Adsorption mechanism of neutral and protonated HQAP on Fe(110): a DFT, Monte Carlo and molecular dynamics study

IF 2.9 4区化学 Q4 BIOCHEMISTRY & MOLECULAR BIOLOGY

Journal of Molecular Modeling Pub Date : 2026-10-17 DOI:10.1007/s00894-026-07008-8

Brahim Amjoud, Soufiane Zerraf, Amrane Younesse, Younes Abboud

{"title":"Adsorption mechanism of neutral and protonated HQAP on Fe(110): a DFT, Monte Carlo and molecular dynamics study","authors":"Brahim Amjoud, Soufiane Zerraf, Amrane Younesse, Younes Abboud","doi":"10.1007/s00894-026-07008-8","DOIUrl":null,"url":null,"abstract":"<div><h3>Context</h3><p>The adsorption of 8-quinolinol-5-azoantipyrine (HQAP) on Fe(110) was investigated to clarify the interfacial behavior of representative neutral and carbonyl-protonated models. Although pKa-based speciation indicated that multiply protonated species dominate under strongly acidic conditions, neutral HQAP-AE and monoprotonated HQAP-OcarbonylH+ were retained for a restricted molecular comparison. Monte Carlo searches identified low-energy starting configurations, and molecular dynamics and radial distribution function analyses showed persistent Fe–N/O proximity over 2000 ps. The nearest-Fe contact of the azo nitrogen on the antipyrine side was shorter in the protonated model over both analysis windows. Other differences depended on the site and time window. The results support persistent multipoint interfacial contacts without demonstrating covalent bonding, chemisorption or a general ranking of adsorption strength.</p><h3>Methods</h3><p>Density functional theory (DFT) calculations were performed using the DMol<sup>3</sup> module in Materials Studio 2023 with the GGA-PBE functional and DNP basis set; aqueous calculations used COSMO. Monte Carlo (MC) searches using Adsorption Locator supplied the initial adsorbed configurations for molecular dynamics (MD) using Forcite and COMPASS III. The molecular charge of HQAP-OcarbonylH+ was retained and balanced by an additional chloride counterion. Production comprised two consecutive 1000 ps NVT segments at 303 K using the Andersen thermostat and a 0.25 fs time step. Radial distribution functions (RDFs) and nearest-Fe distances were compared over 1000–2000 ps and the common final 1500–2000 ps window.</p></div>","PeriodicalId":651,"journal":{"name":"Journal of Molecular Modeling","volume":"32 11","pages":""},"PeriodicalIF":2.9000,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Molecular Modeling","FirstCategoryId":"92","ListUrlMain":"https://link.springer.com/article/10.1007/s00894-026-07008-8","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}

引用次数: 0

Abstract

Context

The adsorption of 8-quinolinol-5-azoantipyrine (HQAP) on Fe(110) was investigated to clarify the interfacial behavior of representative neutral and carbonyl-protonated models. Although pKa-based speciation indicated that multiply protonated species dominate under strongly acidic conditions, neutral HQAP-AE and monoprotonated HQAP-OcarbonylH+ were retained for a restricted molecular comparison. Monte Carlo searches identified low-energy starting configurations, and molecular dynamics and radial distribution function analyses showed persistent Fe–N/O proximity over 2000 ps. The nearest-Fe contact of the azo nitrogen on the antipyrine side was shorter in the protonated model over both analysis windows. Other differences depended on the site and time window. The results support persistent multipoint interfacial contacts without demonstrating covalent bonding, chemisorption or a general ranking of adsorption strength.

Methods

Density functional theory (DFT) calculations were performed using the DMol³ module in Materials Studio 2023 with the GGA-PBE functional and DNP basis set; aqueous calculations used COSMO. Monte Carlo (MC) searches using Adsorption Locator supplied the initial adsorbed configurations for molecular dynamics (MD) using Forcite and COMPASS III. The molecular charge of HQAP-OcarbonylH+ was retained and balanced by an additional chloride counterion. Production comprised two consecutive 1000 ps NVT segments at 303 K using the Andersen thermostat and a 0.25 fs time step. Radial distribution functions (RDFs) and nearest-Fe distances were compared over 1000–2000 ps and the common final 1500–2000 ps window.

查看原文本刊更多论文

中性和质子化HQAP在Fe（110）上的吸附机理：DFT、Monte Carlo和分子动力学研究

研究了8-喹啉-5-偶氮安替吡林（HQAP）在Fe（110）上的吸附行为，以阐明具有代表性的中性和羰基质子化模型的界面行为。尽管基于pka的物种形成表明，在强酸性条件下，多质子化的物种占主导地位，但为了进行有限的分子比较，保留了中性的HQAP-AE和单质子化的hqap - carbonylh +。蒙特卡罗搜索确定了低能量的启动构型，分子动力学和径向分布函数分析显示，在2000 ps以上的时间内，偶氮氮在安替吡啶侧的最近铁接触在质子化模型中都较短。其他差异取决于地点和时间窗口。结果支持持久的多点界面接触，而不显示共价键，化学吸附或吸附强度的一般排名。方法采用Materials Studio 2023中的DMol3模块，采用GGA-PBE泛函和DNP基集进行密度泛函理论（DFT）计算；用COSMO进行水溶液计算。使用吸附定位器的蒙特卡罗（MC）搜索为使用Forcite和COMPASS III的分子动力学（MD）提供了初始吸附构型。hqap -羰基h +的分子电荷被另一个氯离子保留并平衡。生产包括两个连续1000 ps的NVT段，温度为303 K，使用Andersen恒温器，时间步长为0.25 fs。比较了径向分布函数（rdf）和最近铁距离在1000-2000 ps和共同的最终1500-2000 ps窗口。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Journal of Molecular Modeling 化学-化学综合

CiteScore

3.50

自引率

4.50%

发文量

362

审稿时长

2.9 months

期刊介绍： The Journal of Molecular Modeling focuses on "hardcore" modeling, publishing high-quality research and reports. Founded in 1995 as a purely electronic journal, it has adapted its format to include a full-color print edition, and adjusted its aims and scope fit the fast-changing field of molecular modeling, with a particular focus on three-dimensional modeling. Today, the journal covers all aspects of molecular modeling including life science modeling; materials modeling; new methods; and computational chemistry. Topics include computer-aided molecular design; rational drug design, de novo ligand design, receptor modeling and docking; cheminformatics, data analysis, visualization and mining; computational medicinal chemistry; homology modeling; simulation of peptides, DNA and other biopolymers; quantitative structure-activity relationships (QSAR) and ADME-modeling; modeling of biological reaction mechanisms; and combined experimental and computational studies in which calculations play a major role.