Photolabile surfactants based on the diazosulfonate group I. 4-n-Alkylbenzenediazosulfonates

The synthesis and characterization of photolabile surfactants, based on the light-sensitive diazosulfonate group, is described. These compounds can be photochemically cleaved into a sulfite ion and the corresponding diazonium compound, which is further photolysed in a second step. The critical micellar concentrations, determined by conductivity measurements, are compared with corresponding data of structurally similar alkylbenzenesulfonate surfactants. Krafft temperatures were determined by solubility measurements. The thermolysis in water at elevated temperatures was examined by UV spectroscopy and follows first-order kinetics. Thermal decomposition of the solid surfactants, examined by differential scanning calorimetry, starts at temperatures above 150°C.