•Five copper(II) complexes with different number of metal centers have been synthesized and characterized.•The results indicate that the five copper(II) complexes show good cytotoxicity.•The flow cytometry and western blotting show that complex 5 can bring about apoptosis of tumor cells.Five complexes, [Cu(L)2]·4.5H2O (1), [Cu(HL)2](NO3)2·CH3OH (2) {[Cu2(L)2(NO3)(H2O)2]·(NO3)}n (3), [Cu2(HL)2(SO4)2]·2CH3OH (4) and [Cu4(L)4Cl4]·5H2O (5) based on HL (where HL = 2-acetylpyrazine isonicotinoyl hydrazone) have been synthesized and characterized by X-ray diffraction analyses. The counter anion and organic base during the synthesis procedure influence the structures of the complexes efficiently, which generate five complexes as mono-, bi-, tetra-nuclear and one-dimensional structures. The antitumor activities of the complexes 1–5 (except for complex 3 with the poor solubility) against the Patu8988 human pancreatic cancer, ECA109 human esophagus cancer and SGC7901 human gastric cancer cell lines are screened by MTT assay. The results indicate that the chelation of Cu(II) with the ligand is responsible for the observed high cytotoxicity of the copper(II) complexes and the 1:2 copper species 1 and 2 demonstrate lower antitumor activities than that of the 1:1 copper species 4 and 5. In addition, the in vitro apoptosis inducing activity of the copper(II) complex 5 against SGC7901 cell line is determined. And the results show that the complex can bring about apoptosis of the cancerous cells in vitro.

A novel two-fold interpenetrating network, namely, {[Zn(DPTMIA)]·(H2O)2(DMF)0.5}n (HPU-1), with rectangular channels was synthesized and structurally characterized. HPU-1 was shown to be potentially applicable as a multi-functional fluorescent probe. It was shown to specifically detect Fe3+, through a cation exchange mechanism, and hazardous phenol compounds, using a mechanism involving a decrease in the efficiency of the transfer of electrons and energy from the ligands to the metal ions. The detection limits of HPU-1 for Fe3+ and the phenol compounds were found to be lower than those of MOFs reported in the literature. This HPU-1 probe was shown to be functional in aqueous solution and to be affected neither by the type of solvent nor the pH.

The main theme of interest is to design functional metal–organic frameworks (MOFs) for exploring structural correlation with photocatalytic activity. So firstly, three different structural MOFs, namely, Cd(APAPT)2I2·2H2O (1) (APAPT = 3-(5-Amino-1H-pyrazol-4-yl)-5-(3-amino-1H-pyrazol-4-yl)-3,5-dihydro-[1,2,4]triazol-4-ylamine), [Mn(APAPT)(SO4)(H2O)]n (2) and {[Zn3(APAPT)2(SO4)(OH)2]·(H2O)}n (3) constructed by the same parasol-based ligands and different metal ions are reported here. Complex 1 shows one-dimensional chain linked by mononuclear Cd units through π⋯π interactions. Complex 2 possesses two-dimensional layer with left- and right-handed helical chains. Complex 3 with infinite Zn-cluster chains is a three-dimensional porous framework. The structural diversity indicates that the APAPT with different coordination modes play important roles in tuning the dimensionalities and structures of the title complexes. Photocatalytic studies show that the MB degradation rates were 63.2%, 51.3% and 80.3% for complexes 1–3, respectively. The results manifest that the more extended networks may aid in the transport of excited holes/electrons to the surface to initiate the photocatalytic decomposition reaction with MB. Besides, steric hindrance etc. helical chains or weaving structure may lead to a relative lower photocatalytic activity.Three different structural complexes have been constructed by parasol-based ligands and different metal ions for exploring structural correlation with photocatalytic activity.Download high-res image (125KB)Download full-size image

In this article, two new networks, namely, {[Co(L)]·0.5(CH3CN)·5(H2O)}n (HPU-5) and {[Mn2(L)2(H2O)2]·2(CH3OH)·3(H2O)·2(DMA)} (HPU-6) (H2L = (5-(3,5-di-pyridin-4-yl-[1,2,4]triazol-1-ylmethyl)-isophthalic acid)) with different-sized pores were constructed. The photogradation and adsorption of dyes by the two MOFs were studied in detail. The results showed that the dye removal efficiency of degradation was much higher than that of adsorption. Additionally, when the pores of MOFs were enlarged, the contribution of dye removal through adsorption was still relatively low. Our findings suggest that MOFs with high photocatalytic activities should be synthesized to enhance dye removal efficiency to the maximum.

