SPECTROSCOPY AND PHOTOCHEMISTRY OF 1-METHOXYNAPHTHALENE ON SIO2

An excimer-like emission is observed from ground-state associated pair s of 1-methoxynaphthalene molecules adsorbed al an SiO2/air interface although an excimer emission has not been reported for this molecule i n solution. Slow diffusion on the surface and inhomogeneous loading ge nerate conditions that allow the observation of this emission. Photoly sis of 1-methoxynaphthalene at an SiO2/air interface proceeds by two d istinct pathways. One pathway involves electron-transfer and leads to the production of phthalic acid and/or monomethylphthalate (analyzed a s dimethylphthalate). The second mechanistic pathway involves oxidatio n mediated by singlet molecular oxygen and leads to the formation of 1 ,4-naphthoquinone and 4-methoxy-1,2-naphthoquinone.