The chemical effect of light on sodium ρ‐methoxybenzenediazosulphonate

Abstract

It could be derived from kinetic measurements that irradiation of an aqueous solution of ρ‐methoxybenzenediazosulphonate with ultra‐violet light causes a dissociation of the sulphonate ion to form a ρ‐methoxybenzene‐diazonium ion and a sulphite ion. The ions produced photochemically slowly recombine in the dark to form back the original sulphonate ion. The reactions may be represented by the scheme: The occurence of a labile or cis‐diazosulphonate can practically be precluded.

Synthetic Route to Phenyl Diazenes and Pyridazinium Salts from Phenylazosulfonates

“…If bis-sulfite adducts of aromatic diazonium salts can serve as precursors for phenylhydrazines as part of a formal four-electron reduction, then a monosulfite adductnamely, a phenylazosulfonate saltcould possibly provide the desired phenyldiazene as part of a formal two-electron transfer process. As the formation of monosulfite adducts from diazonium salts has however been reported to be reversible, suitable conditions favoring the reduction over the reverse reaction would be required.…”

Diazonium-diazo equilibrium

“…Diazoni u m-d inzo cq ti il i br iu m 75 Benzenediazonium ions which have a hydroxyl group in thc oivllo or p n m position split off the proton even in mildly acidic medium; the py2 value of 4-hydroxybenzenediazoniuni ion is 3.40 27. Thc diazo compounds formed are only slightly reactive and do not form diazotates evcn i n a strongly alkaline medium.…”