Pub Date : 2025-02-01DOI: 10.1016/j.comptc.2025.115065
Rongkai Kang , Han Wang , Boya Zhang , Xingchang Zhang , Dongmei Zhang , Huixin Jin , Yiqun Du , Jianxin Zhang
In nickel-based single-crystal superalloys, the clustering growth of solute atoms is a potential form that can generate a greater strengthening effect. Herein, first-principles calculations are employed to investigate the clustering behavior of W and Co in γ phase, including the occupancy mechanism, interatomic interactions, and electronic properties. It is reveals that compared to dispersed atoms, W shows a greater propensity for forming W–W clusters. After W–W bond formation, the total energy decreases from −634.247 eV to −649.569 eV. Co prefers to occupy the second-nearest neighbor of W–W, further reducing the system total energy (−651.110 eV). The doping of Co is found to strengthen the W–W interactions. The stabilizing mechanism is attributed to the replacement of the weak Ni–Ni with stronger Ni–W, W–W, and W–Co interactions. This work sheds light on the clustering behavior of doped W and Co, contributing to an understanding of the stabilizing mechanisms of atomic clusters.
{"title":"First-principles investigations for clustering behavior of W and Co in nickel-based single-crystal superalloys","authors":"Rongkai Kang , Han Wang , Boya Zhang , Xingchang Zhang , Dongmei Zhang , Huixin Jin , Yiqun Du , Jianxin Zhang","doi":"10.1016/j.comptc.2025.115065","DOIUrl":"10.1016/j.comptc.2025.115065","url":null,"abstract":"<div><div>In nickel-based single-crystal superalloys, the clustering growth of solute atoms is a potential form that can generate a greater strengthening effect. Herein, first-principles calculations are employed to investigate the clustering behavior of W and Co in γ phase, including the occupancy mechanism, interatomic interactions, and electronic properties. It is reveals that compared to dispersed atoms, W shows a greater propensity for forming W–W clusters. After W–W bond formation, the total energy decreases from −634.247 eV to −649.569 eV. Co prefers to occupy the second-nearest neighbor of W–W, further reducing the system total energy (−651.110 eV). The doping of Co is found to strengthen the W–W interactions. The stabilizing mechanism is attributed to the replacement of the weak Ni–Ni with stronger Ni–W, W–W, and W–Co interactions. This work sheds light on the clustering behavior of doped W and Co, contributing to an understanding of the stabilizing mechanisms of atomic clusters.</div></div>","PeriodicalId":284,"journal":{"name":"Computational and Theoretical Chemistry","volume":"1244 ","pages":"Article 115065"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143160053","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 : 2025-02-01DOI: 10.1016/j.comptc.2025.115077
Shangju Chen , Haixia Li , Haowei Wu , Lin Chen , Jinhao Zhang
This study explores the adsorption and gas-sensing properties of Ca-Sr co-doped MoS2 for toxic gases such as CO, CH4, and NO2, prevalent in industrial processes. Using density functional theory (DFT), ten doping configurations were designed and optimized, with the optimal structure identified as Ca and Sr atoms co-doped at Mo top sites, while other configurations exhibited migration toward Mo atoms. Structural and electronic analyses revealed significant changes compared to pristine MoS2. Adsorption energy calculations showed values of −1.282 eV, −0.374 eV, and −4.698 eV for CO, CH4, and NO2, respectively, suggesting chemical adsorption for CO and NO2 and physical adsorption for CH4. Sensitivity evaluations demonstrated high selectivity for NO2 within 298–498 K, and recovery time analysis confirmed its potential as an NO2 adsorbent and cyclic CO detection material. These findings provide new perspectives for the design and application of MoS2-based gas-sensitive materials.
