0000000001320182
AUTHOR
Eiji Nishibori
Multi-temperature synchrotron PXRD and physical properties study of half-Heusler TiCoSb.
Phase pure samples of the half-Heusler material TiCoSb were synthesised and investigated. Multi-temperature synchrotron powder X-ray diffraction (PXRD) data measured between 90 and 1000 K in atmospheric air confirm the phase purity, but they also reveal a decomposition reaction starting at around 750 K. This affects the high temperature properties since TiCoSb is semiconducting, whereas CoSb is metallic. Between 90 K and 300 K the linear thermal expansion coefficient is estimated to be 10.5 × 10(-6) K(-1), while it is 8.49 10(-6) K(-1) between 550 K and 1000 K. A fit of a Debye model to the Atomic Displacement Parameters obtained from Rietveld refinement of the PXRD data gives a Debye tempe…
Coordination nano-space as stage of hydrogen ortho–para conversion
The ability to design and control properties of nano-sized space in porous coordination polymers (PCPs) would provide us with an ideal stage for fascinating physical and chemical phenomena. We found an interconversion of nuclear-spin isomers for hydrogen molecule H 2 adsorbed in a Hofmann-type PCP, {Fe(pz)[Pd(CN) 4 ]} (pz=pyrazine), by the temperature dependence of Raman spectra. The ortho (o)–para (p) conversion process of H 2 is forbidden for an isolated molecule. The charge density study using synchrotron radiation X-ray diffraction reveals the electric field generated in coordination nano-space. The present results corroborate similar findings observed on different systems and confirm …
Similarities and differences between crystal and enzyme environmental effects on the electron density of drug molecules
Abstract The crystal interaction density is generally assumed to be a suitable measure of the polarization of a low‐molecular weight ligand inside an enzyme, but this approximation has seldomly been tested and has never been quantified before. In this study, we compare the crystal interaction density and the interaction electrostatic potential for a model compound of loxistatin acid (E64c) with those inside cathepsin B, in solution, and in vacuum. We apply QM/MM calculations and experimental quantum crystallography to show that the crystal interaction density is indeed very similar to the enzyme interaction density. Less than 0.1 e are shifted between these two environments in total. Howeve…
CCDC 2024395: Experimental Crystal Structure Determination
Related Article: Florian Kleemiss, Erna K. Wieduwilt, Emanuel Hupf, Ming W. Shi, Scott G. Stewart, Dylan Jayatilaka, Michael J. Turner, Kunihisa Sugimoto, Eiji Nishibori, Tanja Schirmeister, Thomas C. Schmidt, Bernd Engels, Simon Grabowsky|2021|Chem.-Eur.J.|27|3407|doi:10.1002/chem.202003978