Half‐sandwich Ruthenium (II) complexes with triphenylamine modified dipyridine skeleton and application in biology/luminescence imaging

Four half‐sandwich ruthenium^II (Ru^II) complexes with triphenylamine‐modifed dipyridine frameworks were synthesized and characterized. The cytotoxicity of target complexes toward A549 (lung cancer cells), HeLa (cervical cancer cells) and HepG2 (hepatoma cells) were obtained by the MTT assay, which were superior to cisplatin with the IC₅₀ values changed from 2.4 ± 0.1 μM to 9.2 ± 2.7 μM. Meanwhile, complexes possess the ability of antimetastasis to cancer cells. Ru^II complexes could be transported by serum albumin, catalyze the conversion of NADH (the reduced state of nicotinamide‐adenine dinucleotide) to NAD⁺ and induce the accumulation of reactive oxygen species, which confirmed the antineoplastic mechanism of oxidation. Ru^II complexes could enter A549 cells followed by a non‐energy dependent cellular uptake mechanism, target lysosomes with the Pearson's colocalization coefficient of 0.75, lead to lysosomal damage, disturb the cell cycle (S phase), and eventually induce apoptosis. The results demonstrate that these Ru^II complexes are potential anticancer agents with dual functions, including metastasis inhibition and lysosomal damage.     

Fe (III)‐grafted Bi2MoO6 nanoplates for enhanced photocatalytic activities on tetracycline degradation and HMF oxidation

Fe (III)‐grafted Bi₂MoO₆ nanoplates (Fe (III)/BMO) with varying small quantity of Fe (III) clusters modification were fabricated through a simple hydrothermal and impregnation process. The characterization results indicate that the modification of Fe (III) clusters on the surface of Bi₂MoO₆ nanoplates with intimate interfacial contact is beneficial to the expansion of visible light absorption range and the separation of photoinduced carriers during the interface charge transfer process. The photocatalytic properties of the samples were studied by degradation of tetracycline (TC) and selective aerobic oxidation of biomass‐derived chemical 5‐hydroxymethylfuraldehyde (HMF) under visible light. The 1.5 wt% Fe (III) clusters‐grafted Bi₂MoO₆ nanoplates exhibited optimum photocatalytic activity, which is the TC degradation kinetic rate constant is 5.3 times higher than that of bare BMO, and the highest HMF conversion of 32.62% can be obtained with a selectivity of 95.30%. Furthermore, a possible visible light photocatalysis mechanism over Fe (III)/BMO sample has been proposed. This study may supply some insight for the development of visible‐light‐driven Bi₂MoO₆‐based photocatalysts applicable to both environmental remediation and biomass‐derived chemical transformation.     

Engineering Multifunctional DNA Hybrid Nanospheres through Coordination‐Driven Self‐Assembly

Developing simple and general approaches for the synthesis of nanometer‐sized DNA materials with specific morphologies and functionalities is important for various applications. Herein, a novel approach for the synthesis of a new set of DNA‐based nanoarchitectures through coordination‐driven self‐assembly of Fe^II ions and DNA molecules is reported. By fine‐tuning the assembly, Fe–DNA nanospheres of precise sizes and controlled compositions can be produced. The hybrid nanoparticles can be tailored for delivery of functional DNA to cells in vitro and in vivo with enhanced biological function. This highlights the potential of metal ion coordination as a tool for directing the assembly of DNA architectures, which conceptualizes a new pathway to expand the repertoire of DNA‐based nanomaterials. This methodology will advance both the fields of DNA nanobiotechnology and metal–ligand coordination chemistry.     

Platinum/Nickel Bicarbonate Heterostructures towards Accelerated Hydrogen Evolution under Alkaline Conditions

Heterostructured nanomaterials, generally have physicochemical properties that differ from those of the individual components, and thus have potential in a wide range of applications. New platinum (Pt)/nickel bicarbonate (Ni(HCO₃)₂) heterostructures are designed for an efficient alkaline hydrogen evolution reaction (HER). Notably, the specific and mass activity of Pt in Pt/Ni(HCO₃)₂ are substantially improved compared to the bare Pt nanoparticles (NPs). The Ni(HCO₃)₂ provides abundant water adsorption/dissociation sites and modulate the electronic structure of Pt, which determine the elementary reaction kinetics of alkaline HER. The Ni(HCO₃)₂ nanoplates offer a platform for the uniform dispersion of Pt NPs, ensuring the maximum exposure of active sites. The results demonstrate that, Ni(HCO₃)₂ is an effective catalyst promoter for alkaline HER.     

