Search

A “three in one” project involved atomically precise biotinylated complex, VBio-CuICuII, composed of a hydroxyl radical-producible Cu(i), a Cu(ii) moiety as a GSH depletor for augmented CDT, and biotin as a cancer-targeting unit.

A robust Zn(ii) MOF with good chemical and thermal stability, was prepared as an effective fluorescent probe for 2,4,6-trinitrophenol (TNP), levofloxacin (LVX) and l-cystine (l-Cys) with recyclability.

A 2D cluster-based coordination polymer of {Fe5}-2D was developed by hierarchical dimension augmentation from its 1D coordination polymer of {Fe5}-1D and discrete 0D cluster of {Fe5}-0D. And a possible bottom-up synthesis mechanism was proposed.

A triphenylphosphine-modified tetra-nuclear Cu(I) coordinated cluster was constructed for enhanced chemodynamic therapy (CDT) by increasing the number of metal centers. Once inside human bladder cancer (T24) cells, a larger amount of copper accumulated compared with the mono-nuclear Cu(I) complex; the additional copper could generate more •OH and then induce more obvious apoptosis

The controllable construction and function expansion of some sophisticated aggregations represent a current hot topic in scientific research. In this paper, using a prefabricated {Co14} cluster as a synthetic precursor, a homometallic {Co24} and a heterometallic {Co12Cd12} giant cluster possessing similar dual-[M12] (M = Co/Cd) skeletons was prepared by reacting the precursor with excess CoCl2 and Cd(OAc)2 salts, respectively. The detailed structural information on {Co24} and {Co12Cd12} was characterized by single-crystal X-ray diffraction and further analyzed by X-ray photoelectron spectroscopy, inductively coupled plasma-mass spectroscopy, and scanning electron microscopy with energy dispersive X-ray (EDX) spectroscopy in the solid state. Compared to the {Co14} precursor, magnetic difference revealed that spin-canting and magnetic ordering had been enhanced in {Co24} and suppressed in {Co12Cd12} when dotted with diamagnetic Cd2+ ions.

Organic reactions using metal–organic frameworks (MOFs) as catalysts are promising with regard to their environmentally friendly features and potential catalyst recyclability. A robust Co(II)-MOF {[Co2(L-mac)(4,4-bpt)(H2O)]·3.5H2O}n (1) and its enantiomer {[Co2(D-mac)(4,4-bpt)(H2O)]·3.5H2O}n (2) (L/D-mac = basic forms of L/D-malic acid, 4,4-Hbpt = 3,5-di(pyridin-4-yl)-4H-1,2,4-triazole) have been gram-scale prepared under solvothermal conditions. Structural analysis reveals that mac manages Co(II) ions to form 1-D chains, which are further extended via 4,4-bpt connectors into a noninterpenetrating 3D framework architecture. It was found that 1 can be as a heterogeneous catalyst for multiple organic reactions, such as azide-alkyne cycloaddition and Friedel–Crafts reactions with good isolated yields and good recycle runs (at least five times without substantial degradation). Additionally, 1 can promote hydrosilylation of alkynes under harsh conditions with moderate yield.

An unprecedented [Mn18(CO3)9] inorganic core and [Mn20] metal–organic periphery composed the largest homometallic single-valence {MnII38} aggregate with a four-shells matryoshka doll that displays a significant magnetocaloric effect (MCE).

A simple and feasible atom-precise biotinylated Cu(i) complex, which can catalyze H2O2 overexpressed commonly in the tumor microenvironment to produce ˙OH through a Fenton-like reaction, was prepared and employed as an effective agent for tumor-targeted chemodynamic therapy.

A NiII-MOF, {[Ni(C2O4)(N2H4)]·2H2O}n (1), was constructed by oxalate and hydrazine under hydrothermal conditions at 130 °C. Single-crystal X-ray structural analysis indicates that 1 has a 3-D porous architecture with (103) topology based on two kinds of 1-D zigzag [Ni(C2O4)]n chains with the same structure but different extension directions in the ab plane separated by N2H4 linker. 1 reveals antiferromagnetic behavior and thermal stability below 283 °C.

