Theoretical Chemistry - Science topic

Quantum computing has recently been emerging in theoretical chemistry as a realistic avenue meant to offer computational speedup to challenging eigenproblems in the context of strongly-correlated molecular systems or extended materials. Most studies so far have been devoted to the quantum treatment of electronic structure and only a few were direct...

A mechanokémia alapvetően azt a jelenséget használja ki, hogy a mechanikai erők, például az őrlés, ütközés, összeomlás vagy súrlódás hogyan befolyásolják az anyagok kémiai viselkedését. A mechanokémiai átalakítások hasznosítása nem új jelenség, és az sem új, hogy a mechanikai erők kémiai átalakításra használhatók. Azonban a meghatározott célú kémia...

This chapter is dedicated to presenting Density Functional Theory (DFT) and exploring its main applications in materials physics and theoretical chemistry. DFT, based on principles of quantum physics, offers a method for analyzing the properties of systems composed of multiple atoms. This approach forms the basis of several of the most efficient ab...

Molecular and lattice vibrations are able to couple to the spin of electrons and lead to their relaxation and decoherence. Ab initio simulations have played a fundamental role in shaping our understanding of this process but further progress is hindered by their high computational cost. Here we present an accelerated computational framework based o...

The field of magnetobiology is garnering increasing interest due to its significant contributions across various disciplines, including biotechnology, medicine, and agriculture. Despite experimental evidence indicating the impact of magnetic fields on living organisms, the precise molecular-level effects of these fields remain unclear. Experimental...

This article provides a comprehensive review of quantum chemical computational studies on the thermal and photochemical reactions of organosilicon compounds, based on fundamental concepts such as initial complex formation, HOMO-LUMO interactions, and subjacent orbital interactions. Despite silicon’s position in group 14 of the periodic table, along...

Heterogeneous oxidation of SO2 by NO2 on aerosols has recently been found to be one of the major formation pathways of sulfate in polluted troposphere, but the chemical mechanisms and kinetics remain uncertain. By combining lab experiments, theoretical chemistry calculations and field measurements, here we show that the SO2 oxidation by NO2 is crit...

Uncertainty quantification (UQ) to detect samples with large expected errors (outliers) is applied to reactive molecular potential energy surfaces (PESs). Three methods–Ensembles, deep evidential regression (DER), and Gaussian Mixture Models (GMM)—were applied to the H-transfer reaction between syn -Criegee and vinyl hydroxyperoxide. The results in...

The multilayer-multiconfiguration time-dependent Hartree (ML-MCTDH) method has garnered significant attention in the realm of theoretical chemistry owing to its powerful ability to perform numerically exact descriptions of multi-dimensional quantum dynamics and exhibit the remarkable performance in simulating the nonadiabatic dynamics of complex sy...

Density-functional theory with extended Hubbard functionals (DFT + U + V ) provides a robust framework to accurately describe complex materials containing transition-metal or rare-earth elements. It does so by mitigating self-interaction errors inherent to semi-local functionals which are particularly pronounced in systems with partially-filled d a...

Several candidates were suggested to evaluate the possible actions of five novel fluoxetine prodrug derivatives. The prodrug approach aims to enhance biopharmaceutical drug delivery, pharmacokinetics, and bioavailability. This approach provides additional advantages, such as therapeutic targeting through enzyme-triggered drug release. The extent of...

The research is currently centered on investigating how FDA approved medications can be used as blockers for HDAC2. The study was started by gathering more than 4,000 drugs that have been approved by the FDA from the DrugBank database. These compounds were virtually screened to find inhibitors for HDAC2. After that the molecules were analyzed for m...

Magnesium-containing molecules, including MgC2H, MgC4H, and MgC6H, have been detected in the interstellar medium, largely facilitated by their high dipole moments. However, despite great efforts, MgC2m + 1H species remain elusive. Given the challenges in obtaining experimental data for these molecules, theoretical studies play a crucial role in gui...

