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Harmful metal ions have received intense attention. In particular, palladium, a rare inner transition metal, is the subject of intense research in light of its catalytic capabilities and the restrictions on the levels of residual harmful metal ions in end products，has attracted wide spread interest from chemists. A near-infrared Pd2+ probe Cy202 has been synthesized that exhibits pronounced fluorescence enhancement in the presence of Pd2+. The Pd2+ recognition properties were examined by using UV–Vis spectroscopy and fluorescence spectroscopy in DMSO/PBS buffer solution (pH 7.40, 8/2, v/v). The solution of the probe exhibits color change turned from yellow to brown upon the addition of Pd2+ while no significant response to other metal ions. The detection limit was calculated as low as 0.52 μM. The probe could be useful for imaging Pd2+ in palladium-containing catalyst and samples.

By modulating the reaction pH value, two new CoII compounds, [Co2(L)(biz)(OH)]·H2O (JLNU-5) and [Co(HL)(biz)] (JLNU-6) (H3L = 5-(4-carboxybenzyloxy)isophthalic acid, biz = benzimidazole, JLNU = Jilin Normal University), have been successfully synthesized under mild hydrothermal conditions. JLNU-5 displays a 2D layer 4-connected sql topolygy. JLNU-6 is a 2D sheet structure and (3,6)-connected net with (43)(46 · 66 · 83) topology. In addition, the magnetic property of JLNU-5 and JLNU-6 is investigated, which shows the antiferromagnetic behavior induced by the external field.

In this study, we developed a fluorescence-enhanced probe (1) based on a simple Schiff-based condensation reaction for Cu2+ selection. We investigated its distinct recognition mechanism through mass spectra, 1H NMR studies, and DFT calculations. The imaging and costaining experiments indicated that the probe could successfully image lysosomal Cu2+.

A fluorescent coordination polymer [Zn(H3TTA)(H2O)2]·2H2O (JLNU-3, JLNU = Jilin Normal University; H3TTA = [2,2′:6′,2″-terpyridine]-4,4′,4″-tricarboxylic acid) has been hydrothermally synthesized and carefully characterized. Particularly, stable suspension of JLNU-3 in aqueous solution showed significant quenching towards Hg2+. The quenching efficiency is up to 98% in the existence of 10−2 M Hg2+. JLNU-3 can be regenerative for 5 cycles by centrifugation of the solution after use and washing several times with H2O. In addition, JLNU-3 displays preeminent anti-interference ability and could be used for sensing in the systems with complicated components. Therefore, JLNU-3 can be used as a fluorescent probe for selective, sensitive and recyclable sensing of heavy-metal cation Hg2+ in aqueous solution.

A luminescent coordination polymer, [Cd(H2biim)2SO4]·3H2O (JLNU-1, JLNU = Jilin Normal University); H2Biim = 2,2′-biimidazole, has been prepared by hydrothermal method and characterized by corresponding analytical tools. JLNU-1 exhibits outstanding chemical stability in aqueous solution and solvent-dependent luminescent behaviour. In particular, stable suspension of JLNU-1 in nitrobenzene showed highest quenching. The emission spectra were nearly completely quenched at a concentration of 100 ppm nitrobenzene in aqueous solution. JLNU-1 can be regenerative for 6 cycles by centrifugation of the solution after use and washing several times with H2O. Therefore, JLNU-1 can be used as a fluorescent probe for sensitive and recyclable sensing of small-molecule pollutant nitrobenzene in aqueous solution.

The proton conductions of open-framework metal phosphates K2[(VO)2(HPO4)2(C2O4)] (KVPC) with large and small particle sizes, namely KVPC-L and KVPC-S, have been evaluated. Varied particle sizes result in different proton conductive behaviors. KVPC-S exhibits a high proton conductivity of 1.15 × 10−2 S cm−1 under 40 °C, 95% RH and possesses a stable proton conduction for 4 h. Furthermore, proton conductivities of composite membranes are investigated, and the value can reach up to 1.19 × 10-3 S cm−1 under 60 °C, 95% RH and remain no significant change within 6 h.

