Self-Assembly and Aggregation-Induced Emission in Aqueous Media of Responsive Luminescent Copper(I) Coordination Polymer Nanoparticles

Luminescent copper(I)-based compounds have recently attracted much attention since they can reach very high emission quantum yields. Interestingly, Cu(I) clusters can also be emissive, and the extension from small molecules to larger architecture could represent the first step towards novel materials that could be obtained by programming the units to undergo self-assembly. However, for Cu(I) compounds the formation of supramolecular systems is challenging due to the coordinative diversity of copper centers. This works shows that this diversity can be exploited in the construction of responsive systems. In detail, the changes in the emissive profile of different aggregates formed in water by phosphine-thioether copper(I) derivatives were followed. Our results demonstrate that the self-assembly and disassembly of Cu(I)-based coordination polymeric nanoparticles (CPNs) is sensitive to solvent composition. The solvent-induced changes are related to modifications in the coordination sphere of copper at the molecular level, which alters not only the emission profile but also the morphology of the aggregates. Our findings are expected to inspire the construction of smart supramolecular systems based on dynamic coordinative metal centers.     

Layered Uranyl Phosphonates Encapsulating Co(II)/Mn(II)/Zn(II) Ions: Exfoliation into Nanosheets and Its Impact on Magnetic and Luminescent Properties

Layered heterometallic 5f–3d uranyl phosphonates can exhibit unique luminescent and/or magnetic properties, but the fabrication and properties of their 2D counterparts have not been investigated. Herein we report three heterobimetallic uranyl phosphonates, namely, [(UO₂)₃M(2-pmbH)₄(H₂O)₄] ⋅ 2H₂O [ MU , M=Co(II), CoU ; Mn(II), MnU ; Zn(II), ZnU ; 2-pmbH₃=2-(phosphonomethyl)benzoic acid]. They are isostructural and display two-dimensional layered structures where the M(II) centers are encapsulated inside the windows generated by the diamagnetic uranyl phosphonate layer. Each M(II) has an octahedral geometry filled with four water molecules in the equatorial positions and two phosphonate oxygen atoms in the axial positions. The uranium atoms adopt UO₇ pentagonal bipyramidal and UO₆ square bipyramidal geometries. The lattice and coordination water molecules can be released by thermal treatment and reabsorbed in a reversible manner, accompanied with changes of magnetic dynamics. Interestingly, the bulk samples of MU can be exfoliated in acetone via freezing and thawing processes forming nanosheets with single-layer or two-layer thickness ( MU-ns ). Magnetic studies revealed that the CoU and MnU systems exhibited field-induced slow magnetization relaxation at low temperature. Compared with crystalline CoU , the magnetic relaxation of the CoU-ns aggregates is significantly accelerated. Moreover, photoluminescence measured at 77 K showed slight red-shift of the five characteristic uranyl emission bands for ZnU-ns in comparison with those of the crystalline ZnU . This work gives the first examples of 2D materials based on 5f–3d heterometallic uranyl phosphonates and illustrates the impact of dimension reduction on their magnetic/optical properties.     

A Luminescent One-Dimensional Copper(I) Polymer

The synthesis and structure of a one-dimensional polymer of formula [Cu₃(dpphp)₂(MeCN)_1.7(CH₂Cl₂)_0.3](ClO₄) _n is reported (where dpphp=6-diphenylphosphino-2-pyridonate). There are three distinct copper(I) sites within the polymer. Two of these sites are four-coordinate, bound to one P- and two O-atoms and a solvate molecule; the third site is bound only to two N-atoms. The Cu*Cu distances within the polymer are around 2.8 Å. The compound is luminescent in the solid-state.     

Synthesis and Characterization of Chelating Hyperbranched Polyester Nanoparticles for Cd(II) Ion Removal from Water

