Currently, key electronic and nonlinear optics (NLO) properties of DPOB chromophore were explored through doping with B12N12 nanocage. Therefore, two complexes I and II were designed by doping nanocage on methoxy and carbonyl group of DPOB at minimum distance. The DFT/TD-DFT approaches at B3LYP-GD3/6-311G(d,p) functional were utilized to accomplished the NLO properties. A band gap: 3.109 and 2.707 eV in complexes I and II, respectively with higher value of softness and least hardness were investigated in doped material than their pure forms (DPOB and B12N12). The hyperpolarizability of studied compounds increases as: B12N12 < DPOB<Complex I<Complex II. Among all investigated compounds, complex II showed the maximum values of dipole moment (15.826 D), linear polarizability (7.04 × 102a.u.) and non-linear polarizability (βtot = 4.13 × 103 and γtot = 6.70 × 105a.u.). These findings illustrated that doping of inorganic nanocages over organic surfaces is an efficient strategy to improve the NLO properties.
{"title":"Structural modulation of methyl 4-(2,11-diisopropylbenzopentaphen-5-yl based chromophore with B12N12 nano cage for enhancing the NLO Properties: A DFT study","authors":"Iqra Shafiq , Romaisa Zahid , Misbah Azhar , Muhammad Haroon , Tansir Ahamad , Saifullah Bullo , Rajeh Alotaibi","doi":"10.1016/j.comptc.2024.114878","DOIUrl":"10.1016/j.comptc.2024.114878","url":null,"abstract":"<div><div>Currently, key electronic and nonlinear optics (NLO) properties of <strong>DPOB</strong> chromophore were explored through doping with B<sub>12</sub>N<sub>12</sub> nanocage. Therefore, two complexes <strong>I</strong> and <strong>II</strong> were designed by doping nanocage on methoxy and carbonyl group of <strong>DPOB</strong> at minimum distance. The DFT/TD-DFT approaches at B3LYP-GD3/6-311G(d,p) functional were utilized to accomplished the NLO properties. A band gap: 3.109 and 2.707 <em>eV</em> in complexes <strong>I</strong> and <strong>II</strong>, respectively with higher value of softness and least hardness were investigated in doped material than their pure forms (<strong>DPOB</strong> and <strong>B<sub>12</sub>N<sub>12</sub></strong>). The hyperpolarizability of studied compounds increases as: <strong>B<sub>12</sub>N<sub>12</sub></strong> < <strong>DPOB</strong><<strong>Complex I</strong><<strong>Complex II</strong>. Among all investigated compounds, complex <strong>II</strong> showed the maximum values of dipole moment (15.826 <em>D</em>), linear polarizability (7.04 × 10<sup>2</sup> <em>a.u.</em>) and non-linear polarizability (<em>β</em><sub>tot</sub> = 4.13 × 10<sup>3</sup> and <em>γ<sub>tot</sub></em> = 6.70 × 10<sup>5</sup><em>a.u.</em>). These findings illustrated that doping of inorganic nanocages over organic surfaces is an efficient strategy to improve the NLO properties.</div></div>","PeriodicalId":284,"journal":{"name":"Computational and Theoretical Chemistry","volume":"1241 ","pages":"Article 114878"},"PeriodicalIF":3.0,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The genus Flavivirus NS3 a non-structural protein of Japanes Encephalitis Virus (JEV), a serious deadly human pathogen responsible for several deaths in South East Asia, consists of helicase/NTPase domain forming a cleft known for their role in the enzymatic activity and viral replication represented biological relevance. S-Adenosyl derivatives act as powerful inhibitors in viral replication in NS5 of the same genus as of NS3, provide a powerful base to test its effectiveness in NS3 protein due to the compatibility of both proteins. The MM-GBSA (Molecular Mechanics-Generalized Born Surface Area) simulation were performed to evaluate the binding free energy, following the 100 (ns) production MD simulation in the periodic boundary condition (PBC) for the selected docked inhibitors with NS3. The residue-wise decomposition energy determined in our study revealed the active site region made the high stability with the potential inhibitors.
