Physical Chemistry Chemical Physics最新文献

{"title":"Selected ion flow tube studies of the reactions of H3O+, NO+, O2+• and O-• ions with alkanes in He and N2 carrier gases at different temperatures","authors":"Maroua Omezzine Gnioua, Stefan J Swift, Patrik Spanel","doi":"10.1039/d4cp03105a","DOIUrl":"https://doi.org/10.1039/d4cp03105a","url":null,"abstract":"The kinetics of the reactions of H3O+, NO+, O2+• and O-• with n-hexane, 3-methylpentane, 2,5-dimethylhexane and 2,3-dimethylheptane were studied experimentally under several selected ion flow tube (SIFT) conditions: in a Profile 3 instrument in He and N2 carrier gases at 300 K and in the Voice200 instrument in N2 carrier gas at 300 and 393 K - where the effect of the extraction lens voltage was also assessed. It was found that H3O+ ions react by association forming adduct ions along with dissociative reactions forming [M-H]+ product ions at reaction rates which are slower than collisional. NO+ ions react via hydride ion transfer. O2+• ions react via charge transfer followed by fragmentation that is highly sensitive to the temperature and the ion extraction lens voltage. Negative ions did not react, except for the O-• ion which reacted via an associative detachment process. Computational analysis using Density Functional Theory (DFT) provided insights into the exothermicities and exergodicities of these reactions. A notable result is that proton transfer from H3O+ does not take place despite its potential exothermicity; this is important for the interpretation of proton transfer reaction (PTR) and SIFT mass spectrometry data.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142384327","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}

{"title":"Solution and Solid-State Fluorescence Emission from Cyanostyrene molecules with multiple nitrogen atoms","authors":"Yang Chen, Smruti Ranjan Sahoo, Glib Baryshnikov, Lei Gao, Zhi-Jia Zhu, Hongwei Wu","doi":"10.1039/d4cp03297g","DOIUrl":"https://doi.org/10.1039/d4cp03297g","url":null,"abstract":"A design strategy has been proposed to utilize structure-driven solution and solid-state fluorescence emission of polynitrogen atoms. The strategy uses benzimidazole as the electron donor and pyridine as the electron acceptor to construct D-A-type cyanopyridine ethylene molecules. Theoretical calculations reveal that compound 1 has energy-close isomers in dilute solutions, with planar conformation in S0 and S1 states, reducing molecular motion and thus enhancing radiation efficiency (quantum yield up to 42.7%). Conversely, the distorted cyanobenzene structure reduces the quenching effect of π-π stacking alignment, and hydrogen bonding between molecules limits molecular vibration and rotation, ultimately leading to strong emission in the solid state (quantum yield up to 27.4%). These dual-state luminescence systems have wide-ranging potential applications in information encryption and temperature sensors.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142384333","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}

{"title":"Electric-Field-Induced Structure and Dynamics of Ethanol-Water Mixture in Hydrophobic-hydrophilic Nanochannels","authors":"Abir Ghosh, Sunandini Swain, Atanu Metya","doi":"10.1039/d4cp02993c","DOIUrl":"https://doi.org/10.1039/d4cp02993c","url":null,"abstract":"Understanding the behavior of confined fluid mixtures under external electric fields is essential for advancing scientific knowledge and improving a wide range of technological applications, from energy systems to biological processes. The electric field widely used to investigate the phase transition of water and modification of interfacial water at the nanoscale. However, a molecular-level understanding of the interfacial layer of a confined fluid mixture under an electric field remains unexplored. In this study, we explore the structural and dynamic behavior of binary ethanol-water mixtures confined within slit like hydrophilic (mica) and hydrophobic (graphene) nanochannels under an external electric-field using classical molecular dynamics (MD) simulations. We find two distinct interfacial water layers near the hydrophilic mica surface, and a more pronounced sharp peak appears near the hydrophobic graphene sheet with increasing electric field. The density maxima of the -OH and -CH3 groups of ethanol shift towards and away from the graphene surface with an increasing electric field. Our simulations reveal that the electric field strongly impacts the inter and intralayer hydrogen bonding among water and ethanol molecules. The diffusion coefficient of water slightly increases with the electric field and then reduces with an electric field for a lower concentration of ethanol. This finding reveals that the electric field influences the desorption of interfacial water near the hydrophilic mica surface, which can be an implication for diverse technological applications like modifying surface wettability.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142383796","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}

