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Zhong Q. Size-dependent linear and nonlinear optical responses of silicon clusters. Phys Chem Chem Phys 2024; 26:6022-6028. [PMID: 38294058 DOI: 10.1039/d3cp05678c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Owing to strong quantum confinement effects and no periodic constraints, the geometric and electronic structures of silicon clusters differ from those of crystalline silicon. Although previous studies have elucidated the optical properties of silicon clusters, some issues remain unresolved. To address these, this study examined the size-dependent linear and nonlinear optical responses of silicon clusters through first-principles calculations. Silicon clusters exhibited lone-pair-electron-dominated optical response behaviors. With the investigated size range, the orientationally average polarizability (αave) and second-order hyperpolarizability (γave) increased with cluster size. However, αave and γave per atom exhibited no evident size-dependent trends owing to co-modulation of the lone-pair-number-to-atomic-number ratio and geometry. αave and γave were notably sensitive to the nuclear binding strength of lone-pair electrons. Thus, the nonlinear optical effects of silicon clusters are superior to those of phosphorus and sulfur clusters. This investigation offers valuable insights into the optical responses of atomic-precision clusters.
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Affiliation(s)
- Quanjie Zhong
- School of Materials Science and Physics, Nanhu Campus, China University of Mining and Technology, No. 1 University Road, Xuzhou 221116, Jiangsu Province, China.
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2
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Medrano Sandonas L, Hoja J, Ernst BG, Vázquez-Mayagoitia Á, DiStasio RA, Tkatchenko A. "Freedom of design" in chemical compound space: towards rational in silico design of molecules with targeted quantum-mechanical properties. Chem Sci 2023; 14:10702-10717. [PMID: 37829035 PMCID: PMC10566466 DOI: 10.1039/d3sc03598k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 08/17/2023] [Indexed: 10/14/2023] Open
Abstract
The rational design of molecules with targeted quantum-mechanical (QM) properties requires an advanced understanding of the structure-property/property-property relationships (SPR/PPR) that exist across chemical compound space (CCS). In this work, we analyze these fundamental relationships in the sector of CCS spanned by small (primarily organic) molecules using the recently developed QM7-X dataset, a systematic, extensive, and tightly converged collection of 42 QM properties corresponding to ≈4.2M equilibrium and non-equilibrium molecular structures containing up to seven heavy/non-hydrogen atoms (including C, N, O, S, and Cl). By characterizing and enumerating progressively more complex manifolds of molecular property space-the corresponding high-dimensional space defined by the properties of each molecule in this sector of CCS-our analysis reveals that one has a substantial degree of flexibility or "freedom of design" when searching for a single molecule with a desired pair of properties or a set of distinct molecules sharing an array of properties. To explore how this intrinsic flexibility manifests in the molecular design process, we used multi-objective optimization to search for molecules with simultaneously large polarizabilities and HOMO-LUMO gaps; analysis of the resulting Pareto fronts identified non-trivial paths through CCS consisting of sequential structural and/or compositional changes that yield molecules with optimal combinations of these properties.
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Affiliation(s)
- Leonardo Medrano Sandonas
- Department of Physics and Materials Science, University of Luxembourg L-1511 Luxembourg City Luxembourg
| | - Johannes Hoja
- Department of Physics and Materials Science, University of Luxembourg L-1511 Luxembourg City Luxembourg
- Institute of Chemistry, University of Graz 8010 Graz Austria
| | - Brian G Ernst
- Department of Chemistry and Chemical Biology, Cornell University Ithaca NY 14853 USA
| | | | - Robert A DiStasio
- Department of Chemistry and Chemical Biology, Cornell University Ithaca NY 14853 USA
| | - Alexandre Tkatchenko