Eight new coordination polymers (CPs) based on a V-shaped carboxylate ligand H2L (H2L = 5-(1-oxo-1,3-dihydro-isoindol-2-yl)-isophthalic acid), namely {[Zn(L)(H2O)]·H2O}n (1), {[Zn2(L)2(phen)2(H2O)2]·CH3OH·2H2O}n (2), {[Zn(L)(2,2′-bpy)(H2O)]·H2O}n (3), [Zn2(L)2(4,4′-bpy)]n (4), {[Cu(L)(H2O)]·H2O·0.5(CH3OH)·0.5(DMF)}n (5), [Cu3(L)2(phen)3(ClO4)2]n (6), {[Co(L)(dbpy)(H2O)]·3CH3CN}n (7), and {[Co(L)(phen)(H2O)2]·DMA·3H2O}n (8), have been synthesized and characterized by IR, XRD, TG analysis, elemental analysis and single crystal X-ray diffraction measurement. Reactions of H2L and ZnSO4 with different auxiliary ligands in similar solvents occurred at the temperature of 80 °C, yielding similar 1D chains 1–3 and a three-dimensional (3D) framework 4. Besides, reactions of H2L and Cu2+ in the absence or presence of phen formed CPs of 5 and 6 associated with the reduction of dimensionality of the self-assembled products from 3D to 2D. Complex 5 presents a 3D framework with nanosize channels which are comprised of interlocked six-fold one-dimensional helical chains, while compound 6 shows a 2D structure. Additional reactions of H2L, Co2+ and auxiliary ligands give rise to two structurally related 2D CPs 7 and 8. Single-crystal-to-single-crystal studies show that Zn2+ ions in complexes 1–3 could be partially exchanged with Cu2+ ions. And we elaborated the reasons for different exchange degrees by comparing the coordination energies of Zn2+. Furthermore, by comparing the photoluminescence and photocatalytic mutation results induced by the interconversion of metal ions, we confirm that the property mutation induced by metal ions is greatly controllable and obvious. Magnetic studies show that there are strong antiferromagnetic interactions in 5 and 6. Moreover, complexes 5–8 are also applied to catalyze the reaction of MB under high-pressure mercury lamp irradiation.

•A new rhodamine-based fluorescent probe for Fe3+ has been developed.•Response of probe to Fe3+ is a coordination reaction.•The probe has been used for imaging of Fe3+ in living cells.•Crystal structure of the possible intermediate of R1 with Ag+ and Hg2+ ions were reported.A rhodamine-2-thioxoquinazolin-4-one derivative (R1) has been synthesized by an addition-elimination reaction of rhodamine 6G ethylenediamine with methyl 2-isothiocyanatobenzoate, which exhibits high selectivity and sensitivity as a fluorescent sensor toward Fe3+ under physiological conditions. Moreover, R1 could sense Fe3+ by “naked eye” with a color change from colorless to yellow. To test the practical use of the probe, the determination of Fe3+ in real water samples was evaluated. The application of the fluorescent sensor in monitoring intracellular Fe3+ in glioma cell line U251 has also been demonstrated. In addition, single crystal structures of R1·1·5H2O·0·5CH3CN, as well as the possible intermediate of R1 with Ag+ and Hg2+ ions were reported.

•A new rhodamine-based off-on fluorescent probe for Cu2+ has been developed.•Response of probe to Cu2+ is a coordination reaction.•The application of the fluorescent sensor in monitoring intracellular Cu2+ was demonstrated.A rhodamine derivative (R1) has been synthesized by an additive reaction of rhodamine 6G hydrazide with methyl 2-isothiocyanatobenzoate, which exhibits high selectivity and sensitivity as a fluorescent sensor toward Cu2+ under physiological conditions. The detection limit of Cu2+ ion is 47.2 nM. Moreover, R1 could sense Cu2+ by “naked eye” with a color change from colorless to pink. This selective signaling behavior is not affected by other canions that might be present in the environmental samples. The application of the fluorescent sensor in monitoring intracellular Cu2+ in HeLa cells was also demonstrated.

•The biological activity of three ternary copper (II) complexes were investigated.•The three complexes can cause DNA damage.•Cell apoptosis was detected by flow cytometry and Western blotting.•All the complexes can effectively induce apoptosis of the human tumor cells.Three ternary copper (II) complexes containing 1,10-phenanthroline (phen, 1), dipyrido[3,2-d:2′,3′-f]quinoxaline (dpq, 2) and dipyrido[3,2-a:2′,3′-c]phenazine (dppz, 3), with the formulation [Cu2(NCL)2(H4PASP)]·4.5H2O (1–3) (where NCL = the diimine coligand, H4PASP = N,N′-(p-xylylene)di-2-aminosuccinic acid), were isolated and characterized. The binding of these complexes with calf thymus DNA was studied using UV–visible absorption titration, emission, and circular dichroism spectroscopy, among other methods. The changes in physicochemical properties that occurred upon binding of these complexes with DNA indicate that binding occurs primarily through intercalative interactions. Human tumor cell lines HeLa, PC3, and HepG2 were treated with the copper(II) complexes in vitro and cell survival rate was assessed by 3-(4,5-dimethyl thiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay and crystal violet survival assay. Flow cytometry was performed on treated cells labeled with AnnexinV/Propidium Iodide staining to determine rates of apoptosis. Western blot was performed to determine the expression levels of the apoptotic markers p53, Bax, and Bcl-2. The complexes reduced cell viability and induced apoptosis in cells of human tumor cell lines in a dose-dependent manner. In addition, using a nude mouse xenograft model, we found that the three ternary copper (II) complexes inhibited human tumor cell growth in vivo. In conclusion, these novel synthetic copper complexes have profound antitumor effects on human tumor cells and are promising therapeutic agents for human tumors.Three ternary copper(II) complexes were isolated and characterized. The complexes exhibited potent antitumor activity against human cancer cells by inducing apoptosis in vitro and in vivo.

