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Pyrazoline and pyrazole compounds are important building blocks in the development of photofunctional compounds. Two new solution-processable platinum-containing polyynes functionalized with these chromophores in the main chain (P1 and P2) were synthesized and characterized by spectroscopic, thermal and optical methods. By changing the spacer from 2-pyrazoline to the electron-rich pyrazole in the main chain, the photophysical properties including energy levels, absorption wavelength and bandgap of the polymers were finely tuned. The photovoltaic properties of P1 with better absorption features were also studied. [ABSTRACT FROM AUTHOR]

Four new solution-processable platinum-containing polyynes functionalized with triphenylamine backbone and different acceptor fragment in the side chain were synthesized and characterized by spectroscopic, thermal and optical methods. The main- and side-chains show different absorption features in the solar spectrum, resulting in broad absorption coverage of the whole visible region. By changing the acceptor group in the side chain, the photophysical properties including energy levels, absorption wavelength and bandgap of the polymers were finely tuned. As the strength of electron acceptor is increased, the power conversion efficiency (PCE) of organic polymer solar cells fabricated with these polymers as electron donor and (6,6)-phenyl-C61-butyric acid methyl ester (PCBM) as electron acceptor was increased. PCE of 1.35% can be obtained from solar cell based on the polyplatinayne with the dicyanovinyl side group under illumination of an AM 1.5 solar cell simulator in a 1:4 (polymer:PCBM) blend ratio. [ABSTRACT FROM AUTHOR]

Anion‐exchange membrane fuel cells and water electrolyzers have garnered significant attention in past years due to their potential role in sustainable and affordable energy conversion and storage. However, the chemical stability of the polymeric anion‐exchange membranes (AEMs), the key component in these devices, currently limits their lifespan. Recently, metallopolymers have been proposed as chemically stable alternatives to organic cations, using metal centers as ion transporters. In metallopolymer AEMs, various properties such as alkaline stability, water uptake, flexibility, and performance, are determined by both the metal complex and polymer backbone. Herein we present a systematic study investigating the influence of the polymer backbone chemistry on some of these properties, focusing on the alkaline stability of low‐oxophilicity gold metallopolymers. Despite the use of a common N‐heterocyclic carbene ligand, upon gold metalation using the same reaction conditions, different polymer backbones end up forming different gold complexes. These findings suggest that polymer chemistry affects the metalation reaction in addition to the other properties relevant to AEM performance. [ABSTRACT FROM AUTHOR]

Terpyridine (TPY) platinum(II) chloride with a triphenylamine (TPA) group was successfully synthesized. The strong intramolecular Donor(TPA)-Acceptor(TPY) interaction induced the low-energy absorption band, mixing the spin-allowed singlet dπ(Pt)→π*(TPY) metal-to-ligand charge transfer (MLCT) with the chloride ligand-to-metal charge transfer (LMCT) and chloride ligand-to-ligand (TPY) charge transfer (LLCT) transitions, to bathochromically shift to λmax = 449 nm with significant enhancement and broadening effects. Using the cyclic voltammetry method, its oxidative electropolymerization (EP) films on working Pt disk and ITO electrodes were produced with tunable thickness and diffusion controlled redox behavior, which were characterized by the SEM, EDS, FT-IR, and AC impedance methods. Upon applying +1.4 V voltage, the sandwich-type electrochromic device (ECD) with ca. 290 nm thickness of the EP film exhibits a distinct color transformation from red (CIE coordinates: L = 50.75, a = 18.58, b = 5.69) to dark blue (CIE coordinates: L = 45.65, a = −1.35, b = −12.49). Good electrochromic (EC) parameters, such as a large optical contrast (ΔT%) of 78%, quick coloration and bleaching response times of 2.9 s and 1.1 s, high coloration and bleaching efficiencies of 278.0 and 390.5 C−1·cm2, and good cycling stability (maintains 70% of the initial ΔT% value after 3200 voltage switching cycles), were obtained. [ABSTRACT FROM AUTHOR]

Metal‐containing polymers represent an ever‐expanding frontier of material science. Of the numerous biocompatible ligands used to create a metallopolymer, piperazine‐containing polymers are still in their early development, even though piperazine is a common functional group in drug design and bioengineering scaffolding elements. We report the first synthesis and characterization (with NMR, IR, GPC, UV–vis spectroscopy, and thermal analysis) of two thermoplastic poly(alkyl piperazine succinate) diols with either propyl or hexyl alkane chains bridging the piperazines. These polyester diols were then chain extended with hexamethylene diisocyanate to create highly amorphous polyester urethane thermoplastic polymers. Ru(III) or Fe(III) was then successfully coordinated with these polymers, with approximately 30% of the bulk metallopolymer product becoming 250x the molecular weight of the non‐metal containing polymers. However, coordination of Fe(III), and to a lesser extent Ru(III), to these polypiperazines accelerated the hydrolysis of the polyester linkage in water over 15 days. Thus, these novel polymers are highly biodegradable with Fe(III) metallopolymers hydrolyzing faster than Ru(III) metallopolymers and poly(propyl piperazine succinate) polymers hydrolyzing faster than poly(hexyl piperazine succinate) polymers. [ABSTRACT FROM AUTHOR]

Conductive electrochemically active metallopolymers are outstanding materials for energy storage and conversion, electrocatalysis, electroanalysis, and other applications. The hybrid inorganic–organic nature of these materials ensures their rich chemistry and offers wide opportunities for fine-tuning their functional properties. The electrochemical modulation of the nanomechanical properties of metallopolymers is rarely investigated, and the correlations between the structure, stiffness, and capacitive properties of these materials have not yet been reported. We use electrochemical atomic force microscopy (EC-AFM) to perform in-situ quantitative nanomechanical measurements of two Schiff base metallopolymers, poly[NiSalphen] and its derivative that contains two methoxy substituents in the bridging phenylene diimine unit poly[NiSalphen(CH3O)2], during their polarization in the electrolyte solution to the undoped and fully doped states. We also get insight into the electrochemical p-doping of these polymers using electrochemical quartz crystal microgravimetry (EQCM) coupled with cyclic voltammetry (CV). Combined findings for the structurally similar polymers with different interchain interactions led us to propose a correlation between Young's modulus of the material, its maximum doping level, and ion and solvent fluxes in the polymer films upon electrochemical oxidation. [ABSTRACT FROM AUTHOR]

