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Ren FD, Liu YZ, Wang XL, Qiu LL, Meng ZH, Cheng X, Li YX. Strong External Electric Fields Reduce Explosive Sensitivity: A Theoretical Investigation into the Reaction Selectivity in NH2NO2∙∙∙NH3. Molecules 2023; 28:molecules28062586. [PMID: 36985558 PMCID: PMC10058811 DOI: 10.3390/molecules28062586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 03/04/2023] [Accepted: 03/07/2023] [Indexed: 03/18/2023] Open
Abstract
Controlling the selectivity of a detonation initiation reaction of explosive is essential to reduce sensitivity, and it seems impossible to reduce it by strengthening the external electric field. To verify this, the effects of external electric fields on the initiation reactions in NH2NO2∙∙∙NH3, a model system of the nitroamine explosive with alkaline additive, were investigated at the MP2/6-311++G(2d,p) and CCSD(T)/6-311++G(2d,p) levels. The concerted effect in the intermolecular hydrogen exchange is characterized by an index of the imaginary vibrations. Due to the weakened concerted effects by the electric field along the −x-direction opposite to the “reaction axis”, the dominant reaction changes from the intermolecular hydrogen exchange to 1,3-intramolecular hydrogen transference with the increase in the field strengths. Furthermore, the stronger the field strengths, the higher the barrier heights become, indicating the lower sensitivities. Therefore, by increasing the field strength and adjusting the orientation between the field and “reaction axis”, not only can the reaction selectivity be controlled, but the sensitivity can also be reduced, in particular under a super-strong field. Thus, a traditional concept, in which the explosive is dangerous under the super-strong external electric field, is theoretically broken. Compared to the neutral medium, a low sensitivity of the explosive with alkaline can be achieved under the stronger field. Employing atoms in molecules, reduced density gradient, and surface electrostatic potentials, the origin of the reaction selectivity and sensitivity change is revealed. This work provides a new idea for the technical improvement regarding adding the external electric field into the explosive system.
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Affiliation(s)
- Fu-De Ren
- School of Chemical Engineering and Technology, North University of China, Taiyuan 030051, China
- Correspondence: ; Tel.: +86-351-392-2117
| | - Ying-Zhe Liu
- State Key Laboratory of Fluorine and Nitrogen Chemicals, Xi’an Modern Chemistry Research Institute, Xi’an 710065, China
| | - Xiao-Lei Wang
- School of Chemical Engineering and Technology, North University of China, Taiyuan 030051, China
| | - Li-Li Qiu
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Zi-Hui Meng
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Xiang Cheng
- School of Intelligent Engineering, Zhengzhou University of Aeronautics, Zhengzhou 450003, China
| | - Yong-Xiang Li
- School of Chemical Engineering and Technology, North University of China, Taiyuan 030051, China
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Saikia J, Dharmalingam K, Anandalakshmi R, Redkar AS, Bhat VT, Ramakrishnan V. Electric field modulated peptide based hydrogel nanocatalysts. SOFT MATTER 2021; 17:9725-9735. [PMID: 34643203 DOI: 10.1039/d1sm00724f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The ability to modulate self-assembly is the key to manufacture application-oriented materials. In this study, we investigated the effect of three independent variables that can modulate the catalytic activity of self-assembling peptides. The first two variables, amino acid sequence and its stereochemistry, were examined for their specific roles in the epitaxial growth and hydrogelation properties of a series of catalytic tripeptides. We observed that aromatic π-π interactions that direct the self-assembly of designed peptides, and the catalytic properties of hydrogels, are governed by the position and chirality of the proline residue. Subsequently, the influence of the third variable, an external electric field, was also tested to confirm its catalytic efficiency for the asymmetric C-C bond-forming aldol reaction. In particular, the electric field treated pff and PFF gels showed 10 and 36% higher stereoselectivity, respectively, compared with the control. Structure-property analysis using CD and FTIR spectroscopy indicates the electric field-induced beta to non-beta conformational transition in the peptide secondary structure, which corroborates with its reduced cross-link density and fibril width, respectively. Amplitude sweep rheology of the gels suggests a decrease in the storage modulus, with increased field strength. The results showed that an electric field of optimal strength can modulate the physical characteristics of the hydrogel, which in turn is manifested in the observed difference in enantioselectivity.
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Affiliation(s)
- Jahnu Saikia
- Molecular Informatics and Design Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Assam 781039, India.
| | - K Dharmalingam
- Advanced Energy & Materials Systems Laboratory, Department of Chemical Engineering, Indian Institute of Technology Guwahati, Assam 781039, India
| | - R Anandalakshmi
- Advanced