Chelating hyperbranched polyester (CHPE) nanoparticles have become an attractive new material family for developing high-capacity nanoscale chelating agents with highly branched structures and many functional groups in the main chains and end groups that can be used to remove heavy metals from water. In this study, a hyperbranched polyester with a particle size of 180–643 nm was synthesized with A₂+B₃ interfacial polymerization, using dimethylmalonyl chloride as the difunctional monomer (A₂) and 1,1,1-tris(4-hydroxyphenyl)ethane (THPE) as the trifunctional monomer (B₃). FTIR and NMR were used to characterize the CHPE and confirm the structure. The CHPE nanoparticles were generally considered hydrophilic, with an observed swelling capacity of 160.70%. The thermal properties of the CHPE nanoparticles were studied by thermal gravimetric analysis (TGA) with 1% mass loss at temperatures above 185 °C. The XRD of the CHPE nanoparticles showed a semi-crystalline pattern, as evident from the presence of peaks at positions ~18° and 20°. The nature of the surface of the CHPE was examined using SEM. Batch equilibrium was used to investigate the removal properties of the CHPE nanoparticles towards Cd(II) ions as a function of temperature, contact time, and Cd(II) concentration. The Cd(II) ion thermodynamics, kinetics, and desorption data on the CHPE nanoparticles were also studied.     

Structure,Luminescent Sensing and Proton Conduction of a Boiling-Water-Stable Zn(II) Metal-Organic Framework

A novel Zn(II) metal-organic framework [Zn₄O(C₃₀H₁₂F₄O₄S₈)₃]_n, namely ZnBPD-4F4TS, has been constructed from a fluoro- and thiophenethio-functionalized ligand 2,2′,5,5′-tetrafluoro-3,3′,6,6′-tetrakis(2-thiophenethio)-4,4′-biphenyl dicarboxylic acid (H₂BPD-4F4TS). ZnBPD-4F4TS shows a broad green emission around 520 nm in solid state luminescence, with a Commission International De L’Eclairage (CIE) coordinate at x = 0.264, y = 0.403. Since d¹⁰-configured Zn(II) is electrochemically inert, its photoluminescence is likely ascribed to ligand-based luminescence which originates from the well-conjugated system of phenyl and thiophenethio moieties. Its luminescent intensities diminish to different extents when exposed to various metal ions, indicating its potential as an optical sensor for detecting metal ion species. Furthermore, ZnBPD-4F4TS and its NH₄Br-loaded composite, NH₄Br@ZnBPD-4F4TS, were used for proton conduction measurements in different relative humidity (RH) levels and temperatures. Original ZnBPD-4F4TS shows a low proton conductivity of 9.47 × 10⁻¹⁰ S cm⁻¹ while NH₄Br@ZnBPD-4F4TS shows a more than 25,000-fold enhanced value of 2.38 × 10⁻⁵ S cm⁻¹ at 40 °C and 90% RH. Both of the proton transport processes in ZnBPD-4F4TS and NH₄Br@ZnBPD-4F4TS belong to the Grotthuss mechanism with E_a = 0.40 and 0.32 eV, respectively.     

配位聚合物[Zn(PDA)(obix)]的合成、晶体结构和荧光性质

Hydrothermal reaction between 1,4-phenylenediacetic acid (H₂PDA) and Zn(NO₃)₂·6H₂O at the presence of the second ligand of 1,2-bis((1H-imidazol-1-yl) methyl)benzene (obix) yields a new 2D metal-organic coordination polymer [Zn(PDA)(obix)] (1), which has been characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy and thermal analysis. Complex 1 presents a two-dimensional (2D) sheet structure and displays strong luminescent emission at room temperature. CCDC: 716984.     

Hydrothermal Synthesis and Crystal Structure of a Zinc（Ⅱ） Polymer with a Two-dimensional Layer Structure： [Zn（pzdc）（phen）]n·nH2O

A metal-organic coordination compound formulated as [Zn（pzdc）（phen）]n·nH2O 1 （H2pzdc = pyrazine-2,3-dicarboxylic acid, phen = 1,10-phenanthroline） has been hydrothermally synthesized and structurally characterized by elemental analysis, IR, fluorescence spectrum and single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic system, space group P21/n with a = 11.607（2）, b = 11.719（2）, c = 13.140（3）A^°, β = 110.707（3）°, V= 1671.9（6）A^°3, C18H12ZnN4O5, Mr= 429.69, De = 1.707 g/cm^3,μ（MoKa） = 1.511 mm^-1, F（000） = 872, Z = 4, the final R = 0.0356 and wR = 0.0853 for 2713 observed reflections （I 〉 2σ（I））. It exhibits an interesting two-dimensional layer structure and shows yellow photoluminescent property at room temperature.     