Metallopolymeric functional nanomaterials have been gained the significant interest of researchers because of their exclusive properties, commercial, biodegradability, high elasticity and efficient nature for their various applications in different fields. These materials are useful for the fabrication of economical energy conversion and optoelectronic devices. The domain of the applicability of these materials is very large such as energy devices, sensor/ actuators, biomedical applications, photodetectors and micromechanical devices. Energy conversion devices like photodetectors, photovoltaic solar cells, and light-dependent resistors can be manufactured by metallopolymer nanomaterials. When polymers are conjugated with the metals, they offer advanced functional opportunities for the advancement of the various energy harvesting materials with their enhanced properties. This article contains the recent accomplishments of the ongoing challenges for the metallopolymeric functional materials for their advanced solar energy applications which can affect human life. [ABSTRACT FROM AUTHOR]

The palladium–salen complex was immobilized by electropolymerization onto a Pt disc electrode and applied as an electrocatalyst for the reduction of CO2 in an aqueous solution. Linear sweep voltammetry measurements and rotating disk experiments were carried out to study the electrochemical reduction of carbon dioxide. The onset overpotential for carbon dioxide reduction was approximately −0.22 V vs. NHE on the poly-Pd(salen) modified electrode. In addition, by combining the electrochemical study with a kinetic study, the rate-determining step of the electrochemical CO2 reduction reaction (CO2RR) was found to be the radial reduction of carbon dioxide to the CO adsorbed on the metal. [ABSTRACT FROM AUTHOR]

Inspired by the cooperative multi-metallic activation in metalloenzyme catalysis, artificial enzymes as multi-metallic catalysts have been developed for improved kinetics and higher selectivity. Previous models about multi-metallic catalysts, such as cross-linked polymer-supported catalysts, failed to precisely control the number and location of their active sites, leading to low activity and selectivity. In recent years, metallopolymers with metals in the sidechain, also named as sidechain metallopolymers (SMPs), have attracted much attention because of their combination of the catalytic, magnetic, and electronic properties of metals with desirable mechanical and processing properties of polymeric backbones. Living and controlled polymerization techniques provide access to SMPs with precisely controlled structures, for example, controlled degree of polymerization (DP) and molecular weight dispersity (Đ), which may have excellent performance as multi-metallic catalysts in a variety of catalytic reactions. This review will cover the recent advances about SMPs, especially on their synthesis and application in catalysis. These tailor-made SMPs with metallic catalytic centers can precisely control the number and location of their active sites, exhibiting high catalytic efficiency. [ABSTRACT FROM AUTHOR]

The present article addresses the preparation of nanostructured scandium polyacrylamide deposited on borosilicate glass substrates of 1.0 cm × 1.0 cm × 0.2 cm dimensions to investigate the variations in the electrical parameters with adsorption/desorption of water in a controlled humidity glass chamber. Field emission scanning electron microscopy (FESEM) analysis showed that the material had spherically shaped clusters. X-ray diffraction (XRD) revealed the amorphous nature of the polymer whereas crystalline nature of the metal part in complex. Minimum particle size was reported as 2 nm by Zeta nanosizer which was further confirmed by high-resolution transmission electron microscopy (HRTEM). Energy band gap of the film was anticipated as 4.03 eV by UV–Vis spectrophotometer. Fourier transform infrared (FTIR) spectroscopy confirmed the presence of the amide group in the material's chemistry. The film was employed as an electrical humidity sensor. Maximum sensitivity was calculated as 1.85 MΩ/%RH with ~ 96.76% reproducible results. This testing device showed the humidity response and recovery times as 24 s and 101 s, respectively. [ABSTRACT FROM AUTHOR]

The synergistic combination of chemotherapy and photodynamic therapy has attracted considerable attention for its enhanced antitumoral effects; however, it remains challenging to successfully delivery photosensitizers and anticancer drugs while minimizing drug leakage at off‐target sites. A red‐light‐activatable metallopolymer, Poly(Ru/PTX), is synthesized for combined chemo‐photodynamic therapy. The polymer has a biodegradable backbone that contains a photosensitizer Ru complex and the anticancer drug paclitaxel (PTX) via a singlet oxygen (1O2) cleavable linker. The polymer self‐assembles into nanoparticles, which can efficiently accumulate at the tumor sites during blood circulation. The distribution of the therapeutic agents is synchronized because the Ru complex and PTX are covalently conjugate to the polymer, and off‐target toxicity during circulation is also mostly avoided. Red light irradiation at the tumor directly cleaves the Ru complex and produces 1O2 for photodynamic therapy. Sequentially, the generated 1O2 triggers the breakage of the linker to release the PTX for chemotherapy. Therefore, this novel sequential dual‐model release strategy creates a synergistic chemo‐photodynamic therapy while minimizing drug leakage. This study offers a new platform to develop smart delivery systems for the on‐demand release of therapeutic agents in vivo. [ABSTRACT FROM AUTHOR]

As polymer‐based thermoelectric (TE) materials possess attractive features such as light weight, flexibility, low toxicity and ease of processibility, an increasing number of conducting polymers and their composites with high TE performances have been developed in recent years. Up to date, however, the research focusing on the structure‐performance relationship remains rare. In this paper, two series of poly(Schiff base)s with either C=C or C≡C linker and their metallopolymers were synthesized and doped with single‐walled carbon nanotubes to evaluate how the linking groups affected the TE properties of the resulting composites. Apart from the effect exerted by the morphology, experimental results suggested that the linkers played a key role in determining the band gaps, preferred molecular conformation and extent of conjugation of the polymers, which became key factors that influenced the TE properties of the resulting materials. Additionally, upon coordination with transition metal ions, the TE properties could be tuned readily. [ABSTRACT FROM AUTHOR]