{"title":"Ca and Sr co-doped MoS2 for adsorption of CO, CH4, and NO2 Gases: A theoretical study","authors":"Shangju Chen , Haixia Li , Haowei Wu , Lin Chen , Jinhao Zhang","doi":"10.1016/j.comptc.2025.115077","DOIUrl":"10.1016/j.comptc.2025.115077","url":null,"abstract":"<div><div>This study explores the adsorption and gas-sensing properties of Ca-Sr co-doped MoS<sub>2</sub> for toxic gases such as CO, CH<sub>4</sub>, and NO<sub>2</sub>, prevalent in industrial processes. Using density functional theory (DFT), ten doping configurations were designed and optimized, with the optimal structure identified as Ca and Sr atoms co-doped at Mo top sites, while other configurations exhibited migration toward Mo atoms. Structural and electronic analyses revealed significant changes compared to pristine MoS<sub>2</sub>. Adsorption energy calculations showed values of −1.282 eV, −0.374 eV, and −4.698 eV for CO, CH<sub>4</sub>, and NO<sub>2</sub>, respectively, suggesting chemical adsorption for CO and NO<sub>2</sub> and physical adsorption for CH<sub>4</sub>. Sensitivity evaluations demonstrated high selectivity for NO<sub>2</sub> within 298–498 K, and recovery time analysis confirmed its potential as an NO<sub>2</sub> adsorbent and cyclic CO detection material. These findings provide new perspectives for the design and application of MoS<sub>2</sub>-based gas-sensitive materials.</div></div>","PeriodicalId":284,"journal":{"name":"Computational and Theoretical Chemistry","volume":"1244 ","pages":"Article 115077"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143160055","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 : 2025-02-01DOI: 10.1016/j.comptc.2024.115041
Teshome A. Lelisho , Jean I. du Toit , Cornelia G.C.E. van Sittert
Chemical fixation of CO2 into useful chemicals has dual significance in view of both environmental protection and sustainable chemistry. The study computationally examined the fixation of CO2 into propylene carbonate catalyzed by a binary system consisting of potassium iodide (KI) and five hydrogen bond donors, including ascorbic acid (AA), ethylene glycol, 2,6-bis(trifluoromethyl)phenylboronic acid, 2,6-dimethylphenylboronic acid, and H2O. Density functional theory (DFT) calculations were performed using M06-2X, B3PW91, B3LYP-D3, 6–31+G(d,p) and 6–311++G(d,p) basis sets for non-iodine atoms, and LANL2DZ for iodine. The mechanistic detail for the catalytic cycloaddition was elucidated. According to the calculated barrier for the rate-determining step (RDS), KI/AA promoted the CO2/propylene oxide (PO) cycloaddition reaction best. The analyses from Quantum Theory of Atoms in Molecules, Reduced Density Gradient scatter and Non-Covalent Interactions plots all confirmed that the ring-opening of PO is facilitated by activating the epoxide and stabilizing the transition state through hydrogen bonding interactions. The ring-opening step promoted by KI/AA is an exothermic, spontaneous process, resulting from increased stability of the alkoxide intermediate due to the migration of a proton from AA to the O atom of PO. The barrier calculated for the RSD in the gas phase ranged from 13.04 to 19.74 kcal/mol, with a slight increase observed in water. Although the barrier for the RDS is slightly higher in water than in the gas phase, DFT calculations show that water, a green solvent with the highest dielectric constant, is a suitable solvent candidate for the studied reaction.