The Corey–Chaykovsky cyclopropanation of readily available masked o‐benzoquinones (MOBs) has been investigated to generate functionalized bicyclo[4.1.0]heptane derivatives with regioselectivity. The resulting bicyclic products were subjected to a sequence of hydrolysis, BF₃ ⋅ Et₂O‐mediated ring‐opening, and then again hydrolysis to access various t...

The fatty liver disease known as steatohepatitis is characterized by liver inflammation. De novo lipogenesis and mevalonate pathway have been identified as contributing to the development of fatty liver. Rheum genus has pharmacological properties such as antioxidant, anti-inflammatory, hepatoprotective, and hypolipidemic. Consequently, the current...

Physical and photophysical properties of starch-based biopolymer films containing 5-(4-nitrophenyl)-1,3,4-thiadiazol-2-amine (NTA) powder as a nanofiller were examined using atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FTIR), stationary UV-Vis and fluorescence spectroscopy as well as resonance light scattering (RLS) and t...

Irreducible Cartesian tensors (ICTs) play a crucial role in the design of equivariant graph neural networks, as well as in theoretical chemistry and chemical physics. Meanwhile, the design space of available linear operations on tensors that preserve symmetry presents a significant challenge. The ICT decomposition and a basis of this equivariant sp...

Ebola and Marburg viruses, biosafety level 4 pathogens, cause severe hemorrhaging and organ failure with high mortality. Although some FDA-approved vaccines or therapeutics like Ervebo for Zaire Ebola virus exist, still there is a lack of effective therapeutics that cover all filoviruses, including both Ebola and Marburg viruses. Therefore, some an...

We developed a general framework for hybrid quantum-classical computing of molecular and periodic embedding approaches based on an orbital space separation of the fragment and environment degrees of freedom. We demonstrate its potential by presenting a specific implementation of periodic range-separated DFT coupled to a quantum circuit ansatz, wher...

We studied the boron-based composite cluster B8Al3+ doped with Al atoms. The global minimum structure of the B8Al3+ cluster is a three-layer structure, consisting of three parts: an Al2 unit, a B8 ring and an isolated Al atom. Charge calculations analysis shows that the cluster can be expressed as [Al]+[B8]2−[Al2]2+, has 6π/6σ double aromaticity an...

A safe and efficient lithium‐ion battery requires including an additive in the electrolyte. Among the additives used, vinylene carbonate (VC) is particularly interesting, because it leads to the formation of a stable and protective solid electrolyte interphase (SEI) on the negative electrode. However, the reduction behavior of VC, resulting in poly...

The main aim of this work was to assess the potential formation of ternary chelate complexes, involving deferasirox (DFX), ciprofloxacin (CP), and ferric iron. The coadministration of CP along with DFX might modulate its efficacy, so it is important that it be investigated. A ternary complex involving DFX, CP, and iron (DFX-CP-Fe) was prepared and...

In this work, we present the preparation of a hybrid material constituted by a Metal-Organic Framework (type MIL-101(Fe)) and a natural clay ceramic monolith (NCCM), the materials were successfully assembled through an in-situ hydrothermal method. The composites were characterized by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA)...

Modelagem molecular pode ser definida como a implementação de formalismos da química teórica em algoritmos de cálculos computacionais para estudar a estrutura e o comportamento dos materiais em escala atômica. Tais ferramentas incluem desde o tratamento dos átomos como a menor unidade individual (mecânica molecular) até a consideração explícita de...

In this paper we derive several (and in many cases sharp) estimates for the L2-trace norm of harmonic functions along circular arcs. More precisely, we obtain geometry-dependent estimates on the norm, spectral radius, and numerical range of the Dirchlet-to-Dirichlet (DtD) operator sending data on the boundary of the disk to the restriction of its h...

The combination of theoretical chemistry and mathematics represents a significant advancement in science since it has yielded insights into the enigmas surrounding atoms and molecules. The advancement of technology has greatly benefited drug development, leading to significant advancements in both medicine and materials research. This summary discu...

The MUSCS (McMaster Undergraduate Society for the Chemical Sciences) Summer Research Symposium is a one-day, student run, undergraduate research symposium. In McMaster University’s Department of Chemistry & Chemical Biology, many undergraduate students participate in research during the Spring and Summer terms. Undergraduate students hold positions...

