Ultrafast Reaction Dynamics

Abstract

With new laser techniques and with gas phase and molecular beam experiments, ist is now possible to tetermine the ultrafast motion in isolated chemical reactions – chemistry on the 10−13‐second time scale.

Ultra-weak protein-protein interactions can modulate proteome-wide searching and binding

“…At the ultra-weak threshold (Fig3A(ii)), the interplay between co-localization and spontaneous Brownian fluctuations brings the search and binding times to nearly the same value, comparable to the timescales of elementary chemical reactions (Gruebele and Zewail, 1990) and protein folding (Bredenbeck et al, 2003). We inferred that UW-PPIs permit many subsequent associations following each binding event by increasing mesoscale proximity, noting that higher-order microstructure (clusters) can keep proteins closer over much longer timescales.…”

“…Intracellular phenomena occur over a range of timescales (upper, green), from bacterial division times as fast as 10 minutes (Rocha, 2004) down to physico-chemical fluctuations on the order of femto-to nano-seconds. The residence times of ultra-weak protein dimers (lower, left) are comparable to the timescales of elementary chemical reactions (Gruebele and Zewail, 1990) and protein conformational fluctuations (Bredenbeck et al, 2003), whereas higher-order clusters can last an order of magnitude longer (lower, center), on par with enzymecatalyzed reactions (Smejkal and Kakumanu, 2019). This ultra-weak clustering regime operates below the timescales of phase separated droplets (Molliex et al, 2015;Tang et al, 2021), cell signaling (Asthagiri and Lauffenburger, 2003), and percolated networks (Ramm et al, 2022;Zia et al, 2014) (lower, right), which are sufficiently durable to be measured in vivo.…”

Energy breathing of nanoparticles

“…The process is contributed by designing lasers of ultrashort femtoand attosecond (Blanchard et al 2007;Goulielmakis et al 2007) pulses, and of the corresponding research methods in particular, of the femto-and attosecond spectroscopy and the femtosecond X-ray holography (Chapman et al 2007), which allow studying, in real time, the superfast processes, for example, chemical reactions (Gruebele and Zewail 1990), and the motion of atoms in molecular systems (Itatani et al 2004), of electrons in gases and solid-state alloys (Corkum and Krausz 2007), etc. At the same time, despite the obvious prospects of the femto-and attosecond spectroscopy from the viewpoint of its practical use in medicine, biology, and other spheres, the studies are basically experimental, contributing to the accumulation of empirical data about the substance on the results of the fixed reactions to the laser radiation in the form of supershort pulses.…”

Time dependence of the photodissociation of strontium(1+) diammoniate cluster

“…of chemical reactions and photodissociation in such species.3 •8"11 In this Letter, we demonstrate initial results from an experiment designed to probe the dynamics of solvent motion in mass-selected gas-phase cluster ions. Recent work from our laboratory on the absorption spectroscopy of mass-selected Sr+(NH3)" clusters for - [1][2][3][4][5][6] has shown a strong size-dependent red shift that signals the onset of spontaneous ionization of Sr+ and stabilization of the electron by several solvent molecules. '213 The analogy between this process in clusters and the bulk phenomenon of electron solvation suggests that time domain measurements of photodissociation processes in these clusters will provide insight into the nature of photoinduced charge transfer and concomitant solvent motion in finite aggregates.…”