Now showing items 81-90 of 758
Trimethylstannyl-2,4-cycloheptadiene: A fluxional molecule
(Elsevier, 1972-05-16)
Trimethylstannyl-2,4-cycloheptadiene (II) was synthesized and shown to be fluxional on the NMR time scale. The activation energy for the [1,5] trimethyltin migration is estimated to be ca. 18 kcal/mole. This value is ...
Quantitative Determination of High Charge Density Polyanion Contaminants in Biomedical Heparin Preparations Using Potentiometric Polyanion Sensors
(WILEY-VCH Verlag, 2010-01)
Quantification of oversulfated chondroitin sulfate (OSCS) in biomedical heparin preparations is achieved using a recently described potentiometric polyanion sensor-based approach operated in a kinetic mode of analysis. ...
Supercritical fluid jet expansions of polar aromatic carboxylic acids using simple derivatization with detection by resonant two-photon ionization
(Elsevier, 1988)
In this work simple derivatization is used as a means of enhancing the solubility of polar aromatic carboxylic acids in supercritical CO2 and N2O. The supercritical fluid is then expanded from 200 atm and 40[deg]C through ...
MOCVD of rhodium, palladium and platinum complexes on fluidized divided substrates: Novel process for one-step preparation of noble-metal catalysts
(John Wiley & Sons, Ltd., 1998-03)
A new one-step method, entitled fluidized-bed metal-organic chemical vapor deposition (FBMOCVD) of preparing highly dispersed metal-supported catalysts is reported. The following complexes were studied and used as CVD ...
Synthesis of the Tetraketide Lactones from the Pikromycin Biosynthetic Pathway
(WILEY-VCH Verlag, 2007-07)
Synthesis of tetraketide lactones 2 and 3 , which are likely to be produced by a model pikromycin polyketide synthase (PKS), has been investigated. The tetraketide lactones with six-membered rings, 2a and 2b , were ...
Thermodynamics of Fe(II)Fe(III) oxide systems II. Zinc- and cadmium-doped Fe3O4 and crystalline magnetite
(Elsevier, 1976-06)
Four doped samples of composition MzFe3 - xO4, in which for M = cadmium, x = 0.005 and 0.010, and for M = zinc, x = 0.005 and 0.066, were prepared using a high-temperature solid-state ceramic technique. X-ray, magneto-t.g.a., ...
Iodine-promoted decomposition of 1-aryl-3,3-dialkyltriazenes: A mild method for the synthesis of aryl iodides
(Elsevier, 1994-08-01)
Iodine promoted decomposition of 1-aryl-3,3-dialkyltriazenes in organic solvents is shown to give high yields of the corresponding aryl iodides under extremely mild conditions. The presence of iodine greatly accelerates ...
Electrophilic alkylation of 1-SB9H9
(Elsevier, 1977-06-21)
Reaction of closo-1-SB9H9 with either ethyl or methyl iodide in the presence of A1C13 produces alkylated derivatives of the type 1-SB9H(9-x)Rx (R = C2H5, CH3;x = 1---5), which were identified by GC/MS, 11B and 1H NMR ...
The enthalpies of combustion and formation of [2.2]-paracyclophane and triptycene
(Elsevier, 1973-09)
The enthalpies of combustion, ΔHoc, for crystalline [2.2]-paracyclophane (C16H16) and triptycene (C20H14) have been measured by oxygen combustion calorimetry. The derived standard enthalpies of formation at 298.15 ...
A study of a C Α, Β -didehydroalanine homo-oligopeptide series in the solid-state by 13 C cross-polarization magic angle spinning NMR
(John Wiley & Sons, Ltd., 2004-06)
The fully extended peptide conformation (2.0 5 -helix) has been investigated for the first time in the solid-state by 13 C cross-polarization magic angle spinning NMR. The compounds examined are members of a terminally ...