Xanthate complexes of {Nb2S4} 4+

D. A. Mainichev; Sokolov M. N.; Rogachev A. V.; Virovets A. V.; Korenev V. S.; Mikhailov M. A.; Laricheva Y. A.; Sinkevich P. L.

?

Xanthate complexes of {Nb2S4} 4+

Russian Journal of Coordination Chemistry/Koordinatsionnaya Khimiya. 2014. Vol. 40. No. 7. P. 460–467.

Mainichev D. A., Sokolov M. N., Rogachev A. V., Virovets A. V., Korenev V. S., Mikhailov M. A., Laricheva Y. A., Sinkevich P. L.

Alkyl xanthate complexes [Nb2S4(S2COR)4] (R = Et (I), iso-Pr (II), n-Bu (III), and iso-Am (IV)) are synthesized by the ligand exchange reaction in solutions from (Et4N)4[Nb2S4(NCS)8] and the corresponding potassium salts in satisfactory yields. The X-ray diffraction analyses are carried out for the isopropyl xanthate (II) and butyl xanthate (III) complexes. From the view point of mutual arrangement of chelate cycles, complexes II and III exist in crystals as ΛΔ isomers. The niobium-niobium distances are 2.8789(4) Å in complex II and 2.8856(3) Å in complex III. The first example for the formation of short S...S contacts between the disulfide ligands of the {Nb2S4}4+ fragments in the crystal structure of III is found (3.146 Å).

Research target: Mathematics Physics

Priority areas: IT and mathematics mathematics engineering science

Language: English

Full text

Text on another site

Keywords: математическое и компьютерное моделирование mathematical and computer modeling nuclear magnetic resonance ядерный магнитный резонанс

Strong Approximations for Markov Chains Weakly Converging to Diffusions

Konakov V., Kucher D., Mammen E., / Series arXiv "math". 2026. No. 2606.11142v1.

In this paper, we construct strong approximations for discrete-time Markov chains weakly converging to continuous diffusion processes, as well as for their perturbed counterparts. Under the assumption of bounded coefficients, we construct closely coupled versions of these processes on a shared probability space. In particular, for both non-degenerate and degenerate cases, we maximize the probability ...

Added: June 11, 2026

On the Ramsey Number R(K_{1,s},P_t)

Kh. Kh. Abdullin, D. B. Mokeev, D. S. Taletskii, Mathematical notes 2026 Vol. 119 No. 1 P. 3–7

By the Ramsey number R(K1,s,Pt) one means the least positive integer n such that, for every n-vertex graph G, the following condition holds: either G contains a vertex of degree at least s or the complement of G contains a simple t-path. In this paper, we ﬁ nd precise values of R(K1,s,Pt) for certain values ...

Added: June 10, 2026

Спонтанное образование скин-слоя в воде с деформацией ОН-полосы КР вкладом компоненты льда 3200 см-1

Першин С. М., Степанов Е. В., Артемова Д. Г. et al., Письма в Журнал экспериментальной и теоретической физики 2026 Т. 123 № 6 С. 383–390

Открыто спонтанное образование в течение 4 ч скин-слоя дистиллированной воды толщиной до 3 мм при комнатной температуре с новыми свойствами. Обнаружены деформация ОН-полосы комбинационного рассеяния вкладом компоненты льда ( 3200 см-1), снижение коэффициента упругого рассеяния и его флуктуаций, а также увеличение на 20 капиллярах. Восстановление слоя после обогащения воздухом в результате перемешивания указывает на стабильность ...

Added: June 8, 2026

Innovations in Information and Decision Sciences. Proceedings of the 13th International Conference on Frontiers in Intelligent Computing: Theory and Applications (FICTA 2025), Volume 4

Springer, 2026.

The book presents the proceedings of the 13th International Conference on Frontiers of Intelligent Computing: Theory and Applications (FICTA 2024), held at Intelligent Systems Research Group (ISRG), London Metropolitan University, London, United Kingdom, during June 6–7, 2025. Researchers, scientists, engineers and practitioners exchange new ideas and experiences in the domain of intelligent computing theories with ...

