Racemic crystals of trolox derivatives compared to their chiral counterparts: Structural studies using solid-state NMR, DFT calculations and X-ray diffraction

Trolox C and its derivatives in enantiomerically pure and in racemic forms (R/S) were studied using NMR spectroscopy in solution and 13C CPMAS NMR in solid phase. The DFT GIPAW calculations of shielding constants provided reliable assignment of 13C resonances in the solid-state NMR spectra. This comparison of X-ray diffraction, CPMAS NMR data and DFT GIPAW calculations of racemic forms and pure enantiomers was conducted for the first time. Our results, particularly the solid-state NMR data for Trolox and Trolox esters, are discussed in relation to Wallach's rule.203