Search results for "tetrahydrofuran"
showing 10 items of 284 documents
N-(Diphenylmethylene)benzenesulfonamide andN-(Diphenylmethylene)-4-methylbenzenesulfonamide
2008
[10398-99-9] C19H15NO2S (MW 332.42) InChI = 1S/C19H15NO2S/c21-23(22,18-14-8-3-9-15-18)20-19(16-10-4-1-5-11-16)17-12-6-2-7-13-17/h1-15H InChIKey = LECLPBHPQOFADH-UHFFFAOYSA-N (reagent used as an activated imine) Physical Data: mp 119–120 °C. Form Supplied in: colorless crystals. Not commercially available. Purification: recrystalization from CH3OH. [10399-00-5] C20H17NO2S (MW 346.45) InChI = 1S/C20H17NO2S/c1-16-12-14-19(15-13-16)24(22,23)21-20(17-8-4-2-5-9-17)18-10-6-3-7-11-18/h2-15H,1H3 InChIKey = ODLFJRFKAOOIKO-UHFFFAOYSA-N (reagent used as an activated imine) Physical Data: mp 103–104 °C1; 102–103 °C2; 101–102 °C5; 103 °C6; 102–104 °C.7 Solubility: soluble in pyridine, dimethylformamide, …
ChemInform Abstract: Reversal of Asymmetric Induction in Stereoselective Strecker Synthesis on Galactosyl Amine as the Chiral Matrix.
1989
Abstract The reversal of the direction of asymmetric induction in Lewis acid catalyzed Strecker synthesis using the 2,3,4,6-tetra-O-pivaloyl-β-D-galactopyranosyl amine 1 is described. In isopropanol or tetrahydrofuran 1 had given ( R )-diastereomers of the corresponding α-amino nitriles preferably. However, in chloroform in the presence of heterogeneous zinc chloride the same auxiliary alternatively leads to an excess of the ( S )-diastereomers.
Thermodynamisches verhalten, expansionskoeffizient und viskositätszahl von polystyrol in tetrahydrofuran
1968
Streulichtmessungen ergeben, das Polystyrollosungen in Tetrahydrofaran stark exothermisch sind; der 2. Virialkoeffizient des osmotischen Druckes A2 wird uberwiegend durch den Enthalpieterm A2,H bestimmt. Der Expansionskoeffizient gehorcht der (α5−α3)-Beziehung mit der Konstante von STOCKMAYER und die h(z)-Funktion der Gleichung von CASASSA. Die Viskositatszahl [η] wird durch die Gleichung von KURATA und YAMAKAWA erfast. Mit den drei Parametern β/M, K0 = r/M und b/M (b = hydrodynamischer Durchmesser) lassen sich A2, α, [η] und der Tragheitsradius r uber einen grosen Molekulargewichts-bereich in guter Ubereinstimmung mit den Meswerten berechnen (vgl. Abb. 3). Light scattering measurements of …
Formation of meso-1,2-Bis(dimethylamino)-1,2-diphenylethane by Oxidative C-C Coupling Reaction
2005
The title compound was obtained from the reaction of N,N-dimethylbenzylamine with n-butyl lithium and sulfur in tetrahydrofuran at room temperature. Its molecular structure was investigated by means of single crystal X-ray diffraction and quantum chemical DFT methods. The formation of meso-1,2-bis(dimethylamino)-1,2-diphenylethane is likely to be due to an unusual α-deprotonation of N,N-dimethylbenzylamine, instead of the well known ortho-lithiation, with a subsequent oxidative C-C coupling of the anions. Ab initio calculations of the corresponding α- and o-deprotonated anions of N,N-dimethylbenzylamine showed the former to be more stable than the latter, due to delocalisation of the negati…
Crystal structure of 3-(tri-phenyl-phosphoranyl-idene)-2,5-di-hydro-furan-2,5-dione tetra-hydro-furan monosolvate.
2018
The title pseudo-polymorph of 3-(triphenylphosphoranylidene)-2,5-dihydrofuran-2,5-dione crystallizes with a tetrahydrofuran solvent molecule, viz. C22H17O3P·C4H8O. The succinic anhydride ring is approximately planar (r.m.s. deviation = 0.032 Å). The tetrahydrofuran molecule is disordered over two orientations about a pseudo-twofold axis with refined occupancy ratio 0.718 (4):0.282 (4). In the crystal, C—H...O hydrogen bonds link molecules of the dihydrofuran-2,5-dione derivative into chains parallel to the b axis and arranged into layers stacked along [100] alternating with hydrogen-bonded tetrahydrofuran layers.
CCDC 1817831: Experimental Crystal Structure Determination
2018
Related Article: Ondřej Jurček, Hennie Valkenier, Rakesh Puttreddy, Martin Novák, Hazel A. Sparkes, Radek Marek, Kari Rissanen, Anthony P. Davis|2018|Chem.-Eur.J.|24|8178|doi:10.1002/chem.201800537
Studies of structural composition distribution heterogeneity in ethylene/1-hexene copolymers using thermal fractionation technique (SSA)
2005
Abstract Investigations into the compositional heterogeneity of ethylene/1-hexene copolymers obtained with various zirconocene/MAO catalysts, either homogeneous or supported on inorganic carriers such as a complex of magnesium chloride with tetrahydrofuran or methyl alcohol, were conducted. The dependence between metallocene structure, as well as catalyst immobilization, and the compositional heterogeneity of the related products was investigated. It was found that the heterogeneity of copolymers is determined by the metallocene catalyst structure. The amount of peaks on the DSC thermograms of copolymers and their division increase with the increase of bulkiness of the ligand in the catalyt…
Transition metal chlorides complexes with tetrahydrofuran [MtCl(4)(THF)(2)] used as precursors of ethylene polymerization
2002
Otrzymano trzy kompleksy chlorków metali przejściowych z THF - [TiCl4(THF)2] (I), [ZrCl4(THF)2] (II), oraz [HfCWTHF),] (III) i zastosowano je jako prekursory katalizatorów tytanowo-magnezowych w niskociśnieniowej polimeryzacji (0,5 MPa, 323 K) etylenu przy użyciu AlEt3 (najkorzystniej), AlEt2Cl lub Al(z'-Bu)3 jako kokatalizatora (rys. 1, tabela 1). Zmierzono gęstość, gęstość nasypową, stopień krystaliczno-ści, ciężary cząsteczkowe i ich rozkład oraz temperaturę topnienia uzyskanego PE-HD (tabela 1). Aktywność katalizatorów wzrastała w szeregu (III) < (II) < (I), tzn. ze wzrostem elektroujemności pierwiastka metalu i ze spadkiem wartości ładunku cząstkowego na atomie metalu grupy przejściowe…
CCDC 863441: Experimental Crystal Structure Determination
2012
Related Article: P.Svec, R.Olejnik, Z.Padelkova, A.Ruzicka, L.Plasseraud|2012|J.Organomet.Chem.|708|82|doi:10.1016/j.jorganchem.2012.02.022
CCDC 1542006: Experimental Crystal Structure Determination
2017
Related Article: Pavel A. Petrov, Dmitry Yu. Naumov, Taisiya S. Sukhikh, Sergey N. Konchenko, Carlos J. Gómez-García, Rosa Llusar|2017|New J.Chem.|41|7849|doi:10.1039/C7NJ01217A