A series of Ru(II)-containing metallopolymers with different polypyridyl complexes, namely [Ru(N^N)2(L)](PF6)2 (L = bipyridine-branched polymer; N^N = bpy: 2,2′-bipyridine (Ru 1); phen: 1,10-phenanthroline (Ru 2); dpp: 4,7-diphenyl-1,10-phenanthroline (Ru 3)), were synthesized with the motive that adjusting π-conjugation length of ligands might produce competent luminescent oxygen probes. The three hydrophobic metallopolymers were studied with 1H NMR, UV-Vis absorption, and emission spectroscopy, and then were utilized to prepare biocompatible nanoparticles (NPs) via a nanoprecipitation method. Luminescent properties of the NPs were investigated against dissolved oxygen by steady-state and time-resolved spectroscopy respectively. Luminescence quenching of the three NPs all followed a linear behavior in the range of 0–43 ppm (oxygen concentration), but Ru 3-NPs exhibited the highest oxygen sensitivity (82%) and longest emission wavelength (λex = 460 nm; λem = 617 nm). In addition, external interferons from cellular environments (e.g., pH, temperature, and proteins) had been studied on Ru 3-NPs. Finally, dissolved oxygen in monolayer cells under normoxic/hypoxic conditions was clearly differentiated by using Ru 3-NPs as the luminescent sensor, and, more importantly, hypoxia within multicellular tumor spheroids was vividly imaged. These results suggest that such Ru(II)-containing metallopolymers are strong candidates for luminescent nanosensors towards hypoxia. [ABSTRACT FROM AUTHOR]

Inspired by the flexibility of the bottom-up approach in choosing building blocks of two-dimensional (2D) materials, a π-conjugated metal complex nanosheet (HHTP-Cu) was successfully prepared by the coordination of the ligand 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP) and Cu(II) ion at the water/oil interface. Field-emission scanning electron microscopy disclosed the large-size domain and transmission electron microscopy revealed the sheet morphology of the nanosheet. The flat and smooth surface was also confirmed by atomic force microscopy which further demonstrated the proposed structure. Energy dispersive X-ray spectroscopy was applied to verify the homogeneous distribution of the elements while X-ray photoelectron spectroscopy was used to investigate the composition of the nanosheet. [ABSTRACT FROM AUTHOR]

In this mini-review article the concept of electron reservoir materials developed in the author's laboratory is summarized. Starting from mono- and bimetallic electron reservoir complexes and their electronic and catalytic properties this concept extends to macromolecular electron-reservoir devices including metallodendrimers, metallopolymers and macromolecule-stabilized late transition-metal nanoparticles. The electronic switch in these devices is discussed as well as the structure-dependent possibilities to stabilize both utilized redox forms. Catalytic and energy-related applications involving redox metallomacromolecules and nanoparticles and their potential extension are briefly discussed. Giant ferrocene and pentamethylferrocene-based dendrimers and polymers are typical electron reservoir macromolecules that have been isolated in both oxidized and reduced forms with the ability to carry a large flow of electrons at about the same potential. The dramatic structural and size changes of the metallomacromolecules upon redox switch is reminiscent of molecular machines. [ABSTRACT FROM AUTHOR]

The mechanical addressability of specific chemical bonds holds a high potential for the improvement of polymeric materials. While in many cases, mechanical forces applied to polymers lead to bond scissoring and materials failure, including mechanophores into the polymer structure can lead to stimuli-responsive materials reacting to an applied force in a predefined manner. In this contribution, the mechanical addressability of bis-terpyridine metal complexes embedded into a polymer structure is investigated. The activation of the transition metal complexes in the metallopolymer is monitored by adding a fluorescent sensor molecule to the metallopolymer solution during ultrasonication. Upon sonication, the activation of the complexes leads to fluorescence-quenching of the sensor. The dependency of the metal ion and the type of polymer as well as their molar mass is investigated in detail, showing that this concept could possibly be used in further application of stimuli-responsive or self-healing materials. [ABSTRACT FROM AUTHOR]

Cobaltocenium-containing polyelectrolyte block copolymer nanoparticles were prepared via polymerizationinduced self-assembly (PISA) using aqueous dispersion RAFT polymerization. The cationic steric stabilizer was a macromolecular chain-transfer agent (macro-CTA) based on poly (2-cobaltocenium amidoethyl methacrylate chloride) (PCoAEMACl), and the core-forming block was poly(2-hydroxypropyl methacrylate) (PHPMA). Stable cationic spherical nanoparticles were formed in aqueous solution with low dispersity without adding any salts. The chain extension of macro-CTA with HPMA was efficient and fast. The effects of block copolymer compositions, solid content, charge density, and addition of salts were studied. It was found that the degree of polymerization of both the stabilizer PCoAEMACl and the coreforming PHPMA had a strong influence on the size of nanoparticles. [ABSTRACT FROM AUTHOR]

Electrochemiluminescence (ECL) is the process of light emission arising from an electrochemically generated excited state. ECL has been demonstrated to be a powerful tool for bioanalysis, in particular when phosphorescent transition metal complexes (TMCs) are used as emitters. Apart from molecular luminophores, there has been increasing interest in the use of both non‐conjugated and π‐conjugated metallopolymers over the last decade. Research efforts in this direction are driven by the appealing possibility to synergistically combine typical features of polymers, such as processability, with the enhanced photophysical and redox properties of several classes of TMCs. Indeed, solid‐state arrangements of ECL‐active metallopolymers enable their straightforward use as sensors with enhanced response. This concept article focuses on ECL‐active metallopolymers and their use in solid‐state platforms, providing a survey with relevant examples together with properties, mechanisms and proposed applications. Finally, the outlook for future applications across different research fields for these materials as well as their limitations for will be discussed. [ABSTRACT FROM AUTHOR]

We report the synthesis of chiral enantiopure polytopic bridging ligands, which may lead to the formation of metallosupramolecular polymers with zinc (II) as metal linker. We show that chiral C2‐symmetric bisoxazoline ligands are useful moieties to efficiently generate heterochiral complexes and thus polymeric entities. The corresponding metallopolymers were further characterized by powder X‐ray diffraction (PXRD) to obtain information on the level of crystallinity of our different metallopolymers. [ABSTRACT FROM AUTHOR]

Three new solution-processable Pt(II)-containing poly(aryleneethynylene) polymers based on diketopyrrolopyrrole moiety and their corresponding diplatinum model complexes were synthesized via the Sonogashira-type coupling reaction of the platinum(II) chloride precursor and each of the diethynyl ligands. The photophysical, thermal stability, electrochemical, carrier mobility and photovoltaic properties of these polymers were fully investigated. These polymers exhibit strong absorption bands in the range of 550–750 nm, and fluorescent bands between 650 and 850 nm. One thiophene flanked diketopyrrolopyrrole based polymer with linear n -octyl chains shows a better photovoltaic performance than that made from the branched 2-ethylhexyl analogue. Image 1 • Diketopyrrolopyrrole-based platinum polyyne polymers were synthesized. • Their photophysical, electrochemical, carrier mobility and photovoltaic properties were investigated. • The effect of the nature of the alkyl chains on the diketopyrrolopyrrole ring was studied. [ABSTRACT FROM AUTHOR]

