Wavepacket Motion via a Conical Intersection in the Photochemistry of Aqueous Transition-Metal Dianions

Primary reactions in the photochemistry of hexahalide complexes of platinum group metals: A minireview

“…The fitting programme corrected for the group velocity dispersion and calculated the response time of the instrument. Experiments on ultrafast kinetic spectroscopy of the Pt IV Br 6 2À , Ir IV Br 6 2À and Os IV Br 6 2À complexes were performed using the setup described in [56][57][58]. Two TOPAS-C optical parametric amplifiers generated 420 or 530 nm pump pulses of 2 mJ and probe pulses tunable between 270 and 400 nm.…”

“…The overall time resolution was 150 fs. High values of the signal-to-noise ratio allowed resolving of the coherent oscillations in the kinetic curves [57,58]. Typically, the kinetic curves obtained in ultrafast pump-probe experiments are fitted globally, using either a biexponential function (1) or a triexponential function (2).…”

“…d(e g *) transitions [57,77]. The absorption in the visible spectral range is caused by forbidden CT and mixed LF/CT transitions [57,58]. Earlier works on the photochemistry of PtBr 6 2À in aqueous solutions proposed contradictory reaction mechanisms.…”

“…Ultrafast spectroscopy was also used to study the primary photophysical and photochemical reactions of Pt IV Br 6 2À in aqueous and alcoholic solutions [10,57,58,90]. The transient absorption spectra were fitted globally using the 3-exponential function (2) [10,90].…”

“…Within 150 fs after the 420 nm excitation pulse, the Pt IV Br 6 2À complex undergoes internal conversion and intersystem crossing into the 3 T 1g lowest triplet dissociative state, loses a ligand, and relaxes via the C 4v conical intersection to the nearly trigonal bipyramidal 3 Pt IV Br 5 À product in its triplet state [58]. The following reaction is the intersystem crossing of 3 Pt IV Br 5 À into its 1 PtBr 5 À singlet state, the direct precursor of the Pt IV Br 5 (H 2 O) À complex, which is the reaction product.…”