Ultra-Long Lived Luminescent Triplet Excited States in Cyclic (Alkyl)(amino)carbene Complexes of Zn(II) Halides

The high element abundance and d¹⁰ electron configuration make Zn^II-based compounds attractive candidates for the development of novel photoactive molecules. Although a large library of purely fluorescent compounds exists, emission involving triplet excited states is a rare phenomenon for zinc complexes. We have investigated the photophysical and -chemical properties of a series of dimeric and monomeric Zn^II halide complexes bearing a cyclic (alkyl)(amino)carbene (cAAC) as chromophore unit. Specifically, [(cAAC)XZn(μ-X)₂ZnX(cAAC)] (X=Cl ( 1 ), Br ( 2 ), I ( 3 )) and [ZnX₂(cAAC)(NCMe)] (X=Br ( 4 ), I ( 5 )) were isolated and fully characterized, showing intense visible light photoluminescence under UV irradiation at 297 K and fast photo-induced transformation. At 77 K, the compounds exhibit improved stability allowing to record ultra-long lifetimes in the millisecond regime. DFT/MRCI calculations confirm that the emission stems from ³XCT/LE_cAAC states and indicate the phototransformation to be related to asymmetric distortion of the complexes by cAAC ligand rotation. This study enhances our understanding of the excited state properties for future development and application of new classes of Zn^II phosphorescent complexes.     

Analytical Separation of Copper(II), Cobalt(II) and Nickel(II) Using Polymer Bound Anthrantic Acid

Abstract

The preferential complexing tendency of different nietal ions towards chelating agents anchored on a polymer has been used for separation of transition metals. the anthranilic acid group was anchored on the polymeric cellulose back-bone by successive coupling with trifunctional reagent cyanuric chloride, in diozane medium, at pH 7 and 9–10, respectively. This polymer bound chelating agent was used to separate copper(II), nickel(II) and cobalt(II) in the concentration range 1.0–0.1 mmol/L. the separation of a mixture of two components was quantitative using column chromatography.     

A Highly Efficient Chelating Polymer for the Adsorption of Uranyl and Vanadyl Ions at Low Concentrations

A new polymer containing double amidoxime groups per repeating unit was synthesized to enhance the metal ion uptake capacity. The adsorption properties of this new polymeric adsorbent, amidoximated poly(N,N-dipropionitrile acrylamide), for U(VI), V(V), Cu(II), Co(II) and Ni(II) ions were investigated by batch and flow-through processes at very low concentration levels (ppb). The chelating polymer showed high adsorption capacity for uranyl as well as vanadyl ions. In selectivity studies from a mixture of metal ions in aqueous solutions, the adsorbent showed high selectivity for uranyl and vanadyl ions in the following order: U(VI) > V(V) Co(II) = Cu(II) Ni(II) as determined by calculating the distribution coefficients D, of corresponding ions. The adsorption of uranyl and vanadyl ions from natural seawater by the new adsorbent was also examined in flow through mode.     

Scanning Ion Conductance Microscopic Study for Cellular Uptake of Cationic Conjugated Polymer Nanoparticles

Positively charged conjugated polymer nanoparticles (CPNs) are emerging biomaterials exhibiting high levels of cellular entry. High rate of cellular entry efficiency is believed that the amphiphilic CPNs interact efficiently with the negatively charged hydrophobic cellular membranes. For the first time, the cell surface morphological changes of human cervical cancer cells treated with CPNs using a scanning probe microscopy technique, scanning ion conductance microscopy (SICM) are imaged. After 1 h of CPN incubation, distinct changes are observed in cell surface morphology such as interconnected protrusions and pits with sub‐micrometer sizes, which are not observed from cells treated with positively charged polyethyleneimine (PEI) under the same treatment conditions. The change on cell surface morphology is quantified by surface roughness ratio, which is increased as CPN concentration increases, while the ratio first increases and then decreases as the incubation time increases. These results suggest that cells respond actively toward CPN with both positive charges on the side chain and the hydrophobicity from rigid aromatic backbone, which leads to subsequent endocytosis. In conclusion, it is demonstrated that SICM is a suitable imaging technique to reveal the dynamic alternations on the cell surface morphology at the early stage of nanoparticles endocytosis with high resolution.

