Magnetically modulated photochemical reaction pathways in anthraquinone molecules and aggregates

Wubin Wu; Baipeng Yin; Wei Peng; Yukun Zhao; Zeyang Zhou; Hua Sheng; Wanhong Ma; Chuang Zhang

doi:10.1016/j.isci.2021.102458

Magnetically modulated photochemical reaction pathways in anthraquinone molecules and aggregates

iScience. 2021 Apr 21;24(5):102458. doi: 10.1016/j.isci.2021.102458. eCollection 2021 May 21.

Authors

Wubin Wu^{1

2}, Baipeng Yin^{1

2}, Wei Peng^{1

2}, Yukun Zhao^{1

2}, Zeyang Zhou^{1

2}, Hua Sheng^{1

2}, Wanhong Ma^{1

2}, Chuang Zhang^{1

2}

Affiliations

¹ Key Laboratory of Photochemistry, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
² University of Chinese Academy of Sciences, Beijing 100049, China.

Abstract

The chemical reactions involving excited-state radical pairs (RPs) of parallel/anti-parallel spin configurations are sensitive to magnetic field, leading to the possibilities of magnetically controlled synthesis of chemical compounds. Here we show that the reaction of anthraquinone (AQ) in sodium dodecyl sulfate (SDS) micellar solution under UV excitation is significantly influenced by applying external field. The steady state and time-resolved spectroscopies reveal that the reaction intermediate (pairs of AQH-SDS radicals) can undergo two distinct pathways depending on whether it is spin singlet or triplet, and the field is beneficial to the conversion between spin configurations of RPs. The applied field not only affects the reaction rate constant but also changes the final products. Besides, the aggregation of AQ molecules would change the population of singlets and triplets and thus enhance magnetic field effect. This work represents a promising way of controlling chemical reaction and improving reaction selectivity via magnetic field methods.

Keywords: Catalysis; Chemistry; Magnetism; Magnetochemistry; Physical chemistry.