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Anjalikrishna PK, Gadre SR, Suresh CH. Topology of electrostatic potential and electron density reveals a covalent to non-covalent carbon-carbon bond continuum. Phys Chem Chem Phys 2023; 25:25191-25204. [PMID: 37721180 DOI: 10.1039/d3cp03268j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
The covalent and non-covalent nature of carbon-carbon (CC) interactions in a wide range of molecular systems can be characterized using various methods, including the analysis of molecular electrostatic potential (MESP), represented as V(r), and the molecular electron density (MED), represented as ρ(r). These techniques provide valuable insights into the bonding between carbon atoms in different molecular environments. By uncovering a fundamental exponential relationship between the distance of the CC bond and the highest eigenvalue (λv1) of V(r) at the bond critical point (BCP), this study establishes the continuum model for all types of CC interactions, including transition states. The continuum model is further delineated into three distinct regions, namely covalent, borderline cases, and non-covalent, based on the gradient, , with the bond distance of the CC interaction. For covalent interactions, this parameter exhibits a more negative value than -5.0 a.u. Å-1, while for non-covalent interactions, it is less negative than -1.0 a.u. Å-1. Borderline cases, which encompass transition state structures, fall within the range of -1.0 to -5.0 a.u. Å-1. Furthermore, this study expands upon Popelier's analysis of the Laplacian of the MED, denoted as ∇2ρ, to encompass the entire spectrum of covalent, non-covalent, and borderline cases of CC interactions. Therefore, the present study presents compelling evidence supporting the concept of a continuum model for CC bonds in chemistry. Additionally, this continuum model is further explored within the context of C-N, C-O, C-S, N-N, O-O, and S-S interactions, albeit with a limited dataset.
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Affiliation(s)
- Puthannur K Anjalikrishna
- Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram, Kerala, 695019, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Shridhar R Gadre
- Departments of Chemistry and Scientific Computing, Modelling & Simulation, Savitribai Phule Pune University, Pune 411007, India
| | - Cherumuttathu H Suresh
- Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram, Kerala, 695019, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
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Anjalikrishna PK, Gadre SR, Suresh CH. Electrostatic Potential for Exploring Electron Delocalization in Infinitenes, Circulenes, and Nanobelts. J Org Chem 2023; 88:4123-4133. [PMID: 36952587 DOI: 10.1021/acs.joc.2c02507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
The π-conjugation, aromaticity, and stability of the newly synthesized 12-infinitene and of other infinitenes comprising 8-, 10-, 14-, and 16-arene rings are investigated using density functional theory. The π-electron delocalization and aromatic character rooted in infinitenes are quantified in terms of molecular electrostatic potential (MESP) topology. Structurally, the infinitene bears a close resemblance of its helically twisted structure to the infinity symbol. The MESP topology shows that infinitene possesses an infinity-shaped delocalization of the electron density that streams over the fused benzenoid rings. The parameter ∑i=13Δλi, derived from the eigenvalues (λi) corresponding to the MESP minima, is used for quantifying the aromatic character of arene rings of infinitene. The structure, stability, and MESP topology features of 8-, 10-, 12-, 14-, and 16-infinitenes are also compared with the corresponding isomeric circulenes and carbon nanobelts. Further, the strain in all such systems is evaluated by considering the respective isomeric planar benzenoid hydrocarbons as reference systems. The 12-infinitene turns out to be the most aromatic and the least strained among all the systems examined.
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Affiliation(s)
- Puthannur K Anjalikrishna
- Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, Kerala, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Shridhar R Gadre
- Department of Scientific Computing, Modelling and Simulation, Savitribai Phule Pune University, Pune 411007, India
| | - Cherumuttathu H Suresh
- Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, Kerala, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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Electrostatic Potential Topology for Probing Molecular Structure, Bonding and Reactivity. Molecules 2021; 26:molecules26113289. [PMID: 34072507 PMCID: PMC8198923 DOI: 10.3390/molecules26113289] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 05/16/2021] [Accepted: 05/25/2021] [Indexed: 11/18/2022] Open
Abstract
Following the pioneering investigations of Bader on the topology of molecular electron density, the topology analysis of its sister field viz. molecular electrostatic potential (MESP) was taken up by the authors’ groups. Through these studies, MESP topology emerged as a powerful tool for exploring molecular bonding and reactivity patterns. The MESP topology features are mapped in terms of its critical points (CPs), such as bond critical points (BCPs), while the minima identify electron-rich locations, such as lone pairs and π-bonds. The gradient paths of MESP vividly bring out the atoms-in-molecule picture of neutral molecules and anions. The MESP-based characterization of a molecule in terms of electron-rich and -deficient regions provides a robust prediction about its interaction with other molecules. This leads to a clear picture of molecular aggregation, hydrogen bonding, lone pair–π interactions, π-conjugation, aromaticity and reaction mechanisms. This review summarizes the contributions of the authors’ groups over the last three decades and those of the other active groups towards understanding chemical bonding, molecular recognition, and reactivity through topology analysis of MESP.
