Crystal chemistry of three new monodimensional fluorometalates templated with ethylenediamine

Three new monodimensional hybrid metal (Ti, In, Al) fluorides are synthesized with ethylenediamine (en) as a templating agent in solvothermal conditions assisted by microwave heating. All structures involve inorganic chains built up from TiO₂F₄ octahedra connected by two opposite O²⁻ vertices in [H₂en]·(TiOF₄) (I), from InF₆(H₂O) pentagonal bipyramids linked by F–F edges in [H₂en]·(InF₄(H₂O))₂·H₂O (II) and from (Al₇F₃₀)⁹⁻ polyanions sharing two opposite AlF₆ octahedra in [H₂en]₃·(Al₆F₂₄) (III). I is tetragonal, P4/ncc, a = 12.761(3) Å, c = 8.041(3) Å; II is orthorhombic, F2dd, a = 6.904(5) Å, b = 16.559(5) Å, c = 19.777(4) Å and III is monoclinic, P2₁/n, a = 9.387(2) Å, b = 6.710(2) Å, c = 21.513(6) Å, β = 97.18(3)°.     

Molecularly imprinted supermacroporous cryogels for cytochrome c recognition

Molecular imprinting is an attractive biomimetic approach that creates specific recognition sites for the shape and functional group arrangement to template molecules. The purpose of this study is to prepare cytochrome c-imprinted poly(hydroxyethyl methacrylate) (PHEMA)-based supermacroporous cryogel which can be used for the separation of cytochrome c from protein mixtures. N-Methacryloyl-(L)-histidinemethylester (MAH) was used as the metal-coordinating monomer. In the first step, Cu(2+) was complexed with MAH, and the cytochrome c imprinted PHEMA (MIP) cryogel was prepared by free radical cryopolymerization initiated by N,N,N',N'-tetramethylene diamine at -12°C. After polymerization is completed, the template cytochrome c molecules were removed from the MIP cryogel using 0.5 M NaCl solution. The maximum cytochrome c binding amount was 126 mg/g polymer. Selective binding studies were performed in the presence of lysozyme and bovine serum albumin. The relative selectivity coefficients of MIP cryogel for cytochrome c/lysozyme and cytochrome c/bovine serum albumin were 1.7 and 5.2 times greater than those of the non-imprinted PHEMA cryogel, respectively. The selectivity of MIP cryogel for cytochrome c was also confirmed with fast protein liquid chromatography. The MIP cryogel could be used many times with no remarkable decrease in cytochrome c binding capacity.     

Preparation,characterization, and binding profile of imprinted semi-IPN cryogel composite for aluminum

Human body is greatly exposed to aluminum due to its high abundance in the environment. This nonessential metal is a threat to the patients of chronic renal disorders, as it is easily retained in their plasma and quickly accumulates in different tissues. Thus, there is great need to remove it from the aqueous environment. In this study, Al³⁺ imprinted semiinterpenetrating polymer network (semi-IPN)-based cryogel composite was prepared and applied for the purification of environmental and drinking water samples from aluminum. Poly (2-hydroxyethyl methacrylate) (pHEMA) discs were produced via cryogenic treatment and imprinted semi-IPN was introduced to the 3-(trimethoxysilyl) propyl acrylatemodified macroporous cryogel discs. The adsorption properties and selectivity of the aluminum (III) imprinted semi-IPN cryogel composite were studied in detail. The imprinted semi-IPN cryogel composite showed good selectivity towards aluminum (III) ions with the imprinting factor (IF) of 76.4 in the presence of competing copper (II), nickle (II), and iron (III) ions. The maximum adsorption capacity of 271 μmol g^-1 was obtained for aluminum (III) at pH 7.0 within 10 min using imprinted semi-IPN cryogel composite. The good selectivity and reusability of aluminum (III)-imprinted semi-IPN cryogel composite makes this material an eligible candidate for the purification of drinking water from aluminum (III) leaving important minerals remained in the water.     

