Quantum Molecular Dynamics Simulations Research Articles

Understanding Trigger Linkage Dynamics in Energetic Materials Using Mixed Picramide Nitrate Ester Explosives.

The ability to predict the handling sensitivity of new organic energetic materials has been a longstanding goal. We report the synthesis and characterization of six new nitropicramide energetic materials with mixed functional groups that mimic known explosives such as nitroglycerin, erythritol tetranitrate (ETN), and pentaerythritol tetranitrate (PETN). The molecules have been studied theoretically using quantum molecular dynamics (QMD) simulations and density functional theory (DFT) calculations to identify the weakest bond in the reactants - the trigger-linkages - which control handling sensitivity, and to quantify their specific enthalpies of explosion. In good accord with the drop weight impact sensitivity data, our calculations predict that the sensitivities of the molecules are very similar owing to the small variations of the energy output and rates of trigger linkage rupture. In addition, both the QMD and DFT calculations point to the nitropicramide N-NO2 bonds as the trigger linkages rather than the more typical O-NO2 bonds. We propose that the switch of the trigger linkage from the nitrate esters to the nitramine groups arises from the strongly electron withdrawing character of the adjacent trinitrobenzene groups.

Experimental and computational studies of cationic Gemini surfactants as corrosion inhibitors for carbon steel in 15% HCl.

In the process of oil and gas exploration, the corrosion of carbon steel pipes results in substantial economic losses, numerous casualties, environmental contamination, and resource waste. The advancement of highly efficient and stable corrosion inhibitors holds significant importance for protecting carbon steel from corrosion during oil and gas exploitation. In this study, two new cationic Gemini surfactants (2CncoesT, where n = 12, 14) were synthesized through a straightforward two-step reaction. Weight-loss tests demonstrated that the inhibition efficiency (ηw%) increases with the increase in temperature. Specifically, the maximum ηw% values for 2C12coesT and 2C14coesT were 98.0% and 98.3% respectively at 85 °C. The adsorption of these surfactants conformed to the Langmuir adsorption isotherm. Electrochemical measurements suggested that the two surfactants functioned as mixed-type inhibitors. The findings obtained from scanning electron microscopy (SEM) were consistent with the experimental outcomes that 2C12coesT and 2C14coesT are efficient corrosion inhibitors for the metal in an acidic environment. The quantum chemical investigation and molecular dynamics simulation (MD) further substantiated the experimental results and offered insights for a deeper comprehension of the inhibition mechanism of Gemini surfactants.

Synthesis and investigation into explosive sensitivity for a series of new picramide explosives

ABSTRACT Tailoring the molecular properties that govern energetic material sensitivity is essential to improve safety and help develop new energetic materials. Despite this need, understanding the complex chemistry and physics of explosive initiation and propagation is still a challenge. Recent work by our group has reinforced the view that explosive sensitivity under sub-shock conditions is connected to the strength of the weakest covalent bond in the molecule, that is, its “trigger linkage.” These correlations have been observed with different classes of energetic molecules and indicate that “trigger linkage” bond breaking, and heat of explosion are good indicators for the sensitivity trends. Herein we report the synthesis of aliphatic energetic materials with ethane, propane and neopentane backbones. Experimental and computational studies show that the trigger linkage model, based on results from quantum molecular dynamics simulations, correctly predicts trends observed in the impact sensitivity of the molecules. However, while the model predicts the impact sensitivities of the ethane series, the neopentane series has higher impact sensitivities than predicted, which is presumably influenced by crystal packing effects.

Mechanistic Insights Into NIR‐II AIEgens Boosted Multimodal Phototheranostics

AbstractExploiting single molecular species synchronously affording powerful second near‐infrared (NIR‐II) fluorescence, superior photoacoustic output, prominent reactive oxygen species generation, and satisfactory photothermal conversion is supremely appealing for phototheranostics, yet remains formidably challenging. In this work, electron donor/π‐bridge engineering is implemented on the basis of 6,7‐di(thiophen‐2‐yl)‐[1,2,5]thiadiazolo[3,4‐g]quinoxaline moiety. The optimal molecule, namely TPATO‐TTQ, is demonstrates to exhibit those notable features requested by exceptional phototheranostics, which are systematically elucidated through the depictions of excited‐state energy dissipation pathways and the influence of intramolecular motion on the photophysical properties, with assistances of quantum chemical calculation and molecular dynamic simulation. By utilizing TPATO‐TTQ nanoparticles, unprecedented performance on NIR‐II fluorescence‐photoacoustic‐photothermal trimodal imaging‐navigated type I photodynamic‐photothermal synergistic therapy to orthotopic breast cancer is authenticates by the precise tumor diagnosis and complete tumor ablation.

