Quick and robust PDF data acquisition using a laboratory single-crystal X-ray diffractometer for study of polynuclear lanthanide complexes in solid form and in solution

Tsymbarenko, Dmitry; Grebenyuk, Dimitry; Burlakova, M. A.; Zobel, Mirijam

doi:10.1107/s1600576722005878

“…These ligands are important for directing the cluster formation, and it was imperative to include them in the modelling of the PDF signal to precisely derive the correct structure. This built on previous work by the Zobel group 17,18) , and confirms PDF analysis as a powerful tool for the analysis of small nanocrystals. 19) Work on new material classes is also important to verify the findings on nucleation theory.…”

Section: Early Transition Metal Oxidessupporting

confidence: 76%

New Materials for Colloidal Nanochemistry/Trendbericht Physikalische Chemie 2024 (2/3)

Boldt

2024

Nachr Chem

0

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Zeitversetzte Laserpulse auf Moleküle verraten, wie photochemische Prozesse ablaufen – dabei sind konische Durchschneidungen entscheidend. Die kolloidale Nanochemie hat neue Materialklassen erschlossen, wie Nickelboride und frühe Übergangsmetalloxid‐Katalysatoren, sowie Synthesen zu photolumineszenten III–V‐Halbleitern verbessert. Mit maschinellem Lernen lassen sich am Rechner Proteine nicht mehr nur falten, sondern solche entwerfen, die nicht mit natürlichen Proteinen verwandt sind.

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“…To get more insight into the structural changes in Ce-MOF upon heating, we performed total scattering experiments with PDF analysis of as-synthesized Ce-MOF and of the products of its heating at 100 ( Ce-MOF –H 2 O ), 250 ([Ce 2 (bdc) 3 (H 2 bdc)]), and 400 °C ([Ce 2 (bdc) 3 ]) in a vacuum (Figure ). The data were collected according to our previously developed procedure . See the Supporting Information for the details on data collection and choice of structure models for the refinements.…”

Section: Resultsmentioning

confidence: 99%

Tuning the Cerium-Based Metal–Organic Framework Formation by Template Effect and Precursor Selection

Grebenyuk,

Shaulskaya,

Shevchenko

et al. 2023

ACS Omega

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6

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The novel metal–organic framework [(CH 3 ) 2 NH 2 ] 2 [Ce 2 (bdc) 4 (DMF) 2 ]·2H 2 O ( Ce-MOF , H 2 bdc—terephthalic acid, DMF— N , N -dimethylformamide) was synthesized by a simple solvothermal method. Ce-MOF has 3D connectivity of bcu type with a dinuclear fragment connected with eight neighbors, while three types of guest species are residing in its pores: water, DMF, and dimethylammonium cations. Dimethylamine was demonstrated to have a decisive templating effect on the formation of Ce-MOF , as its deliberate addition to the solvothermal reaction allows the reproducible synthesis of the new framework. Otherwise, the previously reported MOF Ce 5 (bdc) 7.5 (DMF) 4 ( Ce5 ) or its composite with nano-CeO 2 (CeO 2 @ Ce5 ) was obtained. Various Ce carboxylate precursors and synthetic conditions were explored to evidence the major stability of Ce-MOF and Ce5 within the Ce carboxylate-H 2 bdc-DMF system. The choice of precursor impacts the surface area of Ce-MOF and thus its reactivity in an oxidative atmosphere. The in situ PXRD and TG-DTA-MS study of Ce-MOF in a nonoxidative atmosphere demonstrates that it eliminates H 2 O and DMF along with (CH 3 ) 2 NH guest species in two distinct stages at 70 and 250 °C, respectively, yielding [Ce 2 (bdc) 3 (H 2 bdc)]. The H 2 bdc molecule is removed at 350 °C with the formation of novel modification of Ce 2 (bdc) 3 , which is stable at least up to 450 °C. According to the total X-ray scattering study with pair distribution function analysis, the most pronounced local structure transformation occurs upon departure of DMF and (CH 3 ) 2 NH guest species, which is in line with the in situ PXRD experiment. In an oxidative atmosphere, Ce-MOF undergoes combustion to CeO 2 at a temperature as low as 390 °C. MOF-derived CeO 2 from Ce-MOF , Ce5 , and CeO 2 @ Ce5 exhibits catalytic activity in the CO oxidation reaction.

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“…The Qdamp was set to 0.015 and Qbroad was set to be zero in a fitting r range lower than 10 Å. Usually for high crystalline material, the too low cutoff Qmax leads to a larger broadening of peaks and this make the Qbroad parameter unprecise in calibration, although calibration of Qbroad for low Qmax has been realized [ 37 , 38 ].…”

Section: Methodsmentioning

confidence: 99%

Effects of Grain Refinement and Thermal Aging on Atomic Scale Local Structures of Ultra-Fine Explosives by X-ray Total Scattering

Xing

¹

,

Wang

²

,

Huang

³

et al. 2022

Materials

2

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The atomic scale local structures affect the initiation performance of ultra-fine explosives according to the stimulation results of hot spot formation. However, the experimental characterization of local structures in ultra-fine explosives has been rarely reported, due to the difficulty in application of characterization methods having both high resolution in and small damage to unstable organic explosive materials. In this work, X-ray total scattering was explored to investigate the atomic scale local distortion of two widely applicable ultra-fine explosives, LLM-105 and HNS. The experimental spectra of atomic pair distribution function (PDF) derived from scattering results were fitted by assuming rigid ring structures in molecules. The effects of grain refinement and thermal aging on the atomic scale local structure were investigated, and the changes in both the length of covalent bonds have been identified. Results indicate that by decreasing the particle size of LLM-105 and HNS from hundreds of microns to hundreds of nanometers, the crystal structures remain, whereas the molecular configuration slightly changes and the degree of structural disorder increases. For example, the average length of covalent bonds in LLM-105 reduces from 1.25 Å to 1.15 Å, whereas that in HNS increases from 1.25 Å to 1.30 Å, which is possibly related to the incomplete crystallization process and internal stress. After thermal aging of ultra-fine LLM-105 and HNS, the degree of structural disorder decreases, and the distortion in molecules formed in the synthesis process gradually healed. The average length of covalent bonds in LLM-105 increases from 1.15 Å to 1.27 Å, whereas that in HNS reduces from 1.30 Å to 1.20 Å. The possible reason is that the atomic vibration in the molecule intensifies during the heat aging treatment, and the internal stress was released through changes in molecular configuration, and thus the atomic scale distortion gradually heals. The characterization method and findings in local structures obtained in this work may pave the path to deeply understand the relationship between the defects and performance of ultra-fine explosives.

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Quick and robust PDF data acquisition using a laboratory single-crystal X-ray diffractometer for study of polynuclear lanthanide complexes in solid form and in solution

Cited by 12 publications

References 57 publications

New Materials for Colloidal Nanochemistry/Trendbericht Physikalische Chemie 2024 (2/3)

New Materials for Colloidal Nanochemistry/Trendbericht Physikalische Chemie 2024 (2/3)

Tuning the Cerium-Based Metal–Organic Framework Formation by Template Effect and Precursor Selection

Effects of Grain Refinement and Thermal Aging on Atomic Scale Local Structures of Ultra-Fine Explosives by X-ray Total Scattering

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