The equivalent conductivities (Λ) of B6 vitamin (pyridoxine) in HշՕ and MeOH were measured at different temperatures between 293 to 313 K, as well as in mixtures of H₂O and MeOH at percentages of 10, 20, 30, 40, and, 50% MeOH at 310 K. All the practical results were mathematically processed using the Lee Wheaton equation, which is applied to the de...

This article discusses the rapidly expanding artificial intelligence (AI) tools combined with theoretical and organic chemistry software to point out the fact that near future is being reborn with a new education system and research system in drug discovery. The integration of AI into the field of chemistry and pharmacy has expanded rapidly in rece...

Before a new molecular structure is registered to a chemical structure database, a duplicate check is essential to ensure the integrity of the database. The Simplified Molecular Input Line Entry Specification (SMILES) and the IUPAC International Chemical Identifier (InChI) stand out as widely used molecular identifiers for these checks. Notable lim...

The dissociation of methane is not only an important reaction step in catalytic processes, but also of fundamental interest. Dynamical effects during the dissociative chemisorption of methane on metal surfaces cause significant differences in computed reaction rates, compared to what is predicted by typical transition state theory (TST) models. It...

Although there has been great progress in the development of anticancer medications, significant hurdles remain, including drug resistance, poor effectiveness, and excessive toxicity, which have all profoundly impacted the daily lives of cancer patients. Therefore, finding highly selective, effective, and non-toxic anticancer drugs constitutes a pa...

Herein, we study the London dispersion forces between organic structure directing agents (OSDAs)—here tetraalkyl-ammonium or -phosphonium molecules—and silica zeolite frameworks (FWs). We demonstrate that the interaction energy for these dispersion forces is correlated to the number of H atoms in OSDAs, irrespective of the structures of OSDAs or FW...

Benzodiazepines are frequently encountered in crime scenes, often mixed with adulterants and diluents, complicating their analysis. This study investigates the interactions between two benzodiazepines, lorazepam (LOR) and alprazolam (ALP), with common adulterants/diluents (paracetamol, caffeine, glucose, and lactose) using infrared (IR) spectroscop...

Background The variational method, a quantum mechanical approach, estimates effective charge distributions and ground-state energy by minimizing the Hamiltonian's expectation value using trial wave functions with adjustable parameters. This method provides valuable insights into system behavior and is widely used in theoretical chemistry and physic...

Nickel transition metal complexes have shown various biological activities that depend on the ligands and geometry. In this contribution, six Ni(II) nitrate complexes with pyridoxal-semi, thiosemi, and isothiosemicarbazone ligands were examined using theoretical chemistry methods. The structures of three previously reported complexes ([Ni(PLSC)(H2O...

The pKa value of a molecule is of interest to chemists across a broad spectrum of fields including pharmacology, environmental chemistry and theoretical chemistry. Determination of pKa values can be...

When we want to calculate the properties of a molecule, such as vibrational frequencies and polarizability, we need to start by specifying the positions of the atoms, which is known as the geometry. The properties of the molecule depend on this geometry. Because molecules are not static, we should use the geometry that results in the lowest en...

The study of Laplacian and signless Laplacian spectra extends across various fields, including theoretical chemistry, computer science, electrical networks, and complex networks, providing critical insights into the structures of real-world networks and enabling the prediction of their structural properties. A key aspect of this study is the spectr...

Oxidation of thirty-six monosubstituted benzaldehydes by 2-picoliniumchlorochromate (PICC) in dimethylsulphoxide (DMSO), leads to the formation of corresponding benzoic acids. A Michaelis-Menten type kinetics was observed with respect to the reactants. The reaction is promoted by hydrogen ions; the hydrogen-ion dependence has the form kobs= a + b [...

Chemical, Material Sciences & Nano technology book series aims to bring together leading academic scientists, researchers and research scholars to exchange and share their experiences and research results on all aspects of Chemical, Material Sciences & Nano technology. The field of advanced and applied Chemical, Material Sciences & Nano technology...