Assessment of electron-proton correlation functionals for vibrational spectra of shared-proton systems by constrained nuclear-electronic orbital density functional theory.

Proton transfer plays a crucial role in various chemical and biological processes. A major theoretical challenge in simulating proton transfer arises from the quantum nature of the proton. The constrained nuclear-electronic orbital (CNEO) framework was recently developed to efficiently and accurately account for nuclear quantum effects, particularly quantum nuclear delocalization effects, in quantum chemistry calculations and molecular dynamics simulations. In this paper, we systematically investigate challenging proton transfer modes in a series of shared-proton systems using CNEO density functional theory (CNEO-DFT), focusing on evaluating existing electron-proton correlation functionals. Our results show that CNEO-DFT accurately describes proton transfer vibrational modes and significantly outperforms conventional DFT. The inclusion of the epc17-2 electron-proton correlation functional in CNEO-DFT produces similar performance to that without electron-proton correlations, while the epc17-1 functional yields less accurate results, comparable with conventional DFT. These findings hold true for both asymmetrical and symmetrical shared-proton systems. Therefore, until a more accurate electron-proton correlation functional is developed, we currently recommend performing vibrational spectrum calculations using CNEO-DFT without electron-proton correlation functionals.

Piperine as a molecular bridge mediates a ternary coamorphous system of polyphenols with enhanced pharmaceutical properties.

The coamorphous formulations have attracted increasing interest due to enhanced solubility and bioavailability, together with synergistic pharmacological effects. In this study, a ternary coamorphous system of polyphenols was successfully prepared, wherein baicalein (Bai) and resveratrol (Res) were constructed into a single-phase coamorphous system mediated by piperine (Pip). FTIR and ss 13C NMR spectra together with quantum chemical calculation and molecular dynamics simulation suggested Pip as a molecular bridge connected Bai and Res molecules through π-π stacking and hydrogen bonding interactions. The configuration of coamorphous Bai-Pip-Res could minimize the system energy to facilitate its formation and enhance the stability. The ternary system showed 3.2, 4.3 and 5.3-fold increase in apparent solubilities of Bai, Res and Pip, and maintained the peak concentrations for at least 24 h. Compared to binary coamorphous systems, the ternary system exhibited superior physical stability under temperature and humidity conditions. Furthermore, coamorphous Bai-Pip-Res exhibited enhanced antibacterial activity, significant antioxidant ability and synergistic anti-inflammatory effect. This work offers a promising strategy to construct a ternary coamorphous delivery system with enhanced pharmaceutical properties by incorporating a molecular bridge, especially for components with the lack of intermolecular interactions.

From Molecule to Aggregate: Understanding AIE through Multiscale Experimental and Computational Techniques.

Aggregation-induced emission (AIE) phenomena have garnered significant attention due to their applications in various fields, ranging from materials science to biomedicine. Despite substantial progress, the underlying mechanism governing the AIE activity of molecules remains elusive. This study employs a comprehensive and multiscale approach, combining experimental and theoretical methodologies, to discern the determinants of AIE activity. Our investigations involve synthesizing four organic molecules with D-π-A-D architecture, accompanied by quantum mechanics (QM) and molecular dynamics (MD) simulations, providing a deep understanding of the interactions within aggregates. The symmetry-adapted perturbation theory (SAPT) calculations further corroborate our findings, revealing a clear correlation between AIE activity and the type of aggregate formed. Specifically, we demonstrate that AIE-active molecules exhibit a distinctive J-type aggregation characterized by enhanced emission from the S1 state. In contrast, AIE-inactive molecules adopt an H-type aggregate configuration, where the emission from the S1 state is constrained. In addition, we investigated the subcellular localization of the molecules, revealing localization within the lipid droplets. Our findings contribute to the fundamental understanding of AIE phenomena and provide insights into the design principles for AIE-active materials with potential applications in advanced sensing and imaging technologies.

Extraction of lignin from lignocellulosic biomass (bagasse) as a green corrosion inhibitor and its potential application of composite metal framework organics in the field of metal corrosion protection.

