(a) νCO region of the FT-IR spectrum of 1 dissolved in heptane (black), MeOH (green), and MeCN (blue). The spectra were corrected for solvent absorption and normalized, (b) DFT calculated infrared spectra of 1 for the trans -1 BA-BA (black) and 1 AP-BA (red) isomeric forms, (c) νCO region of FT-IR spectrum of 1 dissolved in heptane at 20 °C and 80 °C. Inset shows the T-induced difference spectrum and arrows indicate the temperature-correlated absorption increases.
Magic angle TR-IR spectra of 1 in heptane (a), MeOH (b), and MeCN (c) at ∼8 ps (black), ∼80 ps (red), and 440 ps (green) pump-probe delay times.
The DFT calculated infrared spectra of trans -1 BA-BA (black), 1 AP-BA (red), and the tricarbonyl photoproduct Fe2(pdt)(CO)3(PMe3)2 (blue) are shown in the lower panel. The dominant parent-molecule spectrum is shown as negative-going peaks for ease of comparison with TRIR bleach signals. Similar predictions for candidate transient molecules, Fe2(pdt)(CO)3(PMe3)2·(propane) (green), Fe2(pdt)(CO)3(HOMe)(PMe3)2 (cyan), and Fe2(pdt)(CO)3(NCMe)(PMe3)2 (navy) are shown in the upper panel. NB pdt: propane dithiolate.
TRIR spectrum (black) and Gaussian lineshape fitting results (red) for 1 in heptane at three pump-probe delay times.
Time dependencies of Gaussian peak lineshapes from fitting results for 1 in heptane (a), MeOH (b), MeCN (c). Black indicates a main parent bleach exhibiting biexponential decay kinetics. Blue shows the high-frequency peak due to the 1 AP-BA isomer, which exhibits a rise time due to isomersiation. Red shows the dynamics of a broad peak formed at early times which decays with single exponential kinetics due to vibrational cooling.
Results of fitting temporal dependencies of Gaussian peak amplitudes of 1 in heptane, MeOH, and MeCN solutions derived from fitting of TR-IR spectra. Lifetimes τ 1 and τ 2 represent exponential decays, while τ R represents an exponential rise.
Article metrics loading...
Full text loading...