Degree-based topological co-indices for QSPR modelling of benzenoid hydrocarbons: a comparative computational study

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Degree-based topological co-indices for QSPR modelling of benzenoid hydrocarbons: a comparative computational study

Chemical Papers. 2026.

Ahsan M., Imran Ali

Benzenoid hydrocarbons are structurally regular aromatic compounds, which makes them well suited for quantitative structure–property relationship (QSPR) studies. This study presents a QSPR analysis of nineteen benzenoid hydrocarbon species using degree-based topological co-indices. We developed a Python program to compute eleven degree-based topological co-indices from molecular graphs and evaluated their ability to explain variations in key physicochemical properties. Using SPSS, we evaluated linear, quadratic, and cubic regression models to correlate the computed co-indices with Henry’s law constant, molecular weight, -electron energy, and other physicochemical properties. The comparative analysis reveals that cubic regression models provide the strongest structure–property correlations, with the forgotten co-index emerging as a particularly robust descriptor for Henry’s law constant. Overall, this study demonstrates that degree-based co-indices are effective and computationally efficient descriptors for capturing structure–property trends in benzenoid hydrocarbons. The predictive stability of the proposed models is confirmed through leave-one-out cross-validation, Y-randomization, and applicability-domain analysis.

Research target: Mathematics Chemistry Chemical Technologies

Language: English

DOI

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Ероховец Николай Юрьевич, Математический сборник 2026 Т. 217 № 5 С. 45–89

Toric topology assigns to each simple convex n-polytope P with m facets an n-dimensional real moment-angle manifold RZP with a canonical action of Zm2=(Z/2Z)m. We consider (not necessarily free) actions of subgroups H⊂Zm2 on RZP. The orbit space N(P,H)=RZP/H carries an action of Zm2/H. For general n we introduce the notion of Hamiltonian C(n,k)-subcomplex in the boundary of an ...

Added: September 17, 2026

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Kuninets A., Malygina E., Cryptography and Communications 2026

In this paper, we determine explicit bases for Riemann–Roch spaces associated with various families of elliptic codes. We establish the feasibility and provide exact algorithms for constructing bases of Riemann–Roch spaces corresponding to arbitrary divisors on elliptic curves, including the non-effective case. These results are subsequently applied to derive bases for quasi-cyclic elliptic codes and ...

Added: September 17, 2026

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Kazakov A., Koryakin V., Safonov K. et al., Journal of Differential Equations 2026 Vol. 480 Article 114626

We study a family of one-dimensional maps that models the dynamics of a system of differential equations with a Lorenz attractor near a bifurcation curve where the system has a pair of homoclinic loops with zero separatrix value. Of particular interest is the region of the parameter plane where the map has a robust chaotic ...

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Letellier C., Stankevich N., Houri S. et al., Chaos 2026 Vol. 36 No. 9 Article 093128

Toroidal chaos designates a chaotic solution that is structured in the neighborhood of a torus. For being chaotic, such a torus needs to be discontinuously fractalized to present a Cantor set, ensuring the great sensitivity to initial conditions required for chaos. A fractal is related to self-similarity and a non-integer dimension. In fact, although clearly ...

Added: September 16, 2026

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Poddiakov A., / Series Social Science Research Network "Social Science Research Network". 2026. No. 7437658.

Clarity of knowledge and reasoning is necessary in many cases. Yet vagueness in scientific thinking related to surprise, curiosity, "ability to engage with not-knowing" (de Freitas) and abductive reasoning is also a crucially important source of scientific creativity which supplements combinatorial logic when dealing with the already known. Starting from studies by C. S. Peirce ...

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Glushak A., Tararushkin E., Smirnov G., Colloids and Surfaces A: Physicochemical and Engineering Aspects 2027 Vol. 752 Article 141756

The molecular-scale behavior of water in heterogeneous clay–quartz systems is critical for understanding cementation processes in natural soils and compacted bentonite, which is crucial for oil recovery and nuclear waste disposal barriers construction. Here we investigate how heterogeneity of mixed Na-montmorillonite and α-quartz surfaces affect water structure and dynamics in nanopores of 2.5 to 60 Å ...

