摘要:

This paper is concerned with the general problem of the interpretation and analysis of nuclear magnetic resonance spectra of systems in which chemical shift and spin-coupling constants are of the same order of magnitude. Only nuclei of spin 1/2 are considered. Detailed methods are developed for:(a) Two chemically non-equivalent nuclei of the same species (writtenAB),(b) Three nuclei of the same species, two of which are equivalent (writtenAB2),(c) Three nuclei (ABX), two of which are of the same species (AB) and the third (X) is either a different species or has a resonance signal well separated fromAandB.Proton resonance spectra of S-guaiazulene, 2,6-lutidine, and 2,3-lutidine are reported and used as examples of the methods of analysis.

ISSN:0008-4042    

DOI:10.1139/v57-011

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

Exchange of deuterium between deuterium oxide and molecular hydrogen is induced by gamma rays from Co60. The reaction was studied by irradiating heavy water solutions saturated with hydrogen gas, and then analyzing the gas with a mass spectrometer. The reaction rate conforms to the exponential exchange law. The exchange yield is independent of dose rate and of hydrogen concentration over a moderate range. Prolonged irradiation leads to a steady state where the isotopic composition of the gas is close to that of the solution. This state differs greatly from that for thermodynamic equilibrium at room temperature.

ISSN:0008-4042    

DOI:10.1139/v57-012

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

In a flow system and at very low pressures, the reactions of CS2, H2S, SO2, and CCl4, on pure and carburized tungsten ribbons, were studied at 1300–2000° K.In the decomposition of CS2, onpuretungsten, CS and S2are found—in that of H2S, H2and S2—in that of SO2, O2and SO or S2, according to the temperature—CCl4gives CCl2, Cl2, and Cl. H2, S2, and Cl2molecules are probably formed by recombination on the walls of atoms produced on the ribbon. Withcarburizedtungsten the formation of S2and O2is replaced by that of CS and CO. On the contrary, no decarburization occurs with chlorine.Ionization potentials of the different species are measured and the deduced bond dissociation energies are discussed.

ISSN:0008-4042    

DOI:10.1139/v57-013

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

not available

ISSN:0008-4042    

DOI:10.1139/v57-014

出版商:NRC Research Press    

年代:1957

数据来源: NRC