{"title":"Synergism of potassium iodide and ascorbic acid in promoting fixation of CO2 with propylene oxide: A DFT study","authors":"Teshome A. Lelisho , Jean I. du Toit , Cornelia G.C.E. van Sittert","doi":"10.1016/j.comptc.2024.115041","DOIUrl":"10.1016/j.comptc.2024.115041","url":null,"abstract":"<div><div>Chemical fixation of CO<sub>2</sub> into useful chemicals has dual significance in view of both environmental protection and sustainable chemistry. The study computationally examined the fixation of CO<sub>2</sub> into propylene carbonate catalyzed by a binary system consisting of potassium iodide (KI) and five hydrogen bond donors, including ascorbic acid (AA), ethylene glycol, 2,6-bis(trifluoromethyl)phenylboronic acid, 2,6-dimethylphenylboronic acid, and H<sub>2</sub>O. Density functional theory (DFT) calculations were performed using M06-2X, B3PW91, B3LYP-D3, 6–31+G(d,p) and 6–311++G(d,p) basis sets for non-iodine atoms, and LANL2DZ for iodine. The mechanistic detail for the catalytic cycloaddition was elucidated. According to the calculated barrier for the rate-determining step (RDS), KI/AA promoted the CO<sub>2</sub>/propylene oxide (PO) cycloaddition reaction best. The analyses from Quantum Theory of Atoms in Molecules, Reduced Density Gradient scatter and Non-Covalent Interactions plots all confirmed that the ring-opening of PO is facilitated by activating the epoxide and stabilizing the transition state through hydrogen bonding interactions. The ring-opening step promoted by KI/AA is an exothermic, spontaneous process, resulting from increased stability of the alkoxide intermediate due to the migration of a proton from AA to the O atom of PO. The barrier calculated for the RSD in the gas phase ranged from 13.04 to 19.74 kcal/mol, with a slight increase observed in water. Although the barrier for the RDS is slightly higher in water than in the gas phase, DFT calculations show that water, a green solvent with the highest dielectric constant, is a suitable solvent candidate for the studied reaction.</div></div>","PeriodicalId":284,"journal":{"name":"Computational and Theoretical Chemistry","volume":"1244 ","pages":"Article 115041"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143160643","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}
The rational design of electrocatalysts possess tremendous potential to overcome the energy crisis; however, construction of multifunctional catalysts remains a great challenge. Here, we report the atomic-level understanding of hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) on a transition metal (TM) atom-anchored polyoxotantalate cluster (POT). Using the spin-polarized density functional theory (DFT) employing VASP, a series of transition metal single-atom catalysts (SACs) are investigated towards finding the multifunctional catalyst. The first principle AIMD simulations were also performed to consider stable configuration. Mn/POT (−0.06 eV) and Pt/POT (0.03 eV) electrocatalysts exhibit excellent HER activity. While the catalyst Pt/POT (0.33 V), and Co/POT (0.43 V) are proven to have potentially remarkable OER activity. In contrast to the noble metal Pt/POT, which achieves an ORR overpotential of (0.34 V), a non-noble metal Co/POT (0.35 V) exhibits a comparable ORR overpotential, making it an economically viable and potential electrocatalyst for ORR. In this study, Pt/POT works as a tri-functional electrocatalyst for HER, OER, and ORR. Co/POT exhibiting bi-functional electrocatalyst for OER and ORR. By analyzing the chemical environment using the solvation model, we find that catalysts with coordination ions (Co/POT, Rh/POT, and Pt/POT) have excellent OER and ORR activity. Ir/POT has the most minimal activation barrier (0.23 eV) among all the most effective catalysts for HER that have been investigated through IS, TS, and FS configurations. These findings demonstrate the effective stabilization of single atoms at fourfold-hollow stable active sites for HER, OER, and ORR performance. This study not only enhances the application of POT clusters also serves as a route for future experimentalists to design multifunctional electrocatalysts.
