbm)2] (3), where acac = acetylacetonate, tfnb = benzoyltrifluoroacetone and dbm = dibenzoylmethane, have been synthesized and structurally characterized as octahedral complexes. The binding ability of the complexes with calf thymus (CT)-DNA has been investigated by spectroscopic and viscosity measurements. Results indicate that all complexes bind to CT-DNA via intercalative mode, and the DNA binding affinity of dppz complex 1 is apparently stronger than that of dpq complexes 2 and 3. Furthermore, DNA photocleavage experiments indicate that these complexes are efficient DNA cleaving agents in UV-A (365 nm) and hydroxyl radical (HO ·), singlet oxygen (1O2) and superoxide anion (1O2 -) serve as the major cleavage active species. In addition, interaction of the complexes with bovine serum albumin (BSA) was investigated using UV - visible and fluorescence methods, which indicated that all complexes could quench the intrinsic fluorescence of BSA in a static quenching process. Copyright © 2014 John Wiley & Sons, Ltd.


Lu J.,Nankai University | Lu J.,Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry | Lu J.,Key Laboratory of Advanced Energy Materials Chemistry MOE | Li J.-L.,Nankai University | And 21 more authors.
Journal of Coordination Chemistry | Year: 2014

[Cu2L(phen)(H2O) 3(ClO4)] (ClO4)3 {phen = 1,10-phenanthroline, L = 4-((bis(pyridine2-ylmethyl)amino)methyl)-N,N-bis(pyridin-2-ylmethyl)aniline} was prepared and characterized by physical chemical techniques. The X-ray single-crystal structure analysis shows an unsymmetrical dinuclear species. The interaction of the complex with calfthymus DNA (CT-DNA) was studied by various spectroscopic and viscosity measurements, which indicate that the complex can interact with CT-DNA through intercalation. In the presence of H 2O2, the complex can cleave pBR322 DNA more efficiently and hydroxyl radicals (HO.) may serve as the major cleavage active species. Interactions of the compound with bovine serum albumin (BSA) were also investigated using UV-Vis and fluorescence spectroscopic methods. The results show that the complex quenches the intrinsic fluorescence of BSA by a static quenching mechanism. © 2014 © 2014 Taylor & Francis.


Wang B.-W.,Nankai University | Wang B.-W.,Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry | Wang B.-W.,Key Laboratory of Advanced Energy Materials Chemistry MOE | Jiang L.,Nankai University | And 20 more authors.
Journal of Coordination Chemistry | Year: 2014

An unsymmetrical oxo-bridged diiron(III) complex [Fe2L 2(μ-O)], {H2L = trans-N,N'-bis-(2hydroxy-1- naphthalidehydene)-cyclohexanediamine} has been synthesized and characterized by various physico-chemical techniques. In the complex, each deprotonated bi-anionic L2- serves as a terminal tetradentate ligand (N 2O2) and coordinates to one Fe to form a [FeL]+ unit. Two [FeL]+ units are further linked by an oxo-bridge to construct the binuclear oxo-Fe species with intramolecular Fe-Fe separation of 3.38 Å. Variable-temperature magnetic susceptibility studies revealed a strong antiferromagnetic interaction between two iron centers with J of -112 cm-1. The interaction of the complex with CT-DNA was studied by various spectroscopic and viscosity measurements, which indicated that the complex could interact with CT-DNA through intercalation. In addition, the complex is able to cleave pBR322 DNA in the presence of H2O 2. Furthermore, the interaction of the compound with BSA was also investigated, which indicated that the complex could quench the intrinsic fluorescence of BSA by a static quenching mechanism. © 2014 © 2014 Taylor & Francis.