A Ligand‐Protected Golden Fullerene: The Dipyridylamido Au328+ Nanocluster

A golden fullerene Au₃₂ cluster has been synthesized with amido and phosphine ligands as the protecting agents. Single‐crystal X‐ray structural analysis revealed that this gold nanocluster, [Au₃₂(Ph₃P)₈(dpa)₆] (SbF₆)₂ (Hdpa=2,2′‐dipyridylamine), has a stable pseudo‐I_h Au₃₂⁸⁺ core with S₆ symmetry, which features an Au₁₂@Au₂₀ Keplerate cage co‐protected by Ph₃P and dpa ligands. Quantum‐chemical studies were conducted to elucidate the origin of the special stability of this cluster, and suggest that it is electronically stabilized through metal–ligand interactions.     

Copper‐Bismuth Bimetallic Microspheres for Selective Electrocatalytic Reduction of CO2 to Formate

Electrocatalytic carbon dioxide reduction holds great promise for reducing the atmospheric CO₂ level and alleviating the energy crisis. High‐performance electrocatalysts are often required in order to lower the high overpotential and expedite the sluggish reaction kinetics of CO₂ electroreduction. Copper is a promising candidate metal. However, it usually suffers from the issues of poor stability and low product selectivity. In this work, bimetallic Cu‐Bi is obtained by reducing the microspherical copper bismuthate (CuBi₂O₄) for selectively catalyzing the CO₂ reduction to formate (HCOO^–). The bimetallic Cu‐Bi electrocatalyst exhibits high activity and selectivity with the Faradic efficiency over 90% in a wide potential window. A maximum Faradaic efficiency of ~95% is obtained at –0.93 V versus reversible hydrogen electrode. Furthermore, the catalyst shows high stability over 6 h with Faradaic efficiency of ~95%. This study provides an important clue in designing new functional materials for CO₂ electroreduction with high activity and selectivity.     

Anion‐directed Silver(I) Coordination Assemblies Based on 1‐(2‐Pyridyl)‐2‐(4‐pyridyl)‐1,2,4‐triazolewith Diverse Supramolecular Networks and Dichromate Removal Capabilities

A series of silver(I) supramolecular complexes, namely, {[Ag(L²⁴)](NO₃)}_n ( 1 ), [Ag₂(L²⁴)(NO₂)₂]_n ( 2 ), and {[Ag_1.25(L²⁴)(DMF)](PF₆)_1.25}_n ( 3 ) were prepared by the reactions of 1‐(2‐pyridyl)‐2‐(4‐pyridyl)‐1,2,4‐triazole (L²⁴) and silver(I) salts with different anions (AgNO₃, AgNO₂, AgPF₆). Single‐crystal X‐ray diffraction indicates that 1 – 3 display diverse supramolecular networks. The structure of dinuclear complex 1 is composed of a six‐membered Ag₂N₄ ring with the Ag ··· Ag distance of 4.4137(3) Å. In complex 2 , the adjacent Ag^I centers are interlinked by L²⁴ ligands into a 1D chain, the adjacent of which are further extended by the bridged nitrites to construct a 2D coordination architecture. Complex 3 shows a 3D (3,4)‐connected framework, which is generated by the linkage of L²⁴ ligands. All complexes were characterized by IR spectra, elemental analysis, and powder X‐ray diffraction. Notably, a structural comparison of the complexes demonstrates that their structures are predominated by the nature of anions. Additionally, 1 and 2 show efficient dichromate (Cr₂O₇^2–) capture in water system, which can be ascribed to the anion‐exchange.     

