Time-Resolved Vibrational Spectroscopy to Measure Lifetime of the E$^3\Pi_g(v=3)$ state of Molecular Iodine

TL;DR

This study used time-resolved vibrational spectroscopy with laser excitation and single photon counting to accurately measure the 21 ns lifetime of the E$^3\Pi_g(v=3)$ state in molecular iodine at room temperature.

Contribution

It introduces a precise measurement of the E$^3\Pi_g(v=3)$ state lifetime using a combination of selective laser excitation and time-correlated photon counting.

Findings

Measured the E$^3\Pi_g(v=3)$ state lifetime as 21 ns

Demonstrated the effectiveness of time-resolved vibrational spectroscopy for molecular state lifetimes

Provided data useful for understanding iodine's excited state dynamics

Abstract

The lifetime of the $E^3\Pi_g(v=3)$ state of molecular iodine was measured in the gas phase at room temperature. The $E^3\Pi_g$ state was selectively populated by two sequential nanosecond pulse laser excitation. Resolved molecular fluorescence for the $B^3\Pi_u^+\leftarrow E^3\Pi_g$ was analyzed and the lifetime of the $E(v=3)$ state, measured using a time-correlated single photon counting technique, is to be $\tau=21 (2)$ ns.