Polymeric Metal Complexes Research Articles

Synthesis and photocatalytic efficiency of novel ZnO-CBS-Ni complex for diclofenac sodium under irradiation of light

The use of diclofenac sodium, a small molecular drug, is essential for treating inflammation in pharmacology. However, its extensive use can lead to environmental and water pollution. To address this issue, a new area of research involving nanomaterials and polymer-metal complexes for photo-degradation processes has emerged. As part of this research, we have developed nano-composites consisting of a biodegradable polymeric metal complex – a chitosan nickel metal complex coupled with a ZnO nanoparticle to eliminate the harmful effects of pharmaceutical residues in the environment is vital for achieving long-term sustainability and protecting natural resources. These nanocomposites have been successfully synthesized and analysed for their structure and optical properties using XRD, FT-IR, SEM, UV–visible, and band gap analysis techniques. The band gap value of the nano-composite falls within the semiconductor range. These synthesized nano-composites have been tested for the photo-degradation of diclofenac sodium in three different sources at various pH levels. The catalyst exhibited better activity in sunlight at acidic pH. We also explored the possible mechanism of photo-activity with the catalyst by combining the results of photo-degradation and the optical characterization of the nano-composite.

Preparation of Antimicrobial Agents: From Interpolyelectrolyte Complexes to Silver-Containing Metal–Polymer Complexes and Nanocomposites

In order to control pathogenic microorganisms, three polymer compositions were prepared and tested. First, a water-soluble positively charged polycomplex was synthesized via the electrostatic binding of anionic polyacrylic acid to an excess of polyethylenimine to enhance the biocidal activity of the polycation. Second, an aqueous solution of AgNO3 was added to the polycomplex, thus forming a ternary polycation-polyanion-Ag1+ complex with an additional antimicrobial effect. Third, the resulting ternary complex was subjected to UV irradiation, which ensured the conversion of Ag1+ ions into Ag nanoparticles ranging in size mainly from 10 to 20 nm. Aqueous solutions of the polymer compositions were added to suspensions of the Gram-positive bacteria S. aureus and the Gram-negative bacteria P. aeruginosa, with the following main results: (a) Upon the addition of the binary polycomplex, 30% or more of the cells survived after 20 h. (b) The ternary complex killed S. aureus bacteria but was ineffective against P. aeruginosa bacteria. (c) When the ternary complex with Ag nanoparticles was added, the percentage of surviving cells of both types did not exceed 0.03%. The obtained results are valuable for the development of antibacterial formulations.

Palladium-Functionalized Polysiloxane Drop-Casted on Carbon Paper as a Heterogeneous Catalyst for the Suzuki-Miyaura Reaction.

In this work, a Pd(II)-C,N-cyclometalated complex was grafted to polysiloxanes via azide-alkyne cycloaddition. The obtained polymer-metal complex (Pd-PDMS) acts as a catalyst in the Suzuki-Miyaura reaction. Pd-PDMS was drop-casted onto a carbon fiber support, and the resulting membrane demonstrated catalytic activity in the cross-coupling reaction without yield loss after several catalytic cycles. The catalytic membrane allows for easy catalyst recycling and provides ultra-low palladium levels in Suzuki-Miyaura reaction products.

Synthesis and Investigation of Catalytic Properties of Metal-Polymer Nanocomposites Based on Unsaturated Polyester Resins

This paper focuses on the hydrogenation process in metal-polymer complexes based on copolymers of polypropylene glycol fumarate phthalate and polypropylene glycol maleate phthalate, using acrylic acid and immobilized cobalt metal particles as catalysts. A classical reaction of the electrocatalytic hydrogenation of pyridine to piperidine was applied. SEM and dynamic light scattering were utilized to investigate the average size and dispersity of cobalt metal nanoparticles. The experimental findings show that the efficiency of hydrogenation can be improved by increasing the temperature from 25 to 40 °C and the current to 2 A. More specifically, increasing the temperature to 40 °C promotes swelling of the polymer and its transition from a globular collapsed state to an open one, which leads to an increase in the number of active catalytic centers and, as a consequence, acceleration of the hydrogenation process. Increasing the current strength to 2 A also helps to increase the rate of the hydrogenation process. Further increasing the current to 3 A is undesirable due to an increase in the yield of by-products and a decrease in the yield of the target product, piperidine. Based on a comparative analysis, it was established that the use of a copolymer of polypropylene glycol maleate phthalate with acrylic acid as the polymer matrix base is the most preferable for obtaining polymer-metal complexes with nanosized cobalt.

