Physicochemical Properties Of Octane Isomers Research Articles

Computational insights into zinc silicate MOF structures: topological modeling, structural characterization and chemical predictions

Metal-organic frameworks (MOFs) play a pivotal role in modern material science, offering unique properties such as flexibility, substantial pore space, distinctive structure, and large surface area. Recently, zinc-based MOFs have attracted significant attention, particularly in the biomedical arena, owing to their versatile applications in drug delivery, biosensing, and cancer imaging. However, there remains a crucial need to explore and understand the structural properties of zinc silicate-based MOFs to fully exploit their potential in various applications. The objective of this study is to address this need by employing topological modeling techniques to characterize zinc silicate networks. Utilizing connection number concept of chemical graph theory and novel AL molecular descriptors, we aim to investigate the structural intricacies of these MOFs. More precisely, zinc silicate-based MOF networks are topologically modeled via novel AL topological indices, and derived mathematical closed form formulae for them. By comparing experimental and calculated values and constructing linear regression models, the predictive capabilities of the proposed descriptors are evaluated. Specifically, the performance of derived topological indices against the physico-chemical properties of octane isomers is assessed, which provide valuable insights into their predictive potential. The findings of this study demonstrated the potential of novel AL indices in predicting a wide range of important physico-chemical properties, further enhancing their practicality in materials science and beyond.

Some novel neighborhood degree sum‐based versus degree‐based topological indices in QSPR analysis of alkanes from n‐butane to nonanes

AbstractThe topological indices are reported to be very useful in various QSPR studies as these indices can be utilized as a tool to predict the physicochemical properties of a diverse set of chemical compounds. The objective of this communication is twofold. First, to introduce some neighborhood degree sum‐based topological indices and perform a comparative QSPR analysis of the indices with their corresponding degree‐based topological indices to analyze the usefulness of the new indices. Second, to investigate isomer discrimination ability of the newly defined indices on the basis of degeneracy test. Neighborhood degree sum‐based topological indices not only consider the degree of each atom in the molecule but also the degrees of its neighboring atoms. Moreover, these indices are expected to provide information about how connected and dense the neighborhoods of atoms are within the molecule. In this study, we observe that the proposed neighborhood degree sum‐based topological indices exhibit better correlation with some physicochemical properties of Octane Isomers and 66 alkanes as compared to their corresponding degree‐based topological indices. Also, the supremacy in terms of sensitivity of the neighbourhood degree sum‐based topological indices as compared to the classical degree‐based ones is established.

HDR Degree Bassed Indices and Mhr-Polynomial for the Treatment of COVID-19

In this research work, We introduce topological indices, namely as an HDR version of Modified Zagreb topological index (HDRM*), HDR version of Modified forgotten topological index (HDRF*), and HDR version of hyper Zagreb index (HDRHM*). Then the relatively study depends on the structure-property regression analysis to test and compute the chemical applicability of these indices to predict the physicochemical properties of octane isomers. Also, we show these HDR indices have well degeneracy properties compared to other degree-based topological indices. Also, We defined and computed the Mhr-polynomial of the newly indices and applied it on COVID-19 treatments. Also, we discussed some mathematical properties of HDR indices.

Novel Degree-Based Topological Descriptors of Carbon Nanotubes

The most significant tool of mathematical chemistry is the numerical descriptor called topological index. Topological indices are extensively used in modelling of chemical compounds to analyse the studies on quantitative structure activity/property/toxicity relationships and combinatorial library virtual screening. In this work, an attempt is made in defining three novel descriptors, namely, neighborhood geometric-harmonic, harmonic-geometric, and neighborhood harmonic-geometric indices. Also, the aforementioned three indices along with the geometric-harmonic index are tested for physicochemical properties of octane isomers using linear regression models and computed for some carbon nanotubes.

