Time‐Resolved Spectroelectrochemical Dynamics of Carotenoid 8’‐apo‐β‐Carotenal

Abstract

This work examines the influence of applied external voltage in bulk electrolysis on the excited‐state properties of 8′‐apo‐β‐carotenal in acetonitrile by steady‐state and ultrafast time‐resolved absorption spectroscopy. The data collected under bulk electrolysis were compared with those taken without applied voltage. The steady‐state measurements showed that although although intensity of the S0‐S2 absorption band varies with the applied voltage, the spectral position remains nearly constant. Comparison of transient absorption spectra shows that the magnitude of the ICT‐like band decreases during the experiment under applied voltage condition, and is associated with a prolongation of the S1/ICT‐like lifetime from 8 ps to 13 ps. Furthermore, switching off the applied voltage resulted in returning to no‐voltage data within about 30 min. Our results show that the amplitude of the signal associated with the ICT state can be tuned by applying an external voltage.