Preparation of gold nanoparticles by photolysis and radiolysis in alcohol solutions of functional hyperbranched polyorganosiloxane/H[AuCl4]: Effect of irradiation mode on nanoparticle size and formation mechanism

Ethanol solutions of functional hyperbranched polyorganosiloxanes (0.2 vol%) with a molar ratio of NH2(CH2)2NH-/H[AuCl4]x3H2O of 8/1 were used as precursors for nanocomposite preparation using UV photolysis and X-ray radiolysis. It was shown that various irradiation modes provide the synthesis of gold nanoparticles (AuNPs) with tunable sizes and narrow size distributions. It was established that size distributions of AuNPs depend on the excitation wavelength. AuNPs with an average size of 3.5 nm were obtained by the direct excitation of gold ions using UV light with λmax = 365 nm. Meanwhile, the action of a higher energy light (λ = 254 nm) on the metal polymer complexes resulted in formation of ultra-small nanoparticles with an average size of 1.5 nm, presumably due to the increased efficiency of their nucleation process. In the case of radiolysis with X-rays, reduction of Au3+ ions occurs due to reactions with radicals produced from ethanol and leads to the formation of AuNPs of 2–3 nm. Thus, the size distribution of the prepared AuNPs may be controlled by the irradiation mode, which critically affects nanomaterial properties. Additionally nanoparticles obtained by photochemical or radiation-chemical methods are free of chemical impurities, which is important for the development of functional materials.

Iridium(III)-Incorporating Self-Healing Polysiloxanes as Materials for Light-Emitting Oxygen Sensors.

Polymer-metal complexes (PMCs) based on poly(2,2'-bipyridine-4,4'-dicarboxamide-co-polydimethylsiloxanes) with cyclometalated di(2-phenylpyridinato-C2,N')iridium(III) fragments and cross-linked by Zn2+ (Zn[Ir]-BipyPDMSs) or Ir3+ (Ir[Ir]-BipyPDMSs) represent flexible, stretchable, phosphorescent, and self-healing molecular oxygen sensors. PMCs provide strong phosphorescence at λem = 595-605nm. Zn[Ir]-BipyPDMS with PDMS chain length of Mn = 5000 has the highest quantum yield of 9.3% and is a molecular oxygen sensor at different O2 concentrations (0-100vol%) compared to Ir[Ir]-BipyPDMSs. A Stern-Volmer constant is determined for Zn[Ir]-BipyPDMS as KSV = 0.014%-1, which is similar to the reported oxygen-sensitive iridium(III) complexes. All synthesized PMCs exhibit high elongation at break (up to 1100%) and self-healing efficiency (up to 99%).

Synthesis of bilaterally thiadiazole substituted vic-dioxime ligands and investigation of their polymeric metal complexes

In this study, three novels substituted 1,3,4-thiadiazole-derived vic-dioxime ligands and their corresponding polymeric transition metal (Co2+and Ni2+) complexes were synthesized and their structural characterizations were performed. For this purpose, 4,4′-bis(chloroacetyldiphenyl) ether (OKS1) was obtained from the reaction of diphenyl ether with chloroacetyl chloride at a 1:2 molar ratio with the help of the Friedel-Crafts reaction. Our first starting oxime compound “2,2′-(oxybis(4,1-phenylene))bis(N‑hydroxy-2-oxoacetimidoyl) chloride (OKS2)” was obtained from the reaction of OKS1 with butyl nitrite at a 1:2 molar ratio under the catalysis of HCl gas. Then, our final starting vic-dioxime compound “2,2′-(oxybis(4,1-phenylene))bis(N‑hydroxy-2-(hydroxyimino) acetimidoyl) chloride (OKS3)” was obtained from the reaction of OKS2 with hydroxylamine hydrochloride in ethanol media at 40 °C. Then, our three original target vic-dioxime compounds (OKL1-OKL3) were synthesized from the reaction of substituted 2-amino-1,3,4-thiadiazole compounds with OKS3. Structural characterizations of all synthesized organic compounds were made using elemental analysis, FTIR, 1H and 13C NMR and mass spectroscopy methods. Target complexes were obtained from the reaction of all ligands with MCl2.nH2O (M: Co2+and Ni2+) salts, and their structures were elucidated using FTIR, magnetic susceptibility, thermogravimetric analysis, elemental analysis, and ICP-OES spectroscopy methods.

