Kinetics of the Reaction of the Ethylene-Mercuric Acetate Addition Compound with Anisole

1959 ◽  
Vol 81 (20) ◽  
pp. 5316-5319 ◽  
Author(s):  
Katsuhiko Ichikawa ◽  
Koichi Fujita ◽  
Hajime Ouchi
Keyword(s):  
Mercuric Acetate ◽  
Addition Compound ◽  
Kinetics Of

The effect of inorganic and organic mercury on growth kinetics of Nitzschia acicularis W. Sm. and Tetraselmis suecica Butch.

1980 ◽  
Vol 26 (8) ◽  
pp. 930-937 ◽  
Author(s):  
B. Mora ◽  
J. Fábregas
Keyword(s):  
Growth Kinetics ◽  
Mercuric Acetate ◽  
Gradual Increase ◽  
Inorganic Mercury ◽  
Inoculum Size ◽  
Lag Phase ◽  
Tetraselmis Suecica ◽  
Initial Effect ◽  
Cellular Area ◽  
Kinetics Of

Studies have been made on the toxicities of three inorganic (HgCl2, HgSO4, and NH2HgCl) and two organic (CH3HgCl and phenyl mercuric acetate (PMA)) mercury derivatives on planktonic algae (Nitzschia acicularis W. Sm. and Tetraselmis suecica Butch.). Growth kinetics and fluorescence changes were used as criteria for assessing algal–metal responses.Methylmercury chloride was found to be the more toxic form, inhibiting growth of both species at levels of 0.025 ppm Hg. PMA inhibited Nitzschia at the same concentration. Inorganic forms prevent growth of the diatom at 0.15–0.20 ppm Hg. Addition of inorganic mercury at concentrations of 0.05 ppm Hg resulted in reduction of the lag phase, increase in exponential growth rate, or both. Increasing mercury concentrations caused a gradual increase in the lag phase in T. suecica and in N. acicularis only with mercuric sulphate. Populations recovered from this initial effect and started to grow. The effect of inoculum size on mercurial toxicity was tested. The higher concentrations of mercury that still permit growth restricted the chlorophyll fluorescence to the central cellular area and the cells appear slimmed. This effect is highest in concentrations that inhibit growth.

Kinetics of complex formation between fluorescein mercuric acetate and DNA

Biopolymers ◽  
1977 ◽  
Vol 16 (10) ◽  
pp. 2105-2111 ◽  
Author(s):  
Shintaro Takeuchi ◽  
Akio Maeda
Keyword(s):  
Complex Formation ◽  
Mercuric Acetate ◽  
Kinetics Of

Oxidative cleavage of cyclopropanes. IV. Kinetics of the cleavage of arylcyclopropanes by mercuric acetate

1968 ◽  
Vol 90 (6) ◽  
pp. 1619-1624 ◽  
Author(s):  
Robert J. Ouellette ◽  
Richard D. Robins ◽  
Aubrey. South
Keyword(s):  
Mercuric Acetate ◽  
Oxidative Cleavage ◽  
Kinetics Of

Kinetics and mechanisms of mercuration of aliphatic carboxylic acids

1965 ◽  
Vol 18 (3) ◽  
pp. 305 ◽  
Author(s):  
W Kitching ◽  
PR Wells
Keyword(s):  
Acetic Acid ◽  
Propionic Acid ◽  
Perchloric Acid ◽  
Mercuric Acetate ◽  
First Order ◽  
Mercuric Nitrate ◽  
Catalysed Reaction ◽  
Aqueous Conditions ◽  
Aliphatic Carboxylic Acids ◽  
Kinetics Of

The kinetics of the mercuration of acetic acid by mercuric acetate under anhydrous and aqueous conditions have been studied. The reaction is first order in mercuric acetate and possibly first order in acetic acid. Radicals are not involved. The reaction is insensitive to added salts and is not catalysed by acetate. Enol or carbanion intermediates are excluded by the absence of H-D exchange. A four-centre (SF2) mechanism is suggested. The reaction is accelerated by perchloric acid and this is attributed to mercuration by acetoxymercuric perchlorate probably in the form of an ion pair. Mercuric perchlorate and mercuric nitrate are more effective mercurating agents than mercuric acetate. Although the perchloric acid catalysed reaction may follow the SE2 mechanism an SF2 pathway is preferred. Propionic acid is mercurated exclusively at the α-carbon atom and trimethylacetic acid is unreactive. Acetic acid is 2.7 times as reactive as propionic acid. Optically active methylethylacetic acid appears to be mercurated stereospecifically.