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Kolin N., Nazarov D., Krivenko K. et al., Dyes and Pigments 2026 Vol. 254 Article 113957

Interaction of thioindigo dianions with metal phthalocyanines, MPc, where M = MgII, MnII, AlIIICl and SiIVCl2, in the presence of cryptand[2.2.2] produces anionic and neutral complexes: {Crypt(K+)}2{(trans-thioindigo2−)⋅(MgIIPc)2}2−⋅2C6H4Cl2 (1); {Crypt(Cs+)}2{(trans-thioindigo2−)⋅(MnIIPc)2}2− (2), {Crypt(K+)}{(cis-Hthioindigo−)2⋅(AlIIIPc)}− (3) and {(cis-Hthioindigo−)2⋅(SiIVPc)} (4). Bidentate thioindigo2− ligand forms symmetric binuclear dimers in 1 and 2 with short M-O(thioindigo2−) bonds of 1.899(2) and 1.984(6) Å length for ...

Added: September 14, 2026

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Faraonov M., Romanenko N., Ivanov T. et al., Dalton Transactions 2026 Vol. 55 No. 24 P. 9428–9438

Doubly reduced phthalocyanine complexes remain largely unexplored despite their potential relevance for molecular spin-based applications. Herein, we report the synthesis of a series of crystalline complexes, {cryptand(Cs + )} 2 [M(Pc) 4– ] 2–. ...

Added: September 14, 2026

Binuclear and trinuclear 3d-metal complexes of HATNA and HAT(CN)6 with unique magnetic behavior: from extremely strong antiferromagnetic coupling to opposite sign of zero-field splitting in the same complex

Mikhailenko M., Astakhova T., Timokhina E. N. et al., Inorganic Chemistry Frontiers 2026 Vol. 13 No. 14 P. 6145–6156

series of anionic bi- and trinuclear complexes of Co II , Fe II , and Mn II with hexaazatrinaphthylene (HATNA) and hexaazatriphenylenehexacarbonitrile (HAT(CN) 6 ), incorporating paramagnetic Cp* 2 Fe + cations ( S = 1/2), were obtained and investigated. ...

Added: September 14, 2026

1D and 2D coordination polymers based on ring-reduced freebase and copper-containing meso-tetra(4-pyridyl)porphyrins and M(III) (TMHD) 3 units (M = Dy, Tb and Gd; TMHD: 2,2,6,6-tetramethyl-3,5-heptanedionate)

Nazaro D. I., Yakushev I. A., Kuzmin A. V. et al., Inorganic Chemistry Frontiers 2026 Vol. 13 No. 11 P. 5039–5050

Reduced tetra(4-pyridyl)porphyrins (H 2 TPyP and Cu II TPyP) form polymers with M III (TMHD) 3 (M = Dy, Tb and Gd). Folded zigzag 2D and linear 1D polymers are obtained. Their structure, optical and magnetic properties are investigated. ...

Added: September 14, 2026

Singlet–Triplet Transitions in the Dianionic Complex of Fullerene C 60 with Iron Carbonyl: (TBA + ) 2 {[Fe 2 (CO) 6 ]-η 2 ,η 2 -C 60 } 2–

Sobov P. A., Yakushev I. A., Shestakov A. et al., Inorganic Chemistry 2026 Vol. 65 No. 16 P. 9107–9115

Interaction of fullerene C60 with Cs2Fe(CO)4 in the presence of two equivalents of tetrabutylammonium iodide (TBAI) yields the first dianionic coordination complex of fullerene: (TBA+)2{[Fe2(CO)6]-η2,η2-C60}2– (1). According to magnetic data and DFT calculations, complex 1 has a diamagnetic ground (S = 0) and a triplet excited state (S = 1) populated above 80 K. As ...

Added: September 14, 2026

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Faraonov M., Romanenko N., Ivanov T. et al., Crystal Growth & Design 2026 Vol. 26 No. 7 P. 2792–2801

A redox-active tetrapyrazinoporphyrazine ligand was used as a platform for the design of multimetallic coordination complexes. The first paramagnetic homo- and heterotrimetallic complexes have been obtained as crystals through the reaction of iron(II) octaethyltetrapyrazinoporphyrazine, FeII(Et8TPyzPz), with 3d- (FeII, CoII) and 4f-metal (DyIII) iodides. In these conditions, tetrapyrazinoporphyrazine can coordinate to metals to form exo- and ...