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Koli AR, Yeole SD. Understanding the interactions between hydrogen-bonded complexes of xylose and water: Quantum Chemical Investigation. J CHEM SCI 2020. [DOI: 10.1007/s12039-020-1741-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Anjalikrishna PK, Suresh CH, Gadre SR. Electrostatic Topographical Viewpoint of π-Conjugation and Aromaticity of Hydrocarbons. J Phys Chem A 2019; 123:10139-10151. [PMID: 31647654 DOI: 10.1021/acs.jpca.9b09056] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A molecular electrostatic potential (MESP) topographical study has been conducted for a variety of conjugated hydrocarbons at B3LYP/6-311+G(d,p) level of theory to understand their π-conjugation features and aromaticity. The value of MESP minimum (Vm) is related to the localized and delocalized distribution of π-electron density. The Vm values are located interior to the rings in polycyclic benzenoid hydrocarbons (PBHs), whereas they lie outside the boundary of the rings in antiaromatic and in fused systems consisting of aromatic and antiaromatic moieties. The Vm points lie on top and bottom of the π-regions in linear polyenes and annulenes, while a degenerate distribution of CPs around the midpoint region of triple bonds is observed in alkynes. The eigenvalues λ1, λ2, and λ3 of the Hessian matrix at Vm(MESP minima) are used to define the aromatic character of the cyclic structures. The eigenvalues follow the trend λ1 ≫ λ2 > λ3 ≅ 0 in PBHs, λ1 > λ2 > λ3 ≅ 0 in linear polyenes, and λ1 > λ2 > λ3 ≠ 0 in antiaromatic systems. The difference in the aromatic character of PBHs from that of benzene is related to the deviations Δλ1, Δλ2, and Δλ3. The total deviation ∑i=13Δλi is found to be ≤ 0.011 au for all aromatic systems and lies between 0.011 and 0.035 au for all nonaromatic systems. For antiaromatic systems, its value is found to be above 0.035 au. Further, ∑i=13Δλi gives a direct interpretation of Clar's aromatic sextet structures for PBHs. In summary, MESP topography mapping is a powerful technique to quantify the localized and delocalized π-electron distribution in a variety of unsaturated hydrocarbon systems.
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Affiliation(s)
- Puthannur K Anjalikrishna
- Chemical Sciences and Technology Division , CSIR-National Institute for Interdisciplinary Science and Technology , Thiruvananthapuram , Kerala 695019 , India.,Academy of Scientific and Innovative Research (AcSIR) , Ghaziabad 201002 , India
| | - Cherumuttathu H Suresh
- Chemical Sciences and Technology Division , CSIR-National Institute for Interdisciplinary Science and Technology , Thiruvananthapuram , Kerala 695019 , India.,Academy of Scientific and Innovative Research (AcSIR) , Ghaziabad 201002 , India
| | - Shridhar R Gadre
- Interdisciplinary School of Scientific Computing , Savitribai Phule Pune University , Pune 411007 , India
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Kulkarni AD. Molecular Hydration of Carbonic Acid: Ab Initio Quantum Chemical and Density Functional Theory Investigation. J Phys Chem A 2019; 123:5504-5516. [PMID: 31244117 DOI: 10.1021/acs.jpca.9b01122] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Molecular hydration of carbonic acid (H2CO3) is investigated in terms of bonding patterns in H2CO3···(H2O) n [ n = 1-4] hydrogen-bonded clusters within ab initio quantum chemical and density functional theory (DFT) frameworks. Successive addition of water molecules to H2CO3···H2O entails elongation of O-H (hydroxyl) bond as well as contraction of specific intermolecular hydrogen bonds signifying hydration of carbonic acid; these structural features get markedly enhanced under the continuum solvation framework. A comparison between the structurally similar clusters H2CO3···(H2O) n and HCOOH···(H2O) n [ n = 1-3] brings out the structural stability of the former. The present investigation in conjunction with the binding energy behavior of approaching water molecule(s) should serve as a precursor for pathways exploring aqueous dissociation of H2CO3 for larger clusters, as well as development of force-field potentials for acid dissociation process.