Structural effects on reactivity in the oxymercuration reaction

1977 ◽  
Vol 55 (17) ◽  
pp. 3086-3095 ◽  
Author(s):  
I. C. Ambidge ◽  
Stephen K. Dwight ◽  
Carolyn M. Rynard ◽  
Thomas T. Tidwell
Keyword(s):  
Positive Charge ◽  
Mercuric Acetate ◽  
High Reactivity ◽  
Structural Effects ◽  
Carbonium Ion ◽  
Acid Catalyzed ◽  
Kinetics Of ◽  
Very High ◽  
Resonance Electron ◽  
Model Reactions

The kinetics of the reaction of mercuric acetate with alkenes in methanol can be measured directly by observing the ultraviolet absorbance of the solution at 265 nm. For more reactive alkenes stopped flow techniques are required, but for less reactive substrates conventional spectrophotometers are adequate. The measured rates are in satisfactory agreement with values obtained by other methods. The rates of several cyclopropylalkenes were measured in this way, and relative reactivities of some of the same substrates were obtained by the competition method. Rates obtained by both methods are in qualitative agreement, and show very high reactivity for the cyclopropylalkenes. These rates are analyzed by comparison with model reactions involving open ions (acid-catalyzed hydration) and bridged ions (sulfenyl halide addition). The comparisons suggest that the oxymercuration of alkenes not substituted with strongly resonance electron-donating substituents, for example ethylene, proceeds through bridged rate-determining transition states that put very little positive charge on carbon, but that when strongly resonance electron-donating substituents such as cyclopropyls are present, the rate-determining transition state resembles an open carbonium ion.

Direct observations of radiation-enhanced transformations in glass

1983 ◽  
Vol 41 ◽  
pp. 354-355
Author(s):  
J. F. DeNatale ◽  
D. G. Howitt
Keyword(s):  
Glass Matrix ◽  
Diffusion Mechanism ◽  
Bubble Formation ◽  
Silicate Glasses ◽  
Phase Decomposition ◽  
Direct Observations ◽  
Thin Foils ◽  
Oxygen Bubble ◽  
Electron Energy Loss ◽  
Kinetics Of

The electron irradiation of silicate glasses containing metal cations produces various types of phase separation and decomposition which includes oxygen bubble formation at intermediate temperatures figure I. The kinetics of bubble formation are too rapid to be accounted for by oxygen diffusion but the behavior is consistent with a cation diffusion mechanism if the amount of oxygen in the bubble is not significantly different from that in the same volume of silicate glass. The formation of oxygen bubbles is often accompanied by precipitation of crystalline phases and/or amorphous phase decomposition in the regions between the bubbles and the detection of differences in oxygen concentration between the bubble and matrix by electron energy loss spectroscopy cannot be discerned (figure 2) even when the bubble occupies the majority of the foil depth.The oxygen bubbles are stable, even in the thin foils, months after irradiation and if van der Waals behavior of the interior gas is assumed an oxygen pressure of about 4000 atmospheres must be sustained for a 100 bubble if the surface tension with the glass matrix is to balance against it at intermediate temperatures.

Irradiation behavior of pyrolytic silicon carbide

1983 ◽  
Vol 41 ◽  
pp. 72-73
Author(s):  
R. J. Lauf
Keyword(s):  
Silicon Carbide ◽  
Fission Products ◽  
Thermodynamics And Kinetics ◽  
Neutron Fluences ◽  
Fuel Particles ◽  
Sic Coatings ◽  
Irradiation Behavior ◽  
Kinetics Of ◽  
Htgr Fuel

Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain a layer of pyrolytic silicon carbide to act as a miniature pressure vessel and primary fission product barrier. Optimization of the SiC with respect to fuel performance involves four areas of study: (a) characterization of as-deposited SiC coatings; (b) thermodynamics and kinetics of chemical reactions between SiC and fission products; (c) irradiation behavior of SiC in the absence of fission products; and (d) combined effects of irradiation and fission products. This paper reports the behavior of SiC deposited on inert microspheres and irradiated to fast neutron fluences typical of HTGR fuel at end-of-life.

The Ordered Phase Formation in Ti-Al-Ga Alloys

1970 ◽  
Vol 28 ◽  
pp. 440-441
Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Titanium Alloys ◽  
Growth Kinetics ◽  
Stoichiometric Composition ◽  
Good Potential ◽  
Alpha Titanium ◽  
Cold Rolled ◽  
Kinetics Of ◽  
Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

Ion Beam Induced Interfacial Reactions in Molybdenum Thin Films on Silicon

1981 ◽  
Vol 39 ◽  
pp. 162-163
Author(s):  
L. J. Chen ◽  
L. S. Hung ◽  
J. W. Mayer
Keyword(s):  
Ion Beam ◽  
Chemical Vapor ◽  
Interfacial Reactions ◽  
Practical Applications ◽  
Microelectronic Devices ◽  
Recent Emergence ◽  
Chemical Vapor Deposited ◽  
Atomic Mixing ◽  
Silicon Interface ◽  
Kinetics Of

When an energetic ion penetrates through an interface between a thin film (of species A) and a substrate (of species B), ion induced atomic mixing may result in an intermixed region (which contains A and B) near the interface. Most ion beam mixing experiments have been directed toward metal-silicon systems, silicide phases are generally obtained, and they are the same as those formed by thermal treatment.Recent emergence of silicide compound as contact material in silicon microelectronic devices is mainly due to the superiority of the silicide-silicon interface in terms of uniformity and thermal stability. It is of great interest to understand the kinetics of the interfacial reactions to provide insights into the nature of ion beam-solid interactions as well as to explore its practical applications in device technology.About 500 Å thick molybdenum was chemical vapor deposited in hydrogen ambient on (001) n-type silicon wafer with substrate temperature maintained at 650-700°C. Samples were supplied by D. M. Brown of General Electric Research & Development Laboratory, Schenectady, NY.

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