Meso-tetra-(p-diazoniumphenyl) porphyrin (TDSPP) can be photolyzed only under anaerobic conditions with a yield of 0.18 during simultaneous irradiation with He-Ne laser light (632.8 nm) and light of the 313 nm line of 0 mercury lamp.
The excited singlet state of TDSPP is quenched by externalp-methoxybenzene diazoniumtetra fluoroborate (MeODS) with a rate constant of 9.7 × 109M−1s−1. TDSPP and MeODS interact in the ground state with an equilibrium constant of about 16M−1 and form a fluorescent but photochemically inactive.
