Modeling the acid-catalyzed cleavage of carbon-oxygen bonds

The acid-catalyzed cleavage of carbon-oxygen bonds is one of the most critical reaction occurring during image formation using chemically-amplified photoresists. Described here is an approach to modelling these important reactions using Spartan'18 software. This modelling predicts the activation energies of catalyzed and uncatalyzed C-O bond breaking reactions for over fifty acetate esters. To verify the capabilities of this modelling approach, we compared the modelled predictions of activation energies against experimental values for hydride ion affinity values for forty carbocations. Using similar modelling techniques, we predicted the activation energies of C-O bond breaking of commonly used 193-nm monomers as catalyzed by perfluorobutanesulfonic (PFBuS) acid. Additionally, we evaluated the effect of carboxylic acid size and the effect of increasing alkyl substitution on the carbocation intermediate.