{"title":"Adenosyl derivatives as a potential inhibitors of NS3 protease of Japanese encephalitis virus (JEV): In silico molecular insight into therapeutic discovery","authors":"Rakesh Kumar Tiwari, Vinayak Pandey, R.P. Ojha, Vishnudatt Pandey, Muralidhar Pandey","doi":"10.1016/j.comptc.2024.114848","DOIUrl":"10.1016/j.comptc.2024.114848","url":null,"abstract":"<div><div>The genus <em>Flavivirus</em> NS3 a non-structural protein of Japanes Encephalitis Virus (JEV), a serious deadly human pathogen responsible for several deaths in South East Asia, consists of helicase/NTPase domain forming a cleft known for their role in the enzymatic activity and viral replication represented biological relevance. S-Adenosyl derivatives act as powerful inhibitors in viral replication in NS5 of the same genus as of NS3, provide a powerful base to test its effectiveness in NS3 protein due to the compatibility of both proteins. The MM-GBSA (Molecular Mechanics-Generalized Born Surface Area) simulation were performed to evaluate the binding free energy, following the 100 (ns) production MD simulation in the periodic boundary condition (PBC) for the selected docked inhibitors with NS3. The residue-wise decomposition energy determined in our study revealed the active site region made the high stability with the potential inhibitors.</div></div>","PeriodicalId":284,"journal":{"name":"Computational and Theoretical Chemistry","volume":"1241 ","pages":"Article 114848"},"PeriodicalIF":3.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the present research, the Schleyer hyperconjugative aromaticity was used to enhance the aromaticity of indene scaffolds. The first section of the research focused on examining the thermodynamic stability and electronic characteristics of the four structural isomers of indene. Results indicate that 1H-indene scaffolds are the most stable thermodynamic isomers of indene derivatives exceeding 100 kJ/mol. The hierarchy of stability is as follows: 1H-indenes > 2H-indenes > 5H-indenes > 4H-indenes. The aromaticity of 5- and 6-membered rings in the isomeric structures was investigated using the B3LYP/6–311 + G(d,p) method in the second section of the study. The hyperconjugative aromaticity of 5MR and 6MR was assessed using the harmonic oscillator model of aromaticity index, Bird index, Shannon index, aromatic fluctuation index, and the nucleus independent chemical shift. The results reveal that introducing electron-donating groups on 6MR enhances the aromaticity of 5MR. Moreover, adding two fluorine atoms on the Csp3 site negatively affects the aromaticity and induces antiaromaticity in the indene scaffold. Based on aromaticity data, the order of increasing aromaticity in the presence of different groups is F < CH3 < H < SiH3 < GeH3 < Si(CH3)3 < Ge(CH3)3. The extent of the Schleyer hyperconjugation interaction was also quantified using the E(2) parameter obtained from the NBO calculations.
{"title":"Schleyer hyperconjugative aromaticity in indene scaffolds","authors":"Niayesh Hajialiakbari , Hamid Saeidian , Zohreh Mirjafary , Javad Mokhtari","doi":"10.1016/j.comptc.2024.114881","DOIUrl":"10.1016/j.comptc.2024.114881","url":null,"abstract":"<div><div>In the present research, the Schleyer hyperconjugative aromaticity was used to enhance the aromaticity of indene scaffolds. The first section of the research focused on examining the thermodynamic stability and electronic characteristics of the four structural isomers of indene. Results indicate that 1H-indene scaffolds are the most stable thermodynamic isomers of indene derivatives exceeding 100 kJ/mol. The hierarchy of stability is as follows: 1H-indenes > 2H-indenes > 5H-indenes > 4H-indenes. The aromaticity of 5- and 6-membered rings in the isomeric structures was investigated using the B3LYP/6–311 + G(d,p) method in the second section of the study. The hyperconjugative aromaticity of 5MR and 6MR was assessed using the harmonic oscillator model of aromaticity index, Bird index, Shannon index, aromatic fluctuation index, and the nucleus independent chemical shift. The results reveal that introducing electron-donating groups on 6MR enhances the aromaticity of 5MR. Moreover, adding two fluorine atoms on the C<sub>sp</sub><sup>3</sup> site negatively affects the aromaticity and induces antiaromaticity in the indene scaffold. Based on aromaticity data, the order of increasing aromaticity in the presence of different groups is F < CH<sub>3</sub> < H < SiH<sub>3</sub> < GeH<sub>3</sub> < Si(CH<sub>3</sub>)<sub>3</sub> < Ge(CH<sub>3</sub>)<sub>3</sub>. The extent of the Schleyer hyperconjugation interaction was also quantified using the E<sup>(2)</sup> parameter obtained from the NBO calculations.</div></div>","PeriodicalId":284,"journal":{"name":"Computational and Theoretical Chemistry","volume":"1241 ","pages":"Article 114881"},"PeriodicalIF":3.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-19DOI: 10.1016/j.comptc.2024.114871
Klinton Brito K. , Sudharsan J.B. , Srinivasan M. , Ramasamy P.