{"title":"Theoretical investigation of single atom electrocatalysts of polyoxotantalate-supported transition-metals for efficient water-splitting and oxygen reduction reaction","authors":"Faheem Abbas , Shamraiz Hussain Talib , Zonish Zeb , Zheyu Wei , Sumaira Nazar Hussain , Yichao Huang , Sharmarke Mohamed , Ahsanulhaq Qurashi , Yongge Wei","doi":"10.1016/j.comptc.2024.115044","DOIUrl":"10.1016/j.comptc.2024.115044","url":null,"abstract":"<div><div>The rational design of electrocatalysts possess tremendous potential to overcome the energy crisis; however, construction of multifunctional catalysts remains a great challenge. Here, we report the atomic-level understanding of hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) on a transition metal (TM) atom-anchored polyoxotantalate cluster (POT). Using the spin-polarized density functional theory (DFT) employing VASP, a series of transition metal single-atom catalysts (SACs) are investigated towards finding the multifunctional catalyst. The first principle AIMD simulations were also performed to consider stable configuration. Mn/POT (−0.06 eV) and Pt/POT (0.03 eV) electrocatalysts exhibit excellent HER activity. While the catalyst Pt/POT (0.33 V), and Co/POT (0.43 V) are proven to have potentially remarkable OER activity. In contrast to the noble metal Pt/POT, which achieves an ORR overpotential of (0.34 V), a non-noble metal Co/POT (0.35 V) exhibits a comparable ORR overpotential, making it an economically viable and potential electrocatalyst for ORR. In this study, Pt/POT works as a tri-functional electrocatalyst for HER, OER, and ORR. Co/POT exhibiting bi-functional electrocatalyst for OER and ORR. By analyzing the chemical environment using the solvation model, we find that catalysts with coordination ions (Co/POT, Rh/POT, and Pt/POT) have excellent OER and ORR activity. Ir/POT has the most minimal activation barrier (0.23 eV) among all the most effective catalysts for HER that have been investigated through IS, TS, and FS configurations. These findings demonstrate the effective stabilization of single atoms at fourfold-hollow stable active sites for HER, OER, and ORR performance. This study not only enhances the application of POT clusters also serves as a route for future experimentalists to design multifunctional electrocatalysts.</div></div>","PeriodicalId":284,"journal":{"name":"Computational and Theoretical Chemistry","volume":"1244 ","pages":"Article 115044"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143160648","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 : 2025-02-01DOI: 10.1016/j.comptc.2024.115031
Fu Li , Hailong Wu , Hao Cui
In this study, we employed first-principles theory to investigate the properties of Pt-doping in a pristine HfS2 monolayer, and to explore the adsorption behavior of the Pt-doped HfS2 (Pt-HfS2) monolayer when interacting with H2S and SOF2 molecules, aiming to harness its sensing capabilities. Our findings indicate that the Pt dopant can be stably anchored within the HfS2 monolayer, with a cohesive energy of −5.73 eV/atom. Besides, Pt-HfS2 monolayer engages in chemisorption with H2S, characterized by an adsorption energy of −0.95 eV, and physisorption with SOF2, with a comparatively weaker adsorption energy of −0.43 eV. Also, the charge transfer in the SOF2 system is more favorable than in the H2S system, leading to a more pronounced modulation in the bandgap of the Pt-HfS2 monolayer. Consequently, the Pt-HfS2 monolayer is evidenced by a better sensing response of −56.7 % to SOF2 compared with that of −29.6 % to H2S. Moreover, the analysis of recovery property reveals the reusability of Pt-HfS2 monolayer as a resistive sensor. These findings uncover the potential of the purposed Pt-HfS2 monolayer for sensing application targeting H2S and SOF2, which is crucial to evaluate the operation status of SF6-insulation devices. Our work lays the groundwork for exploration of innovative HfS2-based sensing materials for gas sensing in electrical engineering and potentially in various environmental and industrial settings.
{"title":"Favorable adsorption and sensing properties of the HfS2 monolayer upon H2S and SOF2 gases by Pt-doping: A first-principles study","authors":"Fu Li , Hailong Wu , Hao Cui","doi":"10.1016/j.comptc.2024.115031","DOIUrl":"10.1016/j.comptc.2024.115031","url":null,"abstract":"<div><div>In this study, we employed first-principles theory to investigate the properties of Pt-doping in a pristine HfS<sub>2</sub> monolayer, and to explore the adsorption behavior of the Pt-doped HfS<sub>2</sub> (Pt-HfS<sub>2</sub>) monolayer when interacting with H<sub>2</sub>S and SOF<sub>2</sub> molecules, aiming to harness its sensing capabilities. Our findings indicate that the Pt dopant can be stably anchored within the HfS<sub>2</sub> monolayer, with a cohesive energy of −5.73 eV/atom. Besides, Pt-HfS<sub>2</sub> monolayer engages in chemisorption with H<sub>2</sub>S, characterized by an adsorption energy of −0.95 eV, and physisorption with SOF<sub>2</sub>, with a comparatively weaker adsorption energy of −0.43 eV. Also, the charge transfer in the SOF<sub>2</sub> system is more favorable than in the H<sub>2</sub>S system, leading to a more pronounced modulation in the bandgap of the Pt-HfS<sub>2</sub> monolayer. Consequently, the Pt-HfS<sub>2</sub> monolayer is evidenced by a better sensing response of −56.7 % to SOF<sub>2</sub> compared with that of −29.6 % to H<sub>2</sub>S. Moreover, the analysis of recovery property reveals the reusability of Pt-HfS<sub>2</sub> monolayer as a resistive sensor. These findings uncover the potential of the purposed Pt-HfS<sub>2</sub> monolayer for sensing application targeting H<sub>2</sub>S and SOF<sub>2</sub>, which is crucial to evaluate the operation status of SF<sub>6</sub>-insulation devices. Our work lays the groundwork for exploration of innovative HfS<sub>2</sub>-based sensing materials for gas sensing in electrical engineering and potentially in various environmental and industrial settings.