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The transition structures and a-carbon 12C/13C kinetic isotope for 22 SN2 reactions between methyl chloride and a wide variety of nucleophiles have been calculated using the B1LYP/aug-cc-pVDZ level of theory. Anionic, neutral, and radical anion nucleophiles were used to give a wide range of SN2 transition states so the relationship between the magnitude of the a-carbon kinetic isotope effect and trasition-state structure could be determined. The results suggest that the a-carbon 12C/13C kinetic isotope effects for SN2 reactions will be large (near the experimental maximum) and that the curve relating the magnitude of the KIE to the percent transfer of the a-carbon from the nucleophile to the leaving group in the transition state has a broad maximum. This means very similar KIEs will be found for early, symmetric, and late transition states and that one cannot use the magnitude of these KIEs to estimate transition-state structure.

A report is given of a study to assess the concentrations of twelve different PAH compounds in several different environments in underground mines where diesel engines are being used. It was found that PAH levels in mines are lower than those reported in other industrial operations and in the air over large cities. The concentration of PAH, and the behaviour of PAH-bearing particulate varies in different types of mine. The type of diesel engine and/or the type of fuel influences the type of PAH., A report is given of a study to assess the concentrations of twelve different PAH compounds in several different environments in underground mines where diesel engines are being used. It was found that PAH levels in mines are lower than those reported in other industrial operations and in the air over large cities. The concentration of PAH, and the behaviour of PAH-bearing particulate varies in different types of mine. The type of diesel engine and/or the type of fuel influences the type of PAH.

The results are presented of an ultra-violet spectroscopy study of the effect of diethylenetriamine (DETA) on the formation of Cu2+ -, Ni2+ - and Fe3+ -amyl xanthate ion (AX-) complexes. The study was carried out in connection with the flotation of Cu, Ni and Fe ores at INCO. DETA was shown to dissolve M(OH)2 and to suppress the formation of M(AX)2 depending on the M2+/AX- ratio. DETA dissolves Cu(OH)2 instantaneously and quantitatively whereas the dissolution of Ni(OH)2 is very slow. While the formation of Ni(AX)2 is dependent on the M2+/AX-/DETA ratio, the formation of Cu(AX)2 was not affected significantly by the solution composition. The M(AX)2 self-reduction products, CuAX and NiAX, isolated from solutions containing M2+, AX- and DETA, were characterised using atomic absorption and FT-IR spectroscopy. The behaviour of Fe3+ is different from that of Cu2+ and Ni2+ with AX- and/or DETA. Even in the presence of a large excess of AX- and/or DETA, Fe3+ exists almost exclusively as Fe(OH)3 at a pH of 9.3. DETA decreases the amount of Fe3+AX- complex in solution., The results are presented of an ultra-violet spectroscopy study of the effect of diethylenetriamine (DETA) on the formation of Cu2+ -, Ni2+ - and Fe3+ -amyl xanthate ion (AX-) complexes. The study was carried out in connection with the flotation of Cu, Ni and Fe ores at INCO. DETA was shown to dissolve M(OH)2 and to suppress the formation of M(AX)2 depending on the M2+/AX- ratio. DETA dissolves Cu(OH)2 instantaneously and quantitatively whereas the dissolution of Ni(OH)2 is very slow. While the formation of Ni(AX)2 is dependent on the M2+/AX-/DETA ratio, the formation of Cu(AX)2 was not affected significantly by the solution composition. The M(AX)2 self-reduction products, CuAX and NiAX, isolated from solutions containing M2+, AX- and DETA, were characterised using atomic absorption and FT-IR spectroscopy. The behaviour of Fe3+ is different from that of Cu2+ and Ni2+ with AX- and/or DETA. Even in the presence of a large excess of AX- and/or DETA, Fe3+ exists almost exclusively as Fe(OH)3 at a pH of 9.3. DETA decreases the amount of Fe3+AX- complex in solution.