- Department of Physics and Materials Science, University of Luxembourg L-1511 Luxembourg City Luxembourg
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3
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Tandon H, Ranjan P, Chakraborty T. A computational and theoretical study of some heavy metal heteronuclear dimers. J INDIAN CHEM SOC 2022. [DOI: 10.1016/j.jics.2022.100643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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4
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Hussain R, Saeed M, Mehboob MY, Khan SU, Usman Khan M, Adnan M, Ahmed M, Iqbal J, Ayub K. Density functional theory study of palladium cluster adsorption on a graphene support. RSC Adv 2020; 10:20595-20607. [PMID: 35517764 PMCID: PMC9054311 DOI: 10.1039/d0ra01059f] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 05/18/2020] [Indexed: 11/21/2022] Open
Abstract
The geometric, thermodynamic and electronic properties of Pd–graphene nanocomposites are comprehensively studied through quantum mechanical methods. Geometries of these clusters are optimized with the well-calibrated Minnesota functional M06-2X. The adsorption energies calculated at the M06-2X/LANL2DZ level show better agreement with those calculated from MP2/ANO-RCC-VDZP. Two different representative models for graphene, coronene and hexabenzocoronene, are used. The adsorption energies analysis reveals that the interaction energies increase with the size of the adsorbed cluster. However, for Pdn/hexabenzocoronene, the interaction energies show a sudden drop at Pd8/hexabenzocoronene. The difference in behavior between the interaction energies of Pdn/hexabenzocoronene and Pdn/coronene is attributed to the edge effect present in coronene. The electronic properties, including highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), Fermi level, molecular electrostatic potential (MEP), dipole moment, vertical ionization potential (VIP), vertical electron affinity (VEA), chemical hardness (η), softness (S) and chemical potential (μ) are studied. The VIP and VEA reveal that Pdn/coronene clusters are stable in nature with the least reactivity. The HOMO–LUMO energy gaps are reduced with the increase in cluster size. The electronic properties show irregular trends, where the most favorable electronic properties are obtained for Pd7/coronene and Pd10/coronene. The geometric, thermodynamic and electronic properties of Pd–graphene nanocomposites are comprehensively studied through quantum mechanical methods.![]()
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Affiliation(s)
- Riaz Hussain
- Department of Chemistry
- University of Okara
- Okara 56300
- Pakistan
| | - Muhammad Saeed
- Department of Chemistry
- Government College University
- Faisalabad 38000
- Pakistan
| | | | - Saif Ullah Khan
- Department of Chemistry
- Government College University
- Faisalabad 38000
- Pakistan
| | | | - Muhammad Adnan
- College of Natural Sciences
- Department of Chemistry
- Chosun University
- South Korea
| | | | - Javed Iqbal
- Department of Chemistry
- University of Agriculture
- Faisalabad 38000
- Pakistan
| | - Khurshid Ayub
- Department of Chemistry
- COMSATS Institute of Information Technology
- Abbottabad
- Pakistan
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Bhakhoa H, Rhyman L, Ramasami P. Theoretical study of the molecular aspect of the suspected novichok agent A234 of the Skripal poisoning. ROYAL SOCIETY OPEN SCIENCE 2019; 6:181831. [PMID: 30891291 PMCID: PMC6408395 DOI: 10.1098/rsos.181831] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 01/14/2019] [Indexed: 05/22/2023]
Abstract
Novichoks are the suspected nerve agents in the March 2018 Skripal poisoning. In this context, the novichok agent A234 (chemical structure proposed by Mirzayanov) was studied using computational methods to shed light on its molecular, electronic, spectroscopic, thermodynamic and toxicity parameters as well as on potential thermal and hydrolysis degradation pathways. The poisoning action and antidote of A234 were also investigated. Some of these parameters were compared to three common G- and V-series nerve agents, namely GB, VR and VX. The research findings should be useful towards the detection, development of antidotes and destruction of A234.
