Axial/Peripheral Chloride/Fluoride-Substituted Boron Subphthalocyanines as Electron Acceptors

Chloroboron subphthalocyanines (Cl-BsubPc) are robust compounds that can be readily modified at the axial and peripheral positions. Peripherally chlorinated derivatives were recently found to be advantageous regarding integration into organic electronic devices. We now report on the effects of fluorides introduced on both the peripheral and axial positions of BsubPcs. Specific attention on the reduction of these compounds revealed that the much fewer electronegative chlorides still shift the redox potentials as much as fluorides. The main advantage of the fluorinated derivatives was deduced to be their stability, allowing for the spectroscopic characterization of mono-anionic and even bis-anionic subphthalocyanines. This study sets the precedence for further tuning of the electrochemical properties of BsubPcs through molecular design, thus increasing their applicability regarding organic electronic devices that undergo multiple redox cycles during operational lifetime.