Binuclear and mononuclear cobalt(II), nickel(II) and copper(II) complexes of 4,4′-bis(alkylaminoisonitrosoacetyl)diphenyl-methane derivatives

4,4-Bis(chloroacetyl)diphenylmethane has been prepared from ClCH₂COCl and Ph₂CH₂. 4,4-Methylenebis(phenylglyoxylohydroximoyl chloride has also been obtained. Four new substituted 4,4-bis(alkylaminoisonitrosoacetyl)diphenylmethanes (ligands) have been prepared from 4,4-methylenebis(phenylglyoxylohydroximoyl chloride) and the corresponding amines. The Ni^II, Cu^II and Co^II complexes of these ligands were prepared and their structures were identified using AAS, i.r., ¹H-n.m.r. spectral data, elemental analyses and magnetic susceptibility measurements.     

Die Sechseck-n-Waben in der Ebene,welche von n Kreisbüscheln erzeugt werden

In this paper, the problem of determining the pencils of circles which form a hexagonal n-web in E₂, is completely solved. It is well-known that n pencils of circles orthogonal to a fixed circle form a hexagonal n-web. Therefore, the main problem is the determination of all circle pencils which form a hexagonal n-web and which do not cut a fixed circle orthogonally. In this connection the following results have been obtained: The number of hexagonal 4-webs is six, whereas the number of hexagonal 5-webs is two.Finally, after having proved that the number of hexagonal 6-webs is one, it is shown that, for n7, there exist no circle pencils forming a hexagonal n-web without being orthogonal to a fixed circle.     

Crystal structure of an unsymmetrical Schiff base, immobilization of its cobalt and manganese complexes on a silica support, and catalytic studies

An unsymmetrical tetradentate Schiff base (H₂L) was synthesized by the reaction of 3-methoxysalicylaldehyde, o-phenylenediamine, and salicylaldehyde in EtOH. H₂L was characterized by single-crystallographic X-ray analysis. Its Co(II) and Mn(III) complexes ([CoL] and [MnLCl]) were prepared and immobilized on 3-aminopropyltriethoxysilane functionalized silica gel. The immobilized materials were found to be efficient catalysts for epoxidation of styrene in the presence of tert-BuOOH in acetonitrile at 40 °C. The catalysts can be reused several times without significant loss of performance.     

Synthesis,characterization and catalytic activity of peripherally tetra‐substituted Co(II) phthalocyanines for cyclohexene oxidation

New 3,3‐diphenylpropoxyphthalonitrile (5) was obtained from 3,3‐diphenylpropanol (3) and 4‐nitrophthalonitrile (4) with K₂CO₃ in DMF at 50 °C. The novel cobalt(II) phthalocyanine complexes, tetrakis‐[2‐(1,4‐dioxa‐8‐azaspiro[4.5]dec‐8‐yl)ethoxy] phthalocyaninato cobalt(II) (2) and tetrakis‐(3,3‐diphenylpropoxy)phthalocyaninato cobalt(II) (6) were prepared by the reaction of the phthalonitrile derivatives 1 and 5 with CoCl₂ by microwave irradiation in 2‐(dimethylamino)ethanol for at 175 °C, 350 W for 7 and 10 min, respectively. These new cobalt(II)phthalocyanine complexes were characterized by spectroscopic methods (IR, UV–visible and mass spectroscopy) as well as elemental analysis. Complexes 2 and 6 are employed as catalyst for the oxidation of cyclohexene using tert‐butyl hydroperoxide (TBHP), m‐chloroperoxybenzoic acid (m‐CPBA), aerobic oxygen and hydrogen peroxide (H₂O₂) as oxidant. It is observed that both complexes can selectively oxidize cyclohexene to give 2‐cyclohexene‐1‐ol as major product, and 2‐cyclohexen‐1‐one and cyclohexene oxide as minor products. TBHP was found to be the best oxidant since minimal destruction of the catalyst, higher selectivity and conversion were observed in the products. Copyright © 2012 John Wiley & Sons, Ltd.     

PHA-L lectin and carbohydrate relationship: conjugation with CdSe/CdS nanoparticles, radiolabeling and in vitro affinities on MCF-7 cells

This research aims to investigate the interaction between phytohemagglutinin-L (PHA-L) and sialic acid, which is abundant on the breast cancer cell (MCF-7) surface and displays monosaccharide characteristics, by experimental and computational methods. Experimentally, CdSe/CdS nanoparticles (QDs) were synthesized; PHA-L was conjugated with QDs and labeled with ¹²⁵I. Radiolabeling yield was found to be 97 ± 1.2 %. Afterwards, in vitro bioaffinities of radiolabeled PHA-L conjugated QDs have been investigated on MCF-7 cells and it has been observed that the cell incorporation increased with time. The results indicated that ¹²⁵I labeled QD-PHA-L conjugates represent significant affinity on MCF-7 cells. In the second step of the study, the crystal structure of carbohydrate interaction surface of PHA-L was extracted from the crystal structure of PHA-L. The interactions between this surface and sialic acid were calculated by computational tools. These calculations revealed specific interactions between PHA-L and sialic acid. Semi-empirical methods, PM3 and AM1, were used in these calculations. Significant outcomes have been obtained from the experimental and computational studies and these results demonstrated that PHA-L may be an effective agent for imagining MCF-7 cells.     

