Solid state oxidation of phenols with TBPA-O-2 were examined. Depending on the electron-releasing ability of p-substituents of phenols, different products were obtained. In the case of p-alkylphenols, successive proton transfers occur from the phenols to TBPA-O-2 to give phenolate anions and a pi-delocalized cation. They are coupled to give 6,15-diaryloxy TBPA. On the other hand, in the case of phenols with electron-releasing substituents (e.g. p-SCH3, p-OCH3), there occurs an electron transfer from a phenolate anion to a pi-delocalized cation which are formed through proton transfer from the phenol to TBPA-O-2. The resulted phenoxy radicals are coupled to afford dimeric products of them. Replacing process of included solvent in the crystal of TBPA-O-2 with the substrate was monitored by a powder X-ray diffraction method.