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Recent advances in industrial catalysis are very important for the development of effective and efficient catalysts and catalytic methods. The review largely focuses on immobilization techniques that have been utilized for metal complexes, usually mesoporous materials such as silica, alumina, and zeolite. The supported catalysts have a wider range of catalytic applications than their neat or homogeneous counterparts. The active metal compound may be retained on the solid support by adsorption, ion exchange, encapsulation, or the formation of a covalent bond between the metal–ligand and the solid support. The supported complexes are used as catalysts for organic transformation reactions, such as oxidation and functionalization of organic compounds.

In this study, biopolymer composites based on chitosan (CS) with enhanced optical properties were functionalized using Manganese metal complexes and black tea solution dyes. The results indicate that CS with Mn 2+ -complexes can produce polymer hybrids with high absorption, high refractive index and controlled optical band gaps, with a significant reduction from 6.24 eV to 1.21 eV. The refractive index and optical dielectric constant measurements show that the doped CS films have more charge carriers and traps than those in pure CS films. The Lorentz-Drude model was used to derive several significant optical parameters, and the W-D model was utilized to calculate the optical moments M -1 changing from 0.35 to 2.13 and M -3 changing from 0.005 to 0.4. It was shown that the doped samples have larger Urbach energy than pure film, increased from 0.29 to 0.55 eV. Tauc and ASF model was also used to calculate the electronic transitions, band structure, and optical characteristics. Bandgap energy based on Tauc model at m = 2, 1/3, 1/2, and 2/3 are 1.77, 1.54, 1.47, and 1.37 eV, based on ASF model are 1.52, 1.42, 1.69, and 1.47 eV, respectively. As a result of changes in the optical diffraction parameters the optical mobility ( ) changed from 1.67 to 1.27 and optical resistivity from 9.36 × 10 –27 to 4.0 × 10 –29 . The dopped samples show an increase in their linear optical susceptibility, third-order nonlinear optical susceptibility and nonlinear refractive indices, changing from 3.165 × 10 –15 to 2.831 × 10 –12 esu. Finally, light propagation velocities, surface resistance, and thermal emissivity were also examined.

The current study used sustainable and green approaches to convey polymer composites with desired optical properties. The extracted green tea dye (GTD) enriched with ligands was used to synthesize zinc metal complexes. Green chitosan biopolymer incorporated with green synthesized metal complex using casting technique was used to deliver polymer composites with improved optical properties. The FTIR-ATR was used to identify the functional groups of the GTD, pure CS, and functional groups surrounding the synthesized zinc metal complex. Distinguished ATR bands were observed in green tea dye spectra, such as OH, C = O, and NH functional groups ascribed to various polyphenols. The ATR bands of the zinc metal complex compared to GDT established that GDT is crucial to capturing zinc cations and producing the Zn 2+ -metal complex. The broadness of the bands observed in CS-based composites inserted with the Zn 2+ - metal complex confirms strong interaction among the components of polymer composites. The XRD achievements confirm that CS films with different Zn2+- metal complex concentrations transferred to an amorphous composite. The XRD pattern of composite films establishes that the zinc metal complex scarified the crystalline phases of chitosan. Linear optical properties such as absorption, refractive index (n), and optical dielectric parameters were improved. The absorption edge of the composite’s films shifted to lower photon energies. Various models were used to determine the optical band gap. The band gap drops from when chitosan is loaded with a 36% Zn 2+ -metal complex. The Spitzer-Fan method is used to get the dielectric constant, and the Drude Lorentz oscillator model was used to calculate vital optical parameters, including N/m* , τ , and µ opt . The W-D single oscillator model was used to determine the E o and E d parameters. The values of optical moments ( M −1 and M −3 ) were calculated with the help of the W-D model. The oscillator’s strength ( ) and wavelength ( ) were determined via the Sellmeier model using the linear refractive index. The first-order nonlinear ( ), second-order non-linear ( ) and third-order nonlinear optical susceptibility ( ) were determined for all the films.