{"title":"Accelerated molecular dynamics study of interaction mechanism between small molecule inhibitors and phosphoglycerate mutantase 1","authors":"Yanqi Sun, Chaoyue Jia, Shaolong Zhang, Qinggang Zhang, Jianzhong Chen, Xinguo Liu","doi":"10.1039/d4cp03309d","DOIUrl":"https://doi.org/10.1039/d4cp03309d","url":null,"abstract":"In 2020, cancer-related deaths reached 9.96 million globally, of which China accounted for 3 million, ranking first in the world. Phosphoglycerate mutase 1 (PGAM1) is a key metabolic enzyme in glycolysis, catalysing the conversion of 3-phosphoglycerate to 2-phosphoglycerate. Based on the excellent anticancer activity of PGMI-004A and HKB99, new small molecules with an anthraquinone core were synthesised to inhibit tumour growth. Developing small molecules with an anthraquinone core targeting PGAM1 may be an effective strategy for treating cancer. In this study, accelerated molecular dynamics (aMD) simulation, dynamic cross-correlation map (DCCM) calculation, principal component analysis (PCA) and free energy landscape (FEL) analysis were used to analyse conformational changes of PGAM1 caused by binding of inhibitors 8KX, 9HU and HKB. DCCM calculation and PCA showed that inhibitor binding significantly affected the kinetic behaviour of PGAM1 and conformational rearrangement of PGAM1. The binding ability and mechanism of 8KX, 9HU and HKB to PGAM1 were studied using the molecular mechanics generalised Born surface area (MM-GBSA) method. The results showed that compared with 8KX, the binding ability of 9HU and HKB to PGAM1 was enhanced by sulphonamide reversal and aminocarboxyl trifluoromethyl substitution. There were several hydrophobic interactions between inhibitors and PGAM1, providing significant contributions for inhibitor binding. Calculation of residue-based free energy decomposition, revealed that F22, R90, Y92, L95, V112, W115, R116, V121, P123, P124, R191 and M206 were key residues of the PGAM1–inhibitor interaction, and could be used as effective targets for designing drugs that inhibit the activity of PGAM1.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142383884","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}

{"title":"Ionic Flow Through Partially Blocked Nanopores","authors":"Sipra Mohapatra, Hema Teherpuria, Santosh Mogurampelly, Matthew Downton, Sridhar Kumar Kannam","doi":"10.1039/d4cp02365j","DOIUrl":"https://doi.org/10.1039/d4cp02365j","url":null,"abstract":"Employing atomistic molecular dynamics simulations, we investigate the conductivity of a partially blocked nanopore containing a centrally positioned spherical constriction, exploring the effects of pore diameter, surface charge, and blockage size. Our results show that ionic mobilities are significantly influenced by the polarity of the surface charge and the size of the pore gap. Particularly, we observe ion-specific effects for K$^+$ and Cl$^-$ ions based on their size and charge, especially in sub-nanometer pore gaps. Furthermore, we find that the current flow in partially blocked nanopores sensitively depends on the surface charges, consistent with the calculated free energy profiles. The percentage of the current drop is found to be correlated to the volume of the spherical constriction with the effects more pronounced when the sizes of the spherical blockage and nanopore are comparable.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142383790","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}