     

Hydrothermal Synthesis, Crystal Structure and Photoluminescent Property of a New Isophthalate- bridged Zinc(II) Polymer with One-dimensional Chain Structure: [Zn(ipt)(im)_2]_(2n)·3nH_2O (ipt = Isophthalate, im = Imidazole)

1 INTRODUCTION The design and synthesis of metal-organic frame- work structure have been studied widely during the past decade not only because of their intriguing architectures but also their unexpected properties for potential practical applications in a wide number of fields, such as asymmetric catalysis, magnetism, pho- toluminescence and so on[1～3]. These novel struc- tures can be rapidly and efficiently synthesized from simple subunits, where the metal ions, bi- or multi- dentate o…     

Chelex100螯合树脂与某些金属离子的发光行为及其分析应用

作者观察到Ｅｕ＾３＋、Ｔｂ＾３＋、Ｇｄ＾３＋、Ａｌ＾３＋、Ｇａ＾３＋、Ｉｎ＾３＋、Ｚｒ＾４＋和Ｈｆ＾４＋的二元络合物在水溶液中能够与ＥＤＴＡ型的螯合树脂ｃｈｅｌｅｘ１００形成配位体－金属离子－ｃｈｅｌｅｘ１００的三元络合物，络合物的形成不但改变了它们的光谱性质，而且大大增强了其磷光或荧光强度。利用这一性质，本文制作了测定上述金属离子的流通式光学传感器。实验表明该传感器提高了测定的灵敏度与选择性。     

Hydrothermal Synthesis, Crystal Structure and Photoluminescent Property of a Zinc(II) Coordination Polymer Assembled by Phthalate and 4,4''-Bipyridine

A metal-organic coordination polymer {[Zn(Pht)(4,4′-bipy)(H2O)2]·2H2O}n (Pht = phthalate, 4,4′-bipy = 4,4′-bipyridine) 1 has been hydrothermally synthesized and characterized by elemental analysis, IR, TG, fluorescence spectrum and single-crystal X-ray diffraction. Yellow crystals crystallize in the monoclinic system, space group P2/n, a = 7.6346(14), b = 11.316(2), c = 10.8133(19) (A), β = 92.444(3)o, V = 933.3(3)(A)3, C18H20N2O8Zn, Mr = 457.73, Dc = 1.629 g/cm3, F(000) = 472, Z = 2, μ(MoKα) = 1.367 mm-1, the final R = 0.0323 and wR = 0.0821 for 1859 observed reflections (I > 2σ(I)). The structure of 1 exhibits a two-dimensional bilayer framework formed by hydrogen bonding interactions. Furthermore, 1 shows yellow photoluminescent pro- perty at room temperature.     

A Zn(II)-Based Sql Type 2D Coordination Polymer as a Highly Sensitive and Selective Turn-On Fluorescent Probe for Al3+

A luminescent coordination polymer with the overall formula {[Zn(tr₂btd)(bpdc)]∙DMF}_n (where tr₂btd = 4,7-di(1H-1,2,4-triazol-1-yl)-2,1,3-benzothiadiazole; bpdc = 4,4′-biphenyldicarboxylate) was synthesized and characterized by single-crystal and powder X-ray diffraction, thermogravimetric, infrared spectroscopy, and elemental analyses. Luminescent properties of the obtained compound were studied in detail both in the solid state and as a suspension in N,N-dimethylacetamide (DMA). It was found that {[Zn(tr₂btd)(bpdc)]∙DMF}_n exhibits bright turquoise luminescence with excellent quantum efficiency and demonstrates turn-on fluorescence enhancement effect upon soaking in DMA Al³⁺ solution. Fluorescence titration experiments were carried out and the detection limit for Al³⁺ ions was calculated to be 120 nM, which is among the lowest reported values for similar materials. Moreover, compound demonstrated excellent selectivity and reusability, and the mechanism of the response is discussed. These results indicate that {[Zn(tr₂btd)(bpdc)]∙DMF}_n is a promising probe for sensitive fluorescent Al³⁺ detection.     

A Zn(II) 5-Aminoisophthalate Coordination Polymer

The title compound, [Zn(AIP)(4,4-bipy)0.5(H2O)]n·0.75nH2O 1, was synthesized via the hydrothermal reaction of Zn(OAc)2 with 5-aminoisophthalic acid (H2AIP) and characterized by elemental analysis and infrared spectra. The complex crystallizes in monoclinic system, space group P21/c with a = 12.672(1), b = 7.6557(4), c = 16.181(1) , β = 109.187(2)o, V = 1482.6(2) 3, Z = 1, C52H52N8O23Zn4, Mr = 1418.58, Dc = 1.589 g/cm3, F(000) = 724 and μ(MoKα) = 1.685mm-1. The final R = 0.0702 and wR = 0.1524 for 1847 observed reflections with I > 2σ(I), and R = 0.0873 and wR = 0.1664 for all data. X-ray diffraction studies reveal that the title compound has an interesting 2D microporous architecture with guest water molecules inside the channel.     