With increasing awareness of environmental protection, additional attention has been given to environmentally friendly metal anticorrosion research. In this paper, the green organic corrosion inhibitor sodium lignosulfonate (SLS) was extracted from bagasse waste, and a Ce-MOF@SLS smart anticorrosive film containing the inhibitor was prepared on the surface of an aluminum alloy by in situ electrodeposition. The material was characterized by SEM, EDS, FT-IR, XRD and XPS, and its corrosion resistance was tested with EIS and neutral salt spray tests. The electrochemical data showed that the Ce-MOF@SLS film reached a corrosion current density of 3.36 × 10-8 A/cm2, and no corrosion spots appeared after 105 days of salt spray experiments, indicating that the smart film provided long-lasting protection for aluminum alloys. The antiseptic mechanism of the Ce-MOF@SLS smart film was verified by quantum chemical calculations and molecular dynamics simulations. The research result not only provide a new method for the study of green intelligent anti-corrosion films for aluminum alloys, but also offer a novel approach to the treatment of domestic waste.

Potentially Bioactive Novel Isophthalic Acid Based Azo Molecules: Synthesis, Characterization, Quantum Chemical Calculations, ADMET Properties, Molecular Docking and Molecular Dynamics Simulations

We report here the synthesis of the two novel molecules 5-((5-hexyl-2,4-dihydroxyphenyl)diazenyl)isophthalic acid (3a) and 5-((5-ethyl-2,4-dihydroxyphenyl)diazenyl)isophthalic acid (3b). The structures of the 3a and 3b were confirmed by using 1H-NMR,13C-NMR, FT-IR, UV-vis, and HR-ESI-MS techniques. The optimized molecular geometry, vibrational frequency,1H- and 13C-NMR spectra calculations were performed using the DFT/B3LYP method with a 6-311G(d,p) basis set. The frontier molecular orbitals and electronic transition wavelengths were calculated at the level of TD-DFT/CAM-B3LYP/6-311G(d,p). The experimental data obtained for the synthesized molecules were in good agreement with the theoretical ones. The calculated HOMO-LUMO band gap revealed that 3a has a softer character and may be more reactive in chemical reactions. Important ADMET parameters of the compounds were also calculated, and the obtained physicochemical, pharmacokinetic, drug similarity, and toxicity data were at the desired level for a candidate bioactive compound. In order to examine the potential anticancer or antibacterial properties of newly synthesized azo molecules, molecular docking studies were performed using four different proteins. The best interaction was determined to be between 3a and VEGFR2 (PDB ID: 2XIR) with a binding energy of 9.0 kcal/mol. Moreover, a 50 ns MD simulation study for 3a-2XIR revealed that the complex maintained both its structural integrity and molecular interactions throughout the simulation.

Experimental and computational investigations on the synergistic inhibition mechanism of biphenyl quinoline quaternary ammonium and hexamethylenetetramine on the corrosion of J55 steel in 20 wt% HCl solution

The present study involves the synthesis of a novel biphenyl quinoline quaternary ammonium salt (BDQ) and its application in combination with hexamethylenetetramine (HMT) as a compounded corrosion inhibitor for acid stimulation, aiming to effectively prevent the corrosion of J55 steel in a 20 wt% HCl solution at 60 °C. The optimized BDQ/HMT mixture (with a mass ratio of 1:3) at 0.4 wt% produced a significant decrease in the corrosion rate of J55 steel to 3.7637 g/(m2·h), much lower than the requirement of 5.0 g/(m2·h) stipulated by the standard SY/T 5404–2019. The electrochemical analysis demonstrated that the BDQ/HMT mixture exhibited a mixed-type corrosion inhibitor with predominantly anodic characteristics, retarding both the anodic oxidation and cathodic reduction reactions of J55 steel in the HCl solution. The adsorption studies revealed that BDQ conformed to a Langmuir-type adsorption isotherm on J55 surfaces, driven by a combination of physisorption and chemical interactions, with chemical interactions playing a dominant role. Additionally, quantum chemical calculations and molecular dynamics simulation were also performed to elucidate the observed synergistic effect of BDQ and HMT.