{"title":"Mechanistic study of double boron-silicon exchange reactions between dibenzosiloles and boron tribromide","authors":"Liam Harrison Britt, Yuming Zhao","doi":"10.1039/d4cp03118k","DOIUrl":"https://doi.org/10.1039/d4cp03118k","url":null,"abstract":"This paper describes a mechanistic study on double boron-silicon exchange reactions between dibenzosiloles and boron tribromide. This type of reaction presents a safe and environmentally benign approach to convert electron-rich siloles into corresponding electron-deficient boroles and hence shows intriguing potential for the synthesis of boron-doped π-conjugated molecular materials. However, the detailed mechanisms for such reactions have not yet been established in the current literature. In this work, we performed density functional theory (DFT) calculations in conjunction with NMR analysis to unravel the reaction pathways and energy profiles for relevant boron-silicon exchange reactions where two dibenzolesiloles and a phenanthrosilole were employed as reactants, respectively. Our results have shown that excess boron tribromide provides beneficial microsolvation effects on key transition states and reactive intermediates to lower the activation energy barrier for the overall reaction. In the meantime, the substitution pattern at the bay region of the dibenzosilole framework exerts significant impacts on the potential energy surface of the reaction; increased steric hindrance at the bay region decelerates the second boron-silicon exchange step, while extended π-conjugation at the bay region makes the first boron-silicon exchange more challenging. Overall, our computational and experimental results provide an in-depth understanding of the reactivity and scope of this type of reaction, which in turn serves as useful guidance for ongoing research in the field of borole-based organic optoelectronic materials.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142383795","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}

{"title":"Effect of meso-pentafluorophenyl group on two-photon absorption in heterocorroles and heterocorrins","authors":"Tejendra Banana, Swati Singh Rajput, Neelam Chandravanshi, Md Mehboob Alam","doi":"10.1039/d4cp03450c","DOIUrl":"https://doi.org/10.1039/d4cp03450c","url":null,"abstract":"Owing to their high reactivity, the meso-position of corroles and corrins are usually protected by some bulky group. These groups in addition to the said purpose may also affect the photophysical properties of such systems. However, there is no systematic study in the literature exploring this effect. In this work, we target to answer how the meso-substitution affects the photophysical properties in some heterocorroles and heterocorrins. We considered one of the commonly used substitutions <em>i.e.,</em> pentafluorophenyl (-PFPh) at meso positions of 26 heterocorroles and heterocorrins. We employed the state-of-the-art CC2 method in conjunction with resolution-of-identity approximation to study the charge-transfer and one- and two-photon absorption in these systems. It is further explored using a four-state model that helps in understanding the contribution of various transition dipole moments and their relative orientation. At the end, we also investigated the effect of other substitutions such as -CH<small>₃</small>, -CF<small>₃</small>, -C<small>₂</small>H<small>₃</small>, -OMe, -Phenyl, and -Tolyl on two-photon activity.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142383798","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}

{"title":"Effect of exohedral functionalization on the magnetic properties in the dysprosium-containing endohedral fullerene DySc2N@C80(CF2)","authors":"Viktor E. Khinevich, Svetlana M. Sudarkova, Ilya N. Ioffe","doi":"10.1039/d3cp05959f","DOIUrl":"https://doi.org/10.1039/d3cp05959f","url":null,"abstract":"We present a quantum-chemical study of the effect of exohedral functionalization with a CF2 group on the lowest electronic states and the zero-field splitting pattern in a potential single-molecule magnet (SMM) compound DySc2N@C80(CF2). Multiconfiguration perturbational methodology is applied to various spin states of the endohedral compound, comparing different active spaces and state-averaging schemes in order to check for the possible involvement of orbitals other than 4f-Dy in the nondynamical electronic correlation and to suggest the most appropriate computational parameters. Combining the spin-orbit coupling calculations with perturbational corrections, we demonstrate that the interactions within the endohedral cluster and with the fullerene cage exert only a small effect on the non-relativistic approximation to the electronic states of the Dy3+ ion, yet they are significant enough to alter the picture of zero-field splitting depending on the orientation of the DySc2N cluster inside the fullerene cage.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142383799","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}