•A new rhodamine-based fluorescent “off-on” probe for Al3+ has been developed.•The probe shows a high sensitivity and selectivity for Al3+.•Response of probe to Al3+ is a cation-catalyzed reaction.•The probe has been used for monitoring Al3+ in drinking water.A rhodamine derivative (R1) has been synthesized by a hydrazone formation of rhodamine 6G hydrazide with 3-methylthiophene-2-carbaldehyde, which exhibits high selectivity and sensitivity as an “off–on” fluorescent sensor toward Al3+ in water containing media. The binding process was confirmed by UV–vis absorption, fluorescence measurements, mass spectroscopy and DFT calculation. The probe functions by Al3+ induced hydrolytic cleavage of the imine-bond to produce an intense rhodamine-based emission. To test the practical use of the probe, the determination of Al3+ in real water samples was also evaluated.

•Two pyrrole containing Schiff base chemo-sensors were synthesized.•Each probe could act as colorimetric and fluorescent off on sensor to Zn2 +.•The detection limits of both sensors to Zn2 + are at the parts per million level.•Selective fluorescence sensing of Zn2 + ion via CN isomerization.•Both sensors have been applied in monitoring Zn2 + in real water samples.Two bis(pyrrol-2-yl-methyleneamine) chemo-sensors, 1, 3- and 1, 4-bis[3,4-dimethyl-5-ethyloxy -carbonyl-pyrrol-2-yl-methyleneamine]benzene (H2L1 and H2L2, respectively) have been synthesized and characterized, which exhibit high selectivity as off-on fluorescence sensors toward Zn2 + in CH3CN/H2O (9:1, v/v) solution. The detection limits of both sensors are at the parts per million level. Moreover, the probes H2L1 and H2L2 could sense Zn2 + by “naked eye” with a color change from colorless to yellow, and from yellow to dark yellow, respectively. To test the practical use of the probes, the determination of Zn2 + in real water samples was also evaluated.

•A new rhodamine-based off-on fluorescent probe for Cu2+ has been developed.•The probe shows fluorescence enhancement toward Cd2+ by a typical ICT response.•Response of probe to Cu2+/Cd2+ are based on coordination reaction.•Probe-Cd2+ complex could act as ratiometric fluorescent sensor for Cu2+.•The probe has been used for imaging of Cu2+ in living cells.A new rhodamine-based derivative bearing pyrrole unit, R1 was synthesized as a dual-mode Cu2+-selective sensor via the rhodamine ring-opening approach and ratiometric displacement. A colorimetric and “off-on” signal for Cu2+ through rhodamine ring opening in R1 and ratiometric fluorescent signal output when Cu2+ displaces the bound Cd2+ in the R1-Cd2+ complex can be observed. The application of fluorescent R1 to biological imaging was also demonstrated.

•A three-dimensional carboxylate-bridged MnII compound containing unique manganese chains has been synthesized.•Alternating Mn chain was arranged as unprecedented J1J2J3J1⋯ mode.•Magnetic susceptibility measurement reveals an antiferromagnetism behavior derived from the topology of the chain.A three-dimensional carboxylate-bridged MnII compound [Mn6(tci)4(H2O)3]·7H2O}n (1) (tci = tris(2-carboxyethyl) isocyanurate) have been synthesized. The structure contains unique manganese chains in which the MnII ions are alternatively bridged by carboxylate groups in different coordination modes. The first example of such alternating Mn chain shows Mn1–(COO)3–Mn2–(COO)2–Mn3–(COO)3–Mn1–(COO)3–Mn2-sequence arranged as J1J2J3J1S⋯ mode. Magnetic susceptibility measurement reveals an antiferromagnetism behavior derived from the topology of the chain. There is no suitable analytical expression for determining the exchange parameters in a 1-D Heisenberg ferrimagnet consisting of alternating interactions J1J2J3J1⋯. The best way to fit the magnetic behavior of these complexes is to proceed by using a Hamiltonian that corresponds to a 12-membered of S = 5/2 with 4 fragments repeating the sequence J1J2J3. The fit was performed by means of the computer program MAGPACK. The fitting for the observed magnetic data gives J1 = − 2.31 cm− 1, J2 = − 1.60 cm− 1, J3 = − 3.10 cm− 1, zJ′ = − 0.03 cm− 1 and g = 1.98, with R = 7.2 × 10− 3.A three-dimensional carboxylate-bridged MnII compound [Mn6(tci)4(H2O)3]·7H2O}n (1) containing unique manganese chains have been synthesized. The first example of such alternating Mn chain was arranged as J1J2J3J1⋯ mode. Magnetic susceptibility measurement reveals an antiferromagnetism behavior derived from the topology of the chain.