The core-electron ionization potentials for mono- and
di(trifluoromethyl)benzene, for chlorofluoromethanes and for
chlorine have been measured in order to give information on
the electron distribution in these molecules and to investigate
differences between the inductive effect of fluorine
and that of CF3. For trifluoromethylbenzene the measured
ionization potentials in eV...
Water and methanol adsorption isotherms at 25° and 37° C.
were determined on a series of organo-bentonite clays. The clays
differed in the length of the carbon chain attached to the amine adsorbed
in the cation exchange position. The amines used had carbon
chains of 4, 6, 8, 10, 12,...
Due to its importance, the phenomenon of hydrogen
bonding has been the subject of much research over the
years. Among the different techniques used to study
hydrogen bonded systems, vibrational spectroscopy is
perhaps the most sensitive because of the striking
changes induced in molecular spectra by the formation of
hydrogen...
Eleven hand specimen whole rock (WR) samples (25-200 g each) and
33 fragments (0.5-0.8 g each) from a single basaltic flow at Picture
Gorge, Oregon were analyzed via instrumental neutron activation
analysis (INAA) for 12 elements (Na, Fe, Cr, Sc, Co, La, Sm, Eu, Yb,
Lu, Hf and Ta). Standard...
A nonflame method for atomic absorption spectroscopy is
described. A helical tungsten filament from a commercially available
6-V, 4-A light bulb, heated to :incandescence in an argon atmosphere
is used to atomize 2-μl aqueous samples for metals analyses. Studies
of two hollow cathode lamp tungsten filament orientations, a
modulated light...
Two studies were conducted involving rare earth elements. In the
first study, the use of rare earth diethylenetriaminepentaacetic acid
(DTPA) complexes as stable actiable tracers, a method of stable-isotope
tracing with post-sampling neutron activation analysis, was explored.
The persistence of rare earth DTPA complexes in estuarine waters was
measured in...
Isomerically pure cis,cis,trans-1-pheny1-1,3,5-
heptatriene was prepared and cyclized. Ring closure
was followed by a 1,5 hydrogen shift, and the only product
observed was 1-phenyl -6-methyl -1,3-cyclohexadiene.
Rough first order rate constants for thermolysis and
the hydrogen shift were determined. Kinetic estimates
indicate that the report of disallowed product in a...
The effects of different nitrogen sources on the primary and secondary pathways of Azotobacter vinelandii cells were studied by means of the radiorespirometric method. C¹⁴ labeled glucose and several key amino acids related to the tricarboxylic acid cycle, such as glutamic acid, aspartic acid, alanine, serine and glycine were used...
The Diels-Alder reaction represents a promising tool for use in
asymmetric synthesis. The reaction involves a rigid transition state
that facilitates the formation of one diastereomeric transition state
and is reversible. This satisfies two necessary criteria for
asymmetric synthesis.
The Diels-Alder reactions of 1,l-dialkylspiro[2.4]-4,6- heptadienes
with maleic anhydride and p-benzoquinone...
A tracer method utilizing stable activable tracers (involving rare earth nuclides with short-lived t[subscript 1/2] < 1 day} activation products) for tracing fluid bound substances in fresh water is explored. Simulated laboratory studies showed these tracers (Dy and in) when chelated with diethylenetriamine2entaacetic acid a7i1W to be stable ( <20%)...