Photochemistry of reactive surface-active compounds in adsorbed monolayers

Article abstract of DOI:10.1016/S0040-4020(01)90279-0

The reactions of long-chain diazo ketones and azides in adsorbed monolayers on inorganic solids were investigated and compared with the corresponding behaviour in monolayers at the air-water interface. The isolated products indicate that reaction of photochemically generated intermediates occurs both with co-adsorbed water and with hydroxyl groups on the solid surface. In the case of 1-diazo-2-oxoheptadecane, for example, the products of these two reactions are heptadecanoic acid and a surface-grafted long-chain ester. The latter can be removed as methyl heptadecanoate by ester exchange using methanolic HCl. Pronounced differences were observed between alumina, silica gel and fumed silica as supports, and were attributed to differences in the amount of adsorbed H₂O and in the density of surface hydroxyl groups.