Related Experiment Video
Updated: Nov 2, 2025
![[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)
[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst
Published on: May 21, 2019
Phenylene-bridged bis(benzimidazolium) (BBIm2+): a dicationic organic photoredox catalyst
Takuya Kodama1, Maiko Kubo1, Wataru Shinji1
1Department of Applied Chemistry, Graduate School of Engineering, Osaka University Suita Osaka 565-0871 Japan tobisu@chem.eng.osaka-u.ac.jp.
Abstract:
A dicationic photoredox catalyst composed of phenylene-bridged bis(benzimidazolium) (BBIm2+) was designed, synthesised and demonstrated to promote the photochemical decarboxylative hydroxylation and dimerisation of carboxylic acids. The catalytic activity of BBIm2+ was higher than that for a monocation analogue, suggesting that the dicationic nature of BBIm2+ plays a key role in these decarboxylative reactions. The rate constant for the decay of the triplet-triplet absorption of the excited BBIm2+ increased with increasing concentration of the carboxylate anion with a saturated dependence, suggesting that photoinduced electron transfer occurs within the ion pair complex composed of the triplet excited state of BBIm2+ and a carboxylate anion.
Related Concept Videos
Benzene to 1,4-Cyclohexadiene: Birch Reduction Mechanism
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
Reduction of Benzene to Cyclohexane: Catalytic Hydrogenation
Hydrolysis of Chlorobenzene to Phenol: Dow Process
Aryldiazonium Salts to Azo Dyes: Diazo Coupling
Electrophilic Aromatic Substitution: Chlorination and Bromination of Benzene

![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)