The chemistry of transition‐metal (TM) complexes with monoanionic bidentate (κ2‐L,Si) silyl ligands has considerably grown in recent years. This work summarizes the advances in the chemistry of TM‐(κ2‐L,Si) complexes (L=N‐heterocycle, phosphine, N‐heterocyclic carbene, thioether, ester, silylether or tetrylene). The most common synthetic method has been the oxidative addition of the Si−H bond to the metal center assisted by the coordination of L. The metal silicon bond distances in TM‐(κ2‐L,Si) complexes are in the range of metal‐silyl bond distances. TM‐(κ2‐L,Si) complexes have proven to be effective catalysts for hydrosilylation and/or hydrogenation of unsaturated molecules among other processes. This work summarizes the advances in the chemistry of transition metal complexes with monoanionic bidentate ligands κ2‐L,Si (L=N‐heterocycle, phosphine, N‐heterocyclic carbene, thioether, ester, silylether or tetrylene).

Photoactive complexes of nonprecious transition metals, mainly including those in the first-row and partially the second-row of the Periodic table of elements, have received increasing attention in view of their low cost and long-term sustainability. They are recognized as promising alternatives to noble transition metal complex congeners that have been extensively studied in optoelectronic devices, artificial photosynthesis, photocatalysis, biodiagnostics, and therapeutics, etc. This review is devoted to a comprehensive summary on the classical and recent advances on photoactive nonprecious transition metal complexes, including photoactive Zr, V, Cr, Mo, and W complexes, Mn complexes and hybrids, Fe, Co, Ni, and Cu complexes, and Zn and Cd complexes and hybrids. A particular focus is given on the molecular design, modulation of photophysical and photochemical properties, and applications of the representative and lately-developed nonprecious metal complexes. In addition, a perspective on the future development in this field is provided at the end of this review.

Schiff bases transition metal complexes have received significant attentions in the scientific community for their versatile applications. The incorporation of metals to Schiff base ligands attracts much attention, since the metals and Schiff base ligands coordinated via bonding. Thus, chelation effects will enhance and improve the biological activities of the derivatives of title compound. Most of these derivatives displayed broad range bioactivities including antibacterial, antifungal, antituberclosis, antimalarial, antioxidant, antidiabetic, anti-inflammatory and anticancer activities. Up to date, continuous efforts are being made in various research groups to design the outcomes of more potent, novel and safe synthetic protocols towards the Schiff base metal complexes. Therefore, this review summarizes the various synthetic protocols and pharmacological activities of Schiff base metal complexes and their derivatives. Here, the synthesis of Schiff base ligands and their complexes with metals Cu(II), Pt(II), Ni(II), Pd(II), Ru(II, III), V(III), Cd (II), Zn(II), Co(II, III) and Mn(II, III) will be presented ( 2013–2022 ).

In this study breakthrough methodology has been used to deliver advanced polymer composites based on polyvinyl alcohol (PVA) integrated with green-synthesized nickel metal complex (NiMC), utilizing a simple casting methodology. The structural and optical characteristics of PVA composite films were studied using XRD, FTIR, and UV-Vis spectroscopy, respectively. Band shifting in FTIR spectra and broadening of sharp peak in PVA composites compared to pure PVA establish strong interaction between NiMC and PVA functional groups. The surface of the films was examined for roughness and phase separation using FESEM investigation. Various optical models were employed to determine the optical band gap (E g ). The E g decreased from 6.05 eV to 1.69 eV for direct and 1.21 eV for indirect transitions. The increase in Urbach energy from 0.28 to 0.62 eV was correlated with XRD results. The oscillator energy parameters were determined from the empirical Wemple-DiDomenico model. The real and imaginary dielectric constants, volume and surface energy loss functions, optical density, 3rd order susceptibility X (3) , nonlinear refractive index n (2) and skin depth was studied in detail. Optical oscillator strengths( f ), optical moments M − 1 and, and interband strength M − 3 were also determined. The ( J ) and figure of merit (φ) versus hv were used to specify the photons that are capable to electron transfer from HOMO to LOMO orbitals. The optoelectronic parameters, including (N/M * ), t , ( w p ), ( u opt ), ( P opt ), the average interband oscillator wavelength, and average oscillator strength( S o ), were also determined for all the films.