Phase equilibrium and separation process of byproduct vinyl acrylate in the ethylene vapor phase method producing vinyl acetate

Vinyl acrylate is one of the byproducts in the ethylene vapor phase method for the production of vinyl acetate (VAc), which not only has a toxic effect on the catalyst but also affects the purity of the product. Currently, phase equilibrium data for vinyl acrylate with water are missing, making the destination of vinyl acrylate in the distillation process uncertain. This has led to a lack of effective removal means, which restricts the optimization of the ethylene vapor phase method. This paper uses a method combining quantum chemistry and molecular dynamics simulation (MD) to investigate the existential form of the water molecule. And based on the ab initio calculation of the first principle, the force field parameters of the special water molecular structure are calculated, and the TIP4P-P force field that can describe the special water structure is established. Using the Gibbs Ensemble Monte Carlo (GEMC) method, the reliability of the improved water molecule force field for modeling the phase equilibrium of a binary system is first verified. Further, vapor–liquid phase equilibrium data for the vinyl acrylate-water binary system at 110 kPa and 150 kPa are calculated and the corresponding x-y and T-x-y phase diagrams are plotted. After performing the thermodynamic consistency test, the phase equilibrium data are fitted to obtain the binary interaction parameters of vinyl acrylate with water. The fitted parameters are applied to the process simulation of the VAc refining process to optimize the conditions and obtain an effective separation scheme for vinyl acrylate. The concentration distribution of vinyl acrylate in the distillation column is investigated, thus clarifying the destination of vinyl acrylate in the distillation process and facilitating the optimization of the ethylene vapor phase method.

2-Halomethyleneoxetanes from 2-Methyleneoxetanes by Reaction with N-Halosuccinimides: Reactant Influences on Stereochemical Outcomes and Reaction Pathways.

The first general synthesis of 2-halomethyleneoxetanes, realized by the reaction of 2-methyleneoxetanes with N-halosuccinimides (NXS), is reported. The relative diastereoselectivities of the transformations were dependent on the halogen of NXS, while alternative reaction outcomes were influenced by substituents on the oxetane. Quantum mechanical calculations and molecular dynamics simulations exploring the basis of the observed diastereoselectivities are described. These highly strained heterocycles underwent standard cross-coupling reactions, demonstrating their utility as synthetic intermediates.

Understanding the adsorption mechanism of benzotriazole and its derivatives as effective corrosion inhibitors for cobalt in chemical mechanical polishing

Cobalt is emerging as the next-generation interconnect material to replace copper for integrated circuit sub-10 nm technology nodes. Due to its susceptibility to corrosion, identifying effective corrosion inhibitors for Co during the chemical mechanical polishing (CMP) is crucial. In this study, theoretical computations and experimental approaches were employed to investigate the corrosion inhibition effects of benzotriazole (BTA) and its derivatives—methylbenzotriazole (TTA) and 5-carboxybenzotriazole—on Co surfaces. Quantum chemical calculations and molecular dynamics simulations were used to reveal the corrosion mechanism at the atomic level. The computational findings were further validated by electrochemical experiments. Among the inhibitors studied, TTA exhibited the highest adsorption affinity for the Co surface, achieving an inhibition efficiency of up to 91.71 %. This is attributed to the formation of a dense protective layer on the Co surface through both physical adsorption via intermolecular forces and chemical adsorption via charge transfer. CMP experiments demonstrated that all three inhibitors significantly reduce the material removal rate (MRR) of Co. Notably, when the TTA concentration reaches 9 mM, the MRR is reduced to 132.64 nm/min, meeting the requirements for Co bulk polishing. These findings suggest that TTA is a highly promising Co corrosion inhibitor for slurry development in CMP processes.

Corrosion resistance and forming mechanism of phytic acid conversion film on copper foil prepared by electrolysis

In this paper, the phytic acid conversion film was prepared on copper foil by electrolysis for the first time. Its morphology and chemical composition were characterized by SEM, EDS, FTIR and XPS, and its corrosion resistance was evaluated using electrochemistry. Finally, the formation mechanism of the phytic acid conversion film on the surface of copper foil and its corrosion resistance mechanism were revealed by quantum chemical calculations and molecular dynamics simulations. The results show that the phytic acid conversion film on the surface of copper foil prepared by electrolysis is uniform and dense. The electrochemical impedance value of copper foil in 3.5 wt% NaCl solution increased from 3956 Ω·cm2 to 24828 Ω·cm2 after the preparation of phytic acid conversion film, and the protection efficiency reached 91 %. During the electrolysis process, copper atoms are oxidized into copper ions, which can be coordinated with phytate ions to form negatively charged complexes. Under the action of electric field force, these complexes move toward the anode copper foil, and finally adsorbed on the surface of the anode copper foil to form phytic acid conversion film. The molecular dynamics show that the adsorption configuration of the phytic acid molecule on Cu(111) surface changed from perpendicular to parallel, and the binding energy increased from 234.87 kJ/mol to 354.23 kJ/mol after applying an electric field, Therefore, the phytic acid conversion film prepared on the surface of copper foil by electrolysis has good corrosion resistance. This study provides a new method for the rapid preparation of phytic acid conversion film with excellent performance on metal surface.