{"title":"Prediction of ternary alkaline-earth metal Sn(II) and Pb(II) chlorides with potential applications as p-type transparent conductors","authors":"Li Wang, Tingting Lin, Jia Wang, Chao Fang, Yuwei Li, Yuancun Qiao","doi":"10.1039/d4cp03090g","DOIUrl":"https://doi.org/10.1039/d4cp03090g","url":null,"abstract":"Non-metallic Sn(II) and Pb(II) compounds, particularly those with <em>p</em>-type properties, are essential functional materials due to their notable electronic arrangement and chemical characteristics. The presence of additional Sn(II) and Pb(II) chlorides is suggested by the existence of known Sn(II) and Pb(II) compounds. By utilizing first-principles calculations and swarm intelligence structure search techniques, we have predicted the existence of up to seven new ternary alkaline-earth metal chlorides: <em>AB</em>Cl<small>₄</small> (where <em>A</em> = Sr and <em>B</em> = Sn or Pb) and <em>AB</em><small>₂</small>Cl<small>₆</small> (where <em>A</em> = Mg, Ca, or Ba and <em>B</em> = Sn, or <em>A</em> = Ca or Sr and <em>B</em> = Pb). These seven chlorides are in the divalent state. The interaction between Sn-5<em>s</em> (or Pb-6<em>s</em>) and Cl-3<em>p</em> in these compounds creates an anti-bonding effect in the upper valence bands, which enhances defect tolerance and promotes high <em>p</em>-type conductivity. These stable chlorides exhibit notable electronic properties, including wide band gaps ranging from 3.91 to 4.94 eV, broad hole effective masses ranging from 0.93 to 5.62 m<small>₀</small>, and high valence band alignments ranging from 6.83 to 8.38 eV under vacuum. Specifically, Ca/BaSn<small>₂</small>Cl<small>₆</small> and CaPb<small>₂</small>Cl<small>₆</small> have the potential to be used as <em>p</em>-type transparent conductors due to their favorable properties, including a lower hole effective mass (0.93 m<small>₀</small> for CaPb<small>₂</small>Cl<small>₆</small>) and higher ionization potentials (6.83/7.05 eV for Ba/CaSn<small>₂</small>Cl<small>₆</small>). Furthermore, the predicted CaPb<small>₂</small>Cl<small>₆</small> crystal exhibits an attenuated negative linear compressibility and negative zero-linear-compressibility of the <em>c</em>-axis in different pressure ranges due to the wine-rack structure. This report highlights potential applications for alkaline-earth metal Sn(II) and Pb(II) chlorides, including their use as transparent conductors, particularly the <em>p</em>-type.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142383755","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}

{"title":"Elemental ferroelectric topological insulator in ψ-bismuthene","authors":"Xuening Han, Fulu Zheng, Thomas Frauenheim, Pei Zhao, Yan Liang","doi":"10.1039/d4cp03456b","DOIUrl":"https://doi.org/10.1039/d4cp03456b","url":null,"abstract":"Ferroelectric quantum spin Hall insulator (FEQSHI) exhibits coexisting ferroelectricity and time-reversal symmetry protected edge states, holding exciting prospects for inviting both scientific and application advances, particularly in two-dimensional systems. However, FEQSHI candidates that consist of only one constituent element are rarely reported. Here, we show that the ψ-bismuthene, an allotrope of bilayer Bi (110), as a concrete example of two-dimensional elemental FEQSHI. It is demonstrated that ψ-bismuthene possesses measurable ferroelectric polarization and nontrivial band gap with moderate switching barrier, making it highly suitable for the detection and observation of ferroelectric topologically insulating states. Additionally, the auxetic behavior, quantum transport property and ferroelectric controllable persistent spin helix in ψ-bismuthene are also discussed. These findings make ψ-bismuthene promising for both fundamental physics and technological innovations.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142383797","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}