Physicochemical Properties of Octane Isomers in View of the Structural Numbers

The structural features of octane isomers were quantified with help of the Structural Numbers. A Mutually Optimized Contribution of the Structural Numbers (MOCSN) was used to calculate which parts of information regarding branching contribute the tested Structural Numbers. Besides the known Structural Numbers, two Asymmetry Numbers were developed in order to quantify the asymmetry of the octane isomers, one regarding the asymmetry along the main chain of the molecule and the other one regarding the asymmetry perpendicular to the main chain of the molecule. Their correlation to the values of 29 tested physicochemical properties of octanes was low, |R| < 0.6. After optimization of the Mutually Optimized Contribution of the Structural Numbers, the Information Content of the Mutually Optimized Contribution of the Structural Numbers ranged from 34.3% to 89.0% of the information contained in the physicochemical properties. The Structural Numbers enable the first step of the structural interpretation of physicochemical properties of octane isomers. In 17 out of 29 cases the most of information contained in the physicochemical properties is presented among the Structural Numbers by the Number of Branches, in 8 cases by the Peripheral Number, in 3 cases by an Asymmetry Number and in 1 case by the Distance Number.

Inverse sum indeg status index of graphs and its applications to octane isomers and benzenoid hydrocarbons

The status or transmission of a vertex u in a graph G is defined by σ(u)=∑v∈Vd(u,v), where V is the set of vertices of the graph G, and d(u,v) stands for the distance between u and v in G. In this paper we have defined inverse sum indeg status (ISIS) index of a graph G as ISIS(G)=∑uv∈Eσ(u)σ(v)σ(u)+σ(v), where E is the set of edges of G. The ISIS index is investigated as a predictor of various physicochemical properties of octane isomers and boiling points of benzenoid hydrocarbons. We further compute this novel index of some specific graphs and also obtain some bounds of the proposed index.

Onsome New Neighbourhood Degree Based Indices

Abstract In this paper, four novel topological indices named as neighbourhood version of forgotten topological index (FN ), modified neighbourhood version of Forgotten topological index (FN * ), neighbourhood version of second Zagreb index (M2 * ) and neighbourhood version of hyper Zagreb index (HMN ) are introduced. Here the relatively study depends on the structure-property regression analysis is made to test and compute the chemical applicability of these indices for the prediction of physicochemical properties of octane isomers. Also it is shown that these newly presented indices have well degeneracy property in comparison with other degree based topological indices. Some mathematical properties of these indices are also discussed here.

A new approach in topological descriptors usage. Iterated line graphs in the theoretical prediction of physico-chemical properties of saturated hydrocarbons

A new look on the problem of the molecular systems index description is presented. The capabilities of iterated line (edge) graphs in characterization of saturated hydrocarbons properties were investigated. It was demonstrated that single selected molecular (graph-theoretical (topological) or informational) descriptor calculated for the sequence of nested line graphs provides quite reliable progressive set of regression equations. Hence, the problem of descriptor set reduction is solved in the presented approach at list partially. Corresponding program complex (QUASAR) has been implemented with Python 3 program language. As the test example physico-chemical properties of octane isomers have been chosen. Among the properties under investigation there are boiling point, critical temperature, critical pressure, enthalpy of vaporization, enthalpy of formation, surface tension and viscosity. The corresponding rather simple linear regression equations which include one, two or three parameters correspondingly have been obtained. The predictive ability of the equations has been investigated using internal validation tests. The test by leave-one-out (LOO) validation and Y‑scrambling evaluate the obtained equations as adequate. For instance, for the regression model for boiling point the best equation characterizes by determination coefficients R2 = 0.943, with LOO procedure – Q2 = 0.918, while for the Y-scrambling test Q2y-scr&lt;0.3 basically. It is shown that all the abovementioned molecular properties in iterated line graph approach can be effectively described by commonly used topological indices. Namely almost every randomly selected topological index can give adequate equation. Effectiveness is demonstrated on the example of Zagreb group indices. Also essential effectiveness and rather universal applicability of the so-called “forgotten” index (ZM3) was demonstrated.

