Spectroscopic properties of a sandwich-like metal phthalocynine, europium bis[2,3,9,10,16,17,23,24-octakis(4-methoxyphenoxy)phthalocyninato], have been studied at different pressures. The pressure tuning effect has been observed in the absorption of the Q band for the complex. With increase of pressure, the LUMO and SUMO(Second Unoccupied Molecular Orbit) of the complex are stabilized to lower level. It increases the energy gap between the LUMO (or SUMO) and the higher energy level, which corresponds to the absorption of the Soret band of the complex. This enhancement of the energy gap slows down the radiationless internal conversion of the electron that has been excited to the higher energy level by the Soret absorption. Thus obvious increase of the emission by the Soret absorption has been observed with increase of pressure.

Key words: sandwich-like metal phthalocynine, high pressure effect, photophysical process