Accurate and efficient method for predicting thermochemistry of furans and ortho-arynes: expansion of the bond-centered group additivity method.

The bond-centered group additivity method (BCGA) method for the estimation of the thermochemical properties of polycyclic aromatic molecules is expanded to aromatic molecules containing furan ring(s) and ortho-arynes. The method is based on enthalpies of formation (deltaH(o)f), entropies (S(o)298), and heat capacities (C(o)p) obtained from B3LYP/6-31G(d) calculations. The enthalpies of formation were obtained using a set of homodesmic reactions that include only aromatic molecules as the reference. Two new atom-centered groups are defined for the description of furan ring(s) and ortho-arynes, leading to the addition of 17 new bond-centered groups to the BCGA method. The deltaH(o)f, S(o)298, and C(o)p contributions of these bond-centered groups is derived.