Influence of iodine substitution on electrochemical properties and energy levels of BODIPY derivatives

Four boron-dipyrromethene derivatives (BODIPYs) were investigated to assess the influence of the iodine substitution on their electrochemical properties. The performed CV and DPV scans revealed an increase in the number of redox pairs in iodine-substituted derivatives compared to unsubstituted ones, from one reduction and one or two oxidations to two reductions and two oxidations. The calculated electrochemical energy band gap was decreased by approx. 0.6 eV in the case of neutral iodinated derivative 3 compared to parent compound 1, indicating the possible future application of substituted species as semiconductors. The electrolysis of 3 and 4 showed the formation of anion radicals of BODIPYs. The additional DFT studies confirmed the decrease of the HOMO-LUMO energy band gap when the halide atom was inserted into the core and allowed to locate the orbitals.

Automated summary

Four boron-dipyrromethene derivatives (BODIPYs) with iodine substitution were studied for their electrochemical properties. The iodine substitution resulted in an increase in the number of redox pairs and a decrease in the energy band gap, indicating potential application as semiconductors. Electrolysis confirmed the formation of anion radicals of BODIPYs. DFT studies supported the decrease in the HOMO-LUMO energy band gap caused by halide atom insertion.