Luminescent Coordination Polymers Constructed from a Flexible,Tetradentate Diisopyrazole Ligand and Copper(I) Halides

One‐ and two‐dimensional coordination polymers composed of a structurally flexible, tetradentate diisopyrazole ligand and copper(I) halides were synthesized as crystalline solids. Complexation with copper(I) chloride or bromide resulted in the formation of infinite coordination chains through connecting each diisopyrazole ligand with two copper(I) ions in a trigonal planar coordination geometry. Contrarily, the combination of a diisopyrazole ligand and copper(I) iodide gave a two‐dimensional coordination network comprising Cu₄I₄ units with stair‐step type geometry and diisopyrazoles that acted as both tetradentate and bidentate bridging ligands. All the coordination polymers exhibited visible photo‐emission upon UV irradiation, and the Cu₄I₄ complex showed thermochromic behavior.     

Hydrothermal Synthesis, Crystal Structure and Photoluminescent Property of a Zinc(II) Coordination Polymer Assembled by Phthalate and 4,4′-Bipyridine

1 INTRODUCTION Inorganic coordination polymers or solid-state po- lymers have received considerable attention in the past few years due to their possible applications as new materials in catalysis, adsorption, ion exchange, separation, magnetic devices, etc.[1] Metal coordina- tion polymers containing dicarboxylate ions as the organic spacer have been the subject of particular interest due to their fascinating architectures and ad- vantageous properties, such as bulk magnetic beha- vior, h…     

Fabrication of Luminescent CdS Nanoparticles on Short‐Peptide‐Based Hydrogel Nanofibers: Tuning of Optoelectronic Properties

The pH‐induced self‐assembly of three synthetic tripeptides in water medium is used to immobilize luminescent CdS nanoparticles. These peptides form a nanofibrillar network structure upon gelation in aqueous medium at basic pH values (pH 11.0–13.0), and the fabrication of CdS nanoparticles on the gel nanofiber confers the luminescent property to these gels. Atomic force microscopy, field‐emission scanning electron microscopy, and high‐resolution transmission electron microscopy clearly reveal the presence of CdS nanoparticles in a well‐defined array on the gel nanofibers. This is a convenient way to make organic nanofiber–inorganic nanoparticle hybrid nanocomposite systems. The size of the CdS nanoparticles remains almost same before and after deposition on the gel nanofiber. Photoluminescence (PL) measurement of the CdS nanoparticles upon deposition on the gel nanofibers shows a significant blue shift in the emission spectrum of the nanoparticles, and there is a considerable change in the PL gap energy of the CdS nanoparticles after immobilization on different gel nanofibrils. This finding suggests that the optoelectronic properties of CdS nanoparticles can be tuned upon deposition on gel nanofibers without changing the size of the nanoparticles.     

Luminescent Ruthenium(II) Polypyridyl Complexes as Nonviral Carriers for DNA Delivery

Two new luminescent ruthenium(II) polypyridyl complexes, [Ru(bpy)₂(tpt‐phen)]Cl₂ ( 1 ; bpy=2,2′‐bipyridine, tpt‐phen=triptycenyl‐1,10‐phenanthroline) and [Ru(phen)₂(tpt‐phen)]Cl₂ ( 2 ; phen=1,10‐phenanthroline), have been developed as potential nonviral vectors for DNA delivery. Photophysical and electrochemical properties of the complexes have been investigated and corroborated with electronic structure calculations. DNA condensation by these complexes has been investigated by UV/Vis and emission spectroscopy, circular dichroism spectroscopy, atomic force microscopy, dynamic light scattering, confocal microscopy, and electrophoretic mobility studies. These complexes interact with DNA and efficiently condense DNA into globular nanoparticles that are taken up efficiently by HeLa cells. DNA cleavage inability and biocompatibility of complexes have been explored. Both complexes have good gene transfection abilities.