Synthesis and TD-DFT investigation of arylhydrazonocyclopentadiene dyes

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Synthesis and TD-DFT investigation of arylhydrazonocyclopentadiene dyes

Dyes and Pigments. 2019. Vol. 161. P. 500–509.

Medvedev M., Salikov R., Trainov K., Davydov D., Lee S., Gerasimov I., Levina A., Belyy A., Tomilov Y.

Two approaches for the synthesis of D-A chromophores containing arylhydrazonocyclopentadiene acceptor moieties were developed. The first approach includes the decarboxylative azo coupling reaction between penta(methoxycarbonyl)cyclopentadienyl potassium or sodium and aryldiazonium salts to give products containing four ester groups at the acceptor moiety. The second one includes the reaction of 1,3-dimethoxycarbonyl-4,5-diphenylcyclopentadienone with arylhydrazine hydrochlorides into arylhydrazonocyclopentadienes with two ester and two phenyl groups. Both series of compounds were investigated by means of absorption spectroscopy and the solvatochromic behavior of two representatives of each series was investigated in various dielectric environments. Both compounds demonstrated relative independence on the environment although the product with the stronger acceptor part was less stable and exhibited a slight hypsochromic shift in polar media. However, the optical properties of this product were strongly affected by the basicity of the medium due to the deprotonation of the NH-group. Quantum chemical modeling of the synthesized products adsorption spectra using different density functionals has shown that PBE0-D3/def2TZVP is an optimal method (out of three tested) for all compounds both in non-vibrationally-resolved and vibrationally-resolved TD-DFT calculations. Accounting for vibronic coupling in TD-DFT calculations is necessary to achieve good agreement with the experiment for compounds synthesized herein.

Research target: Chemistry Computer Science

Priority areas: IT and mathematics

Sodium Hypophosphite Assisted Ruthenium Catalyzed Reductive Amination under Mild Conditions

Зверева О., Клюев Ф. С., Lebedeva N. et al., Organic Letters 2025 Vol. 27 No. 50 P. 13711–13716

Added: May 23, 2026

Coping with AI errors with provable guarantees

Tyukin I., Tyukina T., van Helden D. P. et al., Information Sciences 2024 Vol. 678 Article 120856

AI errors pose a significant challenge, hindering real-world applications. This work introduces a novel approach to cope with AI errors using weakly supervised error correctors that guarantee a specific level of error reduction. Our correctors have low computational cost and can be used to decide whether to abstain from making an unsafe classification. We provide ...

Added: May 23, 2026

Overcoming the Curse of Dimensionality with Synolitic AI

Zaikin A., Sviridov I., Sosedka A. et al., Technologies 2026 Vol. 14 No. 2 Article 84

High-dimensional tabular data are common in biomedical and clinical research, yet conventional machine learning methods often struggle in such settings due to data scarcity, feature redundancy, and limited generalization. In this study, we systematically evaluate Synolitic Graph Neural Networks (SGNNs), a framework that transforms high-dimensional samples into sample-specific graphs by training ensembles of low-dimensional pairwise ...

Added: May 23, 2026

Stable On-the-Fly Learning for Dynamic Neural Networks With Delayed Inputs

Kibkalo Vladislav, Chertopolokhov V., Mukhamedov A. et al., IEEE Access 2026 Vol. 14 P. 14369–14392

This study presents on-the-fly identification and multi-step prediction of nonlinear systems with delayed inputs using a dynamic neural network combined with a smooth projection onto ellipsoids. The projection enforces parameter constraints that guarantee stability, while a Lyapunov–Krasovskii analysis yields computable ultimate error bounds. Riccati-type matrix inequalities are derived, providing an efficient vectorization–projection–devectorization implementation suitable for ...

