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Updated: May 29, 2025

High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
Excited state dynamics of a Bodipy derivative with a twisted molecular structure: Combined experimental and
Bei Li1, Sheng Liao2, Jiayu Li2
1State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, Dalian University of Technology, E-208 West Campus, 2 Ling-Gong Road, Dalian 116024, People's Republic of China.
Abstract:
The photophysical properties of a boron dipyrromethene (Bodipy, BDP) derivative (BDP-SA) in which one F atom at the BDP core was replaced by an O atom and condensed with salicylaldehyde were investigated. This compound has a twisted molecular structure and unusually low fluorescence quantum yield (1% in toluene). No intersystem crossing was observed with a nanosecond transient absorption study. The triplet state lifetime of BDP-SA was determined to be 115 μs by photosensitizing. Femtosecond transient absorption shows a structure relaxation of ∼1.5 ps for the S1 excited state. Theoretical studies show conical intersections, which are responsible for the efficient non-radiative decay of the S1 state, which has extremely weak fluorescence.
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