A Flexible Hexacarboxylate-Samarium(III) Metal–Organic Framework: Synthesis, Structure and Spectroscopic Properties

A new flexible triazine-based polycarboxylate metal–organic framework, [Sm₂(TTHA)(H₂O)₄]·9H₂O (I) (TTHA = 1,3,5-triazine-2,4,6-triamine hexaacetate), has been synthesized under hydrothermal conditions and characterized by single crystal X-ray diffraction, elemental analysis and FT-IR spectroscopy. Crystal data for I are monoclinic C2/c, a = 12.6974(13) Å, b = 16.7309(12) Å, c = 14.8076(15) Å, β = 91.452(8)°, V = 3,144.7(5) Å³. Each Sm^III ion is 9-coordinate in a distorted tri-capped trigonal prismatic geometry; but, the principal inorganic building block is {Sm₂O₁₆}, which comprises two of these polyhedra that share an edge. The complex exhibits a three-dimensional open-framework structure of approximately 31 % void volume, which comprises two types of channels oriented in three directions; [0 0 1], [1 1 0] and [?1 1 0]. The network can be simplified into either the cooperite (pts) or anatase (ant) topologies depending on the choice of nodes. The UV–Vis spectra of the compound are dominated by the absorption of the TTHA ligand. Thermogravimetric analysis shows that the loss of channel and coordinated water upon heating occurs in two distinct steps.     

Effect of l-Histidine Substitution on Sol–Gel of Transition Metal Coordinated Poly Ethyleneimine: Synthesis and Biochemical Characterization

The study was aimed to investigate the effect of chemical modification of branched poly ethyleneimine (PEI) on chelation of transition metal ions (Me²⁺) including Zn²⁺, Cu²⁺ or Ni²⁺ and sol–gel conversion thereof. To modulate chelation property of PEI, imidazole moieties were introduced into the polymer backbone by carbodiimide chemistry at different molar ratios of fmoc-protected l-histidine. The synthesis was characterized by ¹H-NMR spectroscopy and size exclusion chromatography. Potentiometric titration of PEI/Me²⁺ aqueous dispersions showed formation of stable complexes at pH above 5 depending on the degree of l-histidine substitution. FT-IR spectroscopy showed the imidazole ring of l-histidine was involved in the coordination interactions between PEI and Me²⁺. Addition of Zn²⁺ to PEI solution induced sol–gel conversion at a critical molar ratio decreasing by a higher degree of l-histidine modification. The gelation process led to formation of stable globular nanostructures as confirmed by atomic force microscopy with projected mean diameters less than 200 nm. Cellular experiment showed that l-histidine substitution enhanced cyto-compatibility of PEI, moreover cytotoxicity decreased significantly upon coordination of Zn²⁺ with the polymers. Conclusively, the coordination complexes of Zn²⁺ and l-histidine substituted PEI could serve as a nano system for biomedical applications.     

Synthesis, Characterization, Conductivity, Band Gap, and Thermal Analysis of Poly-[(2-mercaptophenyl)iminomethyl]-2-naphthol and Its Polymer–Metal Complexes

Oxidative polycondensation reaction conditions of [(2-mercaptophenyl)iminomethyl]-2-naphthol (2-MPIM-2N) were studied using oxidants such as air and NaOCl in an aqueous alkaline medium between 40 °C and 90 °C. The structure of poly-[(2-mercaptophenyl)iminomethyl]-2-naphthol (P-2-MPIM-2N) was characterized by ¹H- ¹³C NMR, FT-IR, and UV–Vis spectroscopy, size exclusion chromatography (SEC), and elemental analysis. At optimum reaction conditions, the yield of P-2-MPIM-2N was found to be 78 and 82% for air and NaOCl oxidants, respectively. From SEC measurements, the number-average molecular weight (M _n ), weight-average molecular weight (M _w ) and polydispersity index (PDI) of P-2-MPIM-2N are 2900, 3500 g mol⁻¹ and 1.207; 2200, 2500 g mol⁻¹ and 1.136, for air and NaOCl oxidants, respectively. Polymer–metal complexes were synthesized by the reaction of P-2-MPIM-2N with Co²⁺, Cu²⁺, Zn²⁺, Pb²⁺ and Cd²⁺ ions. The highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), and electrochemical band gaps (E^￠_g E^{\prime}_{g} ) of 2-MPIM-2N and P-2-MPIM-2N were −5.97, −2.66 and 3.31 eV and −5.82, −2.68 and 3.14 eV, respectively. The conductivity of polymer and polymer–metal complexes were determined in the solid state. Conductivity measurements of doped and undoped Schiff base polymer and polymer–metal complexes were carried out at room temperature and atmospheric pressure by the four-point probe technique using an electrometer. The conductivities of the polymer and polymer–metal complexes increased when iodine was used as doping agent.     

