Ab initio calculations relevant to the mechanism of chemical carcinogenesis by nitrosamines. Part 5. The role of diazomethane

Recent work suggested that the role of diazomethane in carcinogenesis by nitrosamines should be reinvestigated. Ab initio self-consistent-field gradient calculations using a 4–21 G basis set have shown that on energetic grounds the involvement of diazomethane cannot be excluded. Diazomethane may be formed as a minor product in the presence of methanediazohydroxide and base. The transition structure for the direct formation of diazomethane from methanediazohydroxide is reported; the second-order Møller–Plesset (MP2) energy barrier suggests that this exothermic reaction may proceed slowly.