A new complex formulated as [Mn(H2O)6][Mn2(ett)6]·0.5H2O (1) has been synthesized from 5-(ethylthio)-1H-tetrazole) (Hett) andMn(OAc)2·4H2O. The crystal structure is composed of one [Mn(H2O)6] 2+ cation and an [Mn2(ett)6] 2– anionic chain. Two Mn(II) ions are bridged by μ2-ett – ligands to give [Mn2(ett)6] 2– anionic chains, which is balanced by cationic part of [Mn(H2O)6] 2+ in charge. The hydrogen bonds between anionic/cationic units play an important role in the formation of three-dimensional (3-D) supramolecular structure of 1. Magnetic measurements of 1 exhibit an interesting spin canting behavior and long-range magnetic ordering.

The controllable construction of sophisticated aggregation is an exciting point in assembly chemistry. In this study, a heterometallic aggregation of {Co11Cd6} cluster-based MOFs can be hierarchically built from {Co14} precursors with the {Co4 ⊂ Co4 ⊂ Co6} skeleton directly. The time-dependent electrospray ionization mass spectrometry (ESI-MS) technique was used to track the stepwise Cd2+ capture, and a multi-step hierarchical assembly route was proposed along with the gradual splitting of this {Co11Cd6} aggregation: {Co14} → {Co8} → {Co8Cd2} → {Co8Cd3} → {Co8Cd4} → {Co8Cd5} → {Co8Cd6} → {Co11Cd6}.

Based on 1,2-dimethoxyphenyl (veratrole, open) and 1,2-methylenedioxyphenyl (pepper ring, close)-derived pyridine–triazole analogues, two groups of copper(II) complexes, namely, Group I(C1–C3) and Group II(C4–C6) were synthesized and fully characterized. All ligands and complexes were tested in vitro by MTT assays on seven tumour cell lines (T24, Hep-G2, Sk-Ov-3, MGC-803, HeLa, A549 and NCI-H460) and one normal liver cell line (HL-7702). Surprisingly, the pepper-ring-derived complexes (C4–C6) showed significantly enhanced cytotoxicity compared with the 1,2-bimethoxyphenyl ring-derived complexes (C1–C3) and the standard anticancer drug cisplatin. Cellular uptake assays indicated that the Cu accumulation was consistent with cytotoxicity. In addition, flow cytometry and western blot analysis showed that the apoptosis of the leading complex C4 may be induced by the Bcl-2 family-mediated proteins through the mitochondrial dysfunction pathway. Furthermore, UV-vis and fluorescence spectroscopy assays revealed that C4 has stronger insertion-binding interactions with CT-DNA than C1 and the fluorescence of C1 and C4 with BSA is mainly quenched by static quenching.

A novel discrete {Co14Mo24} nanoscale cluster, {CoIII2CoII10Cl2(dpbt)3(H2O)2[CoIIMoV12O31(CH3O)9]2}·24CH3OH (1) (here, dpbt = 5,5′-di(pyridin-2-yl)-3,3′-bi(1,2,4-triazole)), with a triangular Co4 core encapsulated in two novel capped Co-substituted Keggin-type Co5Mo12O40 anions, has been isolated from alkaline methanol solution. The high-resolution electrospray ionization mass spectrum (HRESI-MS) of microcrystalline 1 in MeOH/CH2Cl2 (v : v = 2 : 1) was recorded. Two prominent overlapping peaks in the range of m/z = 2740–2840 and 1820–1880 for the discrete fragments of [CoIII2CoII12MoV24O62Cl2(dpbt)3(H2O)2(CH3O)x(OH)18−x-2H]2− (x = 9–18, F1) and [CoIII2CoII12MoV24O62Cl2(dpbt)3(H2O)2(CH3O)x(OH)19−x-2H]3− (x = 6–13, F2), respectively, are obtained, confirming the {Co14Mo24} composition in 1. In addition, weak anti-ferromagnetic interactions in 1 are observed.

A unique three-dimensional zinc(II)-dpbt framework with formula {[Zn6Cl6(2,2′-dbpt)3]·4.5H2O}n (1) (here, 2,2′-H2dpbt = 5,5′-di(pyridin-2-yl)-3,3′-bi(1,2,4-triazole)) has been successfully constructed under solvothermal conditions. This complex was fully characterized via single-crystal X-ray diffraction, elemental analysis, powder X-ray diffraction, infrared spectroscopy, thermogravimetric analyses, luminescence spectroscopy, UV-vis spectroscopy, EDS and ICP-MS. The luminescence properties confirm that the emission behavior of the Zn(II) complex exhibits excellent thermal and chemical stabilities. The luminescence performance of 1 in a series of cations and anions was also explored. Importantly, the luminescence experiments reveal that 1 is sensitive, efficient and can be quickly regenerated (at last 4 cycles) as a fluorescent probe for detecting Cu2+, Ag+, MnO4− and Cr(VI) (Cr2O72− and CrO42−) ions.