A luminescent MOF [(Zn4O)(L)(2,6-naphthalic acid)]·4H2O·DMF (JLNU-7, JLNU = Jilin Normal University, H4L = methanetetra(tetrakis[4-(carboxyphenyl)oxamethyl]-methane acid) has been hydrothermally synthesized and carefully characterized. The prepared JLNU-7 displayed permanent porosity in the air. Here we select a reasonable strategy to achieve efficient white-light emission by the combination of blue emission from JLNU-7 and yellow emission from [Ir(ppy)2(bpy)][PF6] (IrIII, Hppy = 2-phenylpyridine, bpy = 2,2ʹ-bipyridine). The blue-emitting JLNU-7 was synthesized as a platform for encapsulating yellow-emitting IrIII complex, namely IrIII@JLNU-7. IrIII@JLNU-7 displays white light emission with Commission International de I’Eclairage (CIE) coordinate of (0.323, 0.298) and high quantum yield up to 11.9%. This strategy may promote the development and application of white phosphors with high performance in the practical lighting.

A novel rhodamine-based hydrazone (1) bearing morpholine as the lysosome-locating group was synthesized via Schiff base condensation. Probe 1 exhibited a remarkable fluorescent turn-on response over the pH range of 4.0–3.0, which corresponds to the acidic microenvironment of lysosomes in cancer cells. The results of fluorescence cell imaging and a subcellular localization study conducted with HeLa and HepG2 cancer cells and 293T normal cells revealed the good cell membrane permeability and potential applications of 1 in the selective differentiation of cancer cells from normal cells.

A novel dicyanomethylene-4H-pyran-based sensor bearing 2-thiophenecarbonyl as a masking group was established for the detection of cyanide anions. Upon the addition of cyanide, sensor 1 manifested a near-infrared emission band at 717 nm, with an extremely large red-shift (~180 nm) in the absorption spectrum. It also showed an obvious color change from yellow to green. Sensor 1 was used to sensitively measure CN− with low detection limit of 1.44 μM. The stoichiometric ratio between probe and CN− were determined as 1:1, with the association constant of 7.87 × 102 M−1. The reaction mechanism was investigated by ESI-MS, 1H NMR, HPLC, and density functional theory methods. Results indicate that the nucleophilicity of the cyanide catalyzes the elimination of 2-thiophenecarbonyl, which strengthens the intramolecular charge transfer effect of the dicyanomethylene-4H-pyran fluorophore. Furthermore, sensor 1 was found to be efficient in detecting cyanide in the intracellular region of MCF-7 cells.

By varying the ratio of mixed reaction solvent, the reactions of PbAc2 with N,N′-bis(1,3,4-thiobiazolyl)-2,6-pyridyldicarboxamide (H2btapca) afford two different crystal structures: a novel discrete hexanuclear cage of formula [Pb6(btapca)6]·(H2O)2 (1) and a 1-D double-chain polymer [Pb2(btapca)2(H2O)2]n (2). Fluorescence investigations reveal that both complexes display enhanced emissions in contrast to the free ligand H2btapca.

Three new coordination polymers, namely, [ML(H2O)]n (M = Co (1), Zn (2)) and [CuL(DMF)]n (3), have been hydrothermally synthesized through the reaction of bifunctional ligand 5-((2-methyl-1H-imidazol-1-yl)methyl)benzene-1,3-dioic acid (H2L) with divalent cobalt, zinc and copper salts, and structurally characterized by elemental analysis, IR and X-ray diffraction. Both complexes 1 and 2 are two-fold interpenetration 3D frameworks. Complex 3 exhibits (3,6)-connected framework with (4.62)2(42.610.83) topology. Furthermore, UV–vis absorption spectra and powder X-ray diffraction (PXRD) were investigated as well.