Added: June 8, 2026

Relativistic effects in the interaction of electrons with a slow extraordinary wave

N.S. Artekha, D.R. Shklyar, Physics of Plasmas 2026 Vol. 33 No. 6 Article 062105

The peculiarities of resonant interaction between slow extraordinary (SE) waves and relativistic electrons have been studied. General equations of motion of relativistic electrons in the field of SE wave and a uniform ambient magnetic field are derived. Conditions of applicability of the isolated resonance approximation are elucidated. In this approximation, the equations of motion are reduced to one-dimensional set of ...

Added: June 6, 2026

Structural and broadband radio-frequency properties of InGaZnO4 nanoparticles synthesized by gel decomposition method

Zirnik G., Ostovari Moghaddam A., Zhukov S. et al., Journal of Materials Science: Materials in Electronics 2026 Vol. 37 Article 738

In regards to the advances in InGaZnO for flexible transistors applications, herein for the first time we measure the broadband radio-frequency range (10 Hz to 1 MHz) dielectric permittivity ε′ and electrical conductivity σ of InGaZnO4 nanoparticle layers at different temperatures ranging from 10 to 300 K. The InGaZnO4 nanoparticles prepared by metal–nitrate–glycol gel decomposition method exhibited ...

Added: June 6, 2026

Wave dynamics within the Whitham-Ostrovsky equation

Flamarion M. V., Pelinovsky E., Nonlinear Dynamics 2026 Vol. 114 Article 784

In this article, we investigate wave packet and solitary wave dynamics in the Whitham–Ostrovsky (WO) equation. By means of a multiple-scales expansion, we formally derive a nonlinear Schrödinger (NLS) equation governing the envelope evolution.The corresponding modulational stability diagram is then obtained using the Lighthill criterion. We show that sufficiently large values of the low-frequency dispersive term render ...

Added: June 5, 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

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

Bifurcations and Structural Stability of Generic PC-HC Families

Dorovskiy A., / Series arXiv "math". 2026.

In this paper the structural stability of generic families of vector fields of the PC-HC class on the two-dimensional sphere is proved. A classification of these families up to moderate equivalence in neighborhoods of their large bifurcation supports is presented, based on such invariants as the configuration and the characteristic set. The realization lemma is proved. ...

Added: May 14, 2026

On the minimum number of maximal distance-k independent sets in trees

Taletskii D., / Series arXiv "math". 2026.

A vertex subset of a graph is called a \textit{distance-$k$ independent set} if the distance between any two of its distinct vertices is at least $k + 1$. For all $n,k \geq 1$, we determine the minimum possible number of inclusion-wise maximal distance-$k$ independent sets among all $n$-vertex trees. It equals~$n$ if $n \leq k ...

Added: May 1, 2026

On Arithmetic Mirror Symmetry for smooth Fano fourfolds

Ovcharenko M., / Series arXiv "math". 2026.

We introduce an explicit class of tempered Laurent polynomials in the sense of Villegas and Doran--Kerr in n⩽4 variables including all Landau--Ginzburg models for smooth Fano threefolds with very ample anticanonical class. We check that it contains Landau--Ginzburg models for various Fano fourfolds which are complete intersections in smooth toric varieties and Grassmannians of planes, ...

Added: April 30, 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

On weak solutions to the 1d compressible Navier-Stokes equations: a Lipschitz continuous dependence on data in weaker norms and an error of their homogenization

Zlotnik Alexander, / Series arXiv "math". 2026. No. 2602.03481v1.

We deal with the global in time weak solutions to the 1D compressible Navier-Stokes system of equations for large discontinuous initial data and nonhomogeneous boundary conditions of three standard types. We prove the Lipschitz-type continuous dependence of the solution $(\eta,u,\theta)$, in a norm slightly stronger than $L^{2,\infty}(Q)\times L^2(Q)\times L^2(Q)$, on the initial data $(\eta^0,u^0,e^0)$ in a ...