The structural, mechanical, electronic, magnetic, and thermoelectric properties of alkali-based half-Heusler alloys (LiCrGe, LiCrSn, and LiCrPb) are investigated using the Wien2k code. These alloys exhibit half-metallic behavior in both ferromagnetic and antiferromagnetic phases. A phase transition from a stable ferromagnetic phase to a more stable antiferromagnetic phase indicates ductility. In the antiferromagnetic phase, using GGA exchange–correlation functional with 10,000 -points, a band gap is observed in the spin-up state, with band gap energies of 0.9367 eV, 0.7762 eV, and 0.7913 eV, respectively. The alloys have a spin magnetic moment of −3, consistent with the Slater–Pauling rule. They also exhibit high Curie temperatures and 100% spin polarization in the spin-down state. The alloys LiCrZ (Z Ge, Sn, Pb) shows promising thermoelectric behavior. Using the BolzTrap package, we observed, high Seebeck coefficient, electrical conductivity, low thermal conductivity, and enhanced power factor. The p-type LiCrZ (Z Ge, Sn, Pb) compounds show thermoelectric figure of merit of 0.52, 0.76, and 0.84 at 1200 K, while n-type compounds have figure of merit of 0.56, 0.65, and 0.80 at the same temperature. These properties make these materials promising for spintronic and thermoelectric applications.
使用 Wien2k 代码研究了碱基半海斯勒合金（LiCrGe、LiCrSn 和 LiCrPb）的结构、机械、电子、磁性和热电特性。这些合金在铁磁性和反铁磁性相中都表现出半金属性。从稳定的铁磁相到更稳定的反铁磁相的相变表明了延展性。在反铁磁相中，使用具有 10,000 个 K 点的 GGA 交换相关函数，可以观察到自旋上升态的带隙，带隙能量分别为 0.9367 eV、0.7762 eV 和 0.7913 eV。这些合金的自旋磁矩为-3μB，符合斯莱特-保龄法则。它们还表现出较高的居里温度和自旋下降态的 100% 自旋极化。合金 LiCrZ（Z = Ge、Sn、Pb）显示出良好的热电特性。利用 BolzTrap 软件包，我们观察到了高塞贝克系数、高电导率、低热导率和更高的功率因数。在 1200 K 的温度下，p 型 LiCrZ（Z = Ge、Sn、Pb）化合物的热电系数分别为 0.52、0.76 和 0.84，而 n 型化合物在相同温度下的热电系数分别为 0.56、0.65 和 0.80。这些特性使得这些材料在自旋电子和热电应用中大有可为。
{"title":"Alkali-based half metals as sustainable materials for spin electronics and energy harvesting application — Materials computation","authors":"Klinton Brito K. , Sudharsan J.B. , Srinivasan M. , Ramasamy P.","doi":"10.1016/j.comptc.2024.114871","DOIUrl":"10.1016/j.comptc.2024.114871","url":null,"abstract":"<div><div>The structural, mechanical, electronic, magnetic, and thermoelectric properties of alkali-based half-Heusler alloys (LiCrGe, LiCrSn, and LiCrPb) are investigated using the Wien2k code. These alloys exhibit half-metallic behavior in both ferromagnetic and antiferromagnetic phases. A phase transition from a stable ferromagnetic phase to a more stable antiferromagnetic phase indicates ductility. In the antiferromagnetic phase, using GGA exchange–correlation functional with 10,000 <span><math><mi>K</mi></math></span>-points, a band gap is observed in the spin-up state, with band gap energies of 0.9367 eV, 0.7762 eV, and 0.7913 eV, respectively. The alloys have a spin magnetic moment of −3<span><math><msub><mrow><mi>μ</mi></mrow><mrow><mi>B</mi></mrow></msub></math></span>, consistent with the Slater–Pauling rule. They also exhibit high Curie temperatures and 100% spin polarization in the spin-down state. The alloys LiCrZ (Z <span><math><mo>=</mo></math></span> Ge, Sn, Pb) shows promising thermoelectric behavior. Using the BolzTrap package, we observed, high Seebeck coefficient, electrical conductivity, low thermal conductivity, and enhanced power factor. The p-type LiCrZ (Z <span><math><mo>=</mo></math></span> Ge, Sn, Pb) compounds show thermoelectric figure of merit of 0.52, 0.76, and 0.84 at 1200 K, while n-type compounds have figure of merit of 0.56, 0.65, and 0.80 at the same temperature. These properties make these materials promising for spintronic and thermoelectric applications.</div></div>","PeriodicalId":284,"journal":{"name":"Computational and Theoretical Chemistry","volume":"1241 ","pages":"Article 114871"},"PeriodicalIF":3.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142315790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-18DOI: 10.1016/j.comptc.2024.114864
Ali Hamzah Alessa