We present here a nested [Co4⊂Co10] cluster consist of an inner [Co4(μ3-OH)4] cubane and a [Co10(dpbt)6Cl12] adamantane periphery, formulated as [Co14(μ3-OH)4(dpbt)6Cl12]·14CH3CH2OH (1) (here, H2dp...

Reactions of the bis((pyridine-2-yl)-1,2,4-triazol-5-yl)methane (H2L) with Zn(NO3)2·6H2O and ZnCl2 conditions afforded three new Zn(II) complexes, namely, {[Zn3L′2(H2O)6]·2NO3} (1), [Zn4L2Cl4(H2O)2] (2) and [Zn6L4(CH3OH)4(NO3)4] (3). Notably in 1, the methylene group in L was in situ oxidized to a rigid ketone group in L′ (here, H2L′ = bis((pyridine-2-yl)-1,2,4-triazol-5-yl)ketone). The three Zn(II) complexes were synthesized under solvothermal conditions and characterized by techniques of Elemental analysis, Fourier transform infrared spectroscopy, Powder X-ray diffraction and single-crystal X-ray diffraction analysis. In addition, the thermogravimetric properties and the luminescent properties of 1–3 were investigated.

Metal-center-driven spontaneous resolution of a pair of chiral doubly interpenetrated metal–organic frameworks (MOFs), [Ni3(ptd)6]·15.5H2O (1), which was synthesized from achiral precursors [ptd = 3-(pyridin-3-yl)-1,2,4-triazine-5,6-diol], shows vertical interpenetrated 2D → 3D frameworks with 1D channels. Interestingly, proceeding with solvothermal recrystallization in methanol, 1, with a high-symmetry tetragonal I4 space group, gives another tilted interpenetrated MOF of [Ni3(ptd)6]·10H2O·3.5MeOH (2), with low-symmetry monoclinic C2 space group. Accompanied with the structure transformation, a red shift in circular dichroism (CD) spectrum and a magnetic response (weak ferromagnetic interactions in 1 to weak antiferromagnetic interactions in 2) can be observed. Strikingly, 1 and 2 feature heterogeneous catalytic activities for the Knoevenagel reaction.

Two symmetrical double-sided Schiff base ligands, H4L1 and H4L2, were synthesized by condensation of salicylaldehyde and 2-hydroxy-1-naphthaldehyde with oxalodihydrazine, respectively. The crystal structures of their vanadium complexes were analyzed by single crystal X-ray diffraction. The interaction between the synthesized complexes and BSA was studied by various spectral methods. The binding parameters including quenching constant KSV, binding constant K, and binding mode were obtained using fluorescence quenching method. The study shows that the quenching type was a static quenching process caused by formation of complex. The SOD activities of the complexes were determined by xanthine oxidase-NBT reduction method. The antioxidant capacity of the complexes was determined by the ABTS method. The results indicate that the activity of hybrid protein was more pronounced than that of the corresponding complex. At the same time, the hybrid protein can catalyze asymmetric oxidation of methyl phenyl sulfide.

Seven new water-soluble chiral/achiral SOD-mimicking metal complexes: NaK[Mn(R-L1)(C2H5OH)4] (Mn-1a), NaK[Mn(S-L1)(C2H5OH)4] (Mn-1b), NaK[Co(R-L1)]·3H2O (Co-2a), NaK[Co(S-L1)]·3H2O (Co-2b), NaK[(VO)(R-L1)(OH)]·5H2O (V-3a), NaK[(VO)(S-L1)(OH)]·5H2O (V-3b) and [MnL2]·[(CH3CH2)3NH]2·5H2O (Mn-4) were synthesized and fully characterized. Furthermore, hybrid protein, binding with complexes and bovine serum albumin (BSA) to enhance the antioxidant activity, were synthesized and evaluated by multispectroscopic techniques. The SOD activities of all complexes and their corresponding hybrid proteins were tested by xanthine/xanthine oxidase method, the antioxidant activity of them were determined by ABTS method. The results show that the SOD activities of the hybrid proteins are higher than that of the corresponding complexes. From the values of the antioxidant activity we obtained, there seems to be some connection between the configuration and antioxidant activity.

