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Infrared Spectra of the CH3NH3PbI3 Hybrid Perovskite: Signatures of Phase Transitions and of Organic Cation Dynamics
Journal of Physical Chemistry C. 2020. Vol. 124. No. 42. P. 23307–23316.
Kirill N. Boldyrev, Vasilisa E. Anikeeva, Marina N. Popova, Semenova O.
The high-resolution terahertz reflection and mid- and near-infrared transmission spectroscopic studies of CH3NH3PbI3 hybrid perovskite single crystals are performed for the temperature range from 5 to 350 K. The observation of the torsional mode of the molecular cation (at 306 cm–1) and of 12 other low-frequency modes not observed before is reported. Mode Grüneisen parameters for the strongest inorganic-cage modes are negative, which points to their interaction with a soft mode. Sharp peculiarities and the hysteresis take place in the multiphonon spectra at the phase transition from the tetragonal to the orthorhombic phase (∼160 K). Moreover, pronounced spectral changes are observed at ∼70 K; they correlate with the transition to tunneling dynamics. A spectral line splitting at this temperature is tentatively attributed to the tunneling splitting.
Novikov A., Journal of Alloys and Compounds 2026 Vol. 1077 Article 189412
A wide series of substitutions in a subsystem of small radii cations M = Al, Cr, Fe, Ga, Sc is possible in rare-earth borates ReM3(BO3)4 with the huntite structure. However, the existence of these compounds where M = Mn still raises doubts. The study presents a synthetic approach developed in the framework of the flux method allowing for the required ...
Added: June 29, 2026
Medvedev M., Journal of Chemical Theory and Computation 2026 Vol. 22 No. 9
Density functional theory (DFT) is the workhorse of modern reactions and materials modeling. While the exact functional remains unknown, many approximations to it have been constructed either by hand-crafting functional forms to satisfy exact constraints or by machine learning. In this work, we show how both of these approaches can be fused to build both ...
Added: June 26, 2026
Laurinavichyute V., Levin E. E., Mironkova A. A. et al., Surfaces and Interfaces 2026 Vol. 81 P. 108389
In this work we characterize mixed Mo-W acidic deposition solutions with Mo content ranging from 0 to 100 mol.% by Raman and UV–Vis spectroscopy. The obtained distribution diagram of mixed isopolyanions allows one to explain the observed change in film deposition rate with increase in Mo content. It was found that the initial decrease in ...
Added: June 24, 2026
Filippova A. V., Yurchenko N. Y., Smirnov S. A. et al., Journal of Alloys and Compounds 2026 No. 1074 Article 189162
This study investigates the effects of post-processing heat treatment at 300–500 °C on the microstructure, hardness, and tensile properties of laser powder bed fusion (PBF-LB) processed Al-bronze processed with energy densities (ED) in the range of 125–938 J/mm3. In the as-printed state, sharp needle-like α + β′ laths form at lower ED whereas with increasing ED, the β′ ...
Added: June 12, 2026
Obijiofor O., Novikov A., New Journal of Chemistry 2026 Vol. 50 No. 23 P. 9749–9768
Rational design of gold-based nanocarriers for neurotherapeutics requires atomic-scale understanding of drug-material interactions. Density functional theory calculations were performed to investigate levodopa (L-DOPA) adsorption on small gold clusters (Au2–Au4) with cationic, neutral, and anionic charges, with additional validation on a larger Au10 cluster using multiple low-energy isomers. Binding free energies (ΔGbind), charge transfer, and electronic descriptors ...
Added: June 3, 2026
Das A., Saikia J., Maji N. et al., ChemNanoMat 2026 Vol. 12 No. 5 Article e202500733
Developing efficient photoactive materials from bio-derived resources is vital yet challenging for achieving effective water splitting performance. In this work, nano carbon dots (CDs) of zero-dimensional (0D) were synthesized from papaya peel through a simple and eco-friendly process and subsequently anchored onto the two-dimensional (2D) layered structure of graphitic carbon nitride (g-C3N4, GCN) at various ...
Added: June 2, 2026
Wary R. R., Mahato B., Sharma N. et al., The Journal of Physical Chemistry Letters 2026 Vol. 17 No. 17 P. 5099–5107
Development of heterojunction materials is an efficient approach for enhancing photocatalytic and photoelectrochemical processes. We develop a ZnO/CuO heterojunction via Cu doping into a ZnO matrix. Structural characterization confirmed that Cu was effectively incorporated into ZnO without any structural changes. The improved optical properties and reduced charge carrier recombination of the doped samples were confirmed ...