In this work, two metallopolymers (P1 and P2) were designed and synthesized through coupling of ferrocene-anchored fluorene derivatives with porphyrin and benzene based diethynyl ligand, respectively. The chemical structure and physical properties of these two metallpolymers were fully characterized, which indicate that these two metallopolymers are thermally stable and semiconducting. Then, sandwich-like organic resistive memory based on P1 and P2 for data storage were explored. The memory device testing results manifest that both P1 and P2 are of the stable electric bistability and show write once read many times memory (WORM) characteristics. Image 1 • Two new ferrocene-based metallopolymers were designed and synthesized. • These two ferrocene-based metallopolymers are thermal stable and semiconducting. • Nonvolatile Memory Behaviors of the ferrocene-based metallopolymers were investigated. [ABSTRACT FROM AUTHOR]

• Ferric porphyrin-based polymers have been successfully synthesized. • They can provide FeNx-based catalytic centers without pyrolysis. • They are catalytically active for oxygen reduction in acidic and alkaline media. Electrochemical oxygen reduction reaction (ORR) is a very important reaction for green and sustainable chemistry. Herein, we report the design and synthesis of a semi-crystalline metallopolymer consisting of ferric porphyrin–based building blocks immobilized by organic linkers (viz. various dialdehydes) through rigid imine bonds. All the materials thus obtained showed moderate to high ORR performance in rotating ring-disk electrode voltammetry with oxygen-saturated 0.5 M H 2 SO 4 and 0.1 M KOH. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The electrochromic properties of transition metal complexes have been outlined. • Different methods for the formation of electrochromic thin films containing transition metal ions have been presented. • The utility of transition metal complexes as active materials in electrochromic devices has been summarized. Abstract Materials exhibiting reversible color changes under an electric stimulus, called electrochromic materials, have been drawing great research interest due to their applications as active materials in organic electronics. New electrochromic materials exhibiting multi-electrochromic properties in a wide range of colors with high contrast ratios and short response times are still in great demand. Well defined redox properties and intense charge transfer absorptions of transition metal complexes make them promising materials for use as electrochromic materials. The absorption wavelength and observed color of transition metal complexes significantly depend on the redox state of both the metal ion and the ligand, and their properties can be modified by changing the ligands or metal ions. This review summarizes the electrochromic properties of metallopolymers, coordination sheets as well as nanocomposites containing transition metal complexes, which can be used as active materials in electrochromic devices. [ABSTRACT FROM AUTHOR]

Abstract Metal-containing monomers are the building blocks for metallopolymers, and play very important role in their functions. As a class of new building block, the incorporation of organically modified polyoxometalates (OMPs) to metallopolymers not only broaden the kind of metal elements in metallopolymers, but also introduce novel functions. Herein, a survey of the progress in the OMPs-based metallopolymers is given. The organic modification methods of OMPs, synthetic strategy of OMPs-based metallopolymers, as well as their applications will be discussed. Graphical abstract Image 1 Highlights • Design and synthesis of POMs-containing monomer were summarized. • Preparation of POMs-containing metallopolymers were summarized. • Supramolecular self-assembly and applications of POMs-containing metallopolymers were summarized. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Humidity sensing properties of Ni (II) nitrate Polyacrylamide films have been studied for the first time. • Optical energy band-gap of the film was estimated as 4.034 eV. • TEM image showed the average grain diameter of 4–21 nm. • The sensing mechanism is administered by highly porous nanostructures of different size distributed throughout the film. • Synthesis method of Ni (II) nitrate polyacrylamide is robust and cost-effective. Abstract The present paper reports the polymer matrix of Ni(NO 3) 2 (AAm) 4 ·2H 2 O thin film as an electrical and opto-electronic humidity sensor. For this purpose, films were prepared by spin-coating method to investigate the adsorption/desorption of humidity at room ambient. The sensing element was investigated through X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM) and UV–Vis absorption techniques. XRD exhibited the crystalline nature of the nanomaterial thin film and evaluated average crystallite size was 30 nm. SEM showed highly porous nanostructures of different size distributed throughout the film. Energy band-gap of the film was estimated as 4.034 eV. TEM image showed the nanostructures with the average grain size of 4-21 nm and SAED confirmed the crystalline nature of the material. The film was further employed for two different modes of humidity sensing i.e., impedance-based electrical humidity measurement and transmission based opto-electronic humidity measurement which gave a maximum average sensitivity of 37.79 MΩ/%RH and 1.31 µW/%RH respectively at room temperature. [ABSTRACT FROM AUTHOR]

Although the organic and the conventional inorganic thermoelectric (TE) materials have been extensively developed in recent years, the number of cases involving conducting metallopolymers is still quite limited. In view of the versatile coordination capability of the terpyridine fraction and the electron-rich nature of the 3,4-ethylenedioxythiophene moiety, a bis-terpyridine-featured ligand was designed, and a series of metallopolymers were then synthesized. Upon the addition of single-walled carbon nanotube (SWCNT), the TE properties of the resulting metallopolymer-SWCNT composite films were investigated. It was found that metal centres played an important role in affecting the morphology of the thin films, which was a key factor that determined the TE performances of the composites. Additionally, the energy levels of the metallopolymers were feasibly tuned by selecting different metal centres. With the combined effects of a uniform and condensed surface and an optimized band structure, the highest power factor was achieved by the Cu(II)-containing metallopolymer-SWCNT composite at the doping ratio of 75%, which reached 38.3 μW·m−1·K−2.