Arsenate and cadmium ions removal from multicomponent solutions of ionic polymers using mesoporous activated biocarbons

Activated biocarbons (AC) obtained in the process of simultaneous pyrolysis and activation of lemon balm (LB) and mint (MT) herbs with H3PO4 were used to purify aqueous solutions of cadmium, arsenate, polyethylenimine (PEI) and poly(acrylic acid) (PAA). The metals show high toxicity in the whole range of their concentrations, whereas the polymers are cytotoxic at high concentrations.The efficiency of As(V) removal from an aqueous solution depends on the pH value, while the Cd(II) adsorption on the activated biocarbons surface is independent on this parameter. The maximum adsorbed amounts are 135.8 mg/g for Cd(II) and 109.6 mg/g for As(V), respectively. The removal of metals ions and polymers from binary systems is lower in comparison to the one-component solutions. This is a consequence of the formation of polymer-metal complexes, that tend to remain in the solution. Additionally, the surface charge density, zeta potential, the size of activated biocarbons aggregates in the aqueous suspensions and the influence of toxic metal ions on the determination of the concentration of polymers in water samples was investigated. The obtained results proved that the PEI concentration can be effectively determined in the presence of metal ions, whereas the procedure of PAA determination requires additional validation.

Новые полимерные комплексы гидразида изоникотиновой кислоты противотуберкулезного и иммуностимулирующего действия

Туберкулез относится к одному из социально значимых заболеваний. В научной литературе обосно-вана целесообразность использования полимерных матриц для иммобилизации протуберкулезных препаратов, что способствует завершению фагоцитоза. Проведено сравнительное исследование противотуберкулезной активности аналогов конденсата гидразида изоникотиновой кислоты при лечении экспериментального туберкулеза у мышей. Установлена эффективность использования хлоргидроксихитозанового комплекса с 1-изоникотинил-2-D-глюкозилгидрозон с включенным Со2+ в сравнении с хитозан-кобальт-1-изоникотинил-2-D-глюкозилгидрозоном при лечении экспериментального туберкулеза. Выявлена иммуностимулирующая активность полимерного металлокомплекса, сравнимая с комплексом хитозан-кобальт-1-изоникотинил-2-D-глюкозилгидрозон. Полученные в эксперименте ре-зультаты могут использоваться при разработке современных методов лечения туберкулеза.

SIMULATION OF THE KINETICS OF HETEROGENEOUS OXIDATION OF N-HEPTANE BY OXYGEN

The catalytic reaction of n-heptane (n-C7H16) oxidation with molecular oxygen has been studied. Various compositions of the polymer catalyst Mn-P4VP/MBAA (where Mn-P4VP is manganese-immobilised poly-4-vinylpyridine and MBAA is N,N′-methylene-bis-acrylamide) containing 2-5 wt% Mn were prepared and tested. The concentration of manganese in the catalyst based on immobilized metal-polymer complexes is within the range of 2-5 wt% Mn. The oxidation reaction was carried out at a ratio of components n-C7H16/O2/polymer catalyst with Mn = 1 : 3.38 : 0.003 and time 6 h within the temperature range 303-383 K. The data on the yield of the major products of n-heptane oxidation are presented, taking into account the initial components, catalyst composition, temperature and the time of oxygen contact with the reacting components. It has been established that during the oxidation of n-C7H16 (303-383 K), the yield of alcohols is higher than the yield of other oxidation products. The oxidative conversion of n-heptane increases from 45 to 75 mol% with an increase in temperature in the range of 303-383 K. For the multistage oxidation of n-heptane with oxygen, a kinetic model was selected and considered. On the basis of this model, the reaction rate constants were calculated in the range of 303-383 K considering the degree of heptane conversion. The activation energy of n-heptane oxidation was estimated, taking into account the method of choosing the most plausible parameter and experimental data on n-heptane convection.

The copolymerized sulfur coordination-metal complex dye sensitizer exhibiting the highest power conversion efficiency (PCE) 11.78% in dye sensitized solar cells

Polymeric metal complex dyes have been recognized as a significant class of dye sensitizer for optoelectronic applications due to their unique properties. In order to improve the light absorption and photovoltaic performance and to decrease costs, five novel D-A-π-A motif copolymerized sulfur coordination-metal complexes (BDTT-BBT-Ni, BDTT-BBT-Cu, BDTT-BBT-Zn, BDTT-BBT-Cd and BDTT-BBT-Hg) have been designed and synthesized for being used as dye sensitizer. And the photovolataic performance test results show that the highest PCE of the copolymer complex BDTT-BBT-Hg of five copolymers has reached 11.78% and the copolymer dye sensitizers are simple and inexpensive to synthesize and have good solubility. These results provide a new way to develop stable and efficient metal complexes with sulfur coordination dye sensitizers in the future.