Efficient separation of diisopropyl ether and ethanol using green solvents: Thermodynamic analysis and process simulation

Ionic liquids (ILs) and deep eutectic solvents (DESs) were first proposed as green solvents to study and compare their azeotropic separation effects in diisopropyl ether (DIPE) and ethanol (EA). The COSMO-RS model was used to screen ILs/DESs, and the feasibility of the extractants were comprehensively analyzed in terms of viscosity, thermal stability, and toxicity. Experiments were carried out on selected ILs and DESs, and the results showed that the separation effect of ILs was significantly stronger than that of DESs. Quantum chemical calculations and molecular dynamics simulations were combined to comprehensively analyze and compare the microscopic mechanisms of extraction separation. Based on the experimental data, a DIPE-EA extraction-coupled separation process was designed. For the first time, life cycle analysis was used to comprehensively evaluate the impact of this process on human health and the environment from multiple perspectives, providing theoretical guidance for the separation of alcohol ethers in the industry.

Investigating the synergistic effect of fish waste extract and KI on the corrosion inhibition of carbon steel in sulfuric acid solution

Biowaste has become a serious problem that can lead to serious environmental pollution and waste of resources if not handled properly. Waste materials are often high in proteins, which are easily extracted and hydrolyzed to provide an adequate quantity of amino acids. This indicates that biowastes can be used as green and efficient corrosion inhibitors (CIs). This work aimed to prepare fish waste extract (FWE) by acid hydrolysis with alkaline leaching using fish waste as the raw material. The results of the characterization analysis identified the presence of 17 amino acids, with Leucine, Phenylalanine, Methionine, and Alanine being the most abundant. FWE was then tested as a corrosion inhibitor (CI) for carbon steel in 0.5 mol/L H2SO4. Further, the effect of KI on the corrosion inhibition performance of FWE for carbon steel in 0.5 mol/L H2SO4 was systematically investigated by the weight loss method, electrochemical method, and surface analysis. The maximum corrosion inhibition efficiencies were 88.7 % and 63.9 % for the FWE and KI alone, and 97.10 % for the combination of FWE and KI. The synergistic coefficient study confirmed that the synergistic coefficients of the FWE and KI exceeded 1 across all concentration conditions, indicating a synergistic effect between them. The surface analysis results showed that the deterioration of carbon steel after adding the compounded CI was mild, and pitting and crevice corrosion was not observed. Theoretical calculations revealed the active reaction sites of four major amino acid molecules via quantum chemical and molecular dynamics simulations. The effect of different types of side chains and heteroatoms of amino acid molecules on their corrosion inhibition performance was elucidated to provide theoretical guidance for designing biowaste CIs.

Catalysis in Extreme Field Environments: A Case Study of Strongly Ionized SiO2 Nanoparticle Surfaces.

High electric fields can significantly alter catalytic environments and the resultant chemical processes. Such fields arise naturally in biological systems but can also be artificially induced through localized nanoscale excitations. Recently, strong field excitation of dielectric nanoparticles has emerged as an avenue for studying catalysis in highly ionized environments, producing extreme electric fields. While the dynamics of laser-driven surface ion emission has been extensively explored, understanding the molecular dynamics leading to fragmentation has remained elusive. Here, we employ a multiscale approach performing nonadiabatic quantum molecular dynamics (NAQMD) simulations on hydrogenated silica surfaces in both bare and wetted environments under field conditions mimicking those of an ionized nanoparticle. Our findings indicate that hole localization drives fragmentation dynamics, leading to surface silanol dissociation within 50 fs and charge transfer-induced water splitting in wetted environments within 150 fs. Further insight into such ultrafast mechanisms is critical for the advancement of catalysis on the surface of charged nanosystems.