</div></div>","PeriodicalId":284,"journal":{"name":"Computational and Theoretical Chemistry","volume":"1244 ","pages":"Article 115031"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143160009","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 : 2025-02-01DOI: 10.1016/j.comptc.2024.115055
Jie Wang , Guoliang Huang , Xueqin Huang , Jiheng Qin , Congmei Chen , Maofei Ran , Wenjing Sun
Molybdenum disulfide (MoS2) monolayers are promising materials for the electrochemical sensing of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) nucleobases. However, pristine MoS2 has low sensitivity and selectivity for nucleobase detection. In this study, we used density functional theory (DFT) calculations to investigate how doping MoS2 with boron (B), carbon (C), nitrogen (N), and oxygen (O) affects its interactions with nucleobases (adenine, cytosine, guanine, thymine, and uracil respectively). We calculated the adsorption energies, response values, and recovery times of nucleobases on doped MoS2 and compared them with those of pristine MoS2. We found that B-, C-, and O-doped MoS2 enhanced the identification and differentiation between nucleobases, but B- and C-doped MoS2 had long recovery times due to the formation of strong chemical bonds between MoS2 and the nucleobases. In contrast, O-doped MoS2 showed good response values for adenine (A) and guanine (G) but poor values for cytosine (C), thymine (T), and uracil (U). Increasing the oxygen doping concentration to 4.16% improved the response values for all nucleobases and reduced the recovery time to less than 0.133 s at 500 Kelvin. Our results suggest that oxygen-doped MoS2 is a promising substrate for DNA/RNA sequencing applications.
{"title":"Design and screening of DNA/RNA sequencing materials based on non-metallic substituted molybdenum sulfide: A density functional theory study","authors":"Jie Wang , Guoliang Huang , Xueqin Huang , Jiheng Qin , Congmei Chen , Maofei Ran , Wenjing Sun","doi":"10.1016/j.comptc.2024.115055","DOIUrl":"10.1016/j.comptc.2024.115055","url":null,"abstract":"<div><div>Molybdenum disulfide (MoS<sub>2</sub>) monolayers are promising materials for the electrochemical sensing of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) nucleobases. However, pristine MoS<sub>2</sub> has low sensitivity and selectivity for nucleobase detection. In this study, we used density functional theory (DFT) calculations to investigate how doping MoS<sub>2</sub> with boron (B), carbon (C), nitrogen (N), and oxygen (O) affects its interactions with nucleobases (adenine, cytosine, guanine, thymine, and uracil respectively). We calculated the adsorption energies, response values, and recovery times of nucleobases on doped MoS<sub>2</sub> and compared them with those of pristine MoS2. We found that B-, C-, and O-doped MoS<sub>2</sub> enhanced the identification and differentiation between nucleobases, but B- and C-doped MoS2 had long recovery times due to the formation of strong chemical bonds between MoS<sub>2</sub> and the nucleobases. In contrast, O-doped MoS<sub>2</sub> showed good response values for adenine (A) and guanine (G) but poor values for cytosine (C), thymine (T), and uracil (U). Increasing the oxygen doping concentration to 4.16% improved the response values for all nucleobases and reduced the recovery time to less than 0.133 s at 500 Kelvin. Our results suggest that oxygen-doped MoS2 is a promising substrate for DNA/RNA sequencing applications.</div></div>","PeriodicalId":284,"journal":{"name":"Computational and Theoretical Chemistry","volume":"1244 ","pages":"Article 115055"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143160073","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 : 2025-02-01DOI: 10.1016/j.comptc.2024.115061
Numair Elahi , Constantinos D. Zeinalipour-Yazdi
Currently the proton mobility in water clusters is an area that is relatively unexplored and very important for biochemical and catalytic processes occurring in water. We therefore investigate the barrier for proton transfer in a concerted fashion in water clusters where n = 3–8. Our findings at the B3LYP/aug-cc-pVDZ level of theory indicate that protons can transfer in a low barrier process of 15.5 kJ/mol per H-bond. This is still larger than the average thermal energy at 298 K and therefore suggests that proton tunneling is also happening in water. We reveal the dynamic behavior of protons in cyclic water clusters in which concerted proton transfer occurs through an intermediate Zundel cation. We also offer the proton transfer barrier per H-bond in cyclic water clusters as a function of the size of the water cluster. This study helps in the understanding of the dynamic properties of protons in water.
