Circularly polarized luminescence of talarolactones(+)/(-)-A and(+)/(-)-C:The application of CPL-calculation in stereochemical assignment

Two pairs of fluorescent natural products,talarolactones(+)/(−)-A and(+)/(−)-C[(+)/(−)-1 and(+)/(−)-2],were discovered and characterized as a new family of circularly polarized luminescence-active small organic molecules(CPL-SOMs)with high fluorescence efficiency and fascinating CPL properties.The CPL(|glum|)levels of enantiomerically pure(+)/(−)-1 and(+)/(−)-2 in solution falls into the usual range(10−5−10−3)considering their pure organic nature,but the sign of CPL were found to be closely related to the absolute configuration of C-8.The high agreement of the measured CPL spectra of(+)/(−)-1 and(+)/(−)-2 with the time-dependent density functional theory(TDDFT)calculated ones demonstrated the usefulness of CPL-calculation as a unique method for stereochemical assignment.This study may open up a new perspective for the stereochemical studies and the future development of CPL materials.