The Internal Heavy Atom Effect on the Deactivation of Triplet States of Porphyrins in the Presence of Molecular Oxygen

• Published in: Journal of applied spectroscopy Vol. 90; no. 5; pp. 1037 - 1042
• Main Authors: Starukhin, A. S., Panarin, A. Yu
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.11.2023; Springer Nature B.V
• Subjects: Analytical Chemistry; Atomic energy levels; Atomic/Molecular Structure and Spectra; Base metal; Coordination compounds; Deactivation; Deoxygenation; Oxygen; Palladium; Phosphorescence; Photolysis; Physics; Physics and Astronomy; Platinum; Porphyrins; Solvents; Zinc; laser photolysis; phosphorescence lifetimes in different solvents; porphyrin free bases and metalloporphyrins with different types of metal ions; triplet state lifetimes
• ISSN: 0021-9037; 1573-8647
• DOI: 10.1007/s10812-023-01629-0

The internal heavy atom effect on the deactivation of triplet states of free porphyrin bases and their metal complexes with Mg(II), Zn(II), Pd(II), and Pt(II) ions in several solvents containing molecular oxygen has been systematically studied. The experiments used laser photolysis techniques and direct measurement of the phosphorescence lifetime of the metal complexes with heavy Pd(II) and Pt(II) ions at 293 K and atmospheric oxygen concentration in solution. The results obtained are compared with previously published data on the laser photolysis of porphyrin metal complexes and a partial discrepancy was found. These data are discussed together with the results of a study of similar compounds in degassed solutions. The triplet state lifetimes of metalloporphyrins at atmospheric oxygen concentration and in deoxygenated solutions were found to be subject to the internal heavy atom effect. The polarity of the solvents used and structural features of the compounds studied were also found to have a significant effect on the triplet states of these porphyrins.