Microwave-assisted formation of sulfonium photoacid generators

摘要

Efficient method for preparing sulfonium photoacid generators (PAGs) by microwave-assisted reaction of diarylsufides in the presence of alkylaryliodonium salts. Microwave-assisted synthesis of the PAGs is significantly faster, reducing reaction time with less energy consumption. Reaction times using the microwave-assisted synthesis are in a range of from 90 to 420 faster than conventional thermal conditions. The photoacid quantum yields of several salts prepared by the microwave reaction were measured; the photoacid quantum yields of new sulfonium PAGs were in a range from 0.01 to 0.4 times greater than yields from conventional synthesis. Incorporating a nitro group in the structures of the sulfonium salts increased photoacid quantum yield, induced intersystem crossing and increased the efficiency of photoacid generation compounds.