The observed lifetime of an excited electronic state of a porphyrin-like metal complex was determined to be 0.35 ns, with rate constants for fluorescence and intersystem crossing of 0.6 * 10⁹ s^-1 and 1.8 * 10⁹ s^-1 respectively. Determine the rate constant for non-radiative internal conversion.

Question

Quizplus · Accepted Answer

The rate constant for non-radiative internal conversion is the difference between the rate constants for all possible deactivation pathways and the observed lifetime of the excited state. In this case, the rate constants for fluorescence and intersystem crossing are 0.6 F1F1F1S1F1F1F10 10⁹ s^-1 and 1.8 F1F1F1S1F1F1F10 10⁹ s^-1 respectively, and the observed lifetime is 0.35 ns. Therefore, the rate constant for non-radiative internal conversion is:k_nr = k_f + k_isc - 1/tau= 0.6 F1F1F1S1F1F1F10 10⁹ s^-1 + 1.8 F1F1F1S1F1F1F10 10⁹ s^-1 - 1/0.35 ns= 0.5 F1F1F1S1F1F1F10 10⁹ s^-1

The Observed Lifetime of an Excited Electronic State of a Porphyrin-Like