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Affiliation(s)
- Hanusha Bhakhoa
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit 80837, Mauritius
| | - Lydia Rhyman
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit 80837, Mauritius
- Department of Applied Chemistry, University of Johannesburg, Doornfontein, Johannesburg 2028, South Africa
| | - Ponnadurai Ramasami
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit 80837, Mauritius
- Department of Applied Chemistry, University of Johannesburg, Doornfontein, Johannesburg 2028, South Africa
- Author for correspondence: Ponnadurai Ramasami e-mail:
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Li X, Chen Y, Basnet P, Luo J, Wang H. Probing the properties of size dependence and correlation for tantalum clusters: geometry, stability, vibrational spectra, magnetism, and electronic structure. RSC Adv 2019; 9:1015-1028. [PMID: 35517637 PMCID: PMC9059546 DOI: 10.1039/c8ra09240k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 12/20/2018] [Indexed: 11/30/2022] Open
Abstract
A comprehensive investigation on the equilibrium geometry, relative stability, vibrational spectra, and magnetic and electronic properties of neutral tantalum clusters (Tan, n = 2–17) was performed using density functional theory (DFT). We perform a study of the size dependence and correlations among those descriptors of parameters, and showed these could provide a novel way to confirm and predict experimental results. Some new isomer configurations that have never been reported before for tantalum clusters were found. The growth behaviors revealed that a compact geometrical growth route is preferred and develops a body-centered-cubic (BCC) structure with the cluster size increasing. The perfectly fitted functional curve, strong linear evolution, and obvious odd–even oscillation behavior proved their corresponding properties depended on the cluster size. Multiple demonstrations of the magic number were confirmed through the correlated relationships with the relative stability, including the second difference in energy, maximum hardness, and minimum polarizability. An inverse evolution trend between the energy gap and electric dipole moment and strong linear correlation between ionization potentials and polarizability indicated the strong correlation between the magnetic and electronic properties. Vibrational spectroscopy as a fingerprint was used to distinguish the ground state among the competitive geometrical isomers close in energy. The charge density difference isosurface, density of states, and molecular orbitals of selected representative clusters were analyzed to investigate the difference and evolutional trend of the relative stability and electronic structure. In addition, we first calculated the ionization potential and magnetic moment and compared these with the current available experimental data for tantalum clusters. A comprehensive investigation on the equilibrium geometry, relative stability, vibrational spectra, and magnetic and electronic properties of neutral tantalum clusters (Tan, n = 2–17) was performed using density functional theory (DFT).![]()
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Affiliation(s)
- Xibo Li
- Science and Technology on Plasma Physics Laboratory
- Laser Fusion Research Center
- China Academy of Engineering Physics
- Mianyang
- China
| | - Yuqi Chen
- School of Physical Science and Technology
- Southwest Jiaotong University
- Chengdu
- China
| | - Pradip Basnet
- School of Materials Science and Engineering
- Georgia Institute of Technology
- Atlanta
- USA
| | - Jiangshan Luo
- Science and Technology on Plasma Physics Laboratory
- Laser Fusion Research Center
- China Academy of Engineering Physics
- Mianyang
- China
| | - Hongyan Wang
- School of Physical Science and Technology
- Southwest Jiaotong University
- Chengdu
- China
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Schwerdtfeger P, Nagle JK. 2018 Table of static dipole polarizabilities of the neutral elements in the periodic table. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1535143] [Citation(s) in RCA: 123] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Peter Schwerdtfeger
- Centre for Theoretical Chemistry and Physics, The New Zealand Institute for Advanced Study and the Institute for Natural and Mathematical Sciences, Massey University Albany, Auckland, New Zealand
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Obuah C, Ainooson MK, Darkwa J. Effects of electrochemical properties of ferrocenylpyrazolylnickel(ii) and palladium(ii) compounds on their catalytic activities in ethylene oligomerisation reactions. RSC Adv 2018; 8:5362-5371. [PMID: 35542429 PMCID: PMC9078115 DOI: 10.1039/c7ra13588b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 01/24/2018] [Indexed: 11/21/2022] Open
Abstract
Palladium complexes of ferrocenylpyrazolylpyridine and ferrocenylpyrazolylamine were synthesised and screened as pre-catalysts (1–4) for olefin polymerisation. The pre-catalysts 1–4 on activation with EtAlCl2 in the presence of ethylene with chlorobenzene or hexane as solvent were highly active with 1 being the most active, with an activity of 360 kg mol Pd−1 h−1. The major product from the reaction was 1-butene and high carbon content oligomers. The molecular weight (m/z) of the high carbon content oligomers is as high as 623.0. When toluene is used as solvent, the products obtained were ethyltoluene and butyltoluene and 1-butene. The electronic properties of the ligands (L1–L7) and complexes (1–10) were determined by cyclic voltammetry (CV) and molecular modelling. The CV results show that the ferrocenyl is easily oxidized upon the introduction of pyrazolyl derivatives, the process is quasi-reversible. However, complexation of the ligands with palladium or nickel results in difficulty in oxidizing the ferrocenyl moiety. This is an indication of the electrophilic nature of both the palladium and nickel centres. The mechanism of the oxidation was observed to be diffusion-controlled and is independent of scan rate. Molecular modelling experiments show that nickel and palladium complexes have lower HOMO–LUMO gaps and high global descriptors, an indication of a highly electrophilic metal centre. A plot of the electrophilicity indices of the pre-catalysts against yield of the oligomers show a linear correlation, an indication that the electrophilicity of the metal centre plays an important role in the activity of these pre-catalysts. Studying the correlation between the electrophilicity of the metal centre and the activity of the resulting catalyst using electrochemistry and computation modelling.![]()
