In search of fullerene-based superacids: synthesis, X-ray structure, and DFT study of C60(C2F5)(5)H

Simply super! The perfluoroalkylfullerene C(60)(C(2)F(5))(5) H is the first structurally characterized perfluoroalkylated fullerene-based acid and is also predicted to be the first gas-phase fullerene-based superacid.     

Light-front QED1+1 at finite temperature

We investigate the thermodynamic properties of quantum electrodynamics in 1+1 dimensions. We derive the partition function of the canonical ensemble in discrete light cone quantization and calculate the thermodynamical potential. This central quantity is evaluated for different system sizes and coupling strengths. We investigate the continuum limit and the thermodynamical limit and present basic thermodynamical quantities as a function of temperature for the interacting system. The results are compared to the idealized cases.     

Proof of Modulational Instability of Stokes Waves in Deep Water

It is proven that small-amplitude steady periodic water waves with infinite depth are unstable with respect to long-wave perturbations. This modulational instability was first observed more than half a century ago by Benjamin and Feir. It has been proven rigorously only in the case of finite depth. We provide a completely different and self-contained approach to prove the spectral modulational instability for water waves in both the finite and infinite depth cases. © 2022 Courant Institute of Mathematics and Wiley Periodicals LLC.     

Eutectic Media Open a Synthetic Route to Oligocitrazinic Acid Fluorophores of Purple Hue

Under isochoric and solvent-free conditions, the reaction between ammonium formate and citric acid results in a deeply purple reaction product with fluorescent properties. This brings this reaction in the realm of bio-based fluorophores and bottom-up carbon nanodots from citric acid. The reaction conditions are optimized in terms of UV–vis spectroscopic properties and, subsequently, the main reaction product is separated. While the structural analysis does not give any indication for carbon nanodots in a general sense, it points towards the formation of molecular fluorophores that consist of oligomerized citrazinic acid derivatives. Furthermore, EPR spectroscopy reveals the presence of stable free radicals in the product. We hypothesize that such open-shell structures may play a general role in molecular fluorophores from citric acid and are not yet sufficiently explored. Therefore, we believe that analysis of these newly discovered fluorophores may contribute to a better understanding of the properties of fluorophores and CND from citric acid in general.