1
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Wehelie AM, Watanabe LK, Zhang B, Nikoo S, Rawson JM. Towards molecular alloys: computational and experimental studies on ( p-NCC 6F 4CNSeSeN) x( p-NCC 6F 4CNSSN) 1-x. Phys Chem Chem Phys 2024; 26:12097-12106. [PMID: 38587473 DOI: 10.1039/d4cp00188e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
The β-phase of the radical p-NCC6F4CNSSN (1β) crystallizes in the orthorhombic space group Fdd2 and orders as a canted antiferromagnet with TN = 36 K. Computational studies (B3LYP or M06-2X functional with the cc-pVTZ-PP(-F)+basis set) of the microscopic nearest-neighbour magnetic exchange coupling in 1β and in the hypothetical isomorphous phase of the selenium radical p-NCC6F4CNSeSeN (2β) revealed that replacement of S by Se should lead to a significant enhancement in the magnetic ordering temperature by ca. 20% (B3LYP) - 30% (M06-2X). Recrystallization of 2 from solution or via vacuum sublimation afforded only the known diamagnetic, dimeric phase, 2α. Computational studies indicated that both the molecular geometry and charge distribution for 1 and 2 are extremely similar and experimental approaches to form alloys of the general form 11-x2x were explored: attempts to cosublime 1 and 2in vacuo were unsuccessful, forming only 1β due to the low volatility of 2. Crystallization of pure 1 by solution evaporation was found to afford polymorph 1α (triclinic, P1̄) selectively, irrespective of the solvent employed (CH2Cl2, MeCN, PhMe or THF) but 1α transformed to 1β upon subsequent vacuum sublimation. Crystallization of 1 in the presence of 2 (up to 20 mol%) from solution evaporation was examined. At 20 mol% there was clear evidence for formation of both 1α and 2α as distinct crystallographic phases by powder X-ray diffraction (PXRD) but some evidence for doping of 2 into 1α at low concentration (≤15 mol percent) was observed. Attempts to sublime a sample of 10.920.1 led to phase separation with the isolation of needle-shaped crystals of pure 1β characterized by X-ray diffraction.
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Affiliation(s)
- Asli M Wehelie
- Department of Chemistry and Biochemistry, The University of Windsor, 401 Sunset Avenue, Windsor, ON, Canada, N9B 3P4.
| | - Lara K Watanabe
- Department of Chemistry and Biochemistry, The University of Windsor, 401 Sunset Avenue, Windsor, ON, Canada, N9B 3P4.
| | - Bin Zhang
- College of Chemistry, Zhengzhou University, Zhengzhou, 450001, P. R. China
| | - Sahar Nikoo
- Department of Chemistry and Biochemistry, The University of Windsor, 401 Sunset Avenue, Windsor, ON, Canada, N9B 3P4.
| | - Jeremy M Rawson
- Department of Chemistry and Biochemistry, The University of Windsor, 401 Sunset Avenue, Windsor, ON, Canada, N9B 3P4.
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Hadi H, Gassoumi B, Nasr S, Safari R, Basha AA, Imran PM, Ghalla H, Caccamo MT, Ayachi S. Design, Transport/Molecular Scale Electronics, Electric Properties, and a Conventional Quantum Study of a New Potential Molecular Switch for Nanoelectronic Devices. ACS OMEGA 2024; 9:1029-1041. [PMID: 38222547 PMCID: PMC10785780 DOI: 10.1021/acsomega.3c07257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 12/12/2023] [Accepted: 12/13/2023] [Indexed: 01/16/2024]
Abstract
In this study, we examined the influence of an external electric field applied in two directions: horizontal (X-axis) and vertical (Y-axis) on the electronic and vibrational properties of a field-effect molecular switch, denoted as M. We employed density functional theory and quantum theory of atoms in molecules for this analysis. The current-voltage (I-V) characteristic curve of molecular switch system M was computed by applying the Landauer formula. The results showed that the switching mechanism depends on the direction of the electric field. When the electric field is applied along the X-axis and its intensity is around 0.01 au, OFF/ON switching mechanisms occur. By utilizing electronic localization functions and localized-orbital locator topological analysis, we observed significant intramolecular electronic charge transfer "back and forth" in Au-M-Au systems when compared to the isolated system. The noncovalent interaction revealed that the Au-M-Au complex is also stabilized by electrostatic interactions. However, if the electric field is applied along the Y-axis, a switching mechanism (OFF/ON) occurs when the electric field intensity reaches 0.008 au. Additionally, the local electronic phenomenological coefficients (Lelec) of this field-effect molecular switch were determined by using the Onsager phenomenological approach. It can also be predicted that the molecular electrical conductance (G) increases as Lelec increases. Finally, the electronic and vibrational properties of the proposed models M and Au-M-Au exhibit a powerful switching mechanism that may potentially be employed in a new generation of electronic devices.