A New Tool for QSPR Researches: ev-degree Randić Index

Topological indices have important role in theoretical chemistry for QSPR researches. Among the all topological indices the Randić index has been used more considerably than any other topological indices in chemical and mathematical literature. Most of the topological indices as in the Randić index are based on the degrees of the vertices of a connected graph. Recently novel two degree concepts have been defined in graph theory; ev-degrees and ve-degrees. In this study ev-degree Randić index is defined by using ev-degree concept as parallel to their corresponding classical degree version. This new ev-degree Randić index is compared with the Randić index by modelling some physicochemical properties of octane isomers. It is showed that the ev-degree Randić index give better correlation than the Randić index to predict the entropy, acentric factor and standard enthalpy of vaporization of octanes. Also the exact values of the ev-degree Randić index for the well-known graph classes such as; paths, cycles, stars and complete graphs are given.

Predicting Some Physicochemical Properties of Octane Isomers: A Topological Approach Using &amp;lt;i&amp;gt;ev&amp;lt;/i&amp;gt;-Degree and &amp;lt;i&amp;gt;ve&amp;lt;/i&amp;gt;-Degree Zagreb Indices

Topological indices have important role in theoretical chemistry for QSPR researches. Among the all topological indices the Randic and the Zagreb indices have been used more considerably than any other topological indices in chemical and mathematical literature. Most of the topological indices as in the Randic and the Zagreb indices are based on the degrees of the vertices of a connected graph. Recently novel two degree concepts have been defined in graph theory; ev-degrees and ve-degrees. In this study ev-degree Zagreb index, ve-degree Zagreb indices and ve-degree Randic index are defined by using these new graph invariants as parallel to their corresponding classical degree versions. These new group ev-degree and ve-degree indices are compared with the other well-known and most used topological indices in literature such as; Wiener, Zagreb and Randic indices by modelling some physicochemical properties of octane isomers. The ev-degree Zagreb index, the ve-degree Zagreb and the ve-degree Randic indices give better correlation than Wiener, Zagreb and Randic indices to predict the some specific physicochemical properties of octanes. The relations between the second Zagreb index and ev-degree and ve-degree Zagreb indices and some mathematical properties of ev-degree and ve-degree Zagreb indices are investigated.

Correlation of domination parameters with physicochemical properties of octane isomers

Abstract In this paper, we find the values of three important domination parameters namely, connected domination number, total domination number and total edge domination number of molecular graph of octane isomers. Further, we show that these parameters are highly correlated with physical properties of octane isomers. Finally we carry out QSPR (Quantitative Structure-Property Relationship) analysis using several physicochemical properties of octane isomers.

Bond-extended stochastic and nonstochastic bilinear indices. I. QSPR/QSAR applications to the description of properties/activities of small-medium size organic compounds

Bond-extended stochastic and nonstochastic bilinear indices are introduced in this article as novel bond-level molecular descriptors (MDs). These novel totals (whole-molecule) MDs are based on bilinear maps (forms) similar to use defined in linear algebra. The proposed nonstochastic indices try to match molecular structure provided by the molecular topology by using the kth Edge(Bond)-Adjacency Matrix (Ek, designed here as a nonstochastic E matrix). The stochastic parameters are computed by using the kth stochastic edge-adjacency matrix, ESk, as matrix operators of bilinear transformations. This new edge (bond)-adjacency relationship can be obtained directly from Ek and can be considered like a new matrix-transformation strategic to obtain new relations for a molecular graph. In both set of MDs, chemical information is codified by using different pair combinations of atomic weightings (in this case four atomic-labels: atomic mass, polarizability, van der Waals volume, and electronegativity). In addition, a local-fragment (bond-type) formalism was also developed. The kth bond-type bilinear indices are calculated by summing the kth bond bilinear indices of all bonds of the same bond type in the molecules. The new set of MDs can be easily and quickly calculated in our in house software TOMOCOMD-CARDD (topological molecular computational design computer-aided-rational-drug design). The reported application and utilization of these MDs for predictive capability correlations of structure with physicochemical and pharmacological properties are reviewed. Three benchmark datasets have been used to evaluate the QSPR/QSAR behavior of the new bond-level TOMOCOMD-CARDD MDs. We developed the QSPR models to describe several physicochemical properties of octane isomers (First Case) and, to analyze of the boiling point of 28 alkyl-alcohols (Second Case) and to examine of the specific rate constant (log k), the partition coefficient (log P), as well as the antibacterial activity of 34 derivatives of 2-furylethylenes (Third Case). For these three rounds, the quantitative models found are significant from a statistical point of view and permit a clear interpretation of the studied properties in terms of the structural features of molecules. A leave-one-out cross-validation procedure revealed that the regression models had a good predictability. The comparison with other approaches reveals good performance of the method proposed. Therefore, it is clearly demonstrated that this suitability is higher than that shown by other 2D/3D well-known sets of MDs. The approach described here appears to be a very promising structural invariant, useful for QSPR/QSAR studies and shown to provide an excellent alternative or guides for discovery and optimization of new lead compounds, reducing the time and cost of the traditional procedure. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2011