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Affiliation(s)
- Anant D Kulkarni
- Solid State and Structural Chemistry Unit , Indian Institute of Science , Bangalore 560012 , India
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Bijina PV, Suresh CH, Gadre SR. Electrostatics for probing lone pairs and their interactions. J Comput Chem 2017; 39:488-499. [PMID: 29094379 DOI: 10.1002/jcc.25082] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 09/22/2017] [Accepted: 09/24/2017] [Indexed: 01/21/2023]
Abstract
The value of the molecular electrostatic potential minimum (Vmin ) and its topographical features (position, as well as the eigenvalues and eigenvectors of the corresponding Hessian matrix) are recently proposed as the criteria for characterizing a lone pair (Kumar A. et al., J. Phys. Chem. 2014, A118, 526). This electrostatic characterization of lone pairs is examined for a large number of small molecules employing MP4/6-311++G(d,p)//MP2/6-311++G(d,p) theory. The eigenvector of the Hessian matrix corresponding to its largest eigenvalue (λmax ), is found to be directed toward the lone pair-bearing-atom, with λmax showing a strong linear correlation with Vmin . Large magnitudes of Vmin and λmax indicate a charge-dense lone pair. The topographical features of Vmin are seen to provide insights into the interactive behavior of the molecules with model electrophiles, viz. HF, CO2 , and Li+ . In all the complexes of HF and majority of the other complexes, the interaction energy (Eint ) correlates well with the respective Vmin, value, but for some deviations occurring due to other competing secondary interactions. The electrostatic interactions are found to be highly directional in nature as the orientation of interacting atom correlates strongly to the position of lone pair. In summary, the present study on a large number of test molecules shows that electrostatics is able to probe lone pairs in molecules and offers a simple interpretation of chemical reactivity. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Padinjare Veetil Bijina
- Chemical Sciences and Technology Division and Academy of Scientific & Innovative Research (AcSIR), CSIR-National Institute for Interdisciplinary Science and Technology, Trivandrum, 695019, India
| | - Cherumuttathu H Suresh
- Chemical Sciences and Technology Division and Academy of Scientific & Innovative Research (AcSIR), CSIR-National Institute for Interdisciplinary Science and Technology, Trivandrum, 695019, India
| | - Shridhar R Gadre
- Interdisciplinary School of Scientific Computing, Savitribai Phule Pune University, Pune, 411007, India
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Hanson-Heine MW, Besley NA. Spectroscopic and structural analysis of mixed carbon dioxide and fluorinated methane clusters. Chem Phys Lett 2015. [DOI: 10.1016/j.cplett.2015.08.056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Affiliation(s)
- Michael A Collins
- †Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia
| | - Ryan P A Bettens
- ‡Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
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Rao SS, Gejji SP. Molecular insights accompanying aggregation in amino acid ionic liquids. COMPUT THEOR CHEM 2015. [DOI: 10.1016/j.comptc.2015.01.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Gadre SR, Kumar A. Understanding Lone Pair-π Interactions from Electrostatic Viewpoint. CHALLENGES AND ADVANCES IN COMPUTATIONAL CHEMISTRY AND PHYSICS 2015. [DOI: 10.1007/978-3-319-14163-3_13] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Comparison of reduced point charge models of proteins: Molecular Dynamics simulations of Ubiquitin. Sci China Chem 2014. [DOI: 10.1007/s11426-014-5109-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Mohan N, Suresh CH, Kumar A, Gadre SR. Molecular electrostatics for probing lone pair-π interactions. Phys Chem Chem Phys 2014; 15:18401-9. [PMID: 24085157 DOI: 10.1039/c3cp53379d] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
An electrostatics-based approach has been proposed for probing the weak interactions between lone pair containing molecules and π deficient molecular systems. For electron-rich molecules, the negative minima in molecular electrostatic potential (MESP) topography give the location of electron localization and the MESP value at the minimum (Vmin) quantifies the electron-rich character of that region. Interactive behavior of a lone pair bearing molecule with electron deficient π-systems, such as hexafluorobenzene, 1,3,5-trinitrobenzene, 2,4,6-trifluoro-1,3,5-triazine and 1,2,4,5-tetracyanobenzene explored within DFT brings out good correlation of the lone pair-π interaction energy (E(int)) with the Vmin value of the electron-rich system. Such interaction is found to be portrayed well with the Electrostatic Potential for Intermolecular Complexation (EPIC) model. On the basis of the precise location of MESP minimum, a prediction for the orientation of a lone pair bearing molecule with an electron deficient π-system is possible in the majority of the cases studied.