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Affiliation(s)
- Hamid Hadi
- Department
of Chemistry, Physical Chemistry Group, Lorestan University, Khorramabad 6815144316, Iran
| | - Bouzid Gassoumi
- Laboratory
of Advanced Materials and Interfaces (LIMA), Faculty of Sciences,
Avenue of the Environment, University of
Monastir, Monastir 5019, Tunisia
| | - Samia Nasr
- Department
of Chemistry, Faculty of Science, King Khalid
University, P.O. Box 9004, Abha 61413, Saudi Arabia
| | - Reza Safari
- Department
of Chemistry, Physical Chemistry Group, University of Qom, Qom 3716146611, Iran
| | - A. Aathif Basha
- Department
of Physics, Islamiah College (Autonomous), Vaniyambadi 635752, India
| | | | - Houcine Ghalla
- Quantum
and Statistical Physics Laboratory, Faculty of Sciences, Avenue of
the Environment, University of Monastir, Monastir 5019, Tunisia
| | - Maria Teresa Caccamo
- Dipartimento
di Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della
Terra, Università di Messina, Viale Ferdinando Stagno D’Alcontres
n°31, Sant’Agata, Messina 98166, Italy
| | - Sahbi Ayachi
- Laboratory
of Physico-Chemistry of Materials (LR01ES19), Faculty of Sciences,
Avenue of the Environment, University of
Monastir, Monastir 5019, Tunisia
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Chvojka M, Madea D, Valkenier H, Šindelář V. Tuning CH Hydrogen Bond-Based Receptors toward Picomolar Anion Affinity via the Inductive Effect of Distant Substituents. Angew Chem Int Ed Engl 2023:e202318261. [PMID: 38063265 DOI: 10.1002/anie.202318261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Indexed: 12/23/2023]
Abstract
Inspired by nature, artificial hydrogen bond-based anion receptors have been developed to achieve high anion selectivity; however, their binding affinity is usually low. The potency of these receptors is usually increased by the introduction of aryl substituents, which withdraw electrons from their binding site through the resonance effect. Here, we show that the polarization of the C(sp3 )-H binding site of bambusuril receptors, and thus their potency to bind anions, can be modulated by the inductive effect. The presence of electron-withdrawing groups on benzyl substituents of bambusurils significantly increases their binding affinities to halides, resulting in the strongest iodide receptor reported to date with an association constant greater than 1013 M-1 in acetonitrile. A Hammett plot showed that while the bambusuril affinity toward halides linearly increases with the electron-withdrawing power of their substituents, their binding selectivity remains essentially unchanged.
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Affiliation(s)
- Matúš Chvojka
- Department of Chemistry, Faculty of Science, Masaryk University, 625 00, Brno, Czech Republic
- RECETOX, Faculty of Science, Masaryk University, 625 00, Brno, Czech Republic
- Engineering of Molecular NanoSystems, École polytechnique de Bruxelles, Université libre de Bruxelles, Avenue F.D. Roosevelt 50, CP165/64, 1050, Brussels, Belgium
| | - Dominik Madea
- Department of Chemistry, Faculty of Science, Masaryk University, 625 00, Brno, Czech Republic
- RECETOX, Faculty of Science, Masaryk University, 625 00, Brno, Czech Republic
| | - Hennie Valkenier
- Engineering of Molecular NanoSystems, École polytechnique de Bruxelles, Université libre de Bruxelles, Avenue F.D. Roosevelt 50, CP165/64, 1050, Brussels, Belgium
| | - Vladimír Šindelář
- Department of Chemistry, Faculty of Science, Masaryk University, 625 00, Brno, Czech Republic
- RECETOX, Faculty of Science, Masaryk University, 625 00, Brno, Czech Republic
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Ramírez-García JC, Vázquez-Ramírez R, Patiño ME, Aguirre-Cabrera C, Carranza V, Álvarez CMG. Theoretical study of Gibbs free energy and NMR chemical shifts, of the effect of methyl substituents on the isomers of (E)-1-(α,Ꞵ-Dimethylbenzyliden)-2,2-diphenylhydrazine. AN ACAD BRAS CIENC 2023; 95:e20220766. [PMID: 37466538 DOI: 10.1590/0001-3765202320220766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Accepted: 02/27/2023] [Indexed: 07/20/2023] Open
Abstract
A theoretical analysis of free Gibbs Energy and NMR 1H 13C chemical shifts of the effect of introduce methyl groups on diphenyl rings, to produce different isomers of (E)-1-(α,Ꞵ-dimethylbenzylidene)-2,2-diphenylhydrazine, is presented. IR vibrational frequencies, Mulliken charges, molecular electrostatic potential (MEP), Gibbs free energy (G) and 1H- and 13C-NMR chemical shifts were obtained by theoretical calculations. In this analysis it was found that the position of the methyl group affects the values of the 1H- and 13C-NMR chemical shifts and the ∆G and ∆H thermodynamic properties of formation and reaction, these properties vary with the same trend, for the isomers studied. Gibbs free energy calculations show that the theoretical (E)-1-(3,4-Dimethylbenzylidene)-2,2-diphenylhydrazine isomer is the most stable, which explains the success of the experimental synthesis of this compound among the other isomers. For this molecule, the C of the HC=N group is the most nucleophilic and the H is the least acidic. The 1H-NMR chemical shifts of protons show a strong correlation with the C=N distance. It was also observed that methyl affects the ν(C=N) frequencies, the C=N distance increases when the inductive effect of the methyl groups is in the structure.
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Affiliation(s)
- Juan Carlos Ramírez-García
- Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Av. 14 Sur Col. San Manuel, Ciudad Universitaria, Puebla, C.P. 72592 México
| | - Ricardo Vázquez-Ramírez
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, D.F. 04510, México
| | - María Eugenia Patiño
- Centro de Química, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Av. 14 Sur Col. Jardines de San Manuel, Ciudad Universitaria, Puebla, P.O. Box 1067, C.P. 72001 México
| | - Carla Aguirre-Cabrera
- Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Av. 14 Sur Col. San Manuel, Ciudad Universitaria, Puebla, C.P. 72592 México
| | - Vladimir Carranza
- Centro de Química, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Av. 14 Sur Col. Jardines de San Manuel, Ciudad Universitaria, Puebla, P.O. Box 1067, C.P. 72001 México
| | - Carmen Mária González Álvarez
- Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Av. 14 Sur Col. San Manuel, Ciudad Universitaria, Puebla, C.P. 72592 México
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