Numerous chemical and biological entities are greatly impacted by non-covalent interactions in terms of their stability and structure. One such example is the interaction of aromatic rings. These interactions are highly valued in the domains of astrochemistry, biology, chemistry, biochemistry, and material science. The main goals of this study are to explore the Potential Energy Surface (PES) of Chrysene (Chy) heterodimers, identify the most stable configurations among the Chy-Bz, Chy-Np, and Chy-Anth heterodimer complexes, and analyze the inter-molecular interactions between these molecules. This analysis was conducted utilizing ab initio computational techniques. On their PES, the Chy-Np heterodimer exhibited four minima, while the Chy-Bz and Chy-Anth heterodimer complexes showed three. Compared to conformers oriented perpendicularly, co-facial arrangement conformers in Chy heterodimer complexes have stable structures. The global minimum structure of Chy-Bz has been determined to be the face isomer, while Chy-Np and Chy-Anth have global minimum structures of the cross isomer. The binding energies of the structures generated by MP2 are higher than those of DFT-D3, DFT-D4, and SCS-MP2. Optimized geometries and binding energies of larger hydrocarbon aromatic systems are explained in detail by B3LYP-D3 and the recently created B3LYP-D4.
许多化学和生物实体的稳定性和结构都受到非共价相互作用的极大影响。其中一个例子就是芳香环的相互作用。这些相互作用在天体化学、生物学、化学、生物化学和材料科学等领域受到高度重视。本研究的主要目标是探索菊烯（Chy）异二聚体的势能面（PES），确定 Chy-Bz、Chy-Np 和 Chy-Anth 异二聚体复合物中最稳定的构型，并分析这些分子之间的分子间相互作用。这项分析是利用 ab initio 计算技术进行的。在它们的 PES 上，Chy-Np 杂二聚体显示出四个最小值，而 Chy-Bz 和 Chy-Anth 杂二聚体复合物显示出三个最小值。与垂直方向的构象相比，Chy 杂二聚体复合物中的共面排列构象具有稳定的结构。Chy-Bz 的全局最小结构被确定为面异构体，而 Chy-Np 和 Chy-Anth 的全局最小结构为交叉异构体。MP2 生成的结构的结合能高于 DFT-D3、DFT-D4 和 SCS-MP2。B3LYP-D3 和最近创建的 B3LYP-D4 详细解释了较大烃类芳香系统的优化几何结构和结合能。
{"title":"Investigation of Chrysene heterodimers complexes potential energy surface using ab initio computational methods","authors":"Ali Hamzah Alessa","doi":"10.1016/j.comptc.2024.114864","DOIUrl":"10.1016/j.comptc.2024.114864","url":null,"abstract":"<div><p>Numerous chemical and biological entities are greatly impacted by non-covalent interactions in terms of their stability and structure. One such example is the interaction of aromatic rings. These interactions are highly valued in the domains of astrochemistry, biology, chemistry, biochemistry, and material science. The main goals of this study are to explore the Potential Energy Surface (PES) of Chrysene (Chy) heterodimers, identify the most stable configurations among the Chy-Bz, Chy-Np, and Chy-Anth heterodimer complexes, and analyze the inter-molecular interactions between these molecules. This analysis was conducted utilizing <em>ab initio</em> computational techniques. On their PES, the Chy-Np heterodimer exhibited four minima, while the Chy-Bz and Chy-Anth heterodimer complexes showed three. Compared to conformers oriented perpendicularly, co-facial arrangement conformers in Chy heterodimer complexes have stable structures. The global minimum structure of Chy-Bz has been determined to be the face isomer, while Chy-Np and Chy-Anth have global minimum structures of the cross isomer. The binding energies of the structures generated by MP2 are higher than those of DFT-D3, DFT-D4, and SCS-MP2. Optimized geometries and binding energies of larger hydrocarbon aromatic systems are explained in detail by B3LYP-D3 and the recently created B3LYP-D4.</p></div>","PeriodicalId":284,"journal":{"name":"Computational and Theoretical Chemistry","volume":"1241 ","pages":"Article 114864"},"PeriodicalIF":3.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142270414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-18DOI: 10.1016/j.comptc.2024.114877
N. Ngom , A.J. Etindele , N.F. Andriambelaza , C. Nithaya , A.S. Wakata , S. Kenmoe