Six Co(II) complexes were synthesized from CoCl2 with positional isomeric ligands: 3-(pyridine-3-yl)-5-(2-methoxyphenol-6-yl)-1H-1,2,4-triazole (3-H2pmpt) and 4-(pyridine-3-yl)-5-(2-methoxyphenol-6-yl)-1H-1,2,4-triazole (4-H2pmpt), namely, {[Co3(3-pmpt)2Cl2(DMF)2]·(DMF)2}n (1), {[Co3(4-pmpt)2Cl2(DMF)2]·(DMF)}n (2), [Co3(3-pmpt)2Cl2(DMF)2]n (3), [Co3(4-pmpt)2Cl2(DMF)2]n (4), {[Co5(3-pmpt)4(HCO2)2(DMF)2]·(H2O)4}n (5), {[Co5(4-pmpt)4(HCO2)2(H2O)2]·(H2O)6}n (6). Structural analysis reveals that pmpt isomers display different coordination modes to manage Co(II) ions to form [Co3] subunits in 1–4, and [Co5] subunits in 5–6, respectively. Which are further extended via different pyridine ring N-orientation to build the 1-D chains (for 1, 5 and 6) and 2-D layers (for 2, 3 and 4). Structural analysis indicate that 3/4-pmpt is an excellent multi-connect linker with pyridine ring at different angles, has an important effect on the structural topologies of such Co(II) complexes. Magnetic susceptibilities reveal weak ferromagnetic and antiferromagnetic exchange interactions between the adjacent metal centers in 5 and 6.

An unprecedented inner [Mn

The controllable construction and function expansion of some sophisticated aggregations represent a current hot topic in scientific research. In this paper, using a prefabricated {Co

A novel discrete {Co14Mo24} nanoscale cluster, {CoIII2CoII10Cl2(dpbt)3(H2O)2[CoIIMoV12O31(CH3O)9]2}·24CH3OH (1) (here, dpbt = 5,5'-di(pyridin-2-yl)-3,3'-bi(1,2,4-triazole)), with a triangular Co4 core encapsulated in two novel capped Co-substituted Keggin-type Co5Mo12O40 anions, has been isolated from alkaline methanol solution. The high-resolution electrospray ionization mass spectrum (HRESI-MS) of microcrystalline 1 in MeOH/CH2Cl2 (v : v = 2 : 1) was recorded. Two prominent overlapping peaks in the range of m/z = 2740-2840 and 1820-1880 for the discrete fragments of [CoIII2CoII12MoV24O62Cl2(dpbt)3(H2O)2(CH3O)x(OH)18-x-2H]2- (x = 9-18, F1) and [CoIII2CoII12MoV24O62Cl2(dpbt)3(H2O)2(CH3O)x(OH)19-x-2H]3- (x = 6-13, F2), respectively, are obtained, confirming the {Co14Mo24} composition in 1. In addition, weak anti-ferromagnetic interactions in 1 are observed.

In this study, four in situ hydro(solvo)thermal metal-ligand reactions, including oxidation (H2L1), C-C coupling (H4L2), nitration (H2L3), and condensation (HL4-6), based on bis[3-(pyridin-2-yl)-1H-1,2,4-triazol-5-yl]methane (H2L0), in the presence of DyIII ions, were carried out. The in situ metal-ligand reaction gave six new ligands existing in eight novel DyIII coordination complexes, which were characterized by crystal structure, mass spectrometry, and magnetism.

We present the synthesis, structural characterization, and magnetic properties of two high-nuclearity cobalt clusters formulated as [Co13(μ3-OH)3(μ3-Cl)(dpbt)5(ptd)Cl10][Co(H2O)2Cl2]·(CH3)2CHOH (1)...

A couple of chiral unsymmtrical Schiff base ligands, (1R,2R) (−)chxn (salH) (naftalH) and (1S,2S) (−)chxn (salH) (naftalH) had been synthesized by the condensation of salicylaldehyde and 2-hydroxy-1-naphthaldehyde with two isomers of (1R,2R)-trans-1,2-cyclohexanediamin and (1S,2S)-trans-1,2-cyclohexanediamin, respectively. At the same time, two manganese complexes have been synthesized and fully characterized by FT-IR spectrum, elemental analyses, single crystal X-ray diffraction. The interaction of the two Mn (III) complexes with bovine serum albumin (BSA) was investigated by spectroscopic techniques. The result reveals that the complexes can strongly quench the intrinsic fluorescence of BSA through a static quenching mechanism. The binding constant and binding mode has been determined. The secondary structure and the amino acid residues microenvironment of BSA change in the presence of these complexes. SOD-like activity and ABTS free radical scavenging ability were also studied. The antioxidant capacity of the compounds showed that the complexes and their corresponding BSA adducts showed some SOD activity. The results of ABTS free radical scavenging showed that the activity of the BSA adduct was more obvious than that of the complex.