Einige Neue N,S-Substituierte 2-Nitrodienverbindungen Aus Reaktionen Von Mono(p-fluorarylthio)substituierten Dienen Mit Aminen

2-Nitrodiene compound 1 was stirred with p-fluorothiophenol for a long time and compound 3 was obtained. Compound 1 gave bis(thio)substituted 2-nitrodiene compound 4 and tris(thio)substituted compound 5 with 2 moles of p-fluorothiophenol in the presence of NaOH in ethanol. The compounds 9a–g have been prepared from 8a–g and 3. Compound 7 was obtained from the reaction of mono(thio)substituted 2-nitrodiene with morpholine. Compound 3 gives 11a–d in the reaction with piperidines in CH₂Cl₂ (or ether). Compound 13a–b have been obtained from the reaction of compound 3 with primary amines 12a–b. Compound 3 gives 15 and 16 in the reaction with 2,5-dimethylpiperazine in CH₂Cl₂.

     

Swelling Characterization of the Superabsorbent Copolymer in the Petroleum-Based Solvent-Water Mixtures

The crosslinked and porous copolymer grains were synthesized by inverse suspension polymerization of acrylamide. The synthesized copolymer was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). It was achieved to absorbed 418 g water by 1 g copolymer after 5 min waiting time. Moreover, it was seen that about 99% of water was absorbed by 1 g copolymer in the solvent water mixtures (300 mL solvent–200 mL distilled water) after 2.5 min waiting time. The diffusion coefficients of the copolymer in the solvent-water mixtures were found between 8.87 · 10⁴ and 10.64 · 10⁴ cm²s^?1. Furthermore, the copolymer in distilled water achieved to reach a high value of the diffusion coefficient (13.2 · 10⁴ cm²s^?1).     

Synthesis and Metal Ion Recognition Properties of a Novel Chiral Calix[4](azoxa)crown-7

A novel chiral calix[4](azoxa)crown-7 (9) has been synthesized and its metal ion recognition properties investigated. The starting reagents, chiral diamine 5 and calix[4]arene diacid chloride derivative 8, were prepared according to literature methods. ¹H and ¹³C NMR data show that 9 exists in a cone conformation. In liquid–liquid extraction experiments, 9 exhibits selectivity for Li⁺ among the other alkali metals and a good extraction ability for transition metal cations, suggesting its potential use in different fields, such as a sensor for ions as well as for chiral molecules.     

Synthesis, characterization, thermal and optical properties of styrene derivatives having pendant p-substituted benzylic ether groups

The derivatives of styrene monomer, 4-chlorophenyl-4-vinylbenzyl ether (M1), 4-methoxyphenyl-4-vinylbenzyl ether (M2), 4-ethylphenyl-4-vinylbenzyl ether (M3) and 1-naphtylphenyl-4-vinylbenzyl ether (M4) were synthesized. The normal free radical polymerization of monomers in 1,4-dioxane were performed by using 2,2′-azobisisobutyronitrile as an initiator at 65 °C. The monomers and their homopolymers were characterized by FT-IR, NMR and elemental analyses measurements. The thermal stability of polymers was investigated by thermogravimetric and differential scanning calorimetric analysis. Thermal degradation activation energies of the polymers were calculated by the Ozawa and Kissinger methods. In addition, photo-stability tests of the polymers under near-UV irradiation were performed.     

Graphene oxide-octadecylsilane incorporated monolithic nano-columns with 50 μm id and 100 μm id for small molecule and protein separation by nano-liquid chromatography

In this study, graphene oxide-octadecylsilane incorporated monolithic nano-columns were developed for protein analysis by nano liquid chromatography (nano LC). The monolithic column with 100 μm id was first prepared by an in situ polymerization using ethylene dimethacrylate (EDMA), 3-chloro-2-hydroxypropylmethacrylate (HPMA-Cl), and methacryloyl graphene oxide nanoparticles (MGONPs). MGONPs were synthesized by the treatment of 3-(trimethoxysilyl)propylmethacrylate (TMSPM) and GO. Tetrahydrofuran (THF) and dodecanol were used as the porogenic solvent. The resulting column was functionalized by dimethyloctadecylch lorosilane (DODCS) for the enhancement of hydrophobicity. The functionalization greatly improved the baseline separation of hydrophobic compounds such as polyaromatic hydrocarbons (PAHs). The optimized monolith with respect to total polymerization mixture was characterized by using Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) X-ray diffraction (XRD) and chromatographic analyses. The blank monoliths without functionalization exhibited poor separation while a good separation performance of MGONPs functionalized monoliths was achieved. The monolith with 100 μm id was evaluated in protein separation in nano LC using RNase A, Cytochrome C, Lysozyme, Trypsin, and Ca isozyme II as the test proteins. It was shown that protein separation mechanism was based on large π-system of GO and hydrophobicity of the monolithic structure. Theoretical plates number up to 57 600 plates were achieved. The nano-column with 50 μm id was also prepared using the same polymerization mixture under the same chemical conditions. These nano-columns were employed for protein separation by nano LC, and the dependence of both nano-column performance on the internal diameter was also discussed.