A new dinuclear copper (II) complex of 2,5–Furandicarboxyclic acid with 4(5)‐Methylimidazole as a high potential α‐glucosidase inhibitor: Synthesis,Crystal structure,Cytotoxicity study,and TD/DFT calculations

A new dinuclear copper (II) complex of 2,5–furandicarboxyclic acid with 4(5)‐methylimidazole, [Cu (FDCA)((4(5)MeI)₂]₂·2H₂O, was synthesized, and its structure characterized by XRD, FT–IR and UV–Vis spectroscopic techniques. The α‐glucosidase inhibition and cytotoxicity study of the synthesized Cu (II) complex were determined by IC₅₀ values. The optimized geometry and vibrational harmonic frequencies for the Cu (II) complex were obtained by using Density Functional Theory (DFT) of HSEh1PBE/6–311++G(d,p)/LanL2DZ level. TD‐DFT/HSEh1PBE/6–311++G(d,p)/LanL2DZ level with CPCM model was applied to examine the electronic spectral properties and major contributions were determined via Swizard program. To investigate linear and nonlinear optical behavior of the synthesized Cu (II) complex, the α, Δα and χ⁽¹⁾/β, γ and χ⁽³⁾ parameters called linear/nonlinear optical parameters in gas phase and ethanol solvent were computed at the same level and basis set. Furthermore, molecular electrostatic potential (MEP) surface was determined by using the same level. The docking study of the Cu (II) complex to the binding site of the target protein (the template structure S. cerevisiae isomaltase) is fulfilled. Natural bond orbital (NBO) analysis was used to investigate the hyperconjugative interactions, inter‐ and intra‐molecular bonding and to determine coordination around Cu (II) ion. Finally, present work is the first remarkable scientific report of mixed‐ligand (H₂FDCA and 4(5)MeI) Cu (II) complex as novel drug candidate for DM II. It is also determined that microscopic third?NLO parameters for the Cu (II) complex is remarkable.     

DFT and TD-DFT calculations on thieno[2,3-b]indole-based compounds for application in organic bulk heterojunction (BHJ) solar cells

Research on Chemical Intermediates - Eight novel organic compounds with donor–π–acceptor (D–π–A) structure were designed for use as donors in organic bulk...     

Enantioseparation of aromatic amino acids using CEC monolith with novel chiral selector,N‐methacryloyl‐l‐histidine methyl ester

A new type of polymethacrylate‐based monolithic column with chiral stationary phase was prepared for the enantioseparation of aromatic amino acids, namely d ,l ‐phenylalanine, d ,l ‐tyrosine, and d ,l ‐tryptophan by CEC. The monolithic column was prepared by in situ polymerization of butyl methacrylate (BMA), N‐methacryloyl‐l ‐histidine methyl ester (MAH), and ethylene dimethacrylate (EDMA) in the presence of porogens. The porogen mixture included DMF and phosphate buffer. MAH was used as a chiral selector. FTIR spectrum of the polymethacrylate‐based monolith showed that MAH was incorporated into the polymeric structure via in situ polymerization. Some experimental parameters including pH, concentration of the mobile phase, and MAH concentration with regard to the chiral CEC separation were investigated. Single enantiomers and enantiomer mixtures of the amino acids were separately injected into the monolithic column. It was observed that l ‐enantiomers of aromatic amino acids migrated before d ‐enantiomers. The reversal enantiomer migration order for tryptophan was observed upon changing of pH. Using the chiral monolithic column (100 μm id and 375 μm od), the best chiral separation was performed in 35:65% ACN/phosphate buffer (pH 8.0, 10 mM) with an applied voltage of 12 kV in CEC. SEM images showed that the chiral monolithic column has a continuous polymeric skeleton and large through‐pore structure.     