Bond-based linear indices of the non-stochastic and stochastic edge-adjacency matrix. 1. Theory and modeling of ChemPhys properties of organic molecules

Novel bond-level molecular descriptors are proposed, based on linear maps similar to the ones defined in algebra theory. The kth edge-adjacency matrix (E(k)) denotes the matrix of bond linear indices (non-stochastic) with regard to canonical basis set. The kth stochastic edge-adjacency matrix, ES(k), is here proposed as a new molecular representation easily calculated from E(k). Then, the kth stochastic bond linear indices are calculated using ES(k) as operators of linear transformations. In both cases, the bond-type formalism is developed. The kth non-stochastic and stochastic total linear indices are calculated by adding the kth non-stochastic and stochastic bond linear indices, respectively, of all bonds in molecule. First, the new bond-based molecular descriptors (MDs) are tested for suitability, for the QSPRs, by analyzing regressions of novel indices for selected physicochemical properties of octane isomers (first round). General performance of the new descriptors in this QSPR studies is evaluated with regard to the well-known sets of 2D/3D MDs. From the analysis, we can conclude that the non-stochastic and stochastic bond-based linear indices have an overall good modeling capability proving their usefulness in QSPR studies. Later, the novel bond-level MDs are also used for the description and prediction of the boiling point of 28 alkyl-alcohols (second round), and to the modeling of the specific rate constant (log k), partition coefficient (log P), as well as the antibacterial activity of 34 derivatives of 2-furylethylenes (third round). The comparison with other approaches (edge- and vertices-based connectivity indices, total and local spectral moments, and quantum chemical descriptors as well as E-state/biomolecular encounter parameters) exposes a good behavior of our method in this QSPR studies. Finally, the approach described in this study appears to be a very promising structural invariant, useful not only for QSPR studies but also for similarity/diversity analysis and drug discovery protocols.

Bond-based global and local (bond, group and bond-type) quadratic indices and their applications to computer-aided molecular design. 1. QSPR studies of diverse sets of organic chemicals

The concept of atom-based quadratic indices is extended to a series of molecular descriptors (MDs) (both total and local) based on adjacency between edges. The kth edge-adjacency matrix (E ( k )) denotes the matrix of bond-based quadratic indices (non-stochastic) with respect to the canonical basis set. The kth "stochastic" edge-adjacency matrix, ES ( k ), is here proposed as a new molecular representation easily calculated from E ( k ). Then, the kth stochastic bond-based quadratic indices are calculated using ES ( k ) as operators of quadratic transformations. The study of six representative physicochemical properties of octane isomers was used to compare the ability of both series of MDs to produce significant quantitative structure-property relationship (QSPR) models. Moreover, the general performance of the new MDs in this QSPR study has been evaluated with respect to other 2D/3D well-known sets of indices and the obtained results shown a quite satisfactory behavior of the present method. The novel bond-level MDs were also used for the description and prediction of the boiling point of 28 alkyl-alcohols and to the modeling of the specific rate constant (log k) of 34 derivatives of 2-furylethylenes. These models were statistically significant and showed very good stability to data variation in leave-one-out (LOO) cross-validation experiment. The comparison with other approaches (edge- and vertices-based connectivity indices, total and local spectral moments, and quantum chemical descriptors as well as E-state/biomolecular encounter parameters) expose a good behavior of our method in this QSPR studies. The approach described in this report appears to be a very promising structural invariant, useful for QSPR/QSAR studies, similarity/diversity analysis, and computer-aided "rational" molecular (drug) design.