SPECTROSCOPY AND PHOTOCHEMISTRY OF MESO-DIPHENYLTRIBENZONAPHTHOPORPHYRIN AT LOW-TEMPERATURES - A NOVEL SYSTEM FOR HOLE-BURNING APPLICATIONS

We present a custom-tailored material for the application of spectral hole-burning in optical storage and imaging spectroscopy. The photoact ive molecule meso-diphenyltribenzonaphthoporphyrin (P(2)TriBNP) combin es the advantages of chlorins and simple porphyrins used so far, namel y, the spectral separation between photoeduct and photoproduct states and a high photochemical hole-burning yield. Basic characteristics of the material were measured. We obtained the values of 3.2 +/- 1.5% for the hole-burning yield, of similar to 0.6 for the Debye-Waller factor in poly(vinyl butyral) (PVB), and a spectral separation between the e duct and product absorption of 120 cm(-1). The difference in the dipol e moment between the ground and the excited state shows two contributi ons. The permanent dipole moment difference has a Value of 0.29 +/- 0. 03 D. A root. mean square value of 0.15 +/- 0.02 D for a distributed, matrix-induced component was measured. Because of their high photochem ical yields and the large absorption cross sections, P(2)TriBNP and si milar compounds open the way for a new class of experiments dealing wi th lower light intensities and shorter exposure times than before. How ever, we observed the lifetime of narrow spectral holes to be limited to several hours. Nevertheless, the material exhibits a high potential for the application in imaging spectroscopy, e.g., the simultaneous r ecording of spatial and spectral information of astronomical objects.