Synthesis,spectral properties,in vitro α-glucosidase inhibitory activity and quantum chemical calculations of novel mixed-ligand M(II) complexes containing 1,10-phenanthroline

A series of mixed-ligand M(II) complexes containing 1,10-phenanthroline (phen) and 3-methylpyridine-2-carboxylic acid (3-mpaH) or 6-methylpyridine-2-carboxylic acid (6-mpaH), namely [Co(3-mpa)₂(phen)]·3H₂O ( 1 ), [Hg(6-mpa)₂(phen)]·2H₂O ( 2 ), [Mn(6-mpa)₂(phen)]·2H₂O ( 3 ), [Co(6-mpa)₂(phen)]·H₂O ( 4 ) and [Ni(6-mpa)₂(phen)]·H₂O ( 5 ), were synthesized for the first time. Among them, 1 was obtained as single crystals. The structural characterization for 1 was conducted using X-ray diffraction and that for 2 – 5 using mass spectrometry. The IC₅₀ values for α-glucosidase inhibition of 1 – 5 were obtained as 0.161 to >600 μM. The spectral properties were also investigated using Fourier transform infrared and UV–visible spectra. Furthermore, to investigate the geometrical parameters, spectral and electronic properties and second- and third-order nonlinear optical parameters for 1 – 5 , density functional calculations were applied.     

Efficient aerial oxidation of different types of alcohols using ZnO nanoparticle–MnCO3-graphene oxide composites

Graphene–metal nanocomposites have been found to remarkably enhance the catalytic performance of metal nanoparticle-based catalysts. In continuation of our previous report, in which highly reduced graphene oxide (HRG)-based nanocomposites were synthesized and evaluated, we present nanocomposites of graphene oxide (GRO) and ZnO nanoparticle-doped MnCO₃ ([ZnO–MnCO₃/(1%)GRO]) synthesized via a facile, straightforward co-precipitation technique. Interestingly, it was noticed that the incorporation of GRO in the catalytic system could noticeably improve the catalytic efficiency compared to a catalyst (ZnO–MnCO₃) without GRO, for aerial oxidation of benzyl alcohol (BzOH) employing O₂ as a nature-friendly oxidant under base-free conditions. The impacts of various reaction factors were thoroughly explored to optimize reaction conditions using oxidation of BzOH to benzaldehyde (BzH) as a model substrate. The catalysts were characterized using X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, Energy dispersive X-ray spectroscopy (EDX), Brunauer-Emmett-Teller (BET), and Raman spectroscopy. The (1%)ZnO–MnCO₃/(1%)GRO exhibited significant specific activity (67 mmol.g⁻¹.hr⁻¹) with full convversion of BzOH and >99% BzH selectivity within just 6 min. The catalytic efficiency of the (1%)ZnO–MnCO₃/(1%)GRO nanocomposite was significantly better than the (1%)ZnO–MnCO₃/(1%)HRG and (1%)ZnO–MnCO₃ catalysts, presumably due to the existence of oxygen-possessing groups on the GRO surface and as well as a very high surface area that could have been instrumental in uniformly dispersing the active sites of the catalyst, i.e., ZnO–MnCO₃. Under optimum circumstances, various kinds of alcohols were selectively transformed to respective carbonyls with full convertibility over the (1%)ZnO–MnCO₃/(1%)GRO catalyst. Furthermore, the highly effective (1%)ZnO–MnCO₃/(1%)GRO catalyst could be successfully reused and recycled over five consecutive runs with a marginal reduction in its performance and selectivity.     

Photooxidation of acyclovir with thermally generated triplet excited ketones. A comparison with type I and II photosensitizers

The antiviral drug acyclovir (Ac, 1) was treated with triplet excited ketones, which have been generated in thermal decomposition of 3-(hydroxymethyl)-3,4,4-trimethyl-1,2-dioxetane (HTMD), in the dark. Three major oxidation products were detected by means of spectroscopic measurements. The products were (2-hydroxyethoxy) methyl spiroiminodihydantoin (2), (2-hydroxyethoxy) methyl (amino)-2-imino-1,2-dihydroimidazole-5-one (3), and 2,2-diamino-4-[(2-hydroxyethoxy) methyl) amino)-5-[2H]-oxazolone (4). Equal amounts of type I and type II photooxidation products were found, as could be established by comparison with predominant type I (riboflavin) and type II (rose bengal) photosensitizers. The concentration and time profiles for the HTMD-induced oxidation of Ac were also determined. The participation of singlet oxygen in HTMD-induced oxidation was confirmed by the substantial D(2)O effect in the formation of spiroiminodihydantoin (2).