The electron that breaks the catalyst's back – excited state dynamics in intermediates of molecular photocatalysts

Abstract

Transient absorption spectroelectrochemistry reveals that the singly reduced bridging ligand in a prototype molecular catalyst light driven proton reduction does not allow for electron transfer to the catalytic center – breaking the catalyst's back.

KiMoPack: A python Package for Kinetic Modeling of the Chemical Mechanism

“…KiMoPack was developed during continuous active use in several research groups and projects. ,,− This motivated the development of advanced modeling capabilities as are required by challenging samples and complex mechanisms, as well as the need to demonstrate the validity of the kinetic modeling approaches. Many analysis approaches simply use the implemented functionality in unexpected ways.…”

“…We have used KiMoPack successfully to analyze datasets obtained from transient X-ray spectroscopy, 5 photocatalysis, 12 and spectroelectrochemistry. 6 , 7 , 13 However, in the following discussions, we will focus on transient optical spectroscopy and the associated data handling. The essential design criteria for KiMoPack are to provide a reproducible workflow tool in which preprocessing, model-free analysis, and fast and advanced modeling are combined with a powerful set of plotting and comparison methods.…”

“…In many chemical disciplines, kinetic modeling is used to extract and understand the mechanisms underlying time-resolved spectroscopic data. It is extensively used in the analysis of time-resolved spectra from optical spectroscopy, − but also in, e.g., X-ray spectroscopy, , spectroelectrochemistry, − and photocatalysis. ,, Common to all techniques is that a spectrum is distorted by one, or multiple processes. The evolution of the distortion can be used to, e.g., disentangle processes or/and to extract additional information from the system.…”

“…In this paper, we present KiMoPack ( ki netic mo deling pack age), a software package designed to model photoinduced chemical kinetic measurements, which is also capable to model modulated data obtained by other initiation methods. We have used KiMoPack successfully to analyze datasets obtained from transient X-ray spectroscopy, photocatalysis, and spectroelectrochemistry. ,, However, in the following discussions, we will focus on transient optical spectroscopy and the associated data handling. The essential design criteria for KiMoPack are to provide a reproducible workflow tool in which preprocessing, model-free analysis, and fast and advanced modeling are combined with a powerful set of plotting and comparison methods.…”

Bridging Platinum and Palladium to Bipyridine-Annulated Perylene for Light-Driven Hydrogen Evolution

“…In a Ru(bpy) 2 linked via tetrapyridophenazine (tpphz) to a PtCl 2 entity, visible light excitation and several chargetransfer processes occur that ultimately inject electrons into the platinum nucleus, processes that overall take below 500 ps. 37 In this study, we investigated the steady-state optical properties as well as the redox-properties of both complexes and the respective ligand precursor. Light-driven hydrogen evolution experiments were carried out with the complexes in the presence of ascorbic acid as the sacrificial electron donor.…”