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 (| g lum |) 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. The first proofs of natural occurring CPL-SOMs with a novel fluorescent core framework were discovered. And the applying of CPL-calculation to the stereochemical studies was performed. This work might be a starting point for the discovery of CPL-SOMs from natural products and open up a new perspective for the stereochemical studies by using the CPL-calculations .