Point Group (PG) symmetries play a fundamental role in many aspects of theoretical chemistry and computational materials science. With the objective to automatize the search of PG symmetry operations of generic atomic clusters, we present a new algorithm called Symmetry Operation FInder (SOFI). SOFI addresses the problem of identifying PG symmetry...

Point Group (PG) symmetries play a fundamental role in many aspects of theoretical chemistry and computational materials science. With the objective to automatize the search of PG symmetry operations of generic atomic clusters, we present a new algorithm called Symmetry Operation FInder (SOFI). SOFI addresses the problem of identifying PG symmetry...

Objective: A de novo antineoplastic drug was planned to suppress and modulate the Head, Neck, and Oral Cancer. Methods: Using the computational software tools including molecular docking, molecular dynamics (MD), and post-molecular dynamics bond contact analyses, it has been shown that the new drug called ''Innovative Head, Neck, and Oral Cancer...

Several of the bacteria responsible for pneumonia had become resistant to available antibiotics. According to the WHO, the resistance of Klebsiella pneumonia to Ciprofloxacin is 79.4%, making infections such as pneumonia and several diseases more difficult, if not impossible to treat. The prevalence of antimicrobial resistance is a global problem a...

The fascination with superheavy elements (SHE) spans the nuclear physics, astrophysics, and theoretical chemistry communities. Extreme relativistic effects govern these elements' chemistry and challenge the traditional notion of the periodic law. The experimental quest for SHE critically depends on theoretical predictions of these elements' propert...

Simulations of photochemical reaction dynamics have been a challenge to the theoretical chemistry community for some time. In an effort to determine the predictive character of current approaches, we predict the results of an upcoming ultrafast diffraction experiment on the photodynamics of cyclobutanone after excitation to the lowest lying Rydberg...

The evaluation of oxidation and reduction potentials is a pivotal task in various chemical fields. However, their accurate prediction by theoretical computations, which is a complementary task and sometimes the only alternative to experimental measurement, may be often resource‐intensive and time‐consuming. This paper addresses this challenge throu...

Distance-based topological indices are numerical parameters that are derived from the distances between atoms in a molecular structure, and they provide a quantitative measure of the topology and geometry of a molecule. The distance-based topological indices uses to predict various properties of molecules, including their boiling points, melting po...

Fused bicycloalkanes have several structures with different orientations of the substituents, such as out,out‐, in,in, and in,out‐structures. Some bicycloalkanes can undergo homeomorphic conversions between certain structures, for instance an out,out‐structure can convert to an in,in‐structure. This homeomorphism can be achieved by one chain passin...

A complex of the natural flavonoid kaempferol with zinc (Kam-Zn) was synthesized, and its physicochemical properties were investigated using spectroscopic methods such as Fourier transform infrared spectroscopy (FT-IR), ultraviolet–visible (UV-Vis) spectroscopy and theoretical chemistry. Biological studies were conducted to evaluate the cytotoxic a...

This work contributes to theoretical chemistry’s knowledge of benzimidazole-hydrazide-hydrazone. Indeed, hydrazides-hydrazones-benzimidazoles have shown anticancer, antibacterial, antiparasitic activities, and many other activities. A benzimidazole-hydrazide-hydrazone compound can exhibit four conformers: E/Z synperiplanar (Esp, Zsp) and E/Z antipe...

Modelling size-realistic nanomaterials to analyse some of their properties, such as toxicity, solubility, or electronic structure, is a current challenge in computational and theoretical chemistry. The representation of the all-atom three-dimensional structure of a nanocompound would be ideal, as it could account explicitly for structural effects....

The fascination with superheavy elements (SHE) spans the nuclear physics, astrophysics, and theoretical chemistry communities. Extreme relativistic effects govern these elements' chemistry and challenge the traditional notion of the periodic law. The experimental quest for SHE critically depends on theoretical predictions of these elements' propert...

Many existing studies show that there exists a strong relationship between structures and characteristics of molecules. Topological indices are often used in modeling the properties of chemical compounds and biological activities in theoretical chemistry. Topological indices are numerical values associated with structures of molecules in such a way...