Four polynuclear mercaptotetrazole-based nickel clusters, [Ni3(hmt)6(H2O)6]·4H2O (1), [(C2H5)4N]2[Ni9(μ3-CH3O)8(hmt)12] (2), [Ni5(μ3-OH)2(Hdmt)6(SCN)8] (3), and [Ni12(μ6-CO3)(μ3-CH3O)12(CH3CO2)3(et)6(H2O)12]·Br·2H2O (4), (here, Hhmt = 1-(2-hydroxyethyl)-5-mercapto-tetrazole, Hdmt = 1-[2-(N,N-dimethylamino)ethyl]-5-mercapto-tetrazole, Het = 5-(ethylthio)-1H-tetrazole), have been synthesized and characterized by elemental analysis, IR, powder X-ray diffraction and X-ray single-crystal diffraction. 1 shows a centrosymmetric linear trinuclear nickel cluster. 2 reveals of a dumbbell-like {Ni9} cluster with S3 symmetry containing two [Ni4(CH3O)4] cubanes linked with a Ni atom through six “ N N ” bridges. 3 reveals of a {Ni5} cluster with a bowtie-like skeleton supported by μ3-OH− ions. 4 exhibits a plane- symmetry {Ni12} cluster with an approximate trefoil shape based on three [Ni4(CH3O)4] cubanes bridged by a µ6-CO32−. The results show that the minor ligand modification accompanying the regulating of reaction conditions (anion, solvent, pH, temperature and the different ratios) have a key role in the structural control of the self-assembly process. Magnetic properties of 1, 2 and 4 in the 2–300 K have also been discussed. The linear {Ni3} (1) core displays dominant anti-ferromagnetic interactions from the nature of the binding modes through “ N N ” bridges. The {Ni9} (2) and {Ni12} (4) clusters display dominant ferromagnetic interactions from the nature of the binding modes through µ3-CH3O− and “ N N ” bridges.

The design and synthesis of macrocyclic ligands has become a hot research field of coordination chemistry for their novel structures and intriguing properties. Starting from bis (5-amion-1H-1,2,4-triazole) ligand (L1), three macrocyclic complexes with a novel double bis-triazole macrocyclic ligand (L2), [MCl2L2] (M = Fe, Co, Ni), were designed and synthesized by in situ reaction. In the process of reaction, metal ions played a key role for contributing to the formation of novel macrocyclic structures. The molecular structures of complexes were characterized by single-crystal X-ray diffraction, and the detailed description of synthesis is presented in this paper. The fluorescence quenching spectra and UV–vis spectra were used to study the interaction of complexes with bovine serum albumin (BSA). The results showed that the fluorescence quenching of BSA by these complexes was the presence of static quenching.

Reactions of the rigid–flexible N-heterocycle 1,3-bis(5-(pyridine-2-yl)-1,2,4-triazole-3-yl) propane (H2L) with MCl2 (M = Fe, Co, Cu or Zn) gave coordination complexes, {[Fe 2 III Cl4(H2L)2]·2Cl}·EtOH·H2O (1), {[Co3Cl5(HL)]·H2O} n (2), {[Co4Cl4(H2L)2(H2O)4]·[CoCl4]2}·H2O (3), [Cu2Cl3(HL)(H2O)]6·5H2O (4), [Cu 2 II CuICl4(HL)] n (5), {[Zn2Cl2(L)H2O]·H2O} n (6) and [Zn4Cl6(HL)2] (7), which have been characterized by single-crystal X-ray diffraction. Structural analysis reveals that the pyridine triazole ligand attains versatile coordination modes in these complexes. Complexes 1, 3, 4 and 7 consist of 0D clusters with binuclear or tetranuclear units; complex 2 presents a 2D network accompanied by HL− and chloride bridges; complexes 5 and 6 show 1D chains with [Cu3] and [Zn2] subunits. In addition, the electrospray ionization mass spectrometry properties of selected complexes were investigated, revealing the stabilities and structural states of these complexes in solution. These results indicate that H2L is an excellent multiconnection linker for the construction of diverse coordination complexes.

