1. HOW ACIDS BEHAVE IN ULTRACOLD INTERSTELLAR SPACE - Science Advances
Acids in water release protons, but how do they behave in interstellar space? Solvation scientists M. Havenith and D.Marx (RUB) have investigated how acids interact with water molecules at extremely low temperatures. Using spectroscopic analyses and computer simulations, they tackled the question of whether hydrochloric acid (HCl) does or does not release its proton in conditions like those found in interstellar space. The answer was neither yes nor no: At temperatures below -263 °C, the dissociation of a hydrochloric acid molecule depends on the order in which the team brought the water and acid molecules together. D. Mani et al., Sci. Adv. 2019; 5 : eaav8179
2. HOW THE SOLVENT CONTROLS A PEPTIDE'S STRUCTURE - ChemPhysChem
Solvent and temperature can affect the structural properties of cyclic peptides by controlling their flexibility. Solvation scientists Wolfram Sander (RUB) and Elsa Sanchez-Garcia (University of Duisburg-Essen) proposed a mechanism behind the temperature-dependent solvent-controlled conformational flexibility of cyclopeptides. They found out that the combined contribution of several weak intermolecular interactions - rather than by strong and specific solvent-peptide interactions - induces changes in the intramolecular interaction pattern of the peptide. This mechanism of solvent regulation of protein structural properties can find applications in the development of peptide ligands that regulate protein-protein interactions. N. Berger et al., ChemPhysChem2019, 20, 1664-1670
3. HOW TWO WATER MOLECULES DANCE TOGETHER - Angew. Chemie
An international team led by solvation scientist Martina Havenith (RUB) has gained new insights into how water molecules interact. For the first time, the researchers were able to completely observe all of the movements between the water molecules. A certain movement of individual water molecules against each other, called hindered rotations, is particularly important. Among other things, the findings help to better determine the intermolecular energy landscape between water molecules and thus to better understand the strange properties of water - for instance, the fact that water reaches its highest density at four degrees Celsius. This is due to the special interactions between the water molecules. R.Schwan et al., Angew. Chem. Int. Ed. 2019, 58,13119-13126
4. HOW EYE-LENS PROTEINS GATHER OR SPREAD WITH PRESSURE - JACS
Just like water in a humid day condenses in drops, proteins in solution can gather into droplet-like ensembles and perform biological functions. Scientists think that these biomolecular systems have played a role in initiating life, as the harsh temperature and pressure conditions of the early Earth may have prompted simple organic compounds to condense into droplets. The group of solvation scientist Roland Winter from the TU Dortmund University could shed new light onto how pressure affects the condensation process of proteins in solution. Winter found that droplets of the eye-lens protein gamma-crystallin become resistant to high pressure by adding a protein stabilizer, called TMAO, found in deep-sea fishes. S.Cinar et al., J. Am. Chem. Soc. 2019, 141, 18, 7347-7354
5. HOW TO DISSOLVE A FOOTBALL-SHAPED FULLERENE - JACS
Fullerenes are spherical molecular structures made only of carbon. The most famous fullerene is the C60, a football-shaped object of 60 carbon atoms. Despite these molecules being of technological relevance, for example in organic solar cells and medical research, chemists find it difficult to tinker with fullerenes, because they dissolve only in a few toxic solvents. Solvation scientist Guido Clever from TU Dortmund University and colleagues from Nagasaki University, Japan, synthesized and described supramolecular cage- and bowl-like structures that can host fullerenes and dissolve them in many more solvents (i.e. acetonitrile, acetone, nitromethane and DMF). B.Chen et al., J. Am. Chem. Soc. 2019, 141, 22, 8907-8913
6. HOW TO ACHIEVE HIGH REACTION RATES IN CATALYS WITHOUT PRECIOUS METALS - JACS
Non-precious metal nanoparticles could one day replace expensive catalysts for hydrogen production. However, it is often difficult to determine what reaction rates (aka efficiency) they can achieve, especially when it comes to oxide particles. This is because the particles must be attached to the electrode using a binder and conductive additives, which distort the results. With the aid of electrochemical analyses of individual nanoparticles, solvation scientist Kristina Tschulik has succeeded in determining the activity and substance conversion of nanocatalysts made from cobalt iron oxide - without any binders. A.E.Arrassi et al., J. Am. Chem. Soc. 2019, 141, 23, 9197-9201