{"title":"A DFT assessment of the activation barrier for concerted proton transfer in cyclic water clusters (H2O)n where n = 3–8","authors":"Numair Elahi , Constantinos D. Zeinalipour-Yazdi","doi":"10.1016/j.comptc.2024.115061","DOIUrl":"10.1016/j.comptc.2024.115061","url":null,"abstract":"<div><div>Currently the proton mobility in water clusters is an area that is relatively unexplored and very important for biochemical and catalytic processes occurring in water. We therefore investigate the barrier for proton transfer in a concerted fashion in water clusters where n = 3–8. Our findings at the B3LYP/aug-cc-pVDZ level of theory indicate that protons can transfer in a low barrier process of 15.5 kJ/mol per H-bond. This is still larger than the average thermal energy at 298 K and therefore suggests that proton tunneling is also happening in water. We reveal the dynamic behavior of protons in cyclic water clusters in which concerted proton transfer occurs through an intermediate Zundel cation. We also offer the proton transfer barrier per H-bond in cyclic water clusters as a function of the size of the water cluster. This study helps in the understanding of the dynamic properties of protons in water.</div></div>","PeriodicalId":284,"journal":{"name":"Computational and Theoretical Chemistry","volume":"1244 ","pages":"Article 115061"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143160075","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 : 2025-02-01DOI: 10.1016/j.comptc.2025.115067
Yu Yang, Yan Yan, Na Hou
Using (time-dependent) density functional theory (DFT) methods, we shed light on the electronic and nonlinear optical (NLO) properties of four (BF2)-oxasmaragdyrin-(3-pyrrolyl) BODIPY derivatives. The static first hyperpolarizabilities (βtot) and hyper-Rayleigh scattering hyperpolarizabilities (βHRS) of expanded porphyrins increase in the order 1 < 2 < 3 < 4. The unit sphere representations further clearly exhibit a remarkable increase in the NLO response from 1 to 4. Noteworthily, the BF2 group and the pyrrole ring yield a positive effect on the enhancement of hyperpolarizabilities of expanded porphyrins. Furthermore, the hyperpolarizability in the static limit is evaluated using the two-state approximation. The calculation results show that four complexes have large HRS hyperpolarizabilities due to the lower excitation energy for the crucial excited state. Furthermore, the HOMO-LUMO energy gap and charge transfer excitation length correlate well with the βHRS response.
