Nuclear quantum and H/D isotope effects on intramolecular hydrogen bond in curcumin

Curcumin and its derivatives possess intramolecular low-barrier hydrogen bonds for intramolecular proton transfer. The pi-delocalization in the OCCCO framework of the hydrogen bond in these compounds is reorganized concomitantly with the proton transfer. To characterize the hydrogen bond and pi-delocalization, we performed path integral molecular dynamics simulations, revealing that although the proton migration and reorganization of the pi-delocalized structure showed a positive correlation, the correlation was weak.

Automated summary

Curcumin and its derivatives have intramolecular low-barrier hydrogen bonds for intramolecular proton transfer. The pi-delocalization in the OCCCO framework of the hydrogen bond in these compounds is reorganized concomitantly with the proton transfer. Path integral molecular dynamics simulations were performed to characterize the hydrogen bond and pi-delocalization, revealing a weak correlation between proton migration and reorganization of the pi-delocalized structure.