Four [CuI(ett)]n coordination polymorphs (1-α, 1-β, 1-γ and 1-δ), based on 5-(ethylthio)-1H-tetrazole (Hett), have been prepared successfully. By regulating the reaction time and reaction temperature, the rich coordination mode of the ett ligands can be regulated. Consequently, 1-α, 1-β and 1-γ show 2D wave-like layers, while 1-δ shows a 3D network. Powder X-ray diffraction (PXRD) analysis of the bulk sample of 1 prepared through a hydrothermal procedure revealed that 1-α and 1-δ can be isolated through temperature-dependent and time-dependent experiments, respectively. Starting from an as-prepared sample of 1-α in aqueous solution, the conversion from 1-α to 1-δ has been tracked over time by PXRD, with observations of the intermediate phases of 1-β and/or 1-γ in the hydrothermal re-crystallization process.

By employing an unprecedented tri-triazole ligand, 4-amino-3,5-bis-(1H-1,2,4-triazole)-1,2,4-triazole (H2L), two Zn(II)/Cd(II) metal-organic frameworks (MOFs), [ZnL]·3H2O (1) and [CdL]·H2O (2), were successfully synthesized and characterized. In the two complexes, M(II) centers are chelated and bridged by L bridges to form a one-dimensional (1-D) 41 helical chain in 1 with high-symmetry Pbca, and a 21 helical chain in 2 with lower symmetry P21/n, respectively. The two chains are further linked by L into two structure-correlated three-dimensional (3-D) architectures. PXRD and TG analysis confirmed the phase purity and stability of 1 and 2. The solid-state fluorescence properties of the prepared MOF revealed a maximum emission at 382 nm and 393 nm (λex = 330 nm), ascribing to the intra-ligand transitions. Interestingly, an additional strong emission peak at 516 nm can be observed in 1 (below 400 °C), while the emission was silenced in 2. The additional emission band may be attributed to the subtle difference of architectural features and coordination configurations between in 1 and 2.

Three transition metal complexes (FeIII, CoIII, and CuII) were synthesized by hydrothermal method from bis(2-hydroxy-1-naphthalene-formaldehyde) 3,4-diaminobenzoic acid (H3L). They were characterized by infrared spectroscopy, elemental analysis, mass spectrometry. Artificial enzymes were constructed by hybridizing bovine serum albumin (BSA) with the metal complexes and characterized by MALDI-TOF-MS. The interaction of the metal complexes with BSA was studied by Raman spectroscopy, fluorescence spectroscopy, and circular dichroism spectroscopy. All the three metal complexes can cause the intrinsic fluorescence quenching of BSA, which is mainly static quenching. The addition of metal complexes changed the conformation of BSA and decreased the content of α–helix structure. The activity of SOD was measured by xanthine oxidase-NBT method. All metal complexes exhibited certain SOD activity, which increased after the formation of hybrid proteins. Asymmetric oxidation of thioether catalyzed by artificial enzymes was studied. The optimum reaction conditions were obtained by optimizing the reaction conditions. Substrate universality experiments were carried out under the optimum reaction conditions, showing good activity and enantioselectivity, with enantioselectivity up to 81%.

Four different transition metal complexes containing dipyridyl triazole ligands, namely [Cu(abpt)2Cl2]·2H2O (1), [Cu(abpt)2(ClO4)2] (2), [Co2(abpt)2(H2O)2Cl2]·Cl2·4H2O (3) and [Co2(Hbpt)2(CH3OH)2(NO3)2] (4) have been designed, synthesized and further structurally characterized by X-ray crystallography, ESI-MS, elemental analysis, IR and Raman spectroscopy. In these complexes, the both ligands act as bidentate ligands with N, N donors. DNA binding interactions with calf thymus DNA (ct-DNA) of the ligand and its complexes 1~4 were investigated via electronic absorption, fluorescence quenching, circular dichroism and viscosity measurements as well as confocal Laser Raman spectroscopy. The results show these complexes are able to bind to DNA via the non-covalent mode i.e. intercalation and groove binding or electrostatic interactions. The interactions with bovine serum albumin (BSA) were also studied using UV-Vis and fluorescence spectroscopic methods which indicated that fluorescence quenching of BSA by these compounds was the presence of both static and dynamic quenching. Moreover, the in vitro cytotoxic effects of the complexes against four cell lines SK-OV-3, HL-7702, BEL7404 and NCI-H460 showed the necessity of the coordination action on the biological properties on the respective complex and that all four complexes exhibited substantial cytotoxic activity.