This study focuses on a comparative analysis of the electronic properties of triangular, irregular hexagonal, and octagonal 2D nanoparticles containing 10, 12, and 14 motifs, made of Au, Cu, MoO2, and MoS2. The investigation was carried out using density functional theory. The formation energies and vibrational frequencies demonstrate that the 2D nanostructure configurations can exist as stable structures. Edge atoms with lower coordination numbers than central atoms, are the preferred sites for CO adsorption. Using orbital-weighting dual descriptors calculated from Fukui functions enabled the identification of a majority nucleophilic attack sites in Au and Cu nanoparticles, while MoO2 and MoS2-based nanoparticles present almost as many electrophilic sites as nucleophilic sites. The charge transferred between the nanostructures and the CO molecule and the redistribution of the projected density of states were used to assess the strength of interfacial bonds and the nature of the fundamental interaction involved in the bonding.
本研究的重点是比较分析由金、铜、二氧化硅和二氧化硅制成的含有 10、12 和 14 个图案的三角形、不规则六边形和八边形二维纳米粒子的电子特性。研究采用密度泛函理论进行。形成能量和振动频率表明，二维纳米结构构型可以作为稳定结构存在。配位数低于中心原子的边缘原子是吸附 CO 的首选位置。利用 Fukui 函数计算出的轨道加权双重描述符，可以在金和铜纳米粒子中识别出大部分亲核攻击位点，而基于 MoO2 和 MoS2 的纳米粒子则呈现出几乎与亲核位点一样多的亲电位点。纳米结构与 CO 分子之间转移的电荷以及投影状态密度的重新分布被用来评估界面键的强度以及键合中涉及的基本相互作用的性质。
{"title":"Comparative study of CO adsorption on Au, Cu, MoO2 and MoS2 2D Nanoparticles","authors":"N. Ngom , A.J. Etindele , N.F. Andriambelaza , C. Nithaya , A.S. Wakata , S. Kenmoe","doi":"10.1016/j.comptc.2024.114877","DOIUrl":"10.1016/j.comptc.2024.114877","url":null,"abstract":"<div><div>This study focuses on a comparative analysis of the electronic properties of triangular, irregular hexagonal, and octagonal 2D nanoparticles containing 10, 12, and 14 motifs, made of Au, Cu, MoO<sub>2</sub>, and MoS<sub>2</sub>. The investigation was carried out using density functional theory. The formation energies and vibrational frequencies demonstrate that the 2D nanostructure configurations can exist as stable structures. Edge atoms with lower coordination numbers than central atoms, are the preferred sites for CO adsorption. Using orbital-weighting dual descriptors calculated from Fukui functions enabled the identification of a majority nucleophilic attack sites in Au and Cu nanoparticles, while MoO<sub>2</sub> and MoS<sub>2</sub>-based nanoparticles present almost as many electrophilic sites as nucleophilic sites. The charge transferred between the nanostructures and the CO molecule and the redistribution of the projected density of states were used to assess the strength of interfacial bonds and the nature of the fundamental interaction involved in the bonding.</div></div>","PeriodicalId":284,"journal":{"name":"Computational and Theoretical Chemistry","volume":"1241 ","pages":"Article 114877"},"PeriodicalIF":3.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-17DOI: 10.1016/j.comptc.2024.114875
Pabitra Narayan Samanta, Devashis Majumdar, Jerzy Leszczynski
The subtle interplay of noncovalent interaction in enhancing the compatibility between the graphene-based material and the oligomers of polyvinyl alcohol (PVA) and polyacrylamide (PAM) in the solvent phase is unraveled within the framework of all-atom classical force field-based molecular dynamics (MD) simulations. The decomposition of binding free energy analysis demonstrates that the interaction between polymer segments and graphene (G)-surface crucially emanates from the van der Waals (vdW) interactions, while the adsorption of polymer chains on the graphene oxide (GO)-surface is influenced by vdW and electrostatic interactions. The influence of diverse factors including the strain rate, the size of the nanofiller, the number of oligomers, and the thermal quenching rate on controlling the morphology, mechanical, and thermophysical properties of the graphene-reinforced polymer nanocomposites are further explored. The uniaxial deformation simulations of the graphene-reinforced PVA and PAM matrices show that the interfacial mechanical strength is escalated for the G-PVA nanocomposite. The inclusion of graphene nanofiller reduces the polymer chain mobility and increases the intermolecular interaction, which in turn enhances the toughness of the graphene-polymer composites. Increasing the strain rate raises the yield strength and modulus, making the composites appear stronger and stiffer. As evidenced by the predicted glass transition temperature, the thermal stability of the PVA and PAM matrices is significantly improved by the graphene reinforcement.
