Alkyl ammonium hydrogen sulfate immobilized on Fe3O4@SiO2 nanoparticles: a highly efficient catalyst for the multi-component preparation of novel tetrazolo[1,5-a]pyrimidine-6-carboxamide derivatives.

In this, a three-component reaction for the preparation of novel tetrazolo[1,5-a]pyrimidine-6-carboxamide derivatives from N,N'-(sulfonylbis(1,4-phenylene))bis(3-oxobutanamide), aldehydes and 1H-tetrazol-5-amine is reported. The application of Fe3O4@SiO2-(PP)(HSO4)2 (A) as a catalyst afforded the desired products (a1-a18) in high yields in DMF as solvent as well as under solvent-free conditions.

Multi-Component Syntheses of Spiro[furan-2,3'-indoline]-3-carboxylate Derivatives Using Ionic Liquid Catalysts.

Two previously described Brønsted acidic ionic liquids, 3,3'-(1,6-hexanediyl)bis(1-methyl)-1H-imidazolium hydrogen sulfate (Cat1) and 1,1'-(1,6-hexanediyl)bis(pyridinium) hydrogen sulfate (Cat2), were used as catalysts for the preparation of spiro[furan-2,3'-indoline]-3-carboxylate derivatives via a three-component reaction of anilines, isatins (N-alkyl-indoline-2,3-diones), and diethyl acetylenedicarboxylate, in high yields. The use of ultrasonic (US) irradiation led to the targeted products (1a-15a) in high yields ranging from 80% to 98%. Under the same conditions, the use of sulfuric acid and acetic acid as a Brønstedt catalyst did not yield the desired benchmark product 1a.

A Sulfonic Acid Polyvinyl Pyridinium Ionic Liquid Catalyzes the Multi-Component Synthesis of Spiro-indoline-3,5'-pyrano[2,3-d]-pyrimidines and -Pyrazines.

A sulfonated poly-4-vinyl pyridinium (PVPy-IL-B-SO3H) containing an acidic pyridinium/HSO3- ionic liquid moiety was prepared and used as a catalyst for the three-component reaction of malononitrile with 1-alkylindoline-2,3-diones and 1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione or methyl 5-hydroxy-1H-pyrazole-3-carboxylate, leading to methyl 6'-amino-5'-cyano-2-oxo-2'H-spiro[indoline-3,4'-pyrano[2,3-c]pyrazole]-3'-carboxylates or -3,4'-pyrano[2,3-d]pyrimidine]-6'-carbonitrile derivatives under ultrasonic irradiation conditions. The solid catalyst allows easy separation, is cheap, produces high yields under mild conditions, and does not require column chromatography for product isolation and purification.

Polyethylenimine Grafted onto Nano-NiFe2O4@SiO2 for the Removal of CrO42-, Ni2+, and Pb2+ Ions from Aqueous Solutions.

Polyethyleneimine (PEI) has been reported to have good potential for the adsorption of metal ions. In this work, PEI was covalently bound to NiFe2O4@SiO2 nanoparticles to form the new adsorbent NiFe2O4@SiO2-PEI. The material allowed for magnetic separation and was characterized via powder X-ray diffraction (PXRD), showing the pattern of the NiFe2O4 core and an amorphous shell. Field emission scanning electron microscopy (FE-SEM) showed irregular shaped particles with sizes ranging from 50 to 100 nm, and energy-dispersive X-ray spectroscopy (EDX) showed high C and N contents of 36 and 39%, respectively. This large amount of PEI in the materials was confirmed by thermogravimetry-differential thermal analysis (TGA-DTA), showing a mass loss of about 80%. Fourier-transform IR spectroscopy (FT-IR) showed characteristic resonances of PEI dominating the spectrum. The adsorption of CrO42-, Ni2+, and Pb2+ ions from aqueous solutions was studied at different pH, temperatures, metal ion concentrations, and adsorbent dosages. The maximum adsorption capacities of 149.3, 156.7, and 161.3 mg/g were obtained for CrO42-, Ni2+, and Pb2+, respectively, under optimum conditions using 0.075 g of the adsorbent material at a 250 mg/L ion concentration, pH = 6.5, and room temperature.

A Cu(ii) complex supported on Fe3O4@SiO2 as a magnetic heterogeneous catalyst for the reduction of environmental pollutants.

