The Photosynthesis of Nitrosoformaldehyde and the Identification of its Spectrum

A transient spectrum previously thought to be that of methoxyl is produced by the flash photolysis of methyl nitrite (McGrath & McGarvey 1964 a, b). We now find that the same spectrum is produced by flashing formaldeyhde, acetaldehyde, methyl formate or glyoxal in the presence of nitric oxide and excess of nitrogen as coolant, and attribute it to nitroso-formaldehyde. The spectrum consists of diffuse bands with centres at 2070, 2043, 2020 (?) 2000 and 1982 Å which possibly constitute a progression in the NCO bending mode. The reaction leading to the decay of the nitrosoformaldehyde in about 0.1 s has not been positively identified, and alternative possibilities are discussed.