Electron Spin Resonance of Vanadyl Phthalocyanine

An electron spin resonance study of vanadyl phthalocyanine magnetically diluted in metal‐free and zinc phthalocyanine salts, and in sulfuric acid solution, confirms the placement of the 3d unpaired electron in the dxy singlet orbital of the vanadium ion. An improved method of synthesis for vanadyl phthalocyanine which increased the yield to 64% is described. The infrared spectrum of vanadyl phthalocyanine indicates that this complex exists in only one polymorphic modification.