Added: September 14, 2026

Complex of fullerene C60 with partial charge transfer: {(dppf)CpFe(CO)}+(C60)-⋅C6H4Cl2 (δ = 0.54–0.86), where dppf is bis(diphenylphosphino)ferrocene ligand

Sobov P. A., Khasanov S., Kuzmin A. V. et al., Inorganic Chemistry Communications 2026 Vol. 185 Article 116055

New complex {(dppf)CpFe(CO)}(C60)⋅C6H4Cl2 (1) was obtained when stoichiometric mixture of C60 and CoII(dppf)Cl2 is reduced by two equivalents of (Cs+){CpFe(CO)2−} (dppf: 1,1`-bis(diphenylphosphino)ferrocene). CpFe(CO)2− anion reduces CoII(dppf)Cl2 and CpFe(CO)2 abstracts the dppf ligand from Co(dppf) forming (dppf)CpFeI(CO). Electron transfer from (dppf)CpFeI(CO) to C60 is observed. As a result, the state of {(dppf)CpFe(CO)}δ+(C60)δ−⋅C6H4Cl2 (δ = 0.54–0.86) is intermediate between ...

Added: September 14, 2026

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Krivenko K., Kuzmin A. V., Mikhailenko M. et al., Dyes and Pigments 2026 Vol. 246 Article 113342

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Added: September 14, 2026

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Sosunov E., Skabitsky I. V., Churakov A. et al., Crystal Growth & Design 2026 Vol. 26 No. 4 P. 1775–1782

Polynuclear 5d–3d assemblies represent a promising class of systems for exploring the interplay among electronic structure, magnetism, and self-assembly. Here, we report the synthesis and structural characterization of the first heterometallic wheel-shaped Pt–Mn cluster, [PtIV12PtII6Mn18(OAc)72(μ3-O)12]·43C6H6(1), which incorporates 36 metal centers. The giant ring is constructed from alternating PtIIMnII paddlewheel fragments and PtIV2Mn2 oxo-acetate units, bridged ...

Added: September 14, 2026

Effect of the size of the substituents in triptycene (TPC-X) on the magnetic and conducting properties of the layered 2D organic metals (MDABCO+)(C60•−)·(TPC-X), where X = H, Br, and I

Sobov P. A., Kuzmin A. V., Shevchun A. F. et al., Synthetic Metals 2025 Vol. 313 Article 117904

Modification of the neutral triptycene TPC-X molecule by increasing the size of the X substituent at the 9th position from X = H to Br and I affects the magnetic and conducting properties of the (MDABCO+)(C60•−)(TPC-X) salts (1–3, respectively), where MDABCO+ is N-methyldiazabicyclooctanium. These salts feature hexagonal fullerene layers composed of C60•−, which remain undimerized owing to ...

Added: September 14, 2026

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Flakina A. M., Nazarov D., Faraonov M. et al., Crystal Growth & Design 2025 Vol. 25 No. 15 P. 6332–6344

Oxidation of tetraselenatetracene (TSeT) and bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) by p-chloranil in the presence of metal hexafluoroacetylacetonates: MnII(hfac)2, CoII(hfac)2 and PrIII(hfac)3 followed by precipitation of crystals by n-hexane produces (TSeT1.5)+{MnII(hfac)3–} (1), (TSeT1.5)+{PrIII(hfac)4–} (3), (TSeT2)+{CoII(hfac)2Cl–} (4), and (ET3)+{MnII(hfac)3–} (5). Thioindigo dye is introduced into (TSeT1.5)+ (Thioindigo1.5){MnII(hfac)3–} (2) due to the appearance of specific C═O···(Se–Se bond) interactions accompanied by ...