Two rhodamine-based Hg2 + probes L1 and L2 were prepared and confirmed by NMR, MS and crystal data. The sensing behavior of these probes was studied by UV–visible and fluorescence spectroscopy. The probe L1 couldn't be widely applied in aqueous media or mixed media because of its poor solubility. However, the probe L2 displayed selective and sensitive fluorescence enhancement response to Hg2 + at physiological pH value for biological use. The selectivity of this system for Hg2 + over other metal ions was remarkably high, and its sensitivity was at ppb level. The probe L2 responded rapidly to Hg2 + in aqueous solutions with a 1:1 stoichiometry and was successfully applied to image Hg2 + in living cells.

Salicylaldehyde 2-phenylquinoline-4-carboylhydrazone (H 2 L), and its novel tetranuclear cobalt(II), nickel(II) complexes have been synthesized and characterized. The crystal structure of (NiL) 2 ·[NiL(H 2 O)(DMF)] 2 ·H 2 O·DMF obtained from DMF solutions of compound 2 was determined by X-ray diffraction analysis. The DNA-binding investigation suggests that the two complexes bind to DNA via groove binding mode. The in vitro antibacterial activity of complexes against Escherichia coli , Staphylococcus aureus , Bacillus subtilis was screened and compared to the activity of the free ligand, the antibacterial activity of complex 1 is active than complex 2 which is in consistent with their DNA-binding behaviors.

The reactions of semi-rigid bidentate ligand 4,4′-bis(benzimidazol-1-ylmethyl)biphenyl (bbmb) with NiCl2 and CuCl2 and Cd(OAc)2 afford novel complexes {[M(bbmb)2(Cl)(OH)](H2O)2}n (M = Ni( 1 ), Cu( 2 )) and [Cd2(OAc)4(bbmb)3]2(CH3OH)3(H2O)2 ( 3 ). Both complexes 1 and 2 feature parallel 2-fold interpenetrating (4,4)-windmill-like layer morphology. Complex 3 presents unique discrete quad-nuclear motif comprised by two couples of alternating single and double twisting chains. The three complexes exhibit active second-order NLO effects.

A novel molybdenum phosphate based on [Mo6P4] inorganic subunits and [Mn(H2O)2]2+ cations, Mn[Mo6O12(OH)3(PO4)(HPO4)2(H2PO4)]2[Mn(H2O)2]2(Hen)4·13H2O (en = ethyl enediamine), has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, IR spectroscopy, EPR spectrum and TGA analysis. The 3-D framework of the compound contains microporous structure with large cavities filled by mono-protonated Hen+ and water molecules. The electrochemical behavior of the compound has been also studied.

A pair of ruthenium(II) complex isomers, Δ- and Λ-[Ru(bpy)2(p-mpip)]2+ {bpy = 2,2′-bipyridine, p-mpip = 2-(4-methylphenyl)imidazo[4,5-f]1,10-phenanthroline} have been synthesized and characterized. Thermodyanmics of binding of the two isomers to calf thymus DNA (CT DNA) has been investigated by isothermal titration calorimetry (ITC). It is rare that the Λ isomer binds to DNA more strongly than the Δ isomer, which has been verified by viscosity measurements, and can be explained by their different thermodynamic driving forces of DNA binding for the first time. This suggests that the dominant factor governing the stereoselectivity of DNA binding of metal complex may be the different thermodynamic driving forces between interactions of its different isomer with DNA. This new finding may be very helpful to understand the nature of steroselective DNA binding of small chiral molecules, and be useful to the development of DNA molecular probes and new DNA targeting therapeutic drugs.

A novel two-dimensional heterometallic iodoplumbate, [Pb3I10Cu4(phen)2]n (phen = 1,10-phenanthroline) constructed from [Pb3I10]4− iodoplumbate chains and [Cu2I4(phen)]2− entities has been hydrothermally synthesized and structurally characterized. The solid compound exhibits an intriguing semiconducting property with Eg = 2.62 eV. The thermochromic behavior of the compound has been also studied.

