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1.
Transition Metal Chemistry - (η5-Dp)Ru(PPh3)2H (Dp?=?C8H9?, 1,2-dihydropentalenyl) was synthesized in 90% yield by reaction of (η5-Dp)Ru(PPh3)2Cl with sodium formate.... 相似文献
2.
Jocelyn M. Bouzaid R. L. Frost W. N. Martens 《Journal of Thermal Analysis and Calorimetry》2007,89(2):511-519
The thermal stability and thermal decomposition pathways for synthesized composite iowaite/woodallite have been determined
using thermogravimetry analysis in conjunction with evolved gas mass spectrometry. Dehydration of the hydrotalcites occurred
over a range of 56–70°C. The first dehydroxylation step occurred at around 255°C and, with the substitution of more iron(III)
for chromium(III) this temperature increased to an upper limit of 312°C. This trend was observed throughout all decomposition
steps. The release of carbonate ions as carbon dioxide gas initialised at just above 300°C and was always accompanied by loss
of hydroxyl units as water molecules. The initial loss of the anion in this case the chloride ion was consistently observed
to occur at about 450°C with final traces evolved at 535 to 780°C depending of the Fe:Cr ratio and was detected as HCl (m/z=36). Thus for this to occur, hydroxyl units must have been retained in the structure at temperatures upwards of 750°C. Experimentally
it was found difficult to keep CO2 from reacting with the compounds and in this way the synthesized iowaite-woodallite series somewhat resembled the natural
minerals. 相似文献
3.
Frost R. L. Weier M. L. Erickson Kristy L. 《Journal of Thermal Analysis and Calorimetry》2004,76(3):1025-1033
Struvite (NH4MgPO4·6H2O) is a mineral often found in urinary tracts and kidneys. Thermal decomposition using slow low heating shows that the 'kidney'
stone can be decomposed at temperatures below 40°C. At this temperature both ammonia and water are evolved. If more rapid
heating is employed the decomposition occurs at around 80°C. The implication of this work rests with the use of low slow heat
for the decomposition of the kidney stones.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
4.
T. Rösel P. Schlemmer J. Röder L. Frost K. Jung H. Ehrhardt 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1992,23(4):359-363
A new method, and first results for an impact energy 2 eV above the threshold of ionisation of helium, are presented for the measurement of absolute triple differential cross sections (TDCS) in a crossed beam experiment. The method is based upon measurement of beam/target overlap densities using known absolute total ionisation cross sections and of detection efficiencies using known absolute double differential cross sections (DDCS). For the present work the necessary absolute DDCS for 1 eV electrons had also to be measured. Results are presented for several different coplanar kinematics and are compared with recent DWBA calculations. 相似文献
5.
Han Y Harlan CJ Stoessel P Frost BJ Norton JR Miller S Bridgewater B Xu Q 《Inorganic chemistry》2001,40(13):2942-2952
A series of oxo complexes, Re(O)X(diyne) (X = I, Me, Et), have been prepared from 2,7-nonadiyne and Re(O)I(3)(PPh(3))(2). Addition of B(C(6)F(5))(3) to Re(O)I(2,7-nonadiyne) (5) results in coordination of the oxo ligand to the boron. The protonation of Re(O)(X)(2-butyne)(2) and Re(O)(X)(2,7-nonadiyne)(2) with a variety of acids has been examined. With 5 and HBF(4)/Et(2)O, the ultimate product was [Re(CH(3)CN)(3)(I)(2,7-nonadiyne)](2+) (7). The conversion of 5 to 7 changes the conformation of the diyne ligand from a "chair" to a "boat" and shifts its propargylic protons considerably downfield in the (1)H NMR. The kinetics of the protonation of Re(O)I(2,7-nonadiyne) (5) by CF(3)SO(3)H in CH(3)CN have been monitored by visible spectroscopy, in a stopped-flow apparatus, and by low temperature (1)H NMR. Two second-order rate constants, presumably successive protonations, were observed in the stopped-flow, k(1) = 11.9 M(-)(1) s(-)(1) and k(2) = 3.8 M(-)(1) s(-)(1). Low temperature (1)H NMR spectroscopy indicated that the resulting solution contained a mixture of two doubly protonated intermediates X and Y, each of which slowly formed the product 7 via an acid-independent process. 相似文献
6.
Detection of the pesticide compound 1080 (sodium monofluoroacetate) using fluorine-19 nuclear magnetic resonance spectroscopy 总被引:2,自引:0,他引:2
Fluorine-19 nuclear magnetic resonance (19F NMR) spectroscopic measurements were used to determine the chemical nature and amounts of organofluorine in dosed meat baits. Earlier work implied that sodium monofluoroacetate (compound 1080) in meat baits was broken down into other organofluorine compounds such as fluorocitrate. No chemical evidence was found for such compounds. Only monofluoroacetate was detected in the prepared 1080 bait samples. Once the baits have aged, aqueous extraction fails to recover all the added 1080. Analysis using 19F NMR confirmed that the 1080 present in the aqueous extracts of the bait is recovered by Kramer's liquid chromatography method. It was shown here that the aqueous extracts do not recover all the 1080 in the meat bait. 相似文献
7.
Bedford RB Bruce DW Frost RM Goodby JW Hird M 《Chemical communications (Cambridge, England)》2004,(24):2822-2823
Iron(III) salen and related complexes are active catalysts for the coupling, under mild and simple reaction conditions, of aryl Grignard reagents with primary and secondary alkyl halide substrates bearing beta-hydrogens. 相似文献
8.
9.
10.
Arthur A. Frost 《Theoretical chemistry accounts》1970,18(2):156-161
The FSGO model has been used to make ab initio calculations of the geometrical structures of borazane and diborane. Where experimental data are available there is good agreement between calculated and observed values.
Zusammenfassung Für ab initio-Rechnungen zur geometrischen Struktur des Borazans und Diborans wurde das FSGO-Modell benutzt. Soweit experimentelle Werte vorhanden sind, stimmen die berechneten und beobachteten Werte gut überein.
Résumé La méthode FSGO a été utilisée pour effectuer des calculs ab-initio sur les structures géométriques du borazane et du diborane. Un bon accord est obtenu entre les valeurs calculées et les valeurs expérimentales existantes.相似文献