Added: May 22, 2026

TBAT as “Multitool” Catalyst for Polysiloxane Synthesis, Modification, and Recycling

Лосев М. А., Козлов А. С., Chusov D. 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

Reductive coupling of nitroarenes with carboxylic acids – a direct route to amide synthesis

Лосев М. А., Козлов А. С., Клюев Ф. С. 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

Опыт применения сетевого анализа (SNA) в историческом нарративе полисубъектного региона (на примере валлийской хроники Brut y Tywysogyon)

Loshkareva M. E., Matveeva N., Вестник Томского государственного университета. История 2026 № 100 С. 112–118

This research is an endeavor to apply social network analysis (SNA) to the study of a medieval narrative source. The authors suppose that the use of network analysis may offer new possibilities in the study of the history of regions characterized by some political fragmentation. Authors tried to construct networks of historical interactions from 1193 ...

Added: May 22, 2026

ML-based Fast Simulation of FARICH Responses

Shipilov F., Barnyakov A., Ivanov A. et al., / Series Physics "arxiv.org". 2026.

A fast simulation of the detector response is a vital task in high-energy physics (HEP). Traditional Monte-Carlo methods form the backbone of modern particle physics simulation software but are computationally expensive. We present a machine-learning-based approach to fast simulation of the Focusing Aerogel Ring Imaging Cherenkov (FARICH) detector response. Given a particle track and momentum, ...

Added: May 19, 2026

Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 3: System Demonstrations)

Rabat: Association for Computational Linguistics, 2026.

Added: May 19, 2026

Dataset of solubility values for organic compounds in binary mixtures of solvents at various temperatures

Bezzubov S., Malikov D., Krasnov L. 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

Aerokinesis: An IoT-Based Vision-Driven Gesture Control System for Quadcopter Navigation Using Deep Learning and ROS2

Pikalov V., Meshcheryakov V., Kondratev S. et al., Technologies 2026 Vol. 14 No. 1 P. 1–27

This paper presents Aerokinesis, an IoT-based software–hardware system for intuitive gesture-driven control of quadcopter unmanned aerial vehicles (UAVs), developed within the Robot Operating System 2 (ROS2) framework. The proposed system addresses the challenge of providing an accessible human–drone interaction interface for operators in scenarios where traditional remote controllers are impractical or unavailable. The architecture comprises ...

Added: May 19, 2026

Aerokinesis: An IoT-Based Vision-Driven Gesture Control System for Quadcopter Navigation Using Deep Learning and ROS2

Kondratev S., Yulia Dyrchenkova, Georgiy Nikitin et al., Technologies 2026 Vol. 14 No. 1 Article 69

Added: May 19, 2026

Parallel Computational Technologies. PCT 2025

Springer, 2025.

This book constitutes the refereed proceedings of the 19th International Conference on Parallel Computational Technologies, PCT 2025, held in Moscow, Russia, during April 8–10, 2025. The 31 full papers included in this volume were carefully reviewed and selected from 122 submissions. These papers were organized under the following topical sections: High Performance Architectures, Tools and Technologies; ...

Added: May 18, 2026

KMHCR: A Key-Controlled Signal-Domain Transformation for 5G IoT Security

Ronglin Z., Wei L., Jiahong C. et al., Journal of Signal Processing Systems 2026 Vol. 98 P. 1–15

To address the need for lightweight and low-latency protection in massive resource-constrained 5G Internet of Things (IoT) systems, this paper proposes Key-Controlled Modulation Hopping and Constellation Rotation (KMHCR). KMHCR is designed as a physical-layer confidentiality-enhancement mechanism that avoids bit-wise full-payload encryption in the protection pipeline. It uses a shared key derived from channel-reciprocity secret key ...

Added: May 16, 2026

DPN Verifier: A Toolkit for Faster Soundness Verification and Repair of Process Models with Data

Suvorov N. M., Proceedings of the Institute for System Programming of the RAS 2026 Vol. 38 No. 3(2) P. 49–66

Data Petri Nets (DPNs) extend classical Petri nets to model processes where data directly influences control-flow, enabling a comprehensive view of system behavior and possibility to detect failure points that could otherwise be hidden. Soundness is a correctness criterion that captures such failure points as deadlocks and livelocks as well as model boundedness and absence ...