Synthesis and Infrared Multi‐band Absorption Properties of Core‐shell NaYF4:Yb3+, Er3+@SiO2 Nanoparticles

Due to the unique size effects, nanomaterials in infrared absorption have attracted much attention for their strong absorption in the infrared region. To achieve the infrared multi‐band absorption, we propose to synthesize a core‐shell structure nanomaterial consisting of NaYF₄:Yb³⁺, Er³⁺ core and a layer of SiO₂ as shell. A series of NaYF₄:Yb³⁺, Er³⁺ nanocrystals were synthesized through hydrothermal method by adjusting the ratio of citric acid(CA)‐to‐NaOH, and the effects of CA concentration, and NaOH concentration were studied in detail. NaYF₄:Yb³⁺, Er³⁺@SiO₂ nanoparticles were synthesized by sol‐gel method using TEOS as silica source. The results show that the core‐shell NaYF₄:Yb³⁺, Er³⁺@SiO₂ nanoparticles were successfully synthesized. Up‐conversion spectra of these nanoparticles were recorded with 980 nm laser excitation under room temperature. There are no changes of the emission centers of nanoparticles before or after silica coating, but the emission intensities of nanoparticles after silica coating are weakened. Furthermore, the property of infrared multi‐band absorption was tested through ultraviolet‐visible‐near infrared spectrophotometer and infrared absorption spectra. The results illustrate that the multi‐band infrared absorption nanomaterial was successfully synthesized.     

Thieno[3,2‐b]Thiophene End‐Capped all‐Sulfur Analog of 3,4‐Ethylenedioxythiophene and its Eletrosynthesized Polymer: Is Distorted Conformation Not Suitable for Electrochromism?

By employing planar thieno[3,2‐b]thiophene (TT) as end‐capped units and famous 3,4‐ethylenedioxythiophene (EDOT) or its all‐sulfur analog 3,4‐ethylenedithiathiophene (EDTT) as cores, two conjugated oligomer, TT‐EDOT‐TT and TT‐EDTT‐TT, have been synthesized and electropolymerized into electrochromic polymer films, P(TT‐EDOT‐TT) and P(TT‐EDTT‐TT), respectively. Due to strongly noncovalent inter/intramolecular interactions from S? S attraction of TT‐EDTT‐TT, it has twisted molecular configuration in contrast to planar TT‐EDOT‐TT. Spectroscopic, electrochemical, morphological as well as theoretical calculation studies of these oligomers or polymers were carried out to reveal the significant influence of such molecular geometry on their physicochemical and optoelectronic properties. According to electrochromic kinetics, P(TT‐EDTT‐TT) presented preferable electrochromic behavior such as the higher optical contrast (70.8%), favorable coloration efficiency (331.3 cm² C^?1) and fast response time (0.72 s). This research will help us deeply understand the effect of spatial organization of precursor molecules on the properties of electrochromic polymers and provides a promising strategy to develop high‐performance electrochromic materials. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 1041–1048     

Synthesis and properties of sulfur‐contained poly(silylene arylacetylene)s

Poly(silylene arylacetylene) (PSA) is a kind of poly(arylacetylene) silicon‐containing resins with excellent heat resistance and good mechanical performances. In this article, the sulfur atom is introduced into the main chain of the PSA molecule to obtain a sulfur‐containing poly(silylene arylacetylene), named S‐PSA. By Williamson and Sonogashira reactions, bis(4‐ethynylphenyl)sulfide and bis(4‐ethynylphenyl)sulfone were synthesized. Thereafter, through Grignard reagent way, the poly(silylene ethynylene phenylene sulfide phenylene ethynylene) (PSESE) and poly(silylene ethynylene phenylene sulfone phenylene ethynylene) (PSESO₂E) were synthesized from bis(4‐ethynylphenyl)sulfide, bis(4‐ethynylphenyl)sulfone, and methylphenyl dichlorosilane. Poly(silylene ethynylene phenylene sulfoxide phenylene ethynylene) (PSESOE) was synthesized by the oxidation of PSESE. The structures and properties of these resins were characterized and the mechanical properties of the T300 reinforced composites were tested. The results show that the novel S‐PSA resins have excellent heat resistance and good mechanical properties, and could be used as resin matrices for high‐performance composites in high‐tech fields. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2324–2332