Triarylmethanes are low cost synthetic dyes with intense absorption in the visible spectrum. This makes it attractive to explore their suitability as sensitizer for dye sensitized solar cell. Using malachite green as a lead dye, we made intuitive structural modifications: incorporation of coumarin-3-carboxylic acid as acceptor/anchor, and substitut...

The critical role of global electron density transfer (GEDT) in increasing the reaction rate of polar organic reactions has been studied within the framework of Molecular Electron Density Theory (MEDT). To this end, the series of the polar Diels–Alder (P-DA) reactions of cyclopentadiene with cyanoethylene derivatives, for which experimental kinetic...

Furfural is an industrially relevant biobased chemical platform. Unlike classical furan, or C‐alkylated furans, which have been previously described in the current literature, the =C5H bond of furfural is unreactive. As a result, on a large scale, C=C and C=O bond hydrogenation/hydrogenolysis is mainly performed, with furfuryl alcohol and methyl te...

Exploring the applications of Laplacian and signless Laplacian spectra extends beyond theoretical chemistry, computer science, electrical networks, and complex networks. These spectra, with their relevance, provide valuable insights into the structures of real-world networks and facilitate the prediction of their structural properties. The focal po...

An important dietary source of physiologically active compounds, coffee also contains phenolic acids, diterpenes, and caffeine. According to a certain study, some coffee secondary metabolites may advantageously modify a number of anti-cancer defense systems. This research looked at a few coffee chemical structures in terms of edge locating numbers...

Forthcoming symposium will concentrate mainly on catalysis for clean hydrogen production and decarbonizing energy, electrocatalysis for green energy, catalysis to green lifestyle, green photocatalysis, catalyst recycling and reuse, and challenges and solutions to industrial catalysis. Topics from related fields, such as theoretical chemistry, react...

CURRICULUM VITAE (C.V.)Select authored documents by Prof. Dr. Loutfy H. Madkour https://www.academia.edu/113182586/C_V_Loutfy_Hamed_Madkour Prof. Loutfy H. Madkour is a professor of physical chemistry and nanoscience at Tanta University (Egypt) and Al Baha University (Saudi Arabia). He received his BSc, MSc, and PhD in Physical Chemistry from the...

Prof. Loutfy H. Madkour is a professor of physical chemistry and nanoscience at Tanta University (Egypt) and Al Baha University (Saudi Arabia). He received his BSc, MSc, and PhD in Physical Chemistry from the Cairo, Minia, and Tanta Universities in Egypt, respectively.He has conducted a series of studies in various areas of the field of physical ch...

The catalytic activity of Vanadium, Scandium, Titanium and Ferrum (Sc, V, Ti and Fe) doped Carbon, Silicon, Germanium, Aluminum Nitride and Boron Phosphide (C60, Si46, Al30N30, Ge72 and B41P41) nanocages for reduction reaction of carbon dioxide are investigated. The ∆Ebinding of V2-C58, Sc2-Si44, V2-Al29N29, Ti2-Ge70 and Fe2-B40P40 nanocages are -5...

Quantum computing is an exciting area, which has grown at an astonishing rate in the last decade. It is specially promising for the computational and theoretical chemistry area. One algorithm has received a lot of attention lately, the variational quantum eigensolver (VQE). Is is used to solve electronic structure problems and it is suitable to the...

In this paper, we address the challenge of obtaining a comprehensive and symmetric representation of point particle groups, such as atoms in a molecule, which is crucial in physics and theoretical chemistry. The problem has become even more important with the widespread adoption of machine-learning techniques in science, as it underpins the capacit...

El estudio teórico computacional aborda la descripción de los complejos enzima-ligando obtenidos mediante el método de difracción de rayos X. El propósito de este estudio es analizar a la enzima bromelina aplicando aspectos de la química teórica y computacional, con un enfoque transdisciplinar, a través de cribados virtuales consecutivos en la plat...

The diversity of scientific methods has received widespread attention and recognition in recent years. Brandon’s Matrix illustrated four categories of scientific methods, which was applied to establish the analytical framework of this study. This paper adopted content analysis to investigate how the diversity of scientific methods is represented in...