Three complexes [Zn2(IPA)2(phen)4](HIPA)2(NO3)2·H2O (1), {[Zn(IPA)2(bipy)]·3H2O}n (2), and {[Mn(IPA)2(bipy)(H2O)]·2H2O}n (3) (HIPA = indole-3-propionic acid, phen = 1,10-phenanthroline, bipy = 4,4′-bipyridine) were synthesized and characterized by physico-chemical and spectroscopic methods. Complex 1 displays a zero-dimensional structure, whilst 2 and 3 show one-dimensional chains, which are linked into supramolecular networks through hydrogen bonding interactions and/or π···π stacking interactions. The luminescence properties of complexes 1 and 2 were investigated.

A novel VIV8 cluster formulated as [V8O12(OH)4(CH3O)4(DAC)4]·7CH3OH (1) (DAC = 1,2-diaminocyclohexane) has been constructed successfully. Enantioselective oxidation of a series of alkyl aryl sulfides catalyzed by 1 is tested in an aqueous medium in the presence of serum albumin. The catalytic procedure is found to be simple and environmentally friendly. The influences of the parameters such as concentration of catalyst and oxidant, pH, and reaction time on the thioanisole as models are investigated. Under optimum conditions, 1 exhibits high conversion (up to 99%), excellent chemoselectivity (≥90% in all cases) and moderate enantioselectivity (up to 75% ee). After binding with serum albumin, the catalytic activity of 1 is promoted. The bovine serum albumin (BSA) and pig serum albumin (PSA) molecules have a more positive effect on the catalytic activity.

By using 5,5′-di(pyridin-2-yl)-3,3′-bi(1,2,4-triazole) (2,2′-H2dbpt) as a building block, six new coordination complexes: Zn3(2,2′-Hdbpt)2(H2O)Cl4 (1), {[Zn2(2,2′-dbpt)Cl3]·Et3NH}n (2), {[Cd3Cl3(2,2′-dbpt)3]·2H2O}n (3), {[Cd3I3(2,2′-dbpt)3]·H2O}n (4), {[Cd2Br2(2,2′-dbpt)]·H2O}n (5), and [Cd2I4(2,2′-H2dbpt)]n (6), based on the M(II)/X (M = Zn, Cd; X = Cl, Br, I) system were generated. 1 and 2 bear a Zn3 supermolecule and a 1D wave-like chain, respectively. 3 and 4 are isostructural, giving a new 3D architecture with a (412·63) topology based on the [Cd6] ring as a node bridged by the μ2-Cl− ion and the μ2-I− ion, respectively. 5 is a 2D framework with a (32·62·72) topology based on the [Cd4] subunit. 6 reveals a 1D modified trapezoid chain with a (42·6) topology based on the trans-bridging 2,2′-H2dbpt. Based on the interesting structural results, the solid-state luminescence properties of complexes 1–6 were investigated, which revealed that the emission maximum wavelengths can be tuned in a large range of 403–498 nm. These results indicate that 2,2′-H2dbpt is not only an excellent building block to construct coordination complexes with interesting structures but also a good precursor to construct potential photoactive materials.

A series of copper(I)-halide complexes with 1-[2-(N,N-dimethylamino)ethyl]-5-mercapto-1H-tetrazole (HMTZ) as ligand, namely, [Cu3Cl3(HMTZ)]n (1), [Cu3Cl3(HMTZ)]n (2), [Cu3Br3(HMTZ)]n (3), [Cu4Cl3Br(HMTZ)3] (4), [Cu8I(MTZ)4(HMTZ)4]3+·2I−·ClO4− (5) have been obtained. Complex 1 shows one dimension (1D) chain structure containing [Cu3Cl3] motifs. Isostructural 2 and 3 show two dimension (2D) inorganic–organic networks containing [Cu6Cl6] and [Cu6Br6] motifs, respectively. Complex 4 exhibits a propeller-like [Cu4] cluster. Complex 5 presents a crown-like [Cu8] cluster basing on an iodine template, which is the first example in Cu(I) halide complexes. The thermal stability properties and the fluorescent properties of complexes 1–5 have been investigated briefly.

