The effect of density functional dispersion correction (DFT-D3) on lignans

The structures of the naturally occurring lignan hydroxymatairesinol (HMR) and TADDOL-like alpha-conidendrin-based chiral 1,4-diols (LIGNOLs) have been studied at DFT/B3LYP/TZVP level of theory, for the first time applying the density functional dispersion correction (DFT-D3) and employing the BJ-damping (-D3(BJ)). This study establishes the necessity of treating the dispersion interactions properly in DFT optimizations. Several of the conformers received were not found in previous studies and the 4Ph4 structure received applying 133 is now published for the first time as a quantum chemically optimized structure. (C) 2015 Elsevier B.V. All rights reserved.