RELATIONSHIP BETWEEN MOLECULAR-STRUCTURE OF A DOPED DYE AND THE EXTENT OF LASER-INDUCED HOLE FILLING IN PHOTOCHEMICAL HOLE-BURNING

This paper reports that the extent of laser-induced hole filling (LIHF) in photochemical hole burning (PHB) is related to the molecular structure of a doped dye. We measured the extent of LIHF for disodium mesoporphyrin (MPS) doped into poly(vinyl alcohol) (PVA) at 20 K, and found it to be smaller than for sulfonated tetraphenylporphine (TPPS) doped into PVA at 20 K. The MPS molecule is flatter, lighter, and more rigid than the TPPS molecule. These features decrease the number of energy levels in the ground state S0 and in the electronically excited state S1 of the dye, resulting in an increase in the site-selectivity in PHB. This causes the smaller extent of LIHF for the MPS system.