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Affiliation(s)
- Collins Obuah
- Department of Chemistry
- University of Johannesburg
- Johannesburg
- South Africa
- Department of Chemistry
| | - Michael K. Ainooson
- Department of Chemistry
- University of Johannesburg
- Johannesburg
- South Africa
- Department of Chemistry
| | - James Darkwa
- Department of Chemistry
- University of Johannesburg
- Johannesburg
- South Africa
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Suvitha A, Venkataramanan NS. DFT calculations on polarizabilities and hyperpolarizabilities for the neutral and anionic yttrium oxide clusters. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2015. [DOI: 10.1142/s0219633615500492] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The electronic properties, polarizabilities, first and second hyperpolarizabilities of YOn clusters of [Formula: see text]–12 were studied using the quantum chemical method. The vertical ionization potential (VIP) values for the anionic clusters increase monotonically with the cluster size. Among the neutral clusters YO3 and YO8 have the least chemical hardness values, where in anionic clusters with size [Formula: see text] possesses the least chemical hardness. Anionic clusters have more electrons attracting tendency than the neutral clusters. The computed static mean polarizability of neutral yttrium oxides has positive values but is close to zero. The incorporation of oxygen atom quenches the polarizability of yttrium. The computed polarizability anisotropy of neutral clusters shows an oscillatory effect both at static and at dynamic conditions. The first hyperpolarizability for many YOn clusters are close to zero. The existence of high symmetry in these clusters reduces the first hyperpolarizability values which was supported by the small dipole moments. The computed [Formula: see text] values for the static neutral and anionic clusters show only a small variation. The decrease in the polarizability and second hyperpolarizability with size can be interpreted in terms of the electronic delocalization and chemical bonding in the clusters.
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Affiliation(s)
- Ambigapathy Suvitha
- School of Chemical and Biotechnology (SCBT), SASTRA University, Tirumalaisamudram, Thanjavur 613401, India
| | - Natarajan Sathiyamoorthy Venkataramanan
- School of Chemical and Biotechnology (SCBT), SASTRA University, Tirumalaisamudram, Thanjavur 613401, India
- Centre for Computational Chemistry and Materials Science (CCCMS), SASTRA University, Tirumalaisamudram, Thanjavur 613401, India
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Avaltroni F, Corminboeuf C. Efficiency of random search procedures along the silicon cluster series: Sin (n = 5-10, 15, and 20). J Comput Chem 2011; 32:1869-75. [DOI: 10.1002/jcc.21769] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Revised: 01/17/2011] [Accepted: 01/18/2011] [Indexed: 11/05/2022]
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Jarmusik KE, Eppell SJ, Lacks DJ, Zypman FR. Obtaining charge distributions on geometrically generic nanostructures using scanning force microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:1803-1810. [PMID: 21250744 DOI: 10.1021/la104153p] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We develop the self-consistent sum of dipoles (SCSD) theory for the purpose of recovering charge densities present on nanostructures using scanning force microscope (SFM) force-separation experiments. The dielectric probe is discretized into volume elements characterized by their atomic polarizabilities. Magnitudes of the induced dipole in each element are calculated based on discrete charges placed on the surfaces, dipole-dipole interactions, and dielectric and ionic properties of the surrounding medium. We perform two model-model comparisons, one with a macroscopic dielectric sphere and one with a nanocluster of silicon atoms. In both cases, using a single adjustable parameter, our SCSD theory agrees with the accepted theories to better than 99%. Force-separation curves between a silicon nitride probe and the basal plane of highly oriented pyrolytic graphite in nine ionic concentration and pH combinations were fit with a root-mean-square error of 3.6 pN, an improvement over the 12 pN error obtained using the Derjaguin approximation. These results suggest that the SCSD will be useful in modeling SFM force-separation data to obtain spatially varying charge densities on surfaces with complex geometries.
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Affiliation(s)
- Keith E Jarmusik
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
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Santos JC, Contreras M, Merino G. Structure and stability of Si6Li6: Aromaticity vs polarizability. Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2010.07.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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