Computational study of bond dissociation enthalpies for lignin model compounds: β-5 Arylcoumaran

► We report MCSCF and M06-2X carbon-oxygen and carbon-carbon BDEs for aryl- coumaran models related to common β-5 substructures in lignin. ► We find agreement between MCSCF and DFT BDEs for bi-radical products. ► Triplet BDEs are suffcient to understand trends. ► Substituent effects on BDEs are small, with the exception of a trans-vinyl lowering the C-O BDE.