Combined (15)N ssNMR and X-ray photoelectron spectroscopy (XPS) investigations for theophylline, a theophylline co-crystal, and a theophyllinium salt demonstrate that XPS allows direct observation of the degree of proton transfer, and thus identification of whether a salt or a co-crystal has been formed. The presence of a strongly binding-energy-shifted N 1s XPS peak with protonation indicates a salt (C==NH(+)), while this peak is unmistakably absent in the co-crystal. XPS should be considered as an alternative and complementary technique to single crystal X-ray diffraction and solid-state nuclear magnetic resonance spectroscopy (ssNMR).
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http://dx.doi.org/10.1002/jps.22164 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
Department of Chemistry, McGill University, Montréal, Québec H3A 0G4, Canada.
Metal powders are crucial precursors for manufacturing surfaces through thermal spraying, cold spraying, and 3D printing methods. However, surface oxidation of these precursors poses a challenge to the coherence of the metallic materials during manufacturing processes. Herein, we introduce a method for surface modification of copper powder with N-heterocyclic carbenes (NHCs) using mechanochemistry to mitigate surface oxidation.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Department of Physics, Indian Institute of Technology (IIT) Delhi, New Delhi 110016, India.
The concept of inert matrix fuel (IMF) has been proposed to utilize the energetic value of Pu and transmute minor actinides in nuclear reactors. In order to offset the initial reactivity of nuclear fuel, gadolinium (Gd) is employed as a burnable poison, owing to its high neutron absorption cross-section. To gain insights into the radiation stability and influence of grain boundaries on irradiation behaviour, 5 mol% Gd-doped ceria samples, sintered at varying temperatures, were subjected to irradiation using 400 Kr ions.
View Article and Find Full Text PDFHeliyon
January 2025
Department of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala, 147004, India.
Deep eutectic solvents (DESs) have attracted significant attention in recent years due to its environment friendly characteristics and its participation in the multi-heteroatom doping of carbon quantum dots (CQDs). In this work, we present a simple, fast, and environment-friendly microwave synthesis approach for the synthesis of DES-assisted nitrogen and chloride co-doped CQDs (N,Cl-CQDs) using a choline chloride-urea based DES. A biomass-based precursor, i.
View Article and Find Full Text PDFInt J Nanomedicine
January 2025
Department of Biopharmacy, School of Pharmaceutical Sciences, Jilin University, Changchun, People's Republic of China.
ACS Appl Mater Interfaces
January 2025
Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
Hydrogen production via water-splitting or ammonia electrolysis using transition metal-based electrodes is one of the most cost-effective approaches. Herein, ca. 1-4% of Pt atoms are stuffed into a wolframite-type NiWO lattice to improve the electrocatalytic efficiency.
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