Correction to: Two New Co(II) Complexes of Picolinate: Synthesis,Crystal Structure,Spectral Characterization, α-Glucosidase İnhibition and TD/DFT Study

Journal of Inorganic and Organometallic Polymers and Materials -     

Metal–Organic Framework Based on Pyridine-2,3-Dicarboxylate and a Flexible Bis-imidazole Ligand: Synthesis, Structure, and Photoluminescence

A novel metal–organic framework {[Zn(2,3-pydc)(bbi)]·0.5CH₃CN·2H₂O} _n (2,3-pydc = pyridine-2,3-dicarboxylate, bbi = 1,1′-(1,4-butanediyl)bis(imidazole)) (1), was prepared under hydrothermal conditions and characterized by elemental analyses, IR and X-ray diffraction. Crystal data for 1 are monoclinic, space group C2/c, a = 19.685(2) Å, b = 14.332(1) Å, c = 16.930(2) Å, β = 121.205(2)°, U = 4085.3(6) Å³, Z = 4. The results reveal that the Zn(II)-atom is five-coordinated with two O-atoms and three N-atoms forming a distorted trigonal bipyramidal geometry. The Zn(II) atoms are bridged by 2,3-pydc and bbi ligands, leading to a three-dimensional network. The Zn···Zn separations are 8.277 Å [through the 2,3-pydc bridge] and 12.638 Å [through the bbi bridge]. Additionally, 1 shows strong fluorescence in the solid state at room temperature.     

Synthesis,Characterization of Fulvic Acid–Poly(Methylmethacrylate) Graft Copolymers Based on Surface-Initiated Atom Transfer Radical Polymerization and its Effect on Performance of Poly(Lactic Acid)

Fulvic acid–poly(methylmethacrylate) graft copolymers were synthesized by surface-initiated atom transfer radical polymerization with fulvic acid. The result demonstrated that the hydrophobicity of fulvic acid–poly(methylmethacrylate) was improved after modification by surface-initiated atom transfer radical polymerization. Furthermore, poly(lactic acid)/fulvic acid–poly(methylmethacrylate) composites were prepared to improve the performances of poly(lactic acid) by blend melting. Compared to poly(lactic acid) with X_c of 5.38%, the X_c of poly(lactic acid)/fulvic acid–poly(methylmethacrylate) composites was 19.94%. Moreover, the impact strength of poly(lactic acid)/fulvic acid–poly(methylmethacrylate) composites was increased by 5.19% compared to poly(lactic acid). In all, this study provided an effective and feasible method for optimizing interface performance and enhancing the thermal stability of poly(lactic acid).     

Novel poly(ε-caprolactone)s bearing amino groups: Synthesis,characterization and biotinylation

A novel functional ε-caprolactone monomer containing protected amino groups, γ-(carbamic acid benzyl ester)-ε-caprolactone (γCABεCL), was successfully synthesized. A series of copolymers [poly(CL-co-CABCL)] were prepared by ring-opening polymerization of ε-caprolactone (CL) and γCABεCL in bulk using tin (II)-2-ethylhexanoate [Sn(Oct)₂] as catalyst. The morphology of the copolymers changed from semi-crystalline to amorphous with increasing γCABεCL monomer content. They were further converted into deprotected copolymers [poly(CL-co-ACL)] with free amino groups by hydrogenolysis in the presence of Pd/C. After deprotection, the free amino groups on the copolymer were further modified with biotin. The monomer and the corresponding copolymers were characterized by ¹H NMR, ¹³C NMR, FT-IR, mass, GPC and DSC analysis. The obtained data have confirmed the desired monomer and copolymer structures.     

