Abstract
Upon excitation of their structural subunits, phenolphthalein and malachite green lactone undergo ultrafast intramolecular charge separation with formation of a long-lived charge-transfer state (intramolecular ``radical ion pair''). The kinetics of the primary charge separation in these molecules in aprotic solvents has been studied using femtosecond pump-probe spectroscopy. The phenol radical cation is formed by electron transfer within 50 fs after excitation of phenolphthalein to the S-1 state. In malachite green lactone the products of charge separation are observed 150 fs after excitation to the S-2 state. The results demonstrate that electron transfer in these molecules occurs faster than the time scale of inertial solvation dynamics. An intramolecular vibrational mode to promote charge separation is indicated.
Dokumententyp: | Zeitschriftenartikel |
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Fakultät: | Physik |
Themengebiete: | 500 Naturwissenschaften und Mathematik > 530 Physik |
ISSN: | 1089-5639 |
Sprache: | Englisch |
Dokumenten ID: | 62219 |
Datum der Veröffentlichung auf Open Access LMU: | 04. Jul. 2019, 14:28 |
Letzte Änderungen: | 04. Nov. 2020, 13:40 |