αααα-meso-Tetra (7-hydroxy-1-naphthyl) porphyrin (1) is prepared as a host molecule for ubiquinone analogue, 2, 3, 5, 6-tetramethoxy-p-benzoquinone (2). The affinity and thermodynamic aspects in porphyrin 1-quinone 2 pairing were determined by titrimetric measurement of electronic absorption and fluorescence spectra. The binding constant of 1 for 2 at 298 K is obtained; K a= 7.9× 10 2 M− 1 in toluene. The fashion of this porphyrin- ...