Richard A. Ogg

Preparation and Proton Magnetic Resonance Studies of Anhydrous Ammonia

Comparison of high‐resolution proton magnetic resonance spectra of anhydrous N14H3 and N15H3 (99.8% N15) leads to the conclusion that the line width in N14H3 is due to quadrupole relaxation. A new method of preparation of anhydrous, sodium‐free ammonia is described. The natural abundance of N15H3 in N14H3 is shown to be observable by magnetic resonance technique.

Nuclear Magnetic Resonance Spectra and Structure of Borohydride Ion and Diborane

High resolution proton magnetic resonance spectra are presented for aqueous NaBH4 and liquid B2H6 at 30 and 40 megacycles. B11 magnetic resonance spectra at 6 megacycles are presented for these same substances. The details of the spectra constitute powerful confirmation of a tetrahedral model for BH4— and a bridge proton model for B2H6. The bridge protons in the latter display resonance at higher applied magnetic field than do the terminal protons, suggesting a more hydride‐ion like character for the former. Quantitative spin‐spin multiplet separations and chemical shifts are recorded.

Proton and Nitrogen Magnetic Resonance Spectra and Structure of Nitramide and Nitrourethane

Nuclear magnetic resonance spectra of both protons and N14 nuclei in nitrourethane and nitramide have been studied. Spectra are interpreted in terms of the structures R–NHNO2 and H2NNO2 for nitrourethane and nitramide, respectively. Protons have been established as all being of amino type.

Kinetics of the Photolysis of Methyl Iodide and the Hydrogen Halides II. Photolysis of Methyl Iodide in the Presence of Iodine and the Hydrogen Halides

The photodissociation of methyl iodide by light of λ2537A has been utilized as a source of methyl radicals for a study of their subsequent reactions with iodine and the hydrogen halides. The observed rate of methane formation has been used to evaluate the ratio of rate constants for the following reactions: CH3+HX→CH4+XCH3+I2→CH3I+I where X represents Cl, Br or I. The reaction with hydrogen chloride has been found to be complicated by the unequal yield of methane and iodine, and possible explanations of this phenomenon have been considered.

Kinetics of the Photolysis of Methyl Iodide and the Hydrogen Halides I. Photolysis of Hydrogen Iodide in the Presence of Iodine, Hydrogen Bromide and Hydrogen Chloride

The photodissociation of hydrogen iodide by light of λ2537A has been utilized as a source of hydrogen atoms for a study of their subsequent reactions with iodine and the hydrogen halides. The observed rate of hydrogen formation has been used to evaluate the ratio of rate constants for the following reactions: H+HX→H2+XH+I2→HI+I where X represents Cl, Br or I.

The Kinetics of the Fast Gas‐Phase Reaction between Nitryl Chloride and Nitric Oxide

The kinetics of the fast reaction between nitryl chloride and nitric oxide has been studied by absorptiometric methods in two systems of greatly different surface‐to‐volume ratio and over a temperature range from 1° to 71°. The pressure of each reactant has been varied from 0.1 mm to 18 mm and the total pressure from 0.2 mm to 384 mm. The reaction proceeds quantitatively according to the equation ClNO2+NO=NO2+ClNO. It is homogeneous and first order with respect to each reactant. The second‐order rate constant is expressed by the equation k=0.83×1012 exp(−6900/RT)cc mole−1 sec−1. An elementary bimolecular mechanism is proposed.

Kinetics of the Nitrogen Dioxide Catalyzed Oxidation of Nitric Oxide

The rate constant for the reverse reaction of the rate controlling step (NO+O2+NO2=NO2+NO3) of high pressure nitrogen pentoxide decomposition has been determined to be 6.58×107 cc2 mole—2 sec—1. This reaction was found to be the rate‐controlling step in the nitrogen dixoide catalyzed oxidation of nitrosyl chloride to nitryl chloride. The equilibrium constant at 25° for the reaction ClNO+NO2=ClNO2+NO as evaluated from the kinetic data was found to be 1×10—4.

Kinetics of the Vapor Phase Reaction of Cyclopropane with Iodine

The thermal and photoreaction (light absorbed by iodine) between gaseous iodine and cyclopropane has been studied, and found to lead to the reversible formation of 1,3 diiodopropane. A slow iodine catalyzed isomerization of cyclopropane to propylene is the only important side reaction. The reaction is essentially homogeneous. For the thermal reaction, in the range 245–280°C, the rate expression is d(C3H6I2)dt=k1[(C3H6)(I2)12−K6(C3H6I2)(I2)12]. For the photoreaction, in the range 180–230°C, the rate expression is d(C3H6I2)/dt=k3Iabs12(C3H6). The respective values of k1 and k3 were found to be 1.17×1013e−35,230/RT(mole/cc)−12sec.−1 and 8.5×106e−18,800/RT(Einstein/cc)−12sec.−12. The mechanism has been established, the rate determining step being the reaction I+C3H6→ICH2CH2CH2, with rate constant 7.36×1012e−17,280/RT(mole/cc)−1sec.−1. The equilibrium constant, Ke, in the temperature range 255°‐280°C, is some 11.7e−17,200/RT(mole/cc). Hence for the reaction C3H6+I2→C3H6I2, ΔE=‐17,200 calories per mole. If the ...

Thermodynamic Properties of Nitryl Chloride

The calorimetric heat of formation of gaseous nitryl chloride from the elements at 25° has been found from the heat of the reaction of gaseous nitryl chloride with nitric oxide as confirmed by the heat of the reaction between nitrosyl chloride and nitrogen pentoxide. The value is +3.12±0.16 kcal/mole (endothermic). From the equilibrium constants for the reactions 2NO2+Cl2=2ClNO2 and NO2+ClNO=NO+ClNO2 the entropy of nitryl chloride at 25° has been found to be 65.46±0.6 eu.

Nuclear magnetic resonance studies of coordinate complex formation by boron trifluoride

Abstract The physical chemistry of coordinate complex formation between boron trifluoride and suitable electron donor substances is readily accessible by the technique of igh resolution nuclear magnetic resonance spectroscopy. Fluorine magnetic resonance is studied in a liquid mixtures of boron trifluoride with two or more donor substances, the latter in stoichiometric excess. At sufficiently low temperatures separated narrow fluorine resonance lines are observed, corresponding to the respective boron trifluoride complexes involved in the various equilibria. The relative line intensities provide an index of the concentrations, and hence enable measurement of the equilibrium constants. In general these constants are the ratios of instability constants. The studies this provide an arrangement of donor substances in a general basicity or ⪡boron trifluoride affinity⪢ series. The examples presented comprise principally oxygen compounds — water, acids, alcohols, ethers, esters, ketones, etc. Kinetic studies are allowed by the fact that at sufficiently high temperatures the fluorine resonance lines broaden and ultimately merge to a single narrow line — the latter phenomenon corresponding to a very rapid exchange of boron trifluoride between the various coordination complexes. Systematic studies furnish the qualitative aspects of the reaction mechanism and quantitative evaluation of rate constants.