Synthesis, Surface Properties, Synergism Parameter and Inhibitive Performance of Novel Cationic Gemini Surfactant on Carbon Steel Corrosion in 1 M HCl Solution

Electrochemical and gravimetric measurements were performed to investigate the effectiveness of a synthesized cationic gemini surfactant as corrosion inhibitor for carbon steel in 1 M HCl solution. The inhibition efficiency obtained from all methods are in good agreement. Potentiodynamic polarization measurements showed that, the prepared surfactant hinders both anodic and cathodic processes, i.e. acted as mixed-type inhibitor. It was found that the adsorption of the synthesized inhibitor followed the Langmuir adsorption isotherm and showed a mixed physical and chemical adsorption. Kinetic parameters were calculated and discussed. The inhibitor exhibited a synergistic effect with Sn²⁺ more than with Cu²⁺. The synthesized cationic gemini surfactant exhibited good surface properties.     

Synthesis and Characterization of Novel CoCr2O4@GeO2@ZnO Core–Shell Nanostructure: Focus on Electrical Conductivity and Gas Sensing Properties

Journal of Inorganic and Organometallic Polymers and Materials - An effort has been made to develop and synthesize novel CoCr2O4@GeO2@ZnO core–shell nanostructure gas sensor via sol–gel...     

Ultrasound-Assisted Synthesis of a Novel Nano-Zigzag-Pattern Lead (II) Metal–Organic System: A New Precursor to Produce Nano-Sized PbO

A sonochemical method was used to synthesize a new nano Pb(II) 1D metal–organic zigzag chain [Pb(p-2-einh)NO₂]_n (1) (p-2-einh?=?(1-(pyridin-2-yl)ethylidene)isonicotinohydrazide). The compound was characterized by scanning electron microscopy (SEM), transmission electron microscopy, elemental analysis, IR spectroscopy, thermogravimetric analysis, X-ray powder diffraction, and single-crystal X-ray analysis. The X-ray analysis reveals a 1D zigzag-chain metal–organic polymer structure for 1 that is further extended to a 3D supramolecular structure by—interaction and other labile interactions. A coordination number of six was determined for the Pb(II) ions in PbN₃O₃. Lead oxide nanoparticles were prepared at 180?°C by thermolysis of 1. The average diameter of the nanoparticles was 20 nm. The size and morphology of the PbO samples were observed using SEM, and the structure of the system was optimized by DFT calculations. The calculated structural parameters and FT-IR spectra are consistent with the crystal structure.     

Four New Metal–Organic Supramolecular Networks Based on Aromatic Acid and Flexible Bis(imidazole) Ligand: Synthesis,Structures and Luminescent Properties

Four new metal–organic supramolecular networks, namely, [Zn(H₂pdc)₂(H₂O)₂]·2H₂O·bbi (1), {[Cd(Hpdc)₂]·2H₂O₂·H₂bbi}_n (2), [Zn(BA)₂(bbi)]_n (3), and {[Cd(BA)₂(bbi)]·H₂O}_n (4) (H₃pdc = 3,5-pyrazoledicarboxylic acid, HBA = 3-hydroxybenzoic acid and bbi = 1,1′-(1,4-butanediyl)bis(imidazole)) have been synthesized under hydrothermal conditions and characterized by IR spectra, elemental analyses, and single-crystal X-ray diffraction analyses. Compound 1 possesses zero-dimensional (0D) structure, which is finally extended into a two-dimensional (2D) supramolecular network via O–H···O and C–H···O hydrogen bonds. Complex 2 displays a 2D network structure built from Cd²⁺ atoms interconnected by Hpdc^2? ligands. The adjacent networks are further assembled into three-dimensional (3D) supramolecular structure through O–H···O hydrogen bonds. Compounds 3 and 4 show similar one-dimensional (1D) chains, in which four-coordinated Zn(II) atoms and six-coordinated Cd(II) atoms are bridged by bbi ligands. Through O–H···O and C-H···O hydrogen bonding interactions, the 1D chains are further packed into 2D and 3D supramolecular frameworks for 3 and 4, respectively. Obviously, the structural differences among compelxes 1–4 are attributed to the different central metal atoms and organic ligands. In addition, compounds 1–4 exhibit blue fluorescent emission in the solid state at room temperature.     