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Affiliation(s)
- Neetha Mohan
- Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Trivandrum, 695019, India.
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Structural and spectroscopic studies of carbon dioxide clusters: a combined genetic algorithm and DFT based study. Struct Chem 2013. [DOI: 10.1007/s11224-013-0360-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Yeole SD, López R, Gadre SR. Rapid topography mapping of scalar fields: large molecular clusters. J Chem Phys 2013; 137:074116. [PMID: 22920112 DOI: 10.1063/1.4746243] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
An efficient and rapid algorithm for topography mapping of scalar fields, molecular electron density (MED) and molecular electrostatic potential (MESP) is presented. The highlight of the work is the use of fast function evaluation by Deformed-atoms-in-molecules (DAM) method. The DAM method provides very rapid as well as sufficiently accurate function and gradient evaluation. For mapping the topography of large systems, the molecular tailoring approach (MTA) is invoked. This new code is tested out for mapping the MED and MESP critical points (CP's) of small systems. It is further applied to large molecular clusters viz. (H(2)O)(25), (C(6)H(6))(8) and also to a unit cell of valine crystal at MP2/6-31+G(d) level of theory. The completeness of the topography is checked by extensive search as well as applying the Poincaré-Hopf relation. The results obtained show that the DAM method in combination with MTA provides a rapid and efficient route for mapping the topography of large molecular systems.
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Affiliation(s)
- Sachin D Yeole
- Department of Chemistry, IIT Kanpur, Kanpur 208016, India
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Sarmah S, Guha AK, Phukan AK, Kumar A, Gadre SR. Stabilization of Si(0) and Ge(0) compounds by different silylenes and germylenes: a density functional and molecular electrostatic study. Dalton Trans 2013; 42:13200-9. [DOI: 10.1039/c3dt50926e] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Sayyed FB, Suresh CH. Accurate prediction of cation-π interaction energy using substituent effects. J Phys Chem A 2012; 116:5723-32. [PMID: 22616763 DOI: 10.1021/jp3034193] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Substituent effects on cation-π interactions have been quantified using a variety of Φ-X···M(+) complexes where Φ, X, and M(+) are the π-system, substituent, and cation, respectively. The cation-π interaction energy, E(M(+)), showed a strong linear correlation with the molecular electrostatic potential (MESP) based measure of the substituent effect, ΔV(min) (the difference between the MESP minimum (V(min)) on the π-region of a substituted system and the corresponding unsubstituted system). This linear relationship is E(M(+)) = C(M(+))(ΔV(min)) + E(M(+))' where C(M(+)) is the reaction constant and E(M(+))' is the cation-π interaction energy of the unsubstituted complex. This relationship is similar to the Hammett equation and its first term yields the substituent contribution of the cation-π interaction energy. Further, a linear correlation between C(M(+))() and E(M(+))()' has been established, which facilitates the prediction of C(M(+)) for unknown cations. Thus, a prediction of E(M(+)) for any Φ-X···M(+) complex is achieved by knowing the values of E(M(+))' and ΔV(min). The generality of the equation is tested for a variety of cations (Li(+), Na(+), K(+), Mg(+), BeCl(+), MgCl(+), CaCl(+), TiCl(3)(+), CrCl(2)(+), NiCl(+), Cu(+), ZnCl(+), NH(4)(+), CH(3)NH(3)(+), N(CH(3))(4)(+), C(NH(2))(3)(+)), substituents (N(CH(3))(2), NH(2), OCH(3), CH(3), OH, H, SCH(3), SH, CCH, F, Cl, COOH, CHO, CF(3), CN, NO(2)), and a large number of π-systems. The tested systems also include multiple substituted π-systems, viz. ethylene, acetylene, hexa-1,3,5-triene, benzene, naphthalene, indole, pyrrole, phenylalanine, tryptophan, tyrosine, azulene, pyrene, [6]-cyclacene, and corannulene and found that E(M)(+) follows the additivity of substituent effects. Further, the substituent effects on cationic sandwich complexes of the type C(6)H(6)···M(+)···C(6)H(5)X have been assessed and found that E(M(+)) can be predicted with 97.7% accuracy using the values of E(M(+))' and ΔV(min). All the Φ-X···M(+) systems showed good agreement between the calculated and predicted E(M(+))() values, suggesting that the ΔV(min) approach to substituent effect is accurate and useful for predicting the interactive behavior of substituted π-systems with cations.
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Affiliation(s)
- Fareed Bhasha Sayyed
- Chemical Sciences and Technology Division, National Institute for Interdisciplinary Science and Technology (CSIR), Trivandrum, India 695019
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