{"title":"Evaluation of the second-order nonlinear optical properties of oxasmaragdyrin-BODIPY derivatives","authors":"Yu Yang, Yan Yan, Na Hou","doi":"10.1016/j.comptc.2025.115067","DOIUrl":"10.1016/j.comptc.2025.115067","url":null,"abstract":"<div><div>Using (time-dependent) density functional theory (DFT) methods, we shed light on the electronic and nonlinear optical (NLO) properties of four (BF<sub>2</sub>)-oxasmaragdyrin-(3-pyrrolyl) BODIPY derivatives. The static first hyperpolarizabilities (<em>β</em><sub>tot</sub>) and hyper-Rayleigh scattering hyperpolarizabilities (<em>β</em><sub>HRS</sub>) of expanded porphyrins increase in the order <strong>1</strong> < <strong>2</strong> < <strong>3</strong> < <strong>4</strong>. The unit sphere representations further clearly exhibit a remarkable increase in the NLO response from <strong>1</strong> to <strong>4</strong>. Noteworthily, the BF<sub>2</sub> group and the pyrrole ring yield a positive effect on the enhancement of hyperpolarizabilities of expanded porphyrins. Furthermore, the hyperpolarizability in the static limit is evaluated using the two-state approximation. The calculation results show that four complexes have large HRS hyperpolarizabilities due to the lower excitation energy for the crucial excited state. Furthermore, the HOMO-LUMO energy gap and charge transfer excitation length correlate well with the <em>β</em><sub>HRS</sub> response.</div></div>","PeriodicalId":284,"journal":{"name":"Computational and Theoretical Chemistry","volume":"1244 ","pages":"Article 115067"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143160081","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 : 2025-02-01DOI: 10.1016/j.comptc.2025.115072
Giridhar Baburao, Gopi Ragupathy
Our study focused on understanding how certain Lewis bases like HO, NH, HCl, and CH, interact with specific nitriles such as, Glycolonitrile (GLY), Cyanic acid (CYA), and 3-Hydroxy-2-propenenitrile (HPN). These interactions form 1:1 complexes through hydrogen bond. Here we observed weak hydrogen bonding interactions such as, CN H, O-HN, O-HO, or O-H in these complexes. In CN H interaction, when a nitrile molecule interacts with a Lewis base, it acts as a proton acceptor, while the corresponding Lewis base acts as a proton donor. However, this is reversed when the molecule possesses an O-HX (X = N, O, Cl, ) interaction. Among these, in most cases, the complexes with O-HX interactions were the most stable, representing the global minima. Detailed Atom in Molecule (AIM) and Natural Bonding Orbital (NBO) analyses confirmed the presence of these hydrogen bonds. Intermolecular bond critical points (BCPs) were identified. The electron density at BCPs was within the range of 0.002 to 0.035 a.u. as described in the Koch and Popelier study. The Laplacian of electron density was positive, further proving hydrogen bonding interaction. NBO analysis showed that O-HN interactions had higher second order perturbation energies compared to O-HO, O-H, and O-HCl interactions.
{"title":"Weak molecular interactions of 1:1 Nitrile–Lewis base complexes: A theoretical perspective on nature of chemical bonding","authors":"Giridhar Baburao, Gopi Ragupathy","doi":"10.1016/j.comptc.2025.115072","DOIUrl":"10.1016/j.comptc.2025.115072","url":null,"abstract":"<div><div>Our study focused on understanding how certain Lewis bases like H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O, NH<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>, HCl, and C<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, interact with specific nitriles such as, Glycolonitrile (GLY), Cyanic acid (CYA), and 3-Hydroxy-2-propenenitrile (HPN). These interactions form 1:1 complexes through hydrogen bond. Here we observed weak hydrogen bonding interactions such as, C<span><math><mo>≡</mo></math></span>N<span><math><mi>⋅</mi></math></span> <span><math><mi>⋅</mi></math></span> <span><math><mi>⋅</mi></math></span>H, O-H<span><math><mrow><mo>⋯</mo><mspace></mspace></mrow></math></span>N, O-H<span><math><mrow><mo>⋯</mo><mspace></mspace></mrow></math></span>O, or O-H<span><math><mrow><mo>⋯</mo><mi>π</mi></mrow></math></span> in these complexes. In C<span><math><mo>≡</mo></math></span>N<span><math><mi>⋅</mi></math></span> <span><math><mi>⋅</mi></math></span> <span><math><mi>⋅</mi></math></span>H interaction, when a nitrile molecule interacts with a Lewis base, it acts as a proton acceptor, while the corresponding Lewis base acts as a proton donor. However, this