Added: May 16, 2026

Perovskite nanoparticles Cs4PbBr6 and CsPbBr3: synthesis, analysis and peculiar optical properties

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

CsPbBr3 and Cs4PbBr6 perovskite nanoparticles: hidden potential of Cs4PbBr6 or ineffective fluorescence?

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

SERS effect on the surface of ZnO nanorods coated with CsPbBr3

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

On the Issue of Biological Activity of Cobalt bis(dicarbollide) Derivatives: Conformation of the [8-EtO-8’-I-3,3’-Co(1,2-C2B9H10)2]− Anion

Мальцева В. Е., Ananyev I., Sivaev I. 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

Расчет энтальпии образования и константы ионного равновесия органических веществ методами квантовой химии

Мальцева В. Е., Оскорбин А. А., Журнал общей химии 2023 Т. 93 № 11 С. 1722–1735

С использованием композитных методов квантово-химических расчетов и метода атомизации выполнены расчеты энтальпии образования для тестового набора из 79 соединений с точностью 3.8, 4.5, 4.7 кДж/моль для методов G4, G4MP2, CBS-QB3 соответственно. По результатам статистического анализа отклонений теоретических значений от экспериментальных выявлено присутствие ошибок, возникающих на этапе оптимизации геометрии из-за неучтенных в расчете корреляционных эффектов. Для ...

Added: May 13, 2026

КВАНТОВО-ХИМИЧЕСКОЕ МОДЕЛИРОВАНИЕ МЕХАНИЗМА ЭКСТРАКЦИИ Fe(III) ИЗ СОЛЯНОКИСЛОГО ВОДНОГО РАСТВОРА ЭВТЕКТИЧЕСКИМИ РАСТВОРИТЕЛЯМИ НА ОСНОВЕ 1-ОКТАНОЛА

Мальцева В. Е., Ananyev I., Милевская А. В. et al., Теоретические основы химической технологии 2025 Т. 59 № 3 С. 13–22

Проведено квантово-химическое моделирование механизма экстракции Fe(III) из солянокислого раствора с использованием гидрофобных эвтектических растворителей на основе 1-октанола. Установлено, что путь реакции существенно различается в зависимости от того, является ли инертный компонент донором или акцептором водородной связи в димере с октанолом. На основе оценки прочности водородных связей показано, что более слабое взаимодействие между компонентами упрощает протекание ...

Added: May 13, 2026

Natural hazard database from Internet publications: text mining with a large language model

Derkacheva A., Sakirkina M., Kraev G. et al., /. 2026.

Comprehensive data on natural hazards and their consequences are crucial for effective for risk assessment, adaptation planning, and emergency response. However, many countries face challenges with fragmented, inconsistent, and inaccessible data, particularly regarding local-scale events. To address this data gap in Russia, we developed an end-to-end processing pipeline that scrapes news from various online sources, ...

Added: April 28, 2026

Algorithmic overlaps as thermodynamic variables: from local to cluster Monte Carlo dynamics in critical phenomena

Pilé I., Deng Y., Shchur L., / Series arXiv "math". 2026. No. 2604.10254.

We investigate the spatial overlap of successive spin configurations in Markov chain Monte Carlo simulations using the local Metropolis algorithm and the Svendsen-Wang and Wolff cluster algorithms. We examine the dynamics of these algorithms for two models in different universality classes: the Ising model and the Potts model with three components. The overlap of two ...

Added: April 20, 2026

Using predefined vector systems to speed up neural network multimillion class classification

Gabdullin N., Androsov I., / Series Computer Science "arxiv.org". 2026.

Label prediction in neural networks (NNs) has O(n) complexity proportional to the number of classes. This holds true for classification using fully connected layers and cosine similarity with some set of class prototypes. In this paper we show that if NN latent space (LS) geometry is known and possesses specific properties, label prediction complexity can ...

Added: April 2, 2026