Today, the presence of pollutants in the environment has become one of the serious problems and concerns of human beings. To eliminate these pollutants, researchers have made many efforts. One of the most important of these efforts is the reduction of such contaminants in the presence of effective catalysts. Two of the most important and widespread types of these pollutants are nitro compounds and organic dyes. In this paper, we report the synthesis of an efficient and reusable magnetic catalyst using Fe3O4@SiO2 core-shell nanoparticles (NPs), N-(4-bromophenyl)-N'-benzoylthiourea, and copper(ii). Specifically, the Cu(ii)-N-(4-bromophenyl)-N'-benzoylthiourea complex supported on Fe3O4-core magnetic NPs (CM)/SiO2-shell (SS) (CM@SS-BBTU-Cu(ii)) has been prepared. CM@SS-BBTU-Cu(ii) was characterized by FT-IR (Fourier transform infrared spectroscopy), XRD (X-ray diffraction), TEM (transmission electron microscopy), HRTEM (high resolution transmission electron microscopy), FFT (fast Fourier transform), VSM (vibrating sample magnetometry), TG-DTA (thermogravimetry-differential thermal analysis), STEM (scanning transmission electron microscopy), EDS (energy-dispersive X-ray spectroscopy), and elemental mapping. The synthesized CM@SS-BBTU-Cu(ii) was applied for the reduction of 4-nitrophenol (4-NP), Congo red (CR), and methylene blue (MB) in the presence of NaBH4 (sodium borohydride) at room temperature. CM@SS-BBTU-Cu(ii) can be recycled and reused 5 times. Our results displayed that the performance of the catalyst was not significantly reduced by recycling.

Molecular dynamics simulation of drug delivery across the cell membrane by applying gold nanoparticle carrier: Flutamide as hydrophobic and glutathione as hydrophilic drugs as the case studies.

In this study, molecular dynamics simulation is applied to investigate drug transport in both pure state and conjugated with neutral gold nanoparticle (AuNP) as a drug carrier inside dipalmitoylphosphatidylcholine (DPPC) membrane. Flutamide (Flu) as a hydrophobic and Glutathione (GSH) as a hydrophilic anticancer drug are selected as the case studies. Dynamics of each drug including adhesion on and penetration into the cell membrane are investigated. Pure and conjugated form of drugs inside the water and near the membrane are studied. Simulation results show that the interaction between drug molecules and DPPC changes after drug conjugating with AuNP. GSH, as a hydrophilic drug, intends to remain above the membrane bilayer and after conjugating with AuNP diffuses inside DPPC. However, hydrophobic Flu molecule likes to diffuse inside DPPC, but after conjugating with AuNP, its diffusion inside the lipid bilayer decreases, and its retention time at the surface of DPPC increases. Presence of Flu-NP at the surface of DPPC could enhance its impact on blocking dihydrotestosterone binding at androgen receptors resulting in tumor cell growth arrest. In addition, the tendency of GSH-NP for diffusion to the DPPC is a positive factor for the successful transport of heavy metals such as AuNP without rapid clearance through either the hepatobiliary pathway or the renal system. In conclusion, such MD simulation results may solve problems in nanomedicine translation and turn into a bridge toward maximizing targeting and minimizing nanotoxicity of metal NPs.

Evolutionary and Ecological Drivers Shape the Emergence and Extinction of Foot-and-Mouth Disease Virus Lineages.

Livestock farming across the world is constantly threatened by the evolutionary turnover of foot-and-mouth disease virus (FMDV) strains in endemic systems, the underlying dynamics of which remain to be elucidated. Here, we map the eco-evolutionary landscape of cocirculating FMDV lineages within an important endemic virus pool encompassing Western, Central, and parts of Southern Asia, reconstructing the evolutionary history and spatial dynamics over the last 20 years that shape the current epidemiological situation. We demonstrate that new FMDV variants periodically emerge from Southern Asia, precipitating waves of virus incursions that systematically travel in a westerly direction. We evidence how metapopulation dynamics drive the emergence and extinction of spatially structured virus populations, and how transmission in different host species regulates the evolutionary space of virus serotypes. Our work provides the first integrative framework that defines coevolutionary signatures of FMDV in regional contexts to help understand the complex interplay between virus phenotypes, host characteristics, and key epidemiological determinants of transmission that drive FMDV evolution in endemic settings.

Platinum(II) complex with 4-nitro-N-(pyridin-2-ylmethylidene)aniline: synthesis, characterization, crystal structure and antioxidant activity.