{"title":"Effects of graphene reinforcement on morphology, thermophysical, and mechanical properties of polyvinyl alcohol and polyacrylamide in condensed phases","authors":"Pabitra Narayan Samanta, Devashis Majumdar, Jerzy Leszczynski","doi":"10.1016/j.comptc.2024.114875","DOIUrl":"10.1016/j.comptc.2024.114875","url":null,"abstract":"<div><div>The subtle interplay of noncovalent interaction in enhancing the compatibility between the graphene-based material and the oligomers of polyvinyl alcohol (PVA) and polyacrylamide (PAM) in the solvent phase is unraveled within the framework of all-atom classical force field-based molecular dynamics (MD) simulations. The decomposition of binding free energy analysis demonstrates that the interaction between polymer segments and graphene (G)-surface crucially emanates from the van der Waals (vdW) interactions, while the adsorption of polymer chains on the graphene oxide (GO)-surface is influenced by vdW and electrostatic interactions. The influence of diverse factors including the strain rate, the size of the nanofiller, the number of oligomers, and the thermal quenching rate on controlling the morphology, mechanical, and thermophysical properties of the graphene-reinforced polymer nanocomposites are further explored. The uniaxial deformation simulations of the graphene-reinforced PVA and PAM matrices show that the interfacial mechanical strength is escalated for the G-PVA nanocomposite. The inclusion of graphene nanofiller reduces the polymer chain mobility and increases the intermolecular interaction, which in turn enhances the toughness of the graphene-polymer composites. Increasing the strain rate raises the yield strength and modulus, making the composites appear stronger and stiffer. As evidenced by the predicted glass transition temperature, the thermal stability of the PVA and PAM matrices is significantly improved by the graphene reinforcement.</div></div>","PeriodicalId":284,"journal":{"name":"Computational and Theoretical Chemistry","volume":"1241 ","pages":"Article 114875"},"PeriodicalIF":3.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-15DOI: 10.1016/j.comptc.2024.114870
Liangyue Cheng
This study employed multiconfigurational CASSCF and MS-CASPT2 methods to investigate the photoinduced isomerization mechanism of 1,1′-azobis-1,2,3-triazole. The MS-CASPT2//CASSCF computational results indicate that the photoisomerization reaction of 1,1′-azobis-1,2,3-triazole involves a non-adiabatic transition pathway through the S2 state. After photoexcitation to the S2 state, the molecule undergoes internal conversion to reach S1-min, followed by a non-radiative transition back to the ground state. The S1/S0-CI and S1-min have similar structures and close energies, which facilitates unidirectional rotation. The weak coupling between the ground state and excited states may be due to the strong electron-withdrawing nature of the N8 chain. Additionally, using the MS-CASPT2//CASSCF computational results as a reference, we compared the differences in describing the photoisomerization process of this compound using the SF-DFT method, both qualitatively and quantitatively. The results demonstrate that the SF-DFT method significantly underestimates the energy of the S1 state. These findings are expected to deepen the understanding of non-adiabatic transitions in the photoinduced rotation of high-nitrogen compounds and provide theoretical insights for other high-nitrogen compounds that may exhibit photochromism.
