Search

Your search keyword '"Havenith, Martina"' showing total 19 results
Start Over Author "Havenith, Martina" Journal angewandte chemie international edition
19 results on '"Havenith, Martina"'

9. Probing Local Electrostatics of Glycine in Aqueous Solution by THz Spectroscopy.

Author

Sebastiani, Federico, Ma, Chun Yu, Funke, Sarah, Bäumer, Alexander, Decka, Dominique, Hoberg, Claudius, Esser, Alexander, Forbert, Harald, Schwaab, Gerhard, Marx, Dominik, and Havenith, Martina

Subjects
AQUEOUS solutions, GLYCINE, ELECTROSTATICS, SUBMILLIMETER waves, SPECTROMETRY, AMIDES
Abstract

Based upon precise terahertz (THz) measurements of the solvated amino acid glycine and accompanying ab‐initio molecular‐dynamics simulations, we show that the N‐C‐C‐O open/close mode at 315 cm−1 serves as a sensitive, label‐free probe for the local protonation of the amide group. Experimentally, we can show that this holds not only for glycine but also for diglycine and valine. The approach is more general, since the changes due to protonation result in intensity changes which can be probed by THz time domain (0–50 cm−1) as well as by precise THz‐FT spectroscopy (50–400 cm−1). A detailed analysis allows us to directly correlate the titration spectra with pKa values. This demonstrates the potential of THz spectroscopy to probe the charge state of a natural amino acid in water in a label‐free manner. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

14. Water Dynamics from THz Spectroscopy Reveal the Locus of a Liquid-Liquid Binodal Limit in Aqueous CaCO3 Solutions.

Author

Sebastiani, Federico, Luong, Trung Quan, Havenith, Martina, Wolf, Stefan L. P., Cölfen, Helmut, Gebauer, Denis, and Born, Benjamin

Subjects
CALCIUM carbonate, TERAHERTZ spectroscopy, NUCLEATION, AMORPHOUS substances, CARBOXYLATES, METASTABLE states, BIOMINERALIZATION
Abstract

Many phenomena depend on CaCO3 nucleation where the role of water remains enigmatic. Changes in THz absorption during the early stages of CaCO3 nucleation evidence altered coupled motions of hydrated calcium and carbonate ions. The direct link between these changes and the continuous development of the ion activity product reveals the locus of a liquid-liquid binodal limit. The data strongly suggest that proto-structured amorphous CaCO3 forms through solidification of initially liquid precursors. Furthermore, polycarboxylates, which stabilize liquid precursors of CaCO3, significantly enhance the kinetic stability of the metastable liquid-liquid state, but they do not affect the locus of the binodal limit. The importance of water network dynamics in phase separation mechanisms can be understood based on the notions of the pre-nucleation cluster pathway, and is likely to be more general for aqueous systems. [ABSTRACT FROM AUTHOR]

Published
2017
Full Text
View/download PDF

19. Solvation Science: A New Interdisciplinary Field.

Author

Havenith, Martina

Subjects
*SOLVATION, *SOLUTION (Chemistry), *SOLVATED electrons, *ANIONS, *TECHNOLOGY
Abstract

The article presents the author's views on the field of solvation science. It is stated that a key to the launch of solvation science is the bringing together and systematic development of a broad array of state-of-the-art synthetic and engineering techniques as well as spectroscopic and theoretical methods.

Published
2016
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results