A new 2-D inorganic–organic hybrid constructed from mixed-valence Cu(I/II) ions and mixed ligands, [ Cu 4 I Cu II ( sip ) 2 ( bipy ) 4 ( H 2 O ) 2 ] n (H3sip = 5-sulfoisophthalic acid, bipy = 4,4′-bipyridine), has been synthesized and characterized by IR, TGA, XPS, EPR and single-crystal X-ray diffraction. Two different kinds of chains in the compound constructed from [CuO4] planar squares and [CuN2O] triangulars, respectively, further interconnect together to give rise to an interesting 2-D layer framework. The compound exhibits strong yellow emission at 445 nm excited by 378 nm in the solid state at room temperature.

A novel luminescent Pb(II) coordination framework, {Pb(II)(C6H4O2N)2}n, have been prepared in situ hydrolysis of 4-cyanopyridine under hydrothermal condition and characterized by the elemental analyses, IR spectra, TG and single crystal X-ray diffraction. The compound presents the first framework compound constructed from isonicotinic acids and lead(II) ions, showing three-dimensional architecture with (4, 4) net self-penetrating (48 67) topology.

Two novel Cd(II) coordination frameworks based on a semirigid asymmetric ligand L and aromatic multi-carboxylate ligands, {[Cd 2 L(btc)(H 2 O) 2 ]·5H 2 O} n ( 1 ) and [Cd 2 L 2 (bdc)] n ( 2 ) (L = (4-((2-(pyridine-2-yl)-1 H -imidazol-1-yl)methyl)benzoic acid, H 3 btc = 1,3,5-benzenetricarboxylic acid, H 2 bdc = 1,3-benzenedicarboxylic acid), have been hydrothermally synthesized, and structurally characterized by elemental analysis, IR spectroscopy, single-crystal X-ray crystallography. Due to various coordination modes and conformations of the semirigid asymmetric ligand, and carboxylate containing co-ligands, therefore, the two complexes exhibit structural and dimensional diversity. Complex 1 exhibits a novel 2D (3, 5)-connected network structure with (3·5 2 )(3 2 ·5 3 ·6 4 ·7) topology. Complex 2 exhibits a novel 3D CdSO 4 topology, which is formed from different dinuclear cadmium units. In addition, the photoluminescence properties of the free ligand L, and complexes 1 and 2 were studied in the solid state at room temperature.

Two Zn(II)-2,2′-biimidazole derivative supramolecular isomers 1 and 2 formulated as [Zn(L)] · 2H 2 O (H 2 L = 4,4′-(1H,1′ H -2,2′-biimidazole-1,1′-diylbis(methylene))dibenzoic acid) have been synthesized, and structurally characterized by elemental analysis, IR spectroscopy, single-crystal X-ray crystallography. Complex 1 exhibits a 2D four-connected network with (4 3 .6 3 ) topology when the zinc center and the L 2− ligand act as four-connected nodes (or a distorted (4,4) grid if the [Zn 2 (imidazole) 4 ] units are considered as four-connected nodes). Complex 2 shows a novel four-connected twofold interpenetrated net with (4 2 .6 2 .8 2 ) topology when the zinc center and the L 2− ligand act as four-connected nodes (or a twofold interpenetrated α-Po topology when [Zn 2 (imidazole) 4 ] units are identified as six-connected nodes). Moreover, complexes 1 and 2 both exhibit strong luminescent properties at room temperature.

Through varying the volume ratio of mixed solvent, we obtained two distinct polymers {[Pb6(2,6-pda)6] · H2O}n (1) (2,6-pda = 2,6-pyridyldicarboxylate) and [Pb(mpcp)(OAc)]n (2) (mpcp = methyl-6-(pyridin-2-ylcarbamoyl)picolinate) by reaction of Pb(OAc)2 · 3H2O and 2,6-dicarboxamido-(2-pyridyl)-pyridine (H2dcapp) decomposed through lead-induced hydrolysis. Photoluminescence investigations reveal that both polymers display enhanced emissions in contrast to the free ligand, respectively.