A novel complex has been prepared using the (E)-4-nitro-N-(pyridin-2-ylmethylidene)aniline bidentate Schiff base ligand and PtCl2, namely, dichlorido[(E)-4-nitro-N-(pyridin-2-ylmethylidene)aniline-κ2N,N']platinum(II) acetonitrile hemisolvate, [PtCl2(C12H9N3O2)]·0.5CH3CN, 1. According to the X-ray measurements of the crystal structure, the PtII ion adopts a PtCl2N2 square-planar coordination. The coordination of the Schiff base ligand to the PtII ion occurs in a cyclic bidentate fashion, as a result of which a five-membered metallacycle is formed. Furthermore, in the structure of 1, the neutral molecules form a one-dimensional chain structure through C-H...Cl and C-H...O hydrogen bonds. The characterization of the complex was performed via single-crystal X-ray diffraction, IR spectroscopy and elemental analysis, and the antioxidant activity of the complex was evaluated using spectrophotometry by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method.

Mannich bases derived from lawsone and their metal complexes: synthetic strategies and biological properties.

Lawsone (2-hydroxynaphthalene-1,4-dione) is a natural product which shows significant biological activity. Aminomethylnaphthoquinone Mannich bases derived from lawsone constitute an interesting class of naphthoquinones and/or their metal complexes have demonstrated a series of important biological properties. So, this review aimed to document the publications concerning the synthesis of aminomethylnaphthoquinone Mannich bases from lowsone, aldehydes and amines and their metal complexes using different conditions, and investigation of their applications.

Domino ring opening/cyclization of oxiranes for synthesis of functionalized 2H-pyran-5-carboxylate.

A simple method for the synthesis of functionalized 2H-pyrans via a catalytic reaction of an oxirane, an alkyne, and a malonate has been developed in which a 6-exo-dig cyclization pathway is observed. In this transformation, the attack of in situ generated copper acetylides on oxiranes formed homopropargylic alcohol intermediates which further transferred to 2H-pyrans with the help of malonates.

Natrolite zeolite supported copper nanoparticles as an efficient heterogeneous catalyst for the 1,3-diploar cycloaddition and cyanation of aryl iodides under ligand-free conditions.

In this paper, we report the preparation of Natrolite zeolite supported copper nanoparticles as a heterogeneous catalyst for 1,3-diploar cycloaddition and synthesis aryl nitriles from aryl iodides under ligand-free conditions. The catalyst was characterized using XRD, SEM, TEM, EDS and TG-DTA. The experimental procedure is simple, the products are formed in high yields and the catalyst can be recycled and reused several times without any significant loss of catalytic activity.

Diiodido{2-[(4-meth-oxy-phen-yl)imino-meth-yl]pyridine-κ(2)N,N'}zinc.

In the title complex, [ZnI(2)(C(13)H(12)N(2)O)], the Zn(II) atom has a distorted tetra-hedral coordination. The organic ligand is bidentate, coordinating the Zn(II) atom via the two N atoms. The benzene and pyridine rings are oriented at a dihedral angle of 11.67 (9)°. In the crystal, weak C-H⋯I and C-H⋯O hydrogen bonds are observed, in addition to π-π stacking inter-actions, with a centroid-centroid distance of 3.72 (5) Å.

A second monoclinic polymorph of di-µ-chlorido-bis-(chlorido{2-[(4-ethyl-phen-yl)imino-meth-yl]pyridine-κ²N,N'}copper(II)).

The title compound, [Cu2Cl4(C14H14N2)2], is a new polymorph of a previously reported compound [Dehghanpour et al. (2011 ▶). Acta Cryst. E67, m1296]. The current polymorph was obtained from an acetonitrile solution of the title compound. Like the first polymorph, it is monoclinic (space group P21/c). The unique Cu(II) ion in the title centrosymmetric dinuclear complex is in a distorted trigonal-bipyramidal coordination environment formed by the bis--chelating N-heterocyclic ligand, two bridging Cl ligands and one terminal Cl ligand. In the crystal, weak C-H⋯Cl hydrogen bonds are observed in addition to π-π stacking inter-actions, with a centroid-centroid distance of 3.6597 (18) Å.

Aqua-[tris-(2-{5-[(4-methyl-phenyl)diazen-yl]-2-oxidobenzyl-idene-amino}-eth-yl)amine]-samarium(III) acetonitrile monosolvate.

In the title compound, [Sm(C(48)H(45)N(10)O(3))(H(2)O)]·CH(3)CN, the Sm(III) ion is coordinated by the hepta-dentate tris-(2-{5-[(4-methyl-pheny)diazen-yl]-2-oxidobenzyl-idene-amino}-eth-yl)amine trianionic ligand and a water mol-ecule. The resulting SmN(4)O(4) coordination polyhedron is a distorted square anti-prism. In the crystal, complex mol-ecules are linked by O-H⋯O hydrogen bonds.