Metal–ligand interactions in monomeric and polymeric transition metal complexes of Schiff base ligands largely define their functional properties and perspective applications. In this study, redox behavior of a nickel(II) N4-anilinosalen complex, [NiAmben] (where H2Amben = N,N′-bis(o-aminobenzylidene)ethylenediamine) was studied by cyclic voltammetry in solvents of different Lewis basicity. A poly-[NiAmben] film electrochemically synthesized from a 1,2-dichloroethane-based electrolyte was investigated by a combination of cyclic voltammetry, electrochemical quartz crystal microbalance, in situ UV-Vis spectroelectrochemistry, and in situ conductance measurements between −0.9 and 1.3 V vs. Ag/Ag+. The polymer displayed multistep redox processes involving reversible transfer of the total of ca. 1.6 electrons per repeat unit, electrical conductivity over a wide potential range, and multiple color changes in correlation with electrochemical processes. Performance advantages of poly-[NiAmben] over its nickel(II) N2O2 Schiff base analogue were identified and related to the increased number of accessible redox states in the polymer due to the higher extent of electronic communication between metal ions and ligand segments in the nickel(II) N4-anilinosalen system. The obtained results suggest that electrosynthesized poly-[NiAmben] films may be viable candidates for energy storage and saving applications.

While the metallocene polymers were comprehensively studied, other metallopolymers are rarely explored. The major challenge is the lack of a synthetic platform for the preparation of metal coordinated derivatives, monomers, and polymers. Therefore, the development of a facile synthesis of new metal coordinated monomers and polymers is critically needed. A novel successfully synthesized methacrylate-containing nickel complex is reported in this communication. Controlled RAFT polymerizations are further carried out to prepare a series of side-chain nickel containing polymers with different molecular weight and narrow Polydispersity Index (PDI). This new metallopolymer performs specific electrochemical and excellent thermal properties. This study provides a novel and convenient strategy to prepare metallopolymer with controllable molecular weight, which has potential applications in assembled, catalytic and magnetic materials.

A tetrazole‐based photoligation protocol for the spatially‐resolved encoding of various defined metallopolymers onto solid surfaces is introduced. By using this approach, fabrication of bi‐ and trifunctional metallopolymer surfaces with different metal combinations were achieved. Specifically, α‐ω‐functional copolymers containing bipyridine as well as triphenylphosphine ligands were synthesized through reversible addition‐fragmentation chain transfer (RAFT) polymerization, and subsequently metal loaded to afford metallopolymers of the widely‐used metals gold, palladium, and platinum. Spatially‐resolved surface attachment was achieved by means of a nitrile imine‐mediated tetrazole‐ene cycloaddition (NITEC) based photoligation protocol, exploiting tethered tetrazoles and metallopolymers equipped with a maleimide chain terminus. Metallopolymer coated surfaces with three different metals were prepared and characterized by time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) and spatially‐resolved X‐ray photoelectron spectroscopy (XPS) mapping, supporting the preserved chemical composition of the surface‐bound metallopolymers. The established photochemical technology platform for arbitrary spatially‐resolved metallopolymer surface designs enables the patterning of multiple metallopolymers onto solid substrates. This allows for the assembly of designer metallopolymer substrates. Behind the mask: Spatially‐resolved surface patterning of various metallopolymers by utilization of a photoligation protocol based on tetrazoles is introduced. Metallopolymer coated surfaces with three different metals were synthesized and characterized by ToF‐SIMS and XPS mappings. The established photochemical technology platform paves the way for the patterning of a wide variety of metallopolymers onto solid substrates. [ABSTRACT FROM AUTHOR]

Abstract A resistance detection device for dissolved molecular oxygen in aqueous solutions is prepared using a chemiresistor material as sensor platform. The chemiresistive circuit element is fashioned from a thin film of a cobalt-salen metallopolymer electrodeposited on a platinum electrode. Electrochemical impedance spectroscopy shows that the resistive and capacitive properties of the sensor platform depend on the presence of dissolved oxygen. The electrical circuit models are R(Q/R)(Q/R) and R(Q/R)(Q/RW) in the absence and presence of oxygen, respectively. The chemiresistor sensor exhibits good sensitivity (0.483 kΩ L mg−1), excellent reversibility and excellent linearity over a range of dissolved oxygen concentrations typically found under environmental conditions (2.72–40.9 mg L−1). The sensor fabricated in this work can potentially serve as an alternative sensor for the detection of dissolved oxygen in environmental samples. Graphical abstract fx1 Highlights • The investigation of the charge transfer of a chemiresistor material in the presence of different concentrations of molecular oxygen. • The resistance values of the material are very sensitive to variations in the O2 concentration. • The sensor exhibited good repeatability in the overall response of the chemiresistor per regeneration cycle. [ABSTRACT FROM AUTHOR]

A series of acrylic monomers based on cyclometalated iridium(III) complexes have been synthesized based on common phosphorescent emitters for organic light‐emitting diodes. A simple room‐temperature polymerization procedure for these materials was developed using Cu(0) reversible deactivation radical polymerization, providing polymers with low dispersities of 1.08–1.14 at conversions from 81 to 93% when the Ir complexes are copolymerized with a carbazole‐based acrylic host. These methods were also found to be suitable for the preparation of high‐molecular‐weight polymers with Mn approaching 40,000 Da, as well as block copolymers formed in one pot from the chain extension of methyl acrylate. This scalable room‐temperature synthesis of iridium‐containing copolymers and block copolymers provides a useful route to optoelectronic materials, which we anticipate can be readily adapted to a broad range of acrylic metallopolymers. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2539–2546 Methods are presented for the preparation of phosphorescent iridium‐containing acrylic copolymers by Cu(0) reversible‐deactivation radical polymerization. Dispersities below 1.12 and conversions up to 93% are achieved using a simple and scalable room‐temperature protocol. [ABSTRACT FROM AUTHOR]

The present paper describes the electrochemical activity of a Ni(II)‐Schiff base metallopolymer electrode for the oxidation of ethanol in alkaline media. The scanning electron microscope results show that the metallopolymer at the glassy carbon surface has a nanoflake‐like lamellar structure, and there is no molecular structural change after treatment with NaOH. Voltammetry measurements indicate that the metallopolymer acts as efficient material for the electrocatalytic oxidation of ethanol, where a high‐valent nickel(IV) was revealed as the reactive intermediate during the anodic scan. An isopotential point can be observed in rotating disk electrode voltammetry for ethanol oxidation. The electrode surface may be considered to consist of two independent electrochemical regions, one corresponding to the ethanol electro‐oxidation by nickel(IV) and the second corresponding to water oxidation. The Tafel slopes were found to be 246 mV dec−1 at low overpotentials and 44 mV dec−1 at high overpotentials, which suggest that the first electron transfer step is the rate controlling step. The specific activity of the metallopolymer‐modified electrode for the ethanol electro‐oxidation reaction was 6.66 mA cm−2 for 0.130 μmol cm−2 of electroactive species of metallopolymer at 0.6 V vs. SCE. The activity of a Ni(II)‐Schiff base metallopolymer electrodes for ethanol oxidation is investigated in alkaline media. Tafel slopes of 246 mV dec−1 at low overpotentials and 44 mV dec−1 at high overpotentials are found, suggesting that the first electron transfer step is rate controlling. An isopotential point is observed, revealing that the electrode surface may be considered to consist of two independent electrochemical regions. [ABSTRACT FROM AUTHOR]