Added: June 2, 2026
Ostovari Moghaddam A., Mehrabi-Kalajahi S., Hossein Vasigh S. A. et al., The Journal of Physical Chemistry Letters 2026 Vol. 17 No. 13 P. 3978–3985
Water electrolysis is a key technology for sustainable energy conversion and hydrogen generation. Recently, high-entropy oxides (HEOs) have emerged as promising materials because they allow tuning of structural, electronic, and catalytic properties in multifunctional systems. Here, we report the synthesis of a multicomponent La(FeCoCuTiNiMnMgSnZn)O3 perovskite, and its hybridization with reduced graphene oxide (rGO) to form a ...
Added: June 1, 2026
Chowdhury U., Mondal S., Dey S. et al., Journal of the american chemical society 2026 Vol. 148 No. 23 P. 24538–24550
Covalent functionalization offers a versatile platform to engineer carbon nanotube properties for optoelectronics applications. We demonstrate by atomistic quantum dynamics simulation that covalent functionalization can renormalize the CNT band gap, split the degenerate CNT band edge states, and strongly influence charge carrier separation and recombination dynamics. Open-ring CNT functionalization (O-CNT) largely retains the π-conjugation, whereas ...
Added: June 1, 2026
Jiménez-Grávalos F., Alexander S. Novikov, Pendás Á. M., Communications in Computational Chemistry 2026 Vol. 8 No. 2 P. 203–210
Chalcogen bonds (ChBs) are often interpreted as 𝜎-hole driven electrostatic interactions between a chalcogen atom and a Lewis base, yet their covalent character remains under active discussion. Here, we present a real-space, reference-free study of prototypical X2Ch···X– complexes (X = F, Cl; Ch = O, S) using the Interacting Quantum Atoms (IQA) energy decomposition within ...
Added: May 27, 2026
Uskov F., Korobkov S., Birin K. P. et al., Journal of Photochemistry and Photobiology A: Chemistry 2026 Vol. 474 Article 116936
Oxidation of sulfides by singlet oxygen has been extensively studied, yet the structure-photoactivity relationship of these photosensitizers remains underinvestigated. In the present work the photocatalytic performance of a set of functionalized palladium(II) porphyrinates was comprehensively investigated in the photocatalytic oxidation of sulfides to reveal mutual influence of structural peculiarities onto the photosensitizing properties. The photophysical ...
Added: May 27, 2026
Mezentsev I., Dudarova N., Druzina A. et al., Journal of Photochemistry and Photobiology A: Chemistry 2026 Vol. 479 Article 117316
Novel cobalt bis(dicarbollide) based terminal alkynes with charge-compensated group in a spacer were synthesized by the nucleophilic ring-opening reactions of cyclic oxonium derivatives of cobalt bis(dicarbollide) with N,N-dimethylbut-3-yn-1-amine. A series of zwitterionic conjugates of cobalt bis(dicarbollide) with BODIPY were synthesized using the copper(I)-catalyzed azide-alkyne cycloaddition reaction. The absorption-emission spectra of the synthesized fluorescent conjugates of cobalt ...
Added: May 27, 2026
Toukach P., Smirnova N. S., Zdorovenko E. L. et al., Analytical Chemistry 2026 Vol. 98 No. 15 P. 10988–10996
Pyruvylation is one of the immunochemically relevant modifications of O-antigens in bacterial and fungal cells. Therefore, fast and relatively simple analytical methods for identifying this modification are highly demanded. 13C NMR spectroscopy is the best candidate for this purpose, but its successful application requires using reference structures and reliable databases. In this work, we collected ...
Added: May 25, 2026
Зверева О., Kliuev F., Lebedeva N. et al., Organic Letters 2025 Vol. 27 No. 50 P. 13711–13716
Added: May 23, 2026
Mikhail A. Losev, Andrey S. Kozlov, Afanasyev O. et al., ACS Catalysis 2026 Vol. 16 No. 10 P. 9380–9386
A convenient, stable, and non-toxic substance, tetrabutylammonium difluorotriphenylsilicate (TBAT), can be used as an organocatalyst in all stages of polymer lifetime: synthesis, modification, and recycling. The fluorine-containing initiator showed high activity in the polymerization of siloxanes compared to classic organocatalytic systems. Using kinetically controlled ROP, a high-molecular-weight PDMS (Mn up to 820 𝑘𝑔/𝑚𝑜𝑙) was prepared at room ...