WATER PURIFICATION FROM HEAVY METAL IONS USING LIME AND PHMG

The method of metal ions' chemical precipitation using polyhexamethylene guanidine (PHMG) and calcium oxide (CaO) was employed for extracting metal ions from concentrated solutions. The order of reagent introduction was found to be crucial in the extraction process, with the best extraction efficiency observed when PHMG was added to water before CaO. This order of addition facilitated the polyelectrolyte effect, resulting in the unfolded conformation of macromolecules and enhancing their interaction with metal ions in solution. Optimal dosage ranges were determined, coinciding with the concentration interval of the polyelectrolyte effect, which maximized the flocculation ability and complex formation of PHMG. The combined use of PHMG and CaO, along with variations in pH, achieved high degrees of metal ion removal (>99%) in a single stage of solution treatment, except for chromium (Cr3+) and cobalt (Co2+). The surface activity of PHMG and ability to transfer metal ions as metal-polymer complexes supported its use in the flotation method for extracting heavy metal ions from low-concentration aqueous solutions. The kinetics of PHMG and metal ion removal by flotation showed rapid binding of metal ions to polymer macromolecules, and regression equations were established to describe the kinetics. The residual concentrations of metal ions after flotation met regulatory sanitary and environmental requirements for wastewater and drinking water. A two-stage scheme for heavy metal ion extraction was developed, involving chemical precipitation and flotation extraction, with a pilot plant designed and manufactured for testing. During wastewater treatment in an electroplating production setting, metal ion concentrations that complied with regulatory standards were achieved.

Polymers with [2,2′-Biquinoline]-diyldimethanamine Units in the Main Chain and Their Metal–Polymer Complexes with Copper(I)

Polymers with [2,2′-Biquinoline]-diyldimethanamine Units in the Main Chain and Their Metal–Polymer Complexes with Copper(I)

Insight into the shear stability of the polymer-metal complexes: Experiment and density functional theory studies

We present a detailed investigation on the shear stability of the PAA-M (M = Co(II), Ni(II) and Cu(II)) complexes using sodium polyacrylate (PAAS) as complexant by shear induced dissociation coupling with ultrafiltration (SID-UF) experiment and density functional theory studies. The theoretical calculations were performed at the PBE0/def2-TZVP level of theory for the complexation geometries which used two monomers of PAAS ligands bind with M cations. Two different coordination modes with or without the hydration of metal cations have been considered in the calculations. Different analyses were carried out: optimized configuration, interaction energy, Gibbs free energy change, frontier molecular orbital and electron transfer. The results of theoretical calculations were in good agreement with experimental work although with quite small stability difference. The presence of water molecules as explicit solvent clearly affected the most favorable binding configurations and presented a more credible prediction on the stability difference of PAA-M complexes. The findings of charge decomposition analysis showed that the origin of the difference in the stability of PAA-M complexes related to the number of electrons transferred from the ligands to the central metal cations.

Synthesis, Characterization and Antimicrobial Study of Polyacetal-Co complex/Nano Chitosan polymer blend

Polycyclicacetal was prepared by the reaction of PEG with 4-nitrobenzaldehyde. Cobalt was used for producing a polymer metal complex and solution casting was used to produce a polymer blend including nano chitosan. All produced compounds have been characterized by FT-IR, DSC/ TGA, and SEM techniques as well as biological activity. The production of polyacetal is illustrated by the FT-IR analysis. The DSC/TGA results indicate the prepared polymer blends' thermal stability. Staphylococcus aureas, Klebsiella pneumoniae, Bacillus subtilis, and Escherichia coli were the four types of bacteria selected to study and evaluate the antibacterial activity of produced polyacetal, its metal complex, and polymer blend. Results indicates that there is a greater potential to kill bacteria by increasing the amount of polyacetal-Co complex.

Sensitizers of Metal Complexes with Sulfur Coordination Achieving a Power Conversion Efficiency of 12.89.