The photo- and electroluminescent properties of a copolymer containing fluorene, terpyridine and complexed sites with trivalent europium ions (LaPPS66Eu) was investigated. The non- complexed backbone (LaPPS66) and an analogous chemical structure of the ligand/Eu 3+ site (LaPPS66M) as a model compound were used for comparison and interpretation of the photophysical properties. Experiments were carried out using PVK as a dispersive matrix either in a blend form or in a bilayer configuration. Absorption and emission spectra, time-resolved emission spectra (TRES) and Förster Resonance Energy Transfer efficiency () were used to account for the differences found for the photophysical properties of each configuration. [ABSTRACT FROM AUTHOR]

The chemically and electrochemically reversible ferrocene/ferricinium redox couple has attracted considerable attention, and a major application is dynamic redox switching of drug delivery systems (DDSs) constructed with ferrocenyl (Fc)-containing polymers. Owing to the accompanying hydrophobic/hydrophilic, neutral/cationic and complexation/dissociation transitions, the “on-demand” release of loaded drugs has been achieved in response to external redox stimuli. Thus, Fc-containing polymers provide a flexible and robust platform for the design and development of functional and smart DDSs. This review summarizes the most recent progress in the fabrication of DDSs with Fc-containing polymers based on the host–guest interactions of Fc/β-cyclodextrin (β-CD) and pillar[6]arene (PA). Fabrication techniques include solution self-assembly, mini-emulsion, layer-by-layer and template techniques. These Fc-containing polymers involve main-chain, side-chain and dendritic topologies in which the polymers behave in various supramolecular fashions. The discussed DDSs contain micelles, vesicles, nanoparticles, nanotubes, multilayer films and bulk hydrogels, and the corresponding stimuli involves electrochemistry, redox reagents, pH and temperature. Focus also is on the mechanisms of stimuli-responsiveness, fabrication methods, controlled release behaviors and potential applications of these DDSs including synergy with medicinal properties of ferrocene derivatives. The prospects of Fc-containing polymer-based DDSs are in nanomedicine whereby it will be possible to selectively deliver specific drugs to sick organs. Many studies detailed here concern chemical studies that still need to be adapted to in vitro , then in vivo studies in animals. From that point an ultimate and formidable challenge will consist in adapting such DDSs to man diagnosis and therapy. [ABSTRACT FROM AUTHOR]

Poly[2-(acetoacetoxy)ethyl methacrylate] (PAEMA), a functional polymer bearing pendant β-keto ester group was prepared via atom transfer radical polymerization (ATRP). The polymers were characterized by 1 H NMR, GPC and DSC analyses. 1 H NMR analysis showed that β-keto ester group present in the side chain of the PAEMA was more in the keto form as compared to the enol form. The reactive pendant β-keto ester group of PAEMA reacted with cobalt(II) ion to form metallopolymer which was characterized by FT-IR, UV–vis, TGA, DSC, FESEM and TEM analyses. This cobalt-polymer complex showed the formation of nanogel, as observed by DLS analysis. Importantly, this cobalt-polymer complex showed superparamagnetic behavior, as observed via superconducting quantum interference device (SQUID) analysis, indicating its potential application in magnetic fluid hyperthermia treatment and radiotherapy. [ABSTRACT FROM AUTHOR]

This paper reports the investigation of transmitted power through the nanostructured scandium polyacrylate (Sc(III) PAcr) deposited on flat borosilicate substrates to examine the adsorption/desorption of humidity at room temperature. For this purpose, the precursor of Sc(CH2 = CH-COO)3 was prepared and used for film deposition. The film was then investigated using scanning electron microscope (SEM) and UV–Visible (Vis) absorption techniques. SEM showed the spherical-shaped clusters of the material. Energy band gap of the film was estimated as 3.887 eV by UV–Vis spectrophotometer. Transmission electron microscope revealed the minimum grain diameter of ~21 nm and selected-area electron diffraction showed its polycrystalline nature. From Zeta nanosizer, minimum particle size was found as 18 nm. Fourier transforms infra-red spectroscopy confirmed the bond formation in the material. The surface area analysis shows that the pore volume of Sc(III) PAcr is 0.15 cm3/g, which is quite small, whereas the surface area and mean pore radius of the spherical structure are 60.1 m2/g and 41.2 Å, respectively. The film was employed as transmission-based opto-electronic humidity sensor. Maximum sensitivity was found as 2.1 \mu \textW /%RH with 89% reproducibility. Response and recovery times of the sensor were found as 25 and 155 s, respectively. [ABSTRACT FROM PUBLISHER]

Metal complexes of a poly(4-vinylpyridine- co -acrylamide) copolymer ( P1 ) exhibit significant hydrolytic and oxidation/oxygenation activities. These metallopolymers exhibit enzyme-mimicking selectivity, cooperativity, and induced-fit mechanism during catalyses. Fe 3+ - P1 exhibits a significant catechol dioxygenase activity in aqueous media with k 2(CA) = 0.011 M −1 s −1 and k 2(O2) = 0.213 M −1 s −1 for aerobic oxidative catechol cleavage, comparable to many structurally characterized complexes. The substrate-bound S –Fe(III)- P1 intermediates are characterized by the use of electronic, resonance Raman, and EPR spectroscopic methods. Copolymers generally lack well-defined structures, which nevertheless should not hinder further development of functional metallopolymers for broad applications. [ABSTRACT FROM AUTHOR]

