Abstract
Direct observation of an unexpected product from excited state fusion of two excited triplet states in platinum octaethylporphyrin is reported. Transient spectroscopy was used to identify the product as a metal centered (d, d) state that decays slowly compared with the rate of fusion. The reaction was demonstrated to be second order with a rate coefficient of kTTF = (5.4 ± 0.4) × 10-10 cm3 · s -1. The results contrast with the common assumption that fusion proceeds directly to annihilation via rapid non-radiative deactivation of the products. Following visible photo-excitation, the fusion process results in energetic upconversion of the incident photons stored in the higher energy (d, d) state at irradiances below the threshold for multi-photon absorption.
Original language | English (US) |
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Article number | 101102 |
Journal | Journal of Chemical Physics |
Volume | 139 |
Issue number | 10 |
DOIs | |
State | Published - Sep 14 2013 |