Added: April 18, 2026

On the dimension of the space of static potentials on three-manifolds

Medvedev V., / Series arXiv "math". 2026.

We investigate the interplay between the dimension of the space of static potentials and the geometric and topological structure of the underlying static three-manifold. A partial classification of boundaryless static manifolds is obtained in terms of this dimension. We also treat the case of static manifolds with boundary. In particular, we prove that if a ...

Added: April 3, 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

1H NMR and EPR Spectroscopies Investigation of Alginate Cross-Linking by Divalent Ions

Forysenkova Anna A., Ivanova V., Fadeeva I. et al., Materials 2023 Vol. 16 No. 7 P. 2832–2843

Alginate is a natural polymer widely applied in materials science, medicine, and biotechnology. Its ability to bind metal ions in order to form insoluble gels has been comprehensively used to create capsules for cell technology, drug delivery, biomedical materials, etc. To modify and predict the properties of cross-linked alginate, knowledge about the mechanism of alginate ...

Added: August 12, 2025

Информатика и кибернетика

Донецк: Донецкий национальный технический университет, 2024.

по материалам XV Международной научно-технической конференции «Информатика, управляющие системы, математическое и компьютерное моделирование-2024» (ИУСМКМ-24) ...

Added: November 18, 2024

Приближенное оценивание с помощью ускоренного метода наибольшей энтропии. Часть 2. исследование свойств оценок часть

Dubnov Y. A., Bulychev A., Информационные технологии и вычислительные системы 2023 № 1 С. 71–81

In this paper, we investigate a method of approximate entropy estimation, designed to speed up the classical method of maximum entropy estimation due to the use of regularization in the optimization problem. This method is compared with the method of maximum likelihood and Bayesian estimation, both experimentally and in terms of theoretical calculations for some ...

Added: June 16, 2023

Приближенное оценивание с помощью ускоренного метода наибольшей энтропии. Часть 1. постановка задачи и реализация для задачи регрессии

Dubnov Y. A., Bulychev A., Информационные технологии и вычислительные системы 2022 № 4 С. 69–80

The work is devoted to the development of an entropy estimation method with “soft” randomization for restoring the parameters of probabilistic mathematical models from the available observations. Soft randomization refers to the technique of adding regularization to the information entropy functional to simplify the optimization problem and speed up learning process compared to the traditional ...

Added: June 16, 2023

Моделирование широкополосного усилителя на печатной плате с диэлектриком повышенной проводимости

Абрамешин Д.А., Пожидаев Е.Д., Саенко В.С. et al., Известия вузов. Электроника. РФ 2022 Т. 27 № 5 С. 635–644

The electrons of the cosmic plasma act on spacecraft, causing the electrification of their dielectric materials. The result of the accumulation of charge is the occurrence of electrostatic discharges leading to failures in the operation of on-board radio electronics, and this phenomenon significantly reduces the duration of the active existence of spacecraft. One of the ...

Added: November 2, 2022

Идентификация модели радиационной проводимости полимерных материалов

Тумковский С. Р., Муллахметов И.Р., Пожидаев Е.Д. et al., Информационные технологии 2022 Т. 28 № 5 С. 233–239

A technique for identifying a model of radiation conductivity of polymeric materials for chip packages of microelectronic equipment has been developed. On the basis of the developed technique, computer simulation of radiation charging of polymer cases of microelectronic equipment with increased conductivity was carried out. The research results are aimed at the development of composite ...

Added: June 1, 2022

Моделирование радиационного заряжения корпусов микроэлектронной аппаратуры космического применения

Abrameshin D., Pozhidaev E., Tumkovskiy S., Информационные технологии 2021 Т. 27 № 2 С. 59–64

A model and a method of mathematical modeling of radiation charging of polymer cases of microelectronic equipment with increased conductivity are developed, which are based on the application of the approximation function of the experimental dependence of the case conductivity on the irradiation time obtained using parametric identification methods. The research results are aimed at ...

Added: June 28, 2021