In the study to improve the light absorption range and intensity of dye sensitizers in the visible region and promote their photovoltaic performance, five novel polymeric metal complexes with sulfur coordination (BDTT-VBT-Ni, BDTT-VBT-Cu, BDTT-VBT-Zn, BDTT-VBT-Cd, and BDTT-VBT-Hg) to be used as D-A-π-A motif dye sensitizers were designed, synthesized, and characterized. In these polymeric metal complexes with sulfur coordination, the metal complexes with sulfur coordination of benzodithiophene derivatives are used as auxiliary electron acceptors, 8-quinolinol derivatives are used as π-bridge and electron acceptors, and thienylbenzene-[1,2-b:4,5-b'] dithiophene (BDTT) are used as electron donors. The effect of different metal complexes with sulfur coordination on the photovoltaic performance of dye sensitizers has been systematically studied. Under AM 1.5 irradiation (100 mW cm-2), the devices of dye-sensitized solar cells (DSSCs) based on five polymeric metal complexes with sulfur coordination exhibited a short-circuit current density (Jsc) of 13.43, 15.07, 18.00, 18.99, and 20.78 mA cm-2, respectively, and their power conversion efficiencies (PCEs) were 7.10, 8.59, 10.68, 11.23, and 12.89%, respectively, and their thermal decomposition temperatures (Td) were 251, 257, 265, 276, and 277 °C, respectively. The result shows that the Jsc and PCE of five polymeric metal complexes increase by degrees, and the PCE of BDTT-VBT-Hg is up to 12.89%, which is because of the strength of the coordination bonds between Ni(II), Cu(II), Zn(II), Cd(II), and Hg(II) and sulfur increases in turn so that the electron-withdrawing ability and electron-transfer ability of auxiliary electron acceptors is enhanced. These results provide a new way to develop stable and efficient metal complexes with sulfur coordination dye sensitizers in the future.

STUDY OF THE LIQUID-PHASE HYDROGENATION OF BENZENE IN THE PRESENCE OF METAL-POLYMER COMPLEXES BASED ON POLYVINYLPYRIDINES

The liquid-phase hydrogenation of benzene on metal-polymer complexes, which were prepared on vinylpyridine polymers containing functional groups and salts of transition metals such as nickel, palladium, and platinum, was studied. Poly-4-vinylpyridine and poly-2-methyl-5-vinylpyridine were used as vinylpyridine polymers. Hydrogenation was carried at a temperature of 20-600 C. The study additionally focussed on the influence of the nature of the medium on the benzene hydrogenation process on poly-4-vinylpyridines. It has been established that in the presence of a platinum-poly-4-vinylpyridine complex, the reaction of liquid-phase hydrogenation of benzene, not only the product of complete hydrogenation, but also products of incomplete hydrogenation, cyclohexene, are formed. It was also found that the nature of the medium affects the yield of cyclohexane and cyclohexene selectively and effectively

Synthesis of new bifunctional derivatives of 2,2′-biquinoline and their polymers and metal-polymer complexes with CuI

Synthesis of new bifunctional derivatives of 2,2′-biquinoline and their polymers and metal-polymer complexes with CuI

Synthesis, Spectroscopic Characterization and Thermal Studies of Polymer-Metal Complexes Derived from Modified Poly Styrene-Alt-(Maleic Anhydride) as a Prospects for Biomedical Applications

Eight polymer-metal complexes were synthesized from complexation of divalent Mn(II), Ni(II), Co(II), and Cu(II) metal ions with modified polystyrene-alt-(maleic anhydride) (PSMAP and PSMAM) ligands. The structures of these new complexes were characterized using a variety of techniques, including magnetic moment susceptibility, conductance measurements, FT-IR spectroscopy, ultraviolet-visible (UV-VIS), thermogravimetric analysis (TGA), as well as scanning electron microscopy (SEM). All metal-polymer complexes have a non-electrolytic nature based on conductance measurements. The polymer molecule behaves as neutral bidentate NO ligand through O atoms of carbonyl (C=O) and N atoms of amide (O=C-NH). Divalent Mn2+, Ni2+, Co2+ and Cu2+ complexes have an octahedral geometry based on their electronic spectra and magnetic values. Based on thermal analysis data, those new complexes are more thermally stable than the ligands. SEM and TEM are manipulated to give the surface structure and the particle size measurements where they give different shapes and sizes of the synthesized complexes.

Facile casting preparation of hydrophilic coordinated PVA–Zn ion coatings with strong adhesion and high water tolerance

Fogging on transparent surfaces may severely influence vision. Thus, antifogging coatings are in high demand. Poly vinyl alcohol (PVA) and zinc chloride were mixed to prepare hydrophilic coatings (denoted as PVA/Zn2+ coatings) on glass substrates using the casting method with contact angles <59°. The polymer-metal complex was formed by the coordination of ZnCl2 with the hydroxyl groups of PVA. The adhesion and water resistance of the coating were improved by adjusting the mole ratio of PVA to Zn2+. A 5B adhesion grade of the optimal mole ratio of PVA to Zn2+ was determined according to the standard of the American Society of Testing Materials D3359, and the lap shear strength was 2.39 ± 0.42 MPa. The coordination between OH and Zn2+ was evidenced by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. UV–vis spectra show that the coating has a high optical transmittance (>90 %). In addition, the coating was applied on four common hydrophobic substrate surfaces to obtain hydrophilic surfaces. The antifogging performance of the coating indicates its potential application to many materials such as in transparent optical devices.