This work explores time-resolved emission imaging microscopy (TREM) for noninvasive imaging and mapping of live cells on a hitherto uncharted microsecond time scale. Simple robust molecules for this purpose have long been sought. We have developed highly emissive, synthetically versatile, and photostable platinum(II) complexes that make TREM a practicable reality. [PtLCl], {HL = 1,3-di(2-pyridyl)benzene and derivatives}, are charge-neutral, small molecules that have low cytotoxicity and accumulate intracellularly within a remarkably short incubation time of 5 min, apparently under diffusion control. Their microsecond lifetimes and emission quantum yields of up to 70% are exceptionally high for transition metal complexes and permit the application of TREM to be demonstrated in a range of live cell types--normal human dermal fibroblast, neoplastic C8161 and CHO cells. [PtLCl] are thus likely to be suitable emission labels for any eukaryotic cell types. The high photostability of [PtLCl] under intense prolonged irradiation has allowed the development of tissue-friendly NIR two-photon excitation (TPE) in conjunction with transition metal complexes in live cells. A combination of confocal one-photon excitation, nonlinear TPE, and microsecond time-resolved imaging has revealed (i) preferential localization of the complexes to intracellular nucleic acid structures, in particular the nucleoli and (ii) the possibility of measuring intracellular emission lifetimes in the microsecond range. The combination of TREM, TPE, and Pt(II) complexes will be a powerful tool for investigating intracellular processes in vivo, because the long lifetimes allow discrimination from autofluorescence and open up the use of commonplace technology.

The development of flame-retardant materials has become an important research direction. For the past dozen years, researchers have been exploring flame retardants with high flame-retardant efficiency, low toxicity, less smoke, or other excellent performance flame retardants. Therefore, this work aimed to synthesize new cyclodiphosph(V)azane derivatives and their Cu(II) and Cd(II) metal complexes and investigated their potential applications as high flame-retardant efficiency. Various techniques were used to characterize the prepared ligand H 2 L and its metal complexes, including elemental analyses, mass spectra, conductivity measurements, electronic spectral data UV–vis, FT-IR, 1 H, 13 C-NMR, TGA, XRD, and molecular docking experiments studies were M. tuberculosis receptors (PDB ID: 5UHF) and the crystal structure of human topoisomerase II alpha (PDB ID: 4FM9). Wood-based paint was physically mixed with the ligand H 2 L and its metal complexes. The obtained results of mechanical characteristics of the dried paint layers were noticed to improve, such as gloss value, which ranged from 85 to 95, hardness 1.5–2.5 kg, adhesion 4B to 5B, and impact resistance, which improved from 1.3 to 2.5 J. Moreover, the obtained results of flame-retardant properties showed a significant retardant impact compared to the blank sample, such as ignitability, which includes the heat flux which increased from 10 to 25 kW/m 2 , and ignition time, ranging from 550 to 1200 s, respectively, and limiting oxygen index (LOI) (%) which has been increased from 21 to 130 compared with the plywood sample and sample blank. The ordering activity of the observed results was noticed that coated sample based on Cd(II) metal complexes > coated sample based on Cu(II) metal complexes of Cyclophosphazene ligand > coated sample based on phosphazene ligand H 2 L > coated sample without additives > uncoated sample. This efficiency may be attributed to (1) the H 2 L is an organophosphorus compound, which contains P, N, Cl, and aromatic six- and five-member ring, (2) Cu(II) and Cd(II) metal complexes characterized by high thermal stability, good stability, excellent performance flame retardants, and wide application.

This work indicates that glycerolized chitosan-NH4F polymer electrolytes incorporated with zinc metal complexes are crucial for EDLC application. The ionic conductivity of the plasticized system was improved drastically from 9.52 × 10−4 S/cm to 1.71 × 10−3 S/cm with the addition of a zinc metal complex. The XRD results demonstrated that the amorphous phase was enhanced for the system containing the zinc metal complex. The transference number of ions (tion) and electrons (te) were measured for two of the highest conducting electrolyte systems. It confirmed that the ions were the dominant charge carriers in both systems as tion values for CSNHG4 and CSNHG5 electrolytes were 0.976 and 0.966, respectively. From the examination of LSV, zinc improved the electrolyte electrochemical stability to 2.25 V. The achieved specific capacitance from the CV plot reveals the role of the metal complex on storage properties. The charge–discharge profile was obtained for the system incorporated with the metal complex. The obtained specific capacitance ranged from 69.7 to 77.6 F/g. The energy and power densities became stable from 7.8 to 8.5 Wh/kg and 1041.7 to 248.2 W/kg, respectively, as the EDLC finalized the cycles.