Search results for "IPR"

Binding characteristics of molecularly imprinted polymers based on fungicides in hydroalcoholic media

2015

An iprodione-imprinted polymer was prepared by copolymerization of methacrylamide and ethylene glycol dimethacrylate using a noncovalent imprinting approach. Methacrylamide was chosen using molecular dynamics simulations. To concentrate iprodione from hydro-alcoholic solutions, batch sorption of iprodione on the imprinted polymer were conducted. The equilibrium time for iprodione sorption is 20 min, and the corresponding kinetic mechanism follows the pseudo-second order indicating a strong interaction between iprodione and the imprinted polymer. Langmuir, Freundlich, and Dubinin-Radushkevich models were used to fit the isotherm of iprodione sorption. The imprinted polymer was found to be mo…

Synthesis and Structural Study of Tetravalent (Zr 4+ , Hf 4+ , Ce 4+ , Th 4+ , U 4+ ) Metal Complexes with Cyclic Hydroxamic Acids

2015

Six- and seven-membered cyclic hydroxamic acids, such as 1-hydroxypiperidine-2-one (1H, 1,2-PIPOH) and 1-hydroxyazepan-2-one (2H), have recently been identified in some mixed siderophores as one of their three chelating subunits. Compared to their ubiquitous noncyclic counterparts, cyclic hydroxamates are preorganized for metal binding. Surprisingly, the coordination chemistry of these bidentate, monoanionic ligands remains virtually unknown, even in the case of iron(III). We report herein the first structural study of the complexes of 1– and of 6–, an unsaturated seven-membered ring analog of 2–, with tetravalent cations of transition metals (zirconium and hafnium), lanthanide (cerium), an…

Experimental design approach in the synthesis of molecularly imprinted polymers specific for iprodione fungicide

2015

International audience; An experimental design (ED) approach was applied to study the weight of three factors in the synthesis of a molecularly imprinted polymer (MIP) specific for iprodione fungicide. The objective was to obtain a high specific polymer with the best performance of iprodione binding. Thirteen iprodione-imprinted polymers and 13 non-imprinted polymers (NIP) were synthesized according to ED having 3 influencing factors: the polymerization method, the crosslinker nature and the functional monomer type. For each factor, two levels were studied: bulk and precipitation polymerization for the first factor, trimethylolpropane trimethacrylate (TRIM) and ethylene glycol dimethacrylat…

Structural study of NaNdGa4S8, a luminescent material with low-concentration quenching

1988

Abstract Single-crystal X-ray diffraction analysis and optical investigations of NaNdGa 4 S 8 show that Nd 3+ ions are essentially distributed in two of the three square antiprismatic sites of a CaGa 2 S 4 -type lattice. The NdS 8 polyhedra are isolated (minimum NdNd distance: 6.07 A) so the interactions responsible for concentration quenching of the luminescence are considerably reduced

Non-steroidal Anti-inflammatory Agents, Part 24[1] Pyrrolidino Enaminones as Models to Mimic Arachidonic Acid

1997

The pyrrolidino enaminones, with the carboxylic acid chain fixed at the nitrogen, inhibit cyclooxygenase more potently or selectively than 5-lipoxygenase. According to the structure-activity relationships discussed the potency depends significantly on the chain length of the carboxylic acid, the substitution pattern of the heterocyclic moiety and of the phenyl group. Compound 4c is the most efficient inhibitor of cyclooxygenase. For the binding profile the unfolded conformation of arachidonic acid and the energy-minimized conformations of flurbiprofen, diclofenac, ML 3000, and lead compound 4a were compared. In addition to known structural features, similar distances of the carboxylic acid …

Entzündungshemmende wirkstoffe. XI. Ringschlußreaktion an 5-phenyl-2-thiobiuret

1988

Die Umsetzung von 5-Phenyl-2-thiobiuret (1) mil α-Chlorcarbonylverbindungen 2 fuhrt zu den N-Phenyl-N′-(2-thiazolyl)harnstoffen (3). Unter den neuen Verbindungen finden sich besonders die entzundungshemmende, anthelminthische und trichomonazide Wirksamkeit stark ausgepragt. The reaction of 5-phenyl-2-thiobiuret (1) with α-chlorocarbonyl compounds 2 leads to the structure type of N-phenyl-N1-(thiazolyl)urea (3). The new compounds exhibit particularly antiinflammatory, anthelminthic, and trichomonacidal activity.

Trichomonazide Wirkstoffe, 5. Mitt. (Dichloranilino)ethentricarbonitrile

1986

Antidiabetische wirkstoffe. V Lang- und verzweigtkettig substituierte chlor-dihexylamino-1,3,5-triazine

1985

Die nucleophile Substitution eines Chloratoms in 2,4-Dichlor-6-dihexylamino-1,3,5-triazin (1) durch Amine (2a-c) fuhrt zu den Alkylamino-chlor-dihexylamino-1,3,5-triazinen 3a-c. Fur Strukturtyp 3 typische Signale in den 1H-NMR-Spektren sind das Triplett bei 0,9 ppm fur die endstandigen Methylgruppen und das Multiplett bei 3,3-3,65 ppm fur die den Stickstoffatomen benachbarten Methylengruppen. In Verbindungsklasse 3 finden sich Vertreter mit antidiabetischer, trichomonazider, antiviraler und anthelminthischer Wirksamkeit. The nucleophilic substitution of one chlorine atom in 2,4-dichloro-6-dihexylamino-1,3,5-triazine (1) by amines 2a-c leads to the alkylamino-chlorodihexylamino-1,3,5-triazin…

Orientation-Dependent Handedness of Chiral Plasmons on Nanosphere Dimers: How to Turn a Right Hand into a Left Hand

2016

Optical activity, which is used as a discriminator of chiral enantiomers, is demonstrated to be orientation dependent on individual, and nominally achiral, plasmonic nanosphere dimers. Through measurements of their giant Raman optical activity, we demonstrate that L/R-handed enantiomers can be continuously turned into their R/L-handed mirror images without passing through an achiral state. The primitive uniaxial multipolar response, with demonstrable broken parity and time reversal symmetry, reproduces the observations as resonant Raman scattering on plasmons that carry angular momentum. The analysis underscores that chirality does not have a quantitative continuous measure and recognizes t…

Recognition and Civic Selection

2021

Large-scale immigration and the refugee crisis have caused many states to adapt ever stricter civic selection processes. This paper discusses the challenges arising from civic selection from the perspective of recognition theories. The argument is that recognition theories provide good conceptual tools with which to critically analyze civic selection and immigration. However, the paper also aims to highlight that many current institutional practices are problematic from the perspective of recognition. In the context of civic selection, it is helpful to understand recognition as something that comes in two analytically distinct modes: horizontal (or interpersonal) and vertical (or institutio…