Three Cu(II) coordination polymers [Cu(taa)2]n (1), [Cu(taa)2 · (H2O)4 · Na0.5 · (ClO4)0.5]n (2) and [Cu(taa)2 · (H2O)4 · Na0.5 · (BF4)0.5]n (3) have been synthesized by the reaction of 1H-1,2,4-triazol-1-acetic acid (Htaa) with different Cu(II) salts. Polymer 1 features a 2-D grid-like network structure constructed by crossed zigzag chains. In both of polymers 2 and 3, there exist rare four-fold 1-D helical chains, which are induced by ClO 4 - or BF 4 - anions. Besides, trapped sodium chains are found to be nested in the channels formed by the intertwist of the helical chains of 2 and 3.

The title organic–inorganic hybrid cadmium molybdenum(V) phosphate has been hydrothermally synthesized. The sandwich-type units [Cd4(H2O)2(2,2′-bpy)2]Cd[Mo6O12(OH)3(PO4)2(HPO4)2]2 ([Cd4]Cd[Mo6P4]2) are connected by octahedrally coordinated cadmium into a chain {[Cd4]Cd[Mo6P4]2}n. The coordination cations [Mo2O4(2,2′-bpy)2]2+ link to the neighboring chains, forming a 3D open framework structure. The title complex represents the first sandwich-type cadmium hetereopolymolybdate with 3D network.

1,10-Phenanthroline-5,6-diol (dpcatH2) was prepared conveniently from 1,10-phenanthroline-5,6-dione using hydrazine sulfate as reductant, and a new bimetallic Cu(II) complex, [(phen)Cu(dpcat)Cu(phen)](ClO4)2, where phen denotes 1,10-phenanthroline was synthesized by a “one-pot” method. Presence of calf thymus DNA would result in an evident change in the electronic absorption, quenching effect on the fluorescence, protection from fluorescence quencher ferrocyanide and disappearance of redox process of the complex, and the viscosity of DNA would be enhanced by addition of the complex. All these facts suggest that the dicopper(II) complex binds to double helix DNA by classical intercalation.

Two 2D metal–organic frameworks (MOFs), {[Zn4(Hbbim)4(bbim)2] 2H2O}n (1) and [Cd2(Hbbim)2(bbim)]n (2) (H2bbim = 2,2′-bibenzimidazole) were obtained by solvothermal reaction and characterized by single crystal X-ray diffraction analysis. Different metal ions, Cd(II)/Zn(II), adopt very different coordination geometries though two title compounds both have a 2D honeycomb network with (6,3) topology. The frameworks of compounds 1 and 2 are stable below 360 °C and 475 °C, respectively. Solid-state luminescent spectroscopy of compound 2 exhibits an emission peak at 407 nm.

A novel organic–inorganic hybrid compounds containing 12-tungstovanadate and 3d–4d heterometallic complex, [V1W12O40][VO2Ag(phen)3]2 (1), have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction and IR analysis. The complex is an uncommon bisupporting polyoxometalate derivative in which the saturated Keggin type polyoxoanions are covalently linked by bimetallic complex [VO2Ag(phen)3]2+. The neighboring Ag+ and V5+ cations are bridged by the oxo atom forming heterometallic cations with the Ag–V distances of 3.556(2) A in [VO2Ag(phen)3]2+ cations. Furthermore, the title compound shows good photocatalytic activity for reduction of Rhodamine B (RB) in a liquid–solid system.

A new ruthenium(II) polypyridyl complex, [Ru(phen) 2 MHPIP] 2+ (phen = 1,10-phenanthroline, MHPIP=2-(3-methoxy-4-hydroxyphenyl)imidazo[4,5- f ]1,10-phenanthroline), has been synthesized and characterized. The binding of this complex with yeast tRNA has been investigated by UV, fluorescence and CD spectroscopy systematically. The experimental results suggest that the complex can bind to yeast tRNA enantioselectively, and that spectroscopic method is effective on studying the interaction of metal complexes with RNA.