2,1,3-Benzothiadiazole (BT) and its derivatives are very important acceptor units used in the development of photofunctional compounds and are applicable for the molecular construction of organic optoelectronic devices. Due to their strong electron-withdrawing ability, construction of molecules with the unit core of BT and its derivatives can usually improve the electronic properties of the resulting organic materials. New organometallic acetylide polymers of platinum(II) bridged by bis(fluorenyl)-benzothiadiazole moiety P1 and P2 have been synthesized via the CuI-catalyzed dehydrohalogenation reaction of the platinum(II) chloride precursors and the corresponding diacetylene ligands. The photophysical, thermal and electrochemical properties of P1 and P2 were investigated. Entry for the Table of Contents: Two new soluble platinum(II)-acetylide polymers bridged by bis(fluorenyl)-benzothiadiazole moiety are synthesized and their photophysical properties are examined. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Photocatalytic hydrogen production by dye photosensitizer and [FeFe]-hydrogenases model metallopolymers. • The catalyst still retains certain catalytic activity after 30 h of operation. • The total hydrogen production within 30 h reaches 9.95 mmol. • The TON number exceeds 24,530. In this paper, a kind of azapropylene [FeFe]-hydrogenases model (1) containing styrene structure was synthesized by classical ammonia condensation reaction. Then, a series of new metallopolymers (2a / 2b / 2c) were synthesized by copolymerization of styrene group and 2-(Dimethylamino)ethyl methacrylate (DMAEMA) with different proportions. The precursor (1) and metallopolymers (2a / 2b / 2c) were characterized by NMR, GPC, XPS, FT-IR, ICP-MS and TG-DTA, and the contents of metal model substance in the metallopolymers (2a / 2b / 2c) were accurately determined. Subsequently, the photocatalytic hydrogen production performance of the catalysts were studied. The photocatalytic system consists of photosensitizer (2,4,5,6-Tetrakis (diphenylamino)-isophthalonitrile), solvent (DMF/H 2 O) and electron donor (NEt 3). Under the optimized conditions, the maximum hydrogen production of the catalytic system can reach 0.704 mmol (1 , 0.34 mg) and 0.812 mmol (2a , 10 mg) within 1 h. The catalysts still have certain catalytic activity after 30 h of photocatalytic reaction. During a catalytic time of up to 30 h, 2c had the highest TON, with a value of 24530. In addition, the effect of the polymerization ratio of precursor 1 to DMAEMA monomer in the metallopolymers (2a / 2b / 2c) on the catalytic efficiency was also studied. [ABSTRACT FROM AUTHOR]

Abstract: Chemical and topographic surface patterning of inorganic polymer‐functionalized nanoparticles (NPs) and their self‐assembly in nanostructures with controllable architectures enable the design of new NP‐based materials. Capping of NPs with inorganic polymer ligands, such as metallopolymers, can lead to new synergetic properties of individual NPs or their assemblies, and enhance NP processing in functional materials. Here, for gold NPs functionalized with polyferrocenylsilane, two distinct triggers are used to induce attraction between the polymer ligands and achieve NP self‐assembly or topographic surface patterning of individual polymer‐capped NPs. Control of polymer–solvent interactions is achieved by either changing the solvent composition or by the electrooxidation of polyferrocenylsilane ligands. These results expand the range of polymer ligands used for NP assembly and patterning, and can be used to explore new self‐assembly modalities. The utilization of electrochemical polymer oxidation stimuli at easily accessible potentials broadens the range of stimuli leading to NP self‐assembly and patterning. [ABSTRACT FROM AUTHOR]

The rational design of under saturated redox-active metal centers distributed on the organo-polymeric surfaces has gained substantial attention in electrocatalysis. Herein, we report the ruthenium ions containing triazine-trithiolate (M-C 3 N 3 S 3 ) metallopolymers chemically coordinated to the copper substrate as a stable, low overpotential electrocatalyst for H 2 evolution in strong acidic media. The XPS analyses confirm the presence of Ru 4+ /Ru 3+ and Cu 2+ /Cu 1+ in the metallopolymers. XPS and FTIR spectral analysis suggest the presence of disulphide linkages. A significant overpotential reduction for hydrogen evolution is observed with CuRu-C 3 N 3 S 3 metallopolymer of just ∼−145 to −155 mV vs RHE to attain −10 mA cm −2 in 0.5 M H 2 SO 4 . The high exchange current densities and double layer capacitance could be attributed to the protonation capacity of redox-active centers and the uncoordinated ligand centers (N and S). The concerted proton-electron transfer mechanism improves the H 2 evolution. These metallopolymers show a low onset hydrogen evolution potential of just −45 mV vs RHE (i = −1 mA cm −2 ). Tafel slope values suggest the Volmer-Heyrovsky mechanism is involved in HER. The potentiostatic impedance spectral analyses indicate, CuRuTCA show the reduction in charge transfer resistance of nearly 10 and 700 times with respect to CuNiTCA and bare Cu electrodes respectively. These electrodes display an excellent long-term stability for hydrogen evolution. [ABSTRACT FROM AUTHOR]

Conducting metallopolymers have attracted a great deal of attention due to their multifunctional properties based on presence of metal centers as well as the interactions metal and p-conjugated polymer backbone. Due to their multifunctional properties, conducting metallopolymers have a great potential to use in various technological applications. In this work, starting with Lawesson's reagent and hydroxyl functionalized thiophene, a simple and rapid synthesis method for design conductive metallopolymer is proposed. Structural and electrochemical characterization of trans–bis[O-(thiopheneth-3-yl)(4-methoxyphenyl)dithiophosphonato]nickel(II) (TBTNi) were achieved. Spectroelectrochemical and electrochromic properties of the copolymer of TBTNi with thiophene were investigated. [ABSTRACT FROM AUTHOR]

The accurate regulation of the size of the ferromagnetic nanoparticle synthesized from the one-pot pyrolysis of metallopolymer is a challenging topic to date. A bimetallic complex TPy-FePd-1 was prepared and used as a single-source precursor to synthesize ferromagnetic FePd nanoparticles (NPs) by one-pot pyrolysis. The resultant FePd NPs have a mean particle size of 19.8 nm and show a coercivity of 1.02 kOe. In addition, the labile ligand NCMe in TPy-FePd-1 was easily substituted by a pyridyl group. A random copolymer PS-P4VP was used to coordinate with TPy-FePd-1 , and the as-synthesized metallopolymer made the metal fraction disperse evenly along the flexible chain. Investigation of FePd NPs from the bimetallic polymers with different metal fractions was also made, and the size of the resultant nanoparticles could be easily controlled by tuning the metal fraction in the polymer. [ABSTRACT FROM AUTHOR]