Added: May 22, 2026
Лосев М. А., Козлов А. С., Kliuev F. et al., Organic and Biomolecular Chemistry 2023 Vol. 21 No. 42 P. 8477–8481
A simple and atom-efficient way to prepare amides directly from carboxylic acids and nitroarenes was developed. Carbon monoxide as a sole reducing agent provides the ultimate selectivity of the protocol. A straightforward and selective way for the preparation of amides from nitroarenes and carboxylic acids using carbon monoxide as a reductant was developed. This protocol ...
Added: May 22, 2026
Malikov D., Krasnov L., Kiseleva M. et al., Scientific data 2026 Vol. 13 Article 727
Solubility is a crucial property of organic compounds, impacting their potential applications in synthetic chemistry, materials science and drug design. Moreover, in technological processes mixtures of solvents are often utilized, making the solubility assessment more complicated. Predicting solubility values in mixtures of solvents from a molecular structure can help to address this issue, although a ...
Added: May 19, 2026
Гущина В. А., / Series chemrxiv-2023-vpzhz-v2 "ChemRxiv". 2023.
All-inorganic perovskite CsPbBr3 and Cs4PbBr6 nanoparticles are being intensively studied due to their unique properties and wide range of applications; however, however, the nature of their optical properties is not yet fully understood due to the difficulty of synthesis of singlephase nanoparticles. In this article we describe the features of the synthesis of single-phase particles ...
Added: May 14, 2026
Гущина В. А., Mendeleev Communications 2025 Vol. 35 No. 2 P. 193–195
All-inorganic perovskite CsPbBr3 and Cs4PbBr6 nanoparticles are intensively studied for their unique optical properties, though synthesizing single-phase nanoparticles has posed challenges. Detailed synthesis method of CsPbBr3 and Cs4PbBr6 single-phase nanoparticles and their chemical and phase analysis are described. Distinctive optical characteristics, such as photoluminescence, optical band gap and the Urbach tail region, are revealed and explained within the current ...
Added: May 14, 2026
Гущина В. А., Physics of Complex System 2026 Vol. 7 No. 1 P. 3–15
Heterostructures based on ZnO nanorods and CsPbBr3 nanocrystals were investigated for their potential as semiconductor SERS substrates. We found that ZnO morphology governs the efficiency of interfacial energy transfer, leading to enhanced photoluminescence under 390 nm excitation and a noticeable reduction of the bandgap in the composites. Raman analysis revealed a pronounced intensity enhancement and ...
Added: May 14, 2026
Dudarova N., Kosenko I., Varvara E. Maltseva et al., Journal of Cluster Science 2025 Vol. 36 No. 5 Article 161
The conformational mobility of the [8-EtO-8’-I-3,3’-Co(1,2-C2B9H10)2]− anion, which has been chosen as a model compound for many potential drugs based on cobalt bis(dicarbollide), was studied by 1H NMR spectroscopy, single crystal X-ray diffraction and quantum chemical calculations. According to the results of quantum chemical calculations, the most favourable conformation for [8-EtO-8’-I-3,3’-Co(1,2-C2B9H10)2]− is the transoid conformation, which is stabilized by one ...
Added: May 13, 2026
Kovaleva N. N., Chvostova D., Fursova T. N. et al., Journal of Chemical Physics 2025 Vol. 163 No. 19 Article 194711
The intrinsic substitutional and antisite defects cause unintentional doping and a shift of the E-F position above the conduction band minimum in the AF topological insulator MnBi2Te4. This prevents measurements of the quantum anomalous Hall effect and the investigation of the topological Dirac states. In the present study, the Mn-Bi-Te films grown by the MBE ...
Added: February 18, 2026
Dmitriev A., Lebedev A., Kornilov V. et al., Frontiers in Physics 2025 Vol. 12 Article 1508465
Our study is based on the hypothesis that stock exchanges, being nonlinear, open and dissipative systems, are capable of self-organization to the edge of a phase transition. To empirically support the hypothesis, we find segments in hourly stock volume series for 3,000 stocks of publicly traded companies, corresponding to the time of stock exchange’s stay ...
Added: January 23, 2025
Sukhoverkhova D., Shchur L., Письма в Журнал экспериментальной и теоретической физики 2024 Т. 120 № 8 С. 644–649
In this paper, we applied a deep neural network to study the issue of knowledge transferability between statistical mechanics models. The following computer experiment was conducted. A convolutional neural network was trained to solve the problem of binary classification of snapshots of snapshots of the location of spins of the Ising model on a two-dimensional ...
Added: September 25, 2024