A facile synthetic route to convert Tb(III) complexes of novel tetra-1,3-diketone calix[4]resorcinarene into hydrophilic luminescent colloids

The work presents the synthesis of a novel calix[4]resorcinarene cavitand bearing four 1,3-diketone groups at the upper rim and its complex formation with Tb(iii) ions in DMF and DMSO solutions. Electrospray ionization mass spectra, 1H NMR, UV-Vis and luminescence spectra indicate a long (three hours at least) equilibration time for the complex formation between the cavitand and Tb(iii) in alkaline DMF and DMSO solutions. These results are explained by the restricted keto-enol conversion, resulting from the steric hindrance effect of the methylenedioxy-groups linking the benzene rings within the cavitand framework. A facile synthetic route to convert luminescent Tb(iii) complexes of various stoichiometries into luminescent hydrophilic colloids is disclosed in this work. The route is based on the reprecipitation of the Tb(iii) complexes from DMF to aqueous solutions with further polyelectrolyte deposition without prior separation of the luminescent complexes. The luminescent colloids exhibit high stability over time and in buffer systems, which is a prerequisite for their applicability in analysis and biolabeling. © the Partner Organisations 2014

Structurization of ceramics based on fusible clays with the addition of wastes of Chromia-alumina catalyst

© 2016, International Journal of Pharmacy and Technology. All rights reserved.In this work are represented results of research of impact of waste of chromia-alumina catalyst (hereinafter CAC) on ceramic samples structure formation. It is established that with increase of CAC dose from 1.5 to 12%, general quantity of pores decreases, structure became denser. Increasing of samples burning temperature from 960 to 1160ºC reduces defectiveness of structure, porosity decreases by cost of more complete filling of inter-grain space, increases the degree of ingredients packing. Results of roentgen-phase analysis and electronic microscopy show that increase of density is stipulated by larger volume of crystalline new growths that are forming in space between grains at high temperature burning, and also by increase of density of glass phase by cost of its armoring by crystals

Structurization of ceramics based on fusible clays with the addition of wastes of Chromia-alumina catalyst

© 2016, International Journal of Pharmacy and Technology. All rights reserved.In this work are represented results of research of impact of waste of chromia-alumina catalyst (hereinafter CAC) on ceramic samples structure formation. It is established that with increase of CAC dose from 1.5 to 12%, general quantity of pores decreases, structure became denser. Increasing of samples burning temperature from 960 to 1160ºC reduces defectiveness of structure, porosity decreases by cost of more complete filling of inter-grain space, increases the degree of ingredients packing. Results of roentgen-phase analysis and electronic microscopy show that increase of density is stipulated by larger volume of crystalline new growths that are forming in space between grains at high temperature burning, and also by increase of density of glass phase by cost of its armoring by crystals

Le Petit Troyen : journal démocratique régional ["puis" journal quotidien de la démocratie de l'Est "puis" grand quotidien de la Champagne]

23 février 18981898/02/23 (A18,N6511).Appartient à l’ensemble documentaire : ChArdenn

Two heads are better than one:improving magnetic relaxation in the dysprosium metallocene DyCp*₂BPh₄ upon dimerization by use of an exceptionally weakly-coordinating anion

Abstract Partial metathesis between two weakly-coordinating anions in the archetypical dysprosium metallocene DyCp*₂BPh₄ results in the first example of [BPh₄]⁻ as a bridging ligand in 4f metals, with a unique η₂,η₂:η₂,η₂-bridge. Magnetic susceptibility and relaxation dynamics studies along with ab initio calculations reveal improved slow relaxation of the magnetization in [Dy₂Cp*₄(μ-BPh₄)][Al(OC(CF₃)₃)₄] over its mononuclear congener, resulting in an energy barrier of 490 K/340 cm⁻¹ and waist-restricted hysteresis up to 6.5 K

Selective Copper Complex-Catalyzed Hydrodefluorination of Fluoroalkenes and Allyl Fluorides: A Tale of Two Mechanisms

The transition to more economically friendly small-chain fluorinated groups is leading to a resurgence in the synthesis and reactivity of fluoroalkenes. One versatile method to obtain a variety of commercially relevant hydrofluoroalkenes involves the catalytic hydrodefluorination (HDF) of fluoroalkenes using silanes. In this work it is shown that copper hydride complexes of tertiary phosphorus ligands (L) can be tuned to achieve selective multiple HDF of fluoroalkenes. In one example, HDF of the hexafluoropropene dimer affords a single isomer of heptafluoro-2-methylpentene in which five fluorines have been selectively replaced with hydrogens. DFT computational studies suggest a distinct HDF mechanisms for L2CuH (bidentate or bulky monodentate phosphines) and L3CuH (small cone angle monodentate phosphines) catalysts, allowing for stereocontrol of the HDF of trifluoroethylene

Single-molecule magnet behaviour in a tetranuclear Dy III complex formed from a novel tetrazine-centered hydrazone Schiff base ligand

International audienc

A facile synthetic route to convert Tb(III) complexes of novel tetra-1,3-diketone calix[4]resorcinarene into hydrophilic luminescent colloids

The work presents the synthesis of a novel calix[4]resorcinarene cavitand bearing four 1,3-diketone groups at the upper rim and its complex formation with Tb(iii) ions in DMF and DMSO solutions. Electrospray ionization mass spectra, 1H NMR, UV-Vis and luminescence spectra indicate a long (three hours at least) equilibration time for the complex formation between the cavitand and Tb(iii) in alkaline DMF and DMSO solutions. These results are explained by the restricted keto-enol conversion, resulting from the steric hindrance effect of the methylenedioxy-groups linking the benzene rings within the cavitand framework. A facile synthetic route to convert luminescent Tb(iii) complexes of various stoichiometries into luminescent hydrophilic colloids is disclosed in this work. The route is based on the reprecipitation of the Tb(iii) complexes from DMF to aqueous solutions with further polyelectrolyte deposition without prior separation of the luminescent complexes. The luminescent colloids exhibit high stability over time and in buffer systems, which is a prerequisite for their applicability in analysis and biolabeling. © the Partner Organisations 2014