{"title":"Photochromic reaction pathways of 1,1′-azobis-1,2,3-triazole: A CASSCF and spin-flip DFT study","authors":"Liangyue Cheng","doi":"10.1016/j.comptc.2024.114870","DOIUrl":"10.1016/j.comptc.2024.114870","url":null,"abstract":"<div><p>This study employed multiconfigurational CASSCF and MS-CASPT2 methods to investigate the photoinduced isomerization mechanism of 1,1′-azobis-1,2,3-triazole. The MS-CASPT2//CASSCF computational results indicate that the photoisomerization reaction of 1,1′-azobis-1,2,3-triazole involves a non-adiabatic transition pathway through the S<sub>2</sub> state. After photoexcitation to the S<sub>2</sub> state, the molecule undergoes internal conversion to reach S<sub>1</sub>-min, followed by a non-radiative transition back to the ground state. The S<sub>1</sub>/S<sub>0</sub>-CI and S<sub>1</sub>-min have similar structures and close energies, which facilitates unidirectional rotation. The weak coupling between the ground state and excited states may be due to the strong electron-withdrawing nature of the N<sub>8</sub> chain. Additionally, using the MS-CASPT2//CASSCF computational results as a reference, we compared the differences in describing the photoisomerization process of this compound using the SF-DFT method, both qualitatively and quantitatively. The results demonstrate that the SF-DFT method significantly underestimates the energy of the S<sub>1</sub> state. These findings are expected to deepen the understanding of non-adiabatic transitions in the photoinduced rotation of high-nitrogen compounds and provide theoretical insights for other high-nitrogen compounds that may exhibit photochromism.</p></div>","PeriodicalId":284,"journal":{"name":"Computational and Theoretical Chemistry","volume":"1241 ","pages":"Article 114870"},"PeriodicalIF":3.0,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142243747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-15DOI: 10.1016/j.comptc.2024.114868
Anupam Yadav , Mohammed Ahmed Mustafa , Esraa Ahmed Said , Kamil K. Atiyah Altameemi , Mustafa Jassim Al-saray , Shahad Abdulhadi Khuder , Abdul Malik , Hussein Muhi Hariz , Ahmed Muzahem Al-Ani , Sally Salih Jumaa , Yusra Mohammed Ali , Munther Kadhim Abosaoda
Even though Ciclopirox (CPX) plays a critical role in the treatment of pancreatic, colorectal, and breast cancers, some side effects are attributable to CPX. Thus, determining the content of CPX in biological specimens is critical. The contribution of CPX to the activity of the intrinsic and Au-decorated BC2N nanotubes (BC2NNT) has been analyzed in this research by employing density functional theory estimations. According to the results, the gold decoration resulted in a noticeable improvement in BC2NNT toward CPX and increased value of BC2NNT sensing response from 9.3 to 307.1. Furthermore, a short recovery was allowed (approximately 1.12 sec) in order to desorb CPX from the Au@BC2NNT exterior. The CPX-Au@ BC2NNT interaction decreased in the aqueous solution, which led to a declined Au@BC2NNT sensing response from a value of 307.1 to 260.0. However, in accordance with our results, by employing the gold-doping process, one may transform BC2NNT into an appropriate sensor for CPX.