Novel nanocomposites based on reactive organoclay of l-tyrosine and amine end-capped poly(amide–imide): Synthesis and characterization

In the present study, a series of nanocomposite materials were successfully prepared using a poly(amide–imide) (PAI) matrix and novel reactive organoclay as a reinforcing agent. The organoclay was synthesized from Cloisite Na⁺ and protonated form of l-tyrosine amino acid via ion-exchange reaction. It was confirmed by Fourier transform infrared spectroscopy, X-ray powder diffraction, field emission scanning electron microscopy, transmission electron microscopy and thermogravimetry analysis techniques. An optically active PAI was synthesized via solution polycondensation reaction of N,N′-(pyromellitoyl)-bis-phenylalanine diacid chloride and 4,4′-diaminodiphenylether. Then it was end-capped with amine end groups near the completion of the reaction to interact chemically with organoclay. Organoclay/PAI nanocomposite films containing different amounts of organoclay were prepared via solution intercalation method through blending of organoclay with the PAI solution. The nanostructures and properties of the organoclay/PAI hybrids were investigated using different techniques. Thermogravimetry analysis results indicated that the addition of organoclay into the PAI matrix increased the thermal decomposition temperatures of the resulting hybrid materials. The presence of amino acids as a biodegradable segment in both novel organoclay and optically active PAI, made the resulting nanostructure materials susceptible for biodegradation.     

Poly(ε-caprolactone)/poly(m-anthranilic acid) and poly(ε-caprolactone)/poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) electrospun nanofibers: Characterization,antioxidant, and electrochemical properties

Conducting polymers are widely used in many biomedical applications, but their non-degradability and non-biocompatibility limit their widespread use in applications. For this reason, many studies have been carried out on the developing degradable, biocompatible, and electrically conductive polymers. In this study, mixtures of conductive polymers (poly(m-antranilic acid) (P3ANA) and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS)) with biocompatible and biodegradable poly(ε-caprolactone) (PCL) were prepared. Their nanofibers were obtained by electrospinning and their antioxidant properties were investigated by 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) and copper ion reducing antioxidant capacity (CUPRAC) assays. Electrochemical properties were also investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The highest antioxidant activity was obtained from PCL/P3ANA3 electrospun nanofiber containing 10% (of PCL w/w) P3ANA with 93 and 614 μg TE/mg values for ABTS and CUPRAC assays, respectively. This nanofiber was found to be non-toxic according to 2,5-diphenyl-2H-tetrazolium bromide (MTT) analysis. PCL/PEDOT:PSS electrospun nanofiber has the highest maximum anodic current value of 0.08 mA. The maximum anodic current value of PCL/P3ANA3 nanofiber with the highest amount of P3ANA is also higher than other PCL/P3ANA nanofibers. These nanofibers were characterized by FT-IR, UV–vis., XRD and TGA and their surface morphologies were examined by scanning electron microscopy (SEM).     

Promising Antifungal and Antibacterial Agents Based on 5-Aryl-2,2′-bipyridines and Their Heteroligand Salicylate Metal Complexes: Synthesis,Bioevaluation, Molecular Docking

A series of new 5-aryl-2,2′-bipyridines and their (polyfluoro)salicylate complexes of Cu(II), Co(II) and Mn(II) were synthesized. Their antimicrobial activity was evaluated in vitro against six strains of Trichophytons, E. floccosum, M. canis, C. ablicans and Gram-negative bacteria N. gonorrhoeae. Among azo-ligands, Ph-bipy and Tol-bipy showed promising antifungal activity (minimum inhibitory concentration (MIC)<0.8–27 μM). Their antifungal action was found can be realized via binding Fe(III) ions. Tol-bipy suppressed growth of Gram-positive bacteria S. aureus, S. aureus MRSA and their monospecies biofilms (MIC 6–16 μM). Using molecular docking, the anti-staphylococcal action mechanism based on the inhibition of S. aureus DNA gyrase GyrB was proposed for the lead compounds. Among metal complexes, Cu(II) and Mn(II) complexes based on tetrafluorosalicylic acid and Tol-bipy or Ph-bipy had the high antifungal activity (MIC<0.24–32 μM). Mn(SalF₄−2H)₂(Tol-bipy)₂] suppressed the growth of seven Candida strains at MIC 12–24 μM. [Cu(Sal−2H)(Ph-bipy)] and [Cu(SalF₃−2H)(Ph-bipy)₂] showed the promising anti-gonorrhoeae activity (MIC 4.2–5.2 μM). (Cu(SalF_n−2H)(Tol-bipy)₂], [Cu(SalF₄−2H)(Ph-bipy)₂] and [Cu(SalF₃−2H)(Ph-bipy)₂]) were found active against the bacteria of S. aureus, S. aureus MRSA and their biofilms (MIC 2.4–41.4 μM). The most active compounds were tested for toxicity in vitro against human embryonic kidney (HEK-293) cells and in vivo experiments with CD-1 mice.     