Artificial metalloenzymes (BSA-ML) have been prepared by non-covalent insertion of transition metal Schiff-base complexes, ML (L = 2-hydroxynaphthalen-1-naphthaldehyde and 3,4-diaminobenzenesulfonic acid; M = Co, Mn, V, Fe, Cr), into bovine serum albumin (BSA) as the host protein and were characterized by UV-visible spectroscopy, ESI-TOF mass spectrometry and molecular docking studies. The catalytic activities of the BSA-ML in the selective oxidation of various prochiral sulfides in aqueous media, using H2O2 as oxidant, have been evaluated. During the optimization process, pH and the concentrations of catalyst and oxidant were found to have a remarkable influence on both yield and enantioselectivity. In certain cases, BSA-ML gave satisfactory results in the oxidation of organic sulfides to sulfoxides (up to 100% conversion, 100% chemoselectivity, 96% ee and 500 h−1 turnover frequency).

We present the synthesis, structural characterization, and magnetic properties of two high-nuclearity cobalt clusters formulated as [Co

In this study, two Ni(II) complexes, namely [Ni(HL1)2(OAc)2] (1) and [Ni(L2)2] (2) (where HL1 and HL2 are (E)-1-((1-(2-hydroxyethyl)-1H-pyrazol-5-ylimino)methyl)-naphthalen-2-ol) and (E)-ethyl-5-((2-hydroxynaphthalen-1-yl)methyleneamino)-1-methyl-1H-pyrazole-4-carboxylate, respectively), were synthesized and characterized by X-ray crystallography, Electrospray Ionization Mass Spectrometry (ESI-MS), elemental analysis, and IR. Their uptake in biological macromolecules and cancer cells were preliminarily investigated through electronic absorption (UV-Vis), circular dichroism (CD) and fluorescence quenching measurements. Bovine serum albumin (BSA) interaction experiments were investigated by spectroscopy which showed that the complexes and ligands could quench the intrinsic fluorescence of BSA through an obvious static quenching process. The spectroscopic studies indicated that these complexes could bind to DNA via groove, non-covalent, and electrostatic interactions. Furthermore, in vitro methyl thiazolyl tetrazolium (MTT) assays and Annexin V/PI flow cytometry experiments were performed to assess the antitumor capacity of the complexes against eight cell lines. The results show that both of the complexes possess reasonable cytotoxicities.

By using a new N-heterocyclic building block, 5,5′-di(pyridin-2-yl)-3,3′-bi(1,2,4-triazole) (2,2′-H2dbpt), five novel coordination complexes, Fe4(2,2′-Hdbpt)2Cl6(H2O)6 (1), [Fe(2,2′-H2dbpt)Cl2·H2O]n (2), [Fe(2,2′-H2dbpt)Cl2]n (3), [Fe2(2,2′-H2dbpt)Cl4]n (4), and [Fe(2,2′-H2dbpt)0.5Cl2]n (5), based on a Fe(II)/Cl system with diversiform connectivity from zero- to two-dimensional (2D) were constructed successfully. By regulating the metal–ligand ratio and solvents, 2,2′-H2dbpt changed various coordination modes. Consequently, 1 reveals a discrete Fe4(2,2′-Hdbpt)2Cl6(H2O)6 supramolecule. 2 and 3 are pseudo-polymorphic. 2 reveals a helical chain based on the cis-FeCl2N4 unit and the cis-bridging 2,2′-H2dbpt ligand, while 3 reveals a straight-chain based on the trans-FeCl2N4 unit and the trans-bridging 2,2′-H2dbpt ligand. 4 and 5 are also supramolecular isomers. Different from 2 and 3, both of them have a cis-FeCl2N4 unit. Owing to the different rotation angles of pyridine rings in 2,2′-H2dbpt, 4 and 5 reveal ...

Based on an achiral 2-benzothiazolylthioacetic acid (HL) ligand, three Co(II) coordination compounds, {[Co(L)2(H2O)3]·H2O}n (1), [Co(L)2(H2O)2]n (2), and [Co(L)2(H2O)4]·2H2O (3), were obtained under different pH environments. Compound 1 possessing an interesting chiral 1-D helical double chain was synthesized with pH of 5.0~6.5, and the chiral symmetry breaking has been probed by single-crystal X-ray diffraction and circular dichroism spectroscopy. Switching pH to 4.0~5.0 and 3.0~4.0 resulted in achiral 2 and 3, respectively. Compound 2 has a 1-D chain structure and 3 is mononuclear.