Photophysics and photochemistry of (n-BuN)[Pt(NO)] in acetonitrile: ultrafast pump-probe spectroscopy and quantum chemical insight.

The ultrafast processes caused by photoexcitation of (n-BuN)[Pt(NO)] complex in acetonitrile were studied by means of transient absorption (TA) pump-probe spectroscopy and verified by quantum chemical calculations. The primary photochemical process was found to be an inner-sphere electron transfer followed by an escape of an NO radical to the bulk solution. The reaction occurs via the dissociative triplet excited LMCT state of the initial complex. Based on the experimental data and quantum chemical calculations, the mechanism of ultrafast photophysical and photochemical processes is proposed.