Electron Paramagnetic Resonance and DFT Analysis of the Effects of Bulky Perfluoroalkyl Substituents on a Vanadyl Perfluoro Phthalocyanine

Abstract

Abstract F64PcVO, the vanadyl complex of the perfluoro-isopropyl-substituted perfluorophthalocyanine ligand F64PcH2, exhibits interesting electronic properties compared to related vanadyl phthalocyanine complexes. X- and W-band continuous-wave electron paramagnetic resonance (CW EPR) of undiluted F64PcVO powders illustrate the absence of π-π stacking in these materials due to the bulky substituents. Furthermore, pulsed EPR and electron nuclear double resonance (ENDOR) experiments in combination with density functional theory (DFT) computations were used to determine the principal g values and the 51V, 14N, 1H and 19F hyperfine couplings of a frozen ethanol solution of F64PcVO. The axial ligation of ethanol to vanadium was proven. Axial accessibility of the vanadyl center combined with the high solubility of the complex in different solvents make F64PcVO an interesting molecule for catalytic applications.