Theoretical characterization of hydroxyfuranones related to biomass burning and their tautomers

The formation of hydroxyfuranones has been observed in biomass plumes and suggested as an indicator for their time evolution.This work focuses on the characterization of three different hydroxyfuranones and their open-chain tautomers.The relationship between thermal stability and structures is studied using density functional theory (DFT) calculations.Furthermore, harmonic and anharmonic IR vibrational frequencies using the generalized second order perturbation model (GVPT2) are compared to several experimental IR spectra.We find good agreement for the most important vibrational modes.It is also shown that the thermodynamical stability depends on substituent positioning and structural features like intramolecular hydrogen bonding.The DFT+GVPT2 approach is successfully used to distinguish between different tautomers.