Di-µ-chlorido-bis-(chlorido{2-[(4-ethyl-phen-yl)imino-meth-yl]pyridine-κN,N'}copper(II)).

The binuclear title complex, [Cu(2)Cl(4)(C(14)H(14)N(2))(2)], is located on a crystallographic inversion centre. The Cu(II) ion is in a distorted square-pyramid coordination environment formed by the bichelating N-heterocyclic ligand, two bridging Cl atoms and one terminal Cl atom. One of the bridging Cu-Cl bonds is significantly longer than the other.

Di-µ-chlorido-bis-{chlorido[4-nitro-N-(pyridin-2-yl-methyl-idene-κN)aniline-κN]mercury(II)}.

In the centrosymmetric dinuclear title complex, [Hg(2)Cl(4)(C(12)H(9)N(3)O(2))(2)], the Hg(II) ion is in a distorted square-pyramidal coordination environment formed by the N atoms of the diimine ligand, two bridging Cl atoms and one terminal Cl atom. One of the bridging Hg-Cl bonds is significantly longer than the other.

Zwitterionic form of tris-({[5-(4-meth-oxy-phenyl-azo)salicyl-idene]amino}-eth-yl)amine.

THE TITLE COMPOUND (SYSTEMATIC NAME: 2-{[2-(bis-{2-[({2-hy-droxy-5-[(4-meth-oxy-phen-yl)diazen-yl]phen-yl}methyl-idene)amino]-eth-yl}amino)-eth-yl]aza-niumylidenemeth-yl}-4-[(4-meth-oxy-phen-yl)diazen-yl]phenolate), C(48)H(48)N(10)O(6), exists as a zwitterion in the solid state. The three arms of the tripodal mol-ecule are located close to each other and an intra-molecular hydrogen bond occurs in each arm (O-H⋯N in two arms and N-H⋯O in the zwitterionic arm). The dihedral angles between the aromatic rings in the three arms are 16.36 (14), 23.94 (14) and, for the zwitterionic arm, 37.14 (14)°. In the crystal, a weak inter-moleclar N-H⋯O hydrogen bond occurs.

2-[1-(3-{2-[(2-Hy-droxy-benzyl-idene)amino]-phen-oxy}prop-yl)-1H-1,3-benzodiazol-2-yl]phenol.

In the title compound, C(29)H(25)N(3)O(3), the imine double bond has an E configuration. The dihedral angle between the hy-droxy-phenyl and benzene rings in the imine moiety is 26.95 (9)°, and the dihedral angle between the hy-droxy-phenyl and benzimidazole rings in the other moiety is 14.83 (9)°. These angles are probably limited to small values as a consequence of two strong intra-molecular O-H⋯N hydrogen bonds formed between the hy-droxy groups and the imine and imidazole N atoms. The aliphatic chain linking the two ring systems has a gauche conformation, as reflected in C-C-C-O torsion angle of 70.9 (2)°.

Dibromido{2-[(4-nitro-phen-yl)imino-meth-yl]pyridine-κN,N'}zinc(II).

In the title compound, [ZnBr(2)(C(12)H(9)N(3)O(2))], the Zn(II) ion is bonded to two Br ions and two N atoms of the diimine ligand in a distorted tetra-hedral geometry. With the exception of the Br atoms, all other atoms are disordered over two sets of sites corresponding to a 180° rotation of the mol-ecule along [[Formula: see text]02]. The refined occupancies of the components are 0.809 (2) and 0.191 (2). In addition, the crystal studied was a non-merohedral twin with a refined component ratio of 0.343 (2):0.657 (2).

Dichlorido{2-[(3,4-dimethyl-phen-yl)imino-meth-yl]pyridine-κN,N'}copper(II).

In the title complex, [CuCl(2)(C(14)H(14)N(2))], the Cu(II) atom exhibits a very distorted tetra-hedral coordination geometry involving two chloride ions and two N-atom donors from the Schiff base ligand. The range for the six bond angles about the Cu(2+) cation is 81.49 (11)-145.95 (9)°. The chelate ring including the Cu(II) atom is approximately planar, with a maximum deviation of 0.039 (4) Šfor one of the C atoms; this plane forms a dihedral angle of 46.69 (9)° with the CuCl(2) plane.