is reversed when the molecule possesses an O-H<span><math><mrow><mo>⋯</mo><mspace></mspace></mrow></math></span>X (X = N, O, Cl, <span><math><mi>π</mi></math></span>) interaction. Among these, in most cases, the complexes with O-H<span><math><mrow><mo>⋯</mo><mspace></mspace></mrow></math></span>X interactions were the most stable, representing the global minima. Detailed Atom in Molecule (AIM) and Natural Bonding Orbital (NBO) analyses confirmed the presence of these hydrogen bonds. Intermolecular bond critical points (BCPs) were identified. The electron density at BCPs <span><math><mrow><mi>ρ</mi><mrow><mo>(</mo><msub><mrow><mi>r</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>)</mo></mrow></mrow></math></span> was within the range of 0.002 to 0.035 a.u. as described in the Koch and Popelier study. The Laplacian of electron density <span><math><mrow><msup><mrow><mo>∇</mo></mrow><mrow><mn>2</mn></mrow></msup><mi>ρ</mi></mrow></math></span> was positive, further proving hydrogen bonding interaction. NBO analysis showed that O-H<span><math><mrow><mo>⋯</mo><mspace></mspace></mrow></math></span>N interactions had higher second order perturbation energies compared to O-H<span><math><mrow><mo>⋯</mo><mspace></mspace></mrow></math></span>O, O-H<span><math><mrow><mo>⋯</mo><mi>π</mi></mrow></math></span>, and O-H<span><math><mrow><mo>⋯</mo><mspace></mspace></mrow></math></span>Cl interactions.</div></div>","PeriodicalId":284,"journal":{"name":"Computational and Theoretical Chemistry","volume":"1244 ","pages":"Article 115072"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143160085","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 : 2025-02-01DOI: 10.1016/j.comptc.2024.115049
Kamal Ziadi, Abdelatif Messaoudi
This computational study analyzes how second-order nonlinear optical (NLO) properties can be enhanced in push–pull π-conjugated compounds of the type A-π-D, where the donor is based on an organic phenoxazine dye. Both the derivative and sum-over-states (SOS) methods were used to compare the molecular components of the known JK-201 species and POZ, as well as derivatives of the latter molecule with different electron-withdrawing substituents (POZ-F, POZ-CF3, and POZ-CN), to explore how molecular design affects the NLO response. Hyper-Rayleigh scattering (βHRS) is evaluated in both static and dynamic conditions with incident wavelengths of 1064 and 1907 nm, respectively. This provides insights into both the scattering efficiency and electronic transitions. The first hyperpolarizability β is visualized by unit sphere representation, with precise β0 calculations compared with the SOS model. Additionally, harmonic light intensity is calculated, and the predicted two-dimensional NLO spectra are examined, focusing on the dominant βXXX component.
{"title":"A theoretical investigation of second-order nonlinear optical properties in push–pull π-conjugated compounds, including phenoxazine-based systems","authors":"Kamal Ziadi, Abdelatif Messaoudi","doi":"10.1016/j.comptc.2024.115049","DOIUrl":"10.1016/j.comptc.2024.115049","url":null,"abstract":"<div><div>This computational study analyzes how second-order nonlinear optical (NLO) properties can be enhanced in push–pull π-conjugated compounds of the type A-π-D, where the donor is based on an organic phenoxazine dye. Both the derivative and sum-over-states (SOS) methods were used to compare the molecular components of the known JK-201 species and POZ, as well as derivatives of the latter molecule with different electron-withdrawing substituents (POZ-F, POZ-CF3, and POZ-CN), to explore how molecular design affects the NLO response. Hyper-Rayleigh scattering (β<sub>HRS</sub>) is evaluated in both static and dynamic conditions with incident wavelengths of 1064 and 1907 nm, respectively. This provides insights into both the scattering efficiency and electronic transitions. The first hyperpolarizability β is visualized by unit sphere representation, with precise β<sub>0</sub> calculations compared with the SOS model. Additionally, harmonic light intensity is calculated, and the predicted two-dimensional NLO spectra are examined, focusing on the dominant β<sub>XXX</sub> component.</div></div>","PeriodicalId":284,"journal":{"name":"Computational and Theoretical Chemistry","volume":"1244 ","pages":"Article 115049"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143160650","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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