In this study, we report the synthesis and characterization of a new bis(pyridyl)-coordinated platinum(II)-containing metallopolyyne polymer. It is found that this metallopolymer can act as a precursor towards the synthesis of Pt nanoparticles upon pyrolysis (600 °C, 5 h). The resultant nanoparticles were characterized by transmission electron microscope (TEM), energy-dispersive X-ray analysis (EDXA) and powder X-ray diffraction (PXRD). The results verify that monodisperse Pt nanoparticles with defined morphology can be obtained. This pilot study reveals the potential of fabricating patterned Pt nanoparticles by using various lithographic methods in the future. [ABSTRACT FROM AUTHOR]

The main aim of this work is to study the respective contribution of the hard and soft blocks of a metal-ligand containing block copolymer to the self-healing behavior. To this aim, different block copolymers containing terpyridine were synthesized using reversible addition-fragmentation chain transfer (RAFT) polymerization. These block copolymers consisted of polystyrene as the hard block, n -butyl acrylate (BA) as soft block and terpyridine units as the ligand moiety placed at different locations in the soft block. These block copolymers were complexed with manganese(II) chloride to introduce transient crosslinks and, thus, self-healing behavior. Homopolymers with the hard and soft block only were also synthesized and tested. A quasi-irreversible crosslinking, i.e. by using nickel(II) nitrate, was performed in order to study the dynamics of the permanently (strongly) crosslinked network. Rheological master curves were generated enabling the determination of the terminal flow in these networks and the reversibility of the supramolecular interactions. Additionally, the macroscopic scratch healing behavior and the molecular mobility of the polymer chains in these supramolecular networks were investigated. A kinetic study of the scratch healing was performed to determine the similarities in temperature dependence for rheological relaxations and macroscopic scratch healing. In our previous work, we have explored the effect of strength of the reversible metal-ligand interaction and the effect of changing the ratio of hard to soft block. This work goes further in separating the individual contributions of the hard and soft blocks as well as the reversible interactions and to reveal their relative importance in the complex phenomenon of scratch healing. [ABSTRACT FROM AUTHOR]

The new ionic heterotrimetallic unsymmetrically-substituted Schiff base complex [Ni{( η -Cp)Fe( η -CH)-C(=O)CH=C(4-HO-CH)NCHCHN=CH-(2-O-( η -CH)Ru( η -Cp*)}][PF] ( 3; Cp = CH and Cp* = C(CH)) was prepared in 86% yield by a one-pot procedure by mixing equimolar amounts of 4-hydroxyphenyl functionalized ferrocenylenaminone 1, the organometallic aldehyde [( η -Cp*)Ru( η -2-HO-CHCHO)][PF] ( 2) and nickel(II) acetate tetrahydrate in refluxing ethanol for 2 h. Its corresponding side-chain metallopolymer 4 was synthesized by reacting the organometallic-inorganic hybrid 3 with polyacrylic acid (DP = 25) in DMF at 110 °C for 48 h with an equimolar quantity of N,N′-dicyclohexylcarbodiimide and a catalytic amount of 4-dimethylaminopyridine. The new complex 3 was characterized by FT-IR and multidimensional NMR spectroscopy, elemental analysis and mass spectrometry. Single crystal X-ray diffraction analysis of 3 showed that the ferrocenyl and [( η -Cp*)Ru] units exhibit an anti-conformation and are almost coplanar with the unsymmetrical Schiff base complex fragment, while the 4-HO-CH plane is almost perpendicular. The four-coordinate Ni metal ion adopts a square planar geometry, with two nitrogen and two oxygen donor atoms that are mutually trans. Size-Exclusion Chromatography established that metallopolymer 4 is formed of approximately three pendant ionic trimetallic units, while Differential Scanning Calorimetry and Thermal Gravimetric Analysis indicated that 3 and 4 are thermally stable with decomposition temperatures that exceed or border to 250 °C. Harmonic Light Scattering measurements at 1.91 µm incident wavelength showed that compounds 3 and 4 exhibit rather high second-order nonlinear responses, with hyperpolarizability β values strongly increasing on passing from the monomeric unit 3 to its metallopolymeric counterpart 4. [ABSTRACT FROM AUTHOR]

In this work, we report two metallopolymers ( Pt-P and Pd-P ) through coupling of Pt II or Pd II porphyrin with fluorene derivatives. The structure and photophysical properties of these two metallpolymers were fully characterized, which indicate that these two metallopolymers are of good capability for bioimaging of cancer cells. Hence, nanoprobes based on Pt-P and Pd-P for bioimaging of HeLa cancer cells were explored. The biological experimental results show that Pt-P NPs exhibit good biocompatibility and specificity to HeLa cancer cells due to its favorable NP size. [ABSTRACT FROM AUTHOR]

Metallomacromolecules are attracting considerable attention as a class of macromolecular materials with unique properties and applications. Although ferrocene (Fc)-containing macromolecules have occupied the dominant position for several decades in this area and have led to a variety of architectures and applications, the class of cobalt-sandwich-containing macromolecules has recently undergone a booming development. Especially, polymers and dendrimers containing the 18-e cationic cobalticenium (Cc) unit isoelectronic to Fc have been developed during the last few years after overcoming Cc functionalization problems and following the burst of living polymers and dendrimers. Subsequently, remarkable applications have been disclosed including materials physical properties, healthcare and engineering. Meanwhile several other metallopolymers with Co sandwiches containing cyclobutadiene or carborane ligands have also emerged. This review summarizes the most recent progress in the synthesis of metallomacromolecules containing cobalt sandwich complexes and their functional materials properties. Polymerization techniques have included radical polymerization, reversible addition fragmentation chain transfer (RAFT), ring-opening metathesis polymerization (ROMP), condensation polymerization, ring-opening polymerization (ROP), and atom transfer radical polymerization (ATRP), and post-polymerization has also been used. The applications include the formation of nanostructured materials, magnetic materials, redox recognition and sensing, lithographic patterning, antimicrobial materials, stimuli-responsive materials, catalysis and electrochemical devices. [ABSTRACT FROM AUTHOR]