Search results for "CHROMIUM"
showing 10 items of 494 documents
CCDC 809141: Experimental Crystal Structure Determination
2011
Related Article: O.Schott, J.Ferrando-Soria, A.Bentama, S.-E.Stiriba, J.Pasan, C.Ruiz-Perez, M.Andruh, F.Lloret, M.Julve|2011|Inorg.Chim.Acta|376|358|doi:10.1016/j.ica.2011.06.039
CCDC 245542: Experimental Crystal Structure Determination
2005
Related Article: L.Toma, R.Lescouezec, J.Vaissermann, P.Herson, V.Marvaud, F.Lloret, M.Julve|2005|New J.Chem.|29|210|doi:10.1039/b413473g
CCDC 809140: Experimental Crystal Structure Determination
2011
Related Article: O.Schott, J.Ferrando-Soria, A.Bentama, S.-E.Stiriba, J.Pasan, C.Ruiz-Perez, M.Andruh, F.Lloret, M.Julve|2011|Inorg.Chim.Acta|376|358|doi:10.1016/j.ica.2011.06.039
Synthesis of new vanadium–chromium and chromium–molybdenum oxynitrides by direct ammonolysis of freeze-dried precursors
2000
Interstitial vanadium–chromium and chromium–molybdenum oxynitrides in the solid solution series V1 − zCrz(OxNy) and Cr1 − zMoz(OxNy) (z = 0.0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0) have been obtained by direct ammonolysis of precursors resulting from the freeze-drying of aqueous solutions of the appropriate metal salts. A study of the influence of the preparative variables on the outcomes of this procedure is presented. Compounds in the V1 − zCrz(OxNy) series are prepared as single phases by nitridation at 1073 K, followed by fast cooling of the samples. Compounds in the Cr1 − zMoz(OxNy) series are prepared as nearly single phases by nitridation at different temperatures, optimized for each composi…
Supramolecular diversity and magnetic properties of novel heterometallic Cu(II)/Cr(III) complexes prepared from copper powder, Reineckes salt and eth…
2009
Abstract Three novel heterometallic complexes [Cu(en) 2 Cr(NCS) 4 (NH 3 ) 2 ][Cr(NCS) 4 (NH 3 ) 2 ] · 6dmf ( 1 ), [Cu(en) 2 Cr(NCS) 4 (NH 3 ) 2 ](OAc) ( 2 ) and [{Cu(en) 2 } 3 {Cr(NCS) 4 (NH 3 ) 2 } 2 (NCS) 2 ](NCS) 2 ( 3 ) have been synthesized in a one-pot reaction from copper powder, Reineckes salt, NH 4 X [X − = OAc − ( 2 ), NCS − ( 3 )] in a dmf ( 1 ) or CH 3 CN ( 2 , 3 ) solution of ethylenediamine (en). X-ray studies showed that 1 and 2 consist of cationic polymeric chains, formed by Cu ( en ) 2 2 + and Cr ( NCS ) 4 ( NH 3 ) 2 - building blocks that bridged through thiocyanate anions. In both complexes, distinct hydrogen bonds are present and serve to increase the dimensionality of …
Mossbauer study on the distribution of iron in high coercivity chromium dioxide particles
1992
/sup 57/Fe Mossbauer spectroscopy is applied to determine the level of iron doping in high-coercivity CrO/sub 2/ particles. It is found that, compared with the conventional preparation process, the particles contain an increased amount of Fe/sup 3+/ ions in the CrO/sub 2/ crystal lattice, giving rise to higher magnetocrystalline anisotropy. This is reflected in coercivities up to over 900 Oe. All samples contain as a secondary iron-containing phase some (Cr/sub 1-x/Fe/sub x/)/sub 2/O/sub 3/. The valence of the iron doping is predominantly +3; very weak signals in the Mossbauer spectra suggest the existence of Fe/sup 4+/ in an amount 2-3% of the total number of iron atoms. >
Chemistry of lanthanide–metal carbonyl systems: the ytterbium–chromium carbonyls interaction
2001
Abstract The interaction of the chromium carbonyl hydrides HCr2(CO)10− or HCr(CO)5− with Yb(acac)3·3H2O has been investigated, and the experimental conditions leading to the isolation of ytterbium–chromium carbonyl complex species are reported. Formulation of the coordination compounds produced by such interactions has been proposed on the basis of analytical data and IR spectroscopy.
Near-IR to Near-IR Upconversion Luminescence in Molecular Chromium Ytterbium Salts
2020
Abstract Upconversion photoluminescence in hetero‐oligonuclear metal complex architectures featuring organic ligands is an interesting but still rarely observed phenomenon, despite its great potential from a basic research and application perspective. In this context, a new photonic material consisting of molecular chromium(III) and ytterbium(III) complex ions was developed that exhibits excitation‐power density‐dependent cooperative sensitization of the chromium‐centered 2E/2T1 phosphorescence at approximately 775 nm after excitation of the ytterbium band 2F7/2→2F5/2 at approximately 980 nm in the solid state at ambient temperature. The upconversion process is insensitive to atmospheric ox…
Biosorption of Cr(III) from Aqueous Solution by Activated Sludge
2016
The biosorption of Cr(III) from aqueous solution using activated sludge (AS) microorganisms was investigated under various experimental conditions regarding pH and temperature. Biosorption equilibrium parameters were determined based on the Langmuir and Freundlich isotherm model. The kinetic parameters were established using the equations of pseudo-first order and pseudo-second order. Moreover thermodynamic parameters have been calculated. Langmuir isotherm provided a better fit to the equilibrium data. The maximum experimentally determined sorption capacity 26.95 mg g–1 obtained at 25o C and pH 5.0. The kinetics model of pseudo-second order row has been better describing experimental data.…
Direct C-H metalation with chromium(ii) and iron(ii): transition- metal host/benzenediide guest magnetic inverse-crown complexes
2009
Check M(etal)ate: The chessboard and the figures represent a special reaction in which different low-polarity metals can metalate arenes directly when they are brought into the right position. In a combination of queen (sodium) and knight (chromium or iron), it is possible for the knight (usually the weaker piece) to make a direct deadly hit on the king (benzene) in this game of elemental chess. Fil: Alborés, Pablo. Johannes Gutenberg Universitat Mainz; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Carrella, Luca M.. Johannes Gutenberg Universitat Mainz; Alemania Fil: Clegg, William. University of Newcastle; Reino Unido Fil: García Álvarez, Pablo. Univ…