Work

Exploiting Transient Anisotropy To Reveal Detailed Molecular-Frame Ultrafast Dynamics

Year: 2026

Type: article

Abstract: Understanding how energy is transformed on ultrafast time scales is fundamental to the study of photophysics. Transient absorption spectroscopy is widely used to follow these processes, yet the usual "magic-angle" approach superimposes signals with differing polarization in the molecular frame. We employ a simple polarization-resolved method that separates parallel and perpendicular components of molecular-frame transient spectra, revealing otherwise obscured excited-state dynamics. Applied to two chromophore dimers capable of singlet fission, the analysis uncovers orthogonal electronic transitions and clarifies the coupling between monomer units. The molecular-frame spectra exhibit features masked by following the conventional approach, allowing extraction of triplet-pair formation dynamics. This accessible method provides richer insight into excited-state coupling and can be extended to a diverse range of photoactive materials.

Source: Journal of the American Chemical Society

DOI: 10.1021/jacs.5c22517