RESOLV is renewed for next 7 years!

Great joy in the Ruhr region: The Cluster of Excellence in solvation science has once again succeeded in the competition! The Ruhr-Universität Bochum (RUB) and the TU Dortmund University have been successful in Germany’s Excellence Strategy: starting from 2019, the new Ruhr Explores Solvation (Resolv) Cluster of Excellence, hosted at both RUB and TU Dortmund University, will receive funding for seven years.

In Resolv – Understanding and Design of Solvent-Controlled Processes –, scientists investigate the role of solvents. Experts from RUB and TU Dortmund University have already been successfully cooperating with scientists from the University of Duisburg-Essen and other non-university partners during the first funding phase of Resolv. The German Research Foundation (DFG) supported the Resolv Cluster of Excellence at RUB from 2012 to 2018. Resolv has since developed a dense network in solvation research– both within the region and internationally, including with CalSOLV at UC Berkeley!

“We are delighted to be funded again and to be able to tackle the future challenges of solvation science”, says Professor Martina Havenith, speaker of Resolv. “We will now explore chemical processes beyond ambient conditions, beyond thermal equilibrium and beyond homogeneous bulk phase to advance the development of important technological applications, such as energy conversion and storage, or the development of smart sensors.”

A radical route to soot: Martin Head-Gordon in Science!

The chemical origin of soot is a persistent puzzle. It is clear that small hydrocarbon fragments formed in flames must aggregate into larger particles, but the initial driving force for aggregation remains a mystery. Johansson et al. combined theory and mass spectrometry to suggest a solution based on resonance-stabilized radicals (see the Perspective by Thomson and Mitra). Aromatics such as cyclopentadiene have a characteristically weak C–H bond because their cleavage produces radicals with extended spans of π-electron conjugation. Clusters thus build up through successive coupling reactions that extend conjugation in stabilized radicals of larger and larger size.

Resolv Grad Fellow Saurabh Belsare explores Solvation Entropy in Enzyme Active Sites

Using a spatially resolved analysis of hydration patterns, intermolecular vibrations, and local solvent entropies, the T. Head-Gordon group in collaboration with RESolv researcher Matthias Hayden and Viren Patti  have identified distinct classes of hydration water and follow their changes upon substrate binding and transition state formation for the designed KE07 and KE70 enzymes and their evolved variants. We observe that differences in hydration of the enzymatic systems are concentrated in the active site and undergo significant changes during substrate recruitment. For KE07, directed evolution reduces variations in the hydration of the polar catalytic center upon substrate binding, preserving strong protein-water interactions, while the evolved enzyme variant of KE70 features a more hydrophobic reaction center for which the expulsion of low-entropy water molecules upon substrate binding is substantially enhanced. While our analysis indicates a system-dependent role of solvation for the substrate binding process, we identify more subtle changes in solvation for the transition state formation, which are less affected by directed evolution.

Resolv Grad Fellow Matthew DiTucci in Williams Group publish in RSC Chemical Sciences

The effect of temperature on the patterning of water molecules located remotely from a single SO42− ion in aqueous nanodrops was investigated for nanodrops containing between 30 and 55 water molecules using instrument temperatures between 135 and 360 K. An SO42− dianion clearly affects the hydrogen bonding network of water to at least ∼0.71 nm at 135 K and ∼0.60 nm at 340 K, consistent with an entropic drive for reorientation of water molecules at the surface of warmer nanodrops. These distances represent remote interactions into at least a second solvation shell even with elevated instrumental temperatures. The results herein provide new insight into the extent to which ions can structurally perturb water molecules even at temperatures relevant to Earth’s atmosphere, where remote interactions may assist in nucleation and propagation of nascent aerosols.
Matthew J DiTucci, Christiane N Stachl, Evan R Williams
Chemical science 9 (16), 3970-3977 (2018)

Saykally Group: Second-harmonic generation with soft X-rays probes buried interfaces

In a proof-of-concept study, Richard J. Saykally and a large team of researchers working at the FERMI facility in Trieste, Italy, have demonstrated that the method can selectively probe layers of graphene inside a graphite sample (Phys. Rev. Lett. 2018, DOI: 10.1103/physrevlett.120.023901). The new technique may eventually enable researchers to use X-rays to track chemical reactions at interfaces with femtosecond resolution.