Proposal of molecules in Möbius nanobelt topology

The study of belt-shaped nanostructures is one of the areas of interest in the current computational physics scenario. Over the years, many topological structures have been synthesized using a diverse array of techniques. Due to their price and more affordable synthesis, carbon structures are of great interest to the technological industry. Since nanostructures can present different physical characteristics, this paper presents those differences using Möbius carbon nanobelt topology obtained in the appendix of the Nature paper: Synthesis of a Möbius carbon nanobelt Segawa Y, Watanabe T, Yamanoue K, Kuwayama M, Watanabe K, Pirillo J, Hijikata Y and Itami K (2022 Nature Synthesis 1 535–541). This investigation using density functional theory (DFT) calculations shows that boron nitride (BN[7,7]), and silicon carbide (SiC[7,7]) nanobelts possess structural stability and the possibility of synthesis. Möbius SiC[7,7] nanobelts behave as semiconductors and absorb in the visible region, while Möbius BN[7,7] nanobelts demonstrate promise as ultraviolet (UV) sensors. Both structures exhibited significant thermal stability during a quantum molecular dynamic simulation. They are capable of withstanding temperatures at least 1500K. It is speculated that the proposed nanobelt molecules could stimulate further experimental investigations into their synthesis and technological applications.

An Integrated Experimental and Modeling Approach for Assessing High-Temperature Decomposition Kinetics of Explosives.

We present a new integrated experimental and modeling effort that assesses the intrinsic sensitivity of energetic materials based on their reaction rates. The High Explosive Initiation Time (HEIT) experiment has been developed to provide a rapid assessment of the high-temperature reaction kinetics for the chemical decomposition of explosive materials. This effort is supported theoretically by quantum molecular dynamics (QMD) simulations that depict how different explosives can have vastly different adiabatic induction times at the same temperature. In this work, the ranking of explosive initiation properties between the HEIT experiment and QMD simulations is identical for six different energetic materials, even though they contain a variety of functional groups. We have also determined that the Arrhenius kinetics obtained by QMD simulations for homogeneous explosions connect remarkably well with those obtained from much longer duration one-dimensional time-to-explosion (ODTX) measurements. Kinetic Monte Carlo simulations have been developed to model the coupled heat transport and chemistry of the HEIT experiment to explicitly connect the experimental results with the Arrhenius rates for homogeneous explosions. These results confirm that ignition in the HEIT experiment is heterogeneous, where reactions start at the needle wall and propagate inward at a rate controlled by the thermal diffusivity and energy release. Overall, this work provides the first cohesive experimental and first-principles modeling effort to assess reaction kinetics of explosive chemical decomposition in the subshock regime and will be useful in predictive models needed for safety assessments.

Rapeseed cake meal extract as an eco-friendly green sustainable inhibitor for the corrosion of cold rolled steel in trichloroacetic acid solution

The inhibitory properties of rapeseed cake meal extract (RCME) on the corrosion of cold rolled steel (CRS) in trichloroacetic acid (TCA) were systematically investigated using gravimetric, electrochemical, surface characterizations and theoretical calculations. The results demonstrate that RCME exhibits excellent inhibitory performance with a maximum inhibition efficiency of 92.7 % for 100 mg L−1 RCME at 20 °C. The adsorption of RCME obeys Langmuir isotherm at 20 and 30 °C, Temkin isotherm at 40 °C, and Freundlich isotherm at 50 °C. RCME acts as a cathodic inhibitor. The charge transfer resistance is increased with the addition of RCME, while the double-layer capacitance decreases. SEM, AFM, CLSM, XPS, XRD and TOF-SIMS analyses confirm that the active components in RCME adsorb onto the surface of CRS, forming a protective film that effectively inhibits the corrosion of CRS by TCA. Along with the increase in the concentration of RCME, the surface tension of the inhibited solution gradually decreases, while the electrical conductivity increases before stabilizing. HPLC-MS and FTIR analyses reveal rutin, linolenic acid, linoleic acid and adenine are the effective substances in RCME. Quantum chemical (QC) calculations and molecular dynamic (MD) simulations indicate that the active centers of the effective inhibitor molecules are predominantly located on benzene rings, O- or N-containing heterocyclic rings, and functional groups such as C=O and C=C. Additionally, their main chains adsorb onto the Fe (001) surface in an approximately flat manner, involving both chemical and physical adsorption processes.