Novel D-π-A system based on zinc porphyrin dyes for dye-sensitized solar cells: Synthesis, electrochemical, and photovoltaic properties

We have designed and synthesized novel zinc porphyrin dyes which have a D-π-A system based on porphyrin derivatives containing a triphenylamine (TPA) electron-donating group and a phenyl carboxyl anchoring group substituted at the meso position of the porphyrin ring, yielding the push-pull porphyrins as the most efficient green dye for dye-sensitized solar cell (DSSC) applications. The synthesis and characterization of a novel D-π-A system based on zinc-porphyrin derivatives have been investigated through their photophysical and photoelectrochemical studies. A large red-shift of the absorption maxima due to introduction of the TPA moiety at the meso position of the porphyrin ring was expected in the D-π-A porphyrins, but the absorption maxima of HKK-Por dyes were a little red-shifted in contrast to Zn[5,-10,15-triphenyl-20-(4-carboxylphenyl)-porphyrin], due to the tilted structure between TPA and the porphyrin unit. Under the photovoltaic performance measurement, the maximum incident photon-to-current conversion efficiency (IPCE) value of the DSSC based on HKK-Por 5 was slightly higher than the efficiencies of the DSSCs based on other HKK-Por dyes due to the introduction of the alkoxy group into the TPA moiety at the meso position of the porphyrin ring. A maximum photon-to-electron conversion efficiency of 3.36% was achieved with the DSSC based on HKK-Por 5 dye (J_SC = 9.04 mA/cm², V_OC = 0.57 V, FF = 0.66) under AM1.5 irradiation (100 m Wcm⁻²).     

Synthesis,Characterization and Effect of a Solvent Mixture on the CMC of a Thio-Based Novel Cationic Surfactant Using a UV–Visible Spectroscopic Technique

A novel thio-based cationic surfactant has been synthesized by a new method. It was characterized by different techniques such as NMR, FTIR and its critical micelle concentration was determined by a UV–Visible spectroscopic technique. It is soluble in polar solvents like ethanol and partially soluble in water due to its thio-based functionality. The detailed study of the compound 4-chloro-N-((dodecanoyl(ethyl)ammonio)carbonothioyl)-N-ethylbenzenaminium bromide (4CDTB) was done using a UV–Visible spectrophotometric technique. The effect of solvent mixtures of different ratios was investigated. On the basis of solvent–solvent interaction the compound showed different results. The critical micelle concentration varied with solvent mixture ratios. The CMC of 4CDTB decreased as the ratio of water increased in the mixture of the ethanol–water system. The decrease in critical micelle concentration with the solvent mixture ratio has been discussed on the basis of solvent properties, structures, and their hydrophilic and hydrophobic interactions.     

α-Sulfo Fatty Methyl Ester Sulfonate: A Review on Chemistry,Processing Technologies,Performance, and Applications in Laundry Detergents

α-Sulfo fatty methyl ester sulfonate (α-MES) is one of the anionic surfactants that is currently used commercially in the cleaning industry. Although the fundamental studies on α-MES were initiated as far back as the 1950s, it was only recognized as a class of surfactant in the 1980s. In the initial stage of development, α-MES has been associated with many technical impediments, which created a fear factor for the detergent industry to consider this oleo-based anionic surfactant for commercial production. However, all the technical adversities have been resolved after five decades of continuous active research and development activities. This paper will review the history, chemistry, process development, processing technologies, performance, commercial production, and applications of oleo-based based α-MES with special emphasis on palm oil-based α-MES. The paper also will highlight the challenges and adversities faced by the technology developers and product formulators toward the commercialization of α-MES as an active ingredient in the production of powder and liquid laundry detergents.