Zhou X.-Q.,Nankai University | Zhou X.-Q.,Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry | Zhou X.-Q.,Key Laboratory of Advanced Energy Materials Chemistry MOE | Sun Q.,Nankai University | And 13 more authors.
Dalton Transactions | Year: 2015

Six novel copper(ii) complexes of [CuL1Cl]ClO4 (1), [CuL1(acac)]PF6 (2), [CuL2(R)Cl]2(PF6)2 (3), [CuL2(S)Cl]2(PF6)2 (4), [CuL2(R)(acac)]PF6 (5) and [CuL2(S)(acac)]PF6 (6), (L1 = 1-naphthyl-N,N-[bis(2-pyridyl)methyl]amine, L2 = R/S-1-naphthyl-N,N-[bis(2-pyridyl)methyl]ethanamine, acac = diacetone) were synthesized to serve as artificial nucleases. All complexes were structurally characterized using X-ray crystallography. The crystal structures showed the presence of distorted square-planar CuLCl (1, 3 and 4) and distorted tetragonal-pyramidal CuL(acac) (2, 5 and 6) geometry. The interaction of these complexes with calf thymus DNA (CT-DNA) was researched by means of several spectroscopy methods, which indicated that the complexes were bound to CT-DNA by an intercalation binding mode. DNA cleavage experiments revealed that the complexes exhibited remarkable DNA cleavage activities in the presence of H2O2, and single oxygen (1O2) or hydroxyl radicals may serve as the major cleavage active species. In particular, the in vitro cytotoxicity of the complexes on four human cancer cell lines (HeLa, MCF-7, Bel-7404 and HepG-2) demonstrated that the six compounds had broad-spectrum anti-cancer activity with low IC50 values. The stronger cytotoxicity and DNA cleavage activity of the chiral enantiomers compared with chiral analogues verified the influence of chirality on the antitumor activity of complexes. Meanwhile, the protein binding ability was revealed by quenching of tryptophan emission with the addition of complexes using BSA as a model protein. The results indicated that the quenching mechanism of BSA by the complexes was a static process. © The Royal Society of Chemistry 2015.


Gao C.-Y.,Nankai University | Gao C.-Y.,Shanxi Agricultural University | Ma Z.-Y.,Tianjin Medical University | Zhang Y.-P.,Shanxi Agricultural University | And 11 more authors.
RSC Advances | Year: 2015

Four closely related mononuclear nickel(ii) complexes [Ni(L)(diimine)Cl](ClO4) (1-4), where L is a tridentate polypyridyl ligand of 4-methyl-N,N-bis(pyridin-2-ylmethyl)aniline and diimine is 2,2′-bipyridine (bpy, 1), 1,10-phenanthroline (phen, 2), dipyrido[3,2-d:20,30-f]quinoxaline (dpq, 3) or dipyrido[3,2-a:20,30-c]phenazine (dppz, 4), have been synthesized and characterized using various physico-chemical techniques. All Ni centers adopt a distorted octahedral geometry with N5Cl donor sets. From 1 to 4, the dihedral angles between the benzene ring of L and the plane of the diimine gradually decline (52.5-6.8°), leading to increasing steric encumbrance. The interactions of the complexes with CT-DNA and BSA have been explored using absorption and emission spectral methods. These complexes display binding propensity to CT-DNA in the order: 4 (dppz) > 3 (dpq) > 2 (phen) > 1 (bpy), and the quenching mechanisms of BSA by all the complexes are static procedures. In the absence of any external agents, only 1 (bpy) and 4 (dppz) exhibit apparent DNA cleavage activity, while with the addition of GSH or on the irradiation with UV-A light of 365 nm, the DNA cleavage abilities of the complexes are obviously enhanced, which vary as 1 > 2 > 3 > 4 (GSH) and 4 > 3 > 2 > 1 (UV-A). In addition, the in vitro cytotoxicity of the complexes on tumor cells lines (MCF-7, HepG-2 and SGC-7901) have been examined by MTT and the morphological assessment obtained using Hoechst 33342 staining reveals that 4 induces apoptosis against HepG-2. © The Royal Society of Chemistry 2015.

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