{"title":"The computational investigation of the role of pristine and metal-doped BC2N nanotubes for sensitive detection of ciclopirox drug","authors":"Anupam Yadav , Mohammed Ahmed Mustafa , Esraa Ahmed Said , Kamil K. Atiyah Altameemi , Mustafa Jassim Al-saray , Shahad Abdulhadi Khuder , Abdul Malik , Hussein Muhi Hariz , Ahmed Muzahem Al-Ani , Sally Salih Jumaa , Yusra Mohammed Ali , Munther Kadhim Abosaoda","doi":"10.1016/j.comptc.2024.114868","DOIUrl":"10.1016/j.comptc.2024.114868","url":null,"abstract":"<div><div>Even though Ciclopirox (CPX) plays a critical role in the treatment of pancreatic, colorectal, and breast cancers, some side effects are attributable to CPX. Thus, determining the content of CPX in biological specimens is critical. The contribution of CPX to the activity of the intrinsic and Au-decorated BC<sub>2</sub>N nanotubes (BC<sub>2</sub>NNT) has been analyzed in this research by employing density functional theory estimations. According to the results, the gold decoration resulted in a noticeable improvement in BC<sub>2</sub>NNT toward CPX and increased value of BC<sub>2</sub>NNT sensing response from 9.3 to 307.1. Furthermore, a short recovery was allowed (approximately 1.12 <em>sec</em>) in order to desorb CPX from the Au@BC<sub>2</sub>NNT exterior. The CPX-Au@ BC<sub>2</sub>NNT interaction decreased in the aqueous solution, which led to a declined Au@BC<sub>2</sub>NNT sensing response from a value of 307.1 to 260.0. However, in accordance with our results, by employing the gold-doping process, one may transform BC<sub>2</sub>NNT into an appropriate sensor for CPX.</div></div>","PeriodicalId":284,"journal":{"name":"Computational and Theoretical Chemistry","volume":"1241 ","pages":"Article 114868"},"PeriodicalIF":3.0,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-15DOI: 10.1016/j.comptc.2024.114876
Mengna Bai , Erguang Huo , Shukun Wang , Shouyin Cai , Shijie Zhang
The development of degradation treatment technology for waste hydrofluorocarbons (HFCs) was urgent. Copper, a commonly used catalyst, can be used to efficiently catalyze the pyrolysis of pure HFCs, but the catalytic pyrolysis study of HFC mixtures was lacking. In this work, the catalytic pyrolysis of R134a/R32 refrigerant mixture over Cu(1 1 1) surface was studied by using density functional theory method. Four initial catalytic pyrolysis reactions of R134a in adsorbed R134a/R32 mixture and adsorbed R134a, two initial catalytic pyrolysis reactions of R32 in adsorbed R134a/R32 mixture and adsorbed R32 were investigated. The results showed that copper had a better catalytic effect on the pyrolysis of adsorbed R134a/R32 mixture, adsorbed R134a and adsorbed R32. On the Cu(1 1 1) surface, the pyrolysis of R134a was inhibited and the pyrolysis of R32 was improved by the mixture of R134a and R32.
{"title":"Catalytic pyrolysis mechanism of waste R134a/R32 refrigerant mixture over Cu(1 1 1) surface: Density functional theory study","authors":"Mengna Bai , Erguang Huo , Shukun Wang , Shouyin Cai , Shijie Zhang","doi":"10.1016/j.comptc.2024.114876","DOIUrl":"10.1016/j.comptc.2024.114876","url":null,"abstract":"<div><p>The development of degradation treatment technology for waste hydrofluorocarbons (HFCs) was urgent. Copper, a commonly used catalyst, can be used to efficiently catalyze the pyrolysis of pure HFCs, but the catalytic pyrolysis study of HFC mixtures was lacking. In this work, the catalytic pyrolysis of R134a/<em>R</em>32 refrigerant mixture over Cu(1 1 1) surface was studied by using density functional theory method. Four initial catalytic pyrolysis reactions of R134a in adsorbed R134a/<em>R</em>32 mixture and adsorbed R134a, two initial catalytic pyrolysis reactions of <em>R</em>32 in adsorbed R134a/<em>R</em>32 mixture and adsorbed <em>R</em>32 were investigated. The results showed that copper had a better catalytic effect on the pyrolysis of adsorbed R134a/<em>R</em>32 mixture, adsorbed R134a and adsorbed <em>R</em>32. On the Cu(1 1 1) surface, the pyrolysis of R134a was inhibited and the pyrolysis of <em>R</em>32 was improved by the mixture of R134a and <em>R</em>32.</p></div>","PeriodicalId":284,"journal":{"name":"Computational and Theoretical Chemistry","volume":"1241 ","pages":"Article 114876"},"PeriodicalIF":3.0,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142243853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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