Figure 4.

Picosecond TRIR spectra of Re^I(dmp)(Y)AzZn^II measured at selected time delays after 400 nm, ~150 fs excitation. Positive and negative bands correspond to excited-state and bleached ground-state absorptions, respectively. The experimental points are separated by 4-5 cm^-1. The black arrow shows the dynamical evolution of the excited-state A’(1) band shifting with time from about ~2014 to ~2039 cm^-1. The ground-state band occurs at 2029 cm^-1. Virtually identical TRIR spectra were obtained for 1.9 mM solutions of Re^I(dmp)(Y)AzCu^II and Re^I(dmp)(F)AzCu^II in 50 mM KP_i buffer in D₂O (pD ~7.0) at 21 °C. See Figure S1 for the ns TRIR.