Added: September 14, 2026

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Osipov N., Faraonov M., Yakushev I. A. et al., Dalton Transactions 2025 Vol. 54 No. 32 P. 12180–12188

The interaction of photochromic 8-methoxy-1′,3′,3′-trimethyl-6-nitro-spiro[chromene-2,2′-indole] (MNSP) spiropyran with copper(II) hexafluoroacetylacetonate yields a deep red–violet solution due to a coordination-induced transition of MNSP from its closed form to the colored, open merocyanine (MC) form. The crystal structure of {CuII(hfac)2·MNSP} (1) shows coordination of two oxygen atoms in MNSP to CuII, forming a distorted octahedral geometry with ...

Added: September 14, 2026

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Krivenko K., Shestakov A., Faraonov M. et al., European Journal of Inorganic Chemistry 2025 Vol. 28 No. 14 Article e202400760

Truxenone (Tr) with high C3h symmetry forms crystalline radical anion and dianion salts. The {Bu3MeP+}(Tr⋅−) (1) and {Cp*2Co+)}(Tr⋅−)⋅2 C6H4Cl2 (2) show intense low‐energy absorption up to 2000 nm. Calculations predict Jahn–Teller distortions for Tr⋅−, which are enhanced by the asymmetric approach of cations to Tr⋅−, leading to C=O bond length alternation and EPR signal asymmetry in 2. ...

Added: September 14, 2026

Complexes (TBA+){(TMI-NPS)2·LnIIII4}− (Ln = Dy, Tb) with two axial photochromic spiropyran ligands: photoswitching and zero-field SIM behaviour with a high magnetization blocking barrier for the Dy complex

Osipov N., Faraonov M., Kuzmin A. V. et al., Inorganic Chemistry Frontiers 2025 Vol. 12 No. 5 P. 2092–2102

Two photochromic spiropyran molecules (1,3,3-trimethylindolino-β-naphthopyrylospiran, TMI-NPS) react in the open form with LnIII iodides (Ln = Dy, Tb) to form in the presence of TBAI crystalline (TBA+){(TMI-NPS)2·LnIIII4}−·0.5C6H4Cl2 (1 and 2, respectively). Two TMI-NPS ligands are coordinated to lanthanides (Ln) by oxygen atoms at the axial position, and four iodide anions located at the equatorial position ...

Added: September 14, 2026

Macrocycle- and metal-centered reduction of cobalt trithiadodecaazahexaphyrin (Hhp). Metal-to-ligand charge transfer in {(Co(I)2Co(II)O){Hhp(•4-))}(2-)

Nazarov D., Kuzmin A. V., Islyaikin M. et al., New Journal of Chemistry 2025 Vol. 49 No. 5 P. 1631–1639

Reduction of free-base trithiadodecaazahexaphyrin, H3Hhp, by potassium graphite in the presence of cobalt(II) acetylacetonate and cryptand[2.2.2] produces {Cryptand[2.2.2](K+)}2{(CoI2CoIIO)2+(Hhp˙4−)}2−·2C6H4Cl2 (1). Co atoms in Co3O have square-planar geometry with short Co–N and Co–O bonds of 1.852–1.898(3) Å length. A nearly planar shape of Hhp macrocycles in 1 with equal Nmeso–C bonds indicates the aromatic character of Hhp˙4−. ...

Added: September 14, 2026

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Yin Z., Вестник Пермского университета. Серия: Политология 2025 Vol. 19 No. 2 P. 130–142

International society has noted a series of interlinked events that have implications for the construction of national representations within media discourse. This study probes how The Times represented China's image during global crises, with special focus on the period after Russia initiated its special military operation on February 24, 2022. Although this provides key context, ...

Added: January 20, 2026

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Viazmin A., Чапанова М. Р., Морозов М. С. et al., Нервно-мышечные болезни 2025 Т. 15 № 2 С. 28–36

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Князева И., Лысов И. И., Курочкин Е. et al., Astronomy and Computing 2025 Vol. 51 P. 100918–0

The advancement of observational technologies and software for processing and visualizing spectro-polarimetric microwave data obtained with the RATAN-600 radio telescope opens new opportunities for studying the physical characteristics of solar plasma at the levels of the chromosphere and corona. These levels remain some difficult to detect in the ultraviolet and X-ray ranges. The development of ...

Added: December 10, 2024