Inelastic X-ray scattering spectroscopy (IXS) has been used in many fields of solid state physics and theoretical chemistry as an accurate and quantitative probe of elementary excitations. We show that...

Nanosheets with boron elements have excellent characteristics which makes the boron polymorphs unique and super hard. A boron α-icosahedral nanosheet in crystalline form has superconductivity and thermal electronic properties. In theoretical chemistry and QSPR/QSAR study, a topological descriptor is an important analytical tool. It helps to anal...

Single-molecule magnets are among the most promising platforms for achieving molecular-scale data storage and processing. Their magnetisation dynamics are determined by the interplay between electronic and vibrational degrees of freedom, which can couple coherently, leading to complex vibronic dynamics. Building on an ab initio description of the e...

Nanostar dendrimers are tree-like nanostructures with a well-defined, symmetrical architecture. They are built in a step-by-step, controlled synthesis process, with each layer or generation building on the previous one. Dendrimers are made up of a central core, a series of repeating units or branches, and a surface group shell. A weighted graph is...

Understanding the thermal decomposition behavior of TATB (1,3,5-triamino-2,4,6-trinitrobenzene) is a major focus in energetic materials research because of safety issues. Previous research and modelling efforts have suggested benzo-monofurazan condensation producing H 2 O is the initiating decomposition step. However, early evolving CO 2 (m/z 44) a...

In nuclear medicine, radionuclides can be attached to a carrier via a chelating molecule for introduction as a radiopharmaceutical, enabling the whole to reach the target cells. The complexes formed between chelating molecules and radionuclides must be highly stable to prevent the metal from being released into the body. When in contact with radioi...

Here, the catalytic activity of Mn-C48, Mn-Si48, Cu-C38, Cu-B19N19, Ni-C44, Ni-B22P22, Fe-C80, Fe-Al40P40 nanocages for N2-RR are investigated. The possible mechanisms of N2-RR on metal adsorbed nanocages are examined. The limiting step in distal, enzymatic and alternating pathways for N2-RR on metal adsorbed nanocages is metal-*NN → Metal-*NNH. Th...

Here, the potential of Zn doped carbon nanostructures and Zn doped silicon nanostructures to catalyze the OER and ORR processes is investigated by theoretical methods. The O*, H*, *OH, *OOH, O2 and H2O species are adsorbed on Zn-CNT(5, 0) and Zn-SiNT(5, 0). The potential-determining steps on catalysts are *OH removal and *OOH formation. The overpot...

It is well known that metal corrosion causes serious economy losses worldwide. One of the most effective ways to prevent corrosion is the continuous development of high-efficient and environment-friendly corrosion inhibitors. Among the widely used organic and inorganic corrosion inhibitors, plant extracts are top candidates due to their nontoxic na...

The evaluation of oxidation and reduction potentials is a pivotal task in various chemical fields. However, their accurate prediction by theoretical computations, which is a complementary task and sometimes the only alternative to experimental measurement, may be often resource-intensive and time-consuming. This paper addresses this challenge throu...

The solvent effects on the linear and second-order nonlinear optical properties of an aminonaphtylethenylpyridinium (ANEP) dye are investigated by combining experimental and theoretical chemistry methods. On the one hand, deep near infrared (NIR) hyper-Rayleigh scattering (HRS) measurements (1840–1950 nm) are performed on solutions of di-8-ANEPPS i...

This research focuses on the photochemical activities of Ricinodendron heudeulotii (AKPI) oil, a fatty acid. In general, the latter, a bioactive organic compound, is employed to fight the atherosclerosis, the hypertension, the obesity, or the cancer. Ricinodendron heudeulotii oil contains mainly α-eleostearic acid C18:3c,t,t. This is characterized...

In this study, a series of electron donor (-NH 2 ,-NMe 2 and-t Bu) and electron-withdrawing substituents (-F,-CN and-NO 2) were used to tune the nucleophilicity or electrophilicity of a series of square planar Ni 2+ , Pd 2+ and Pt 2+ malonate coordination complexes towards a pentafluoroiodoben-zene and a pyridine molecule. In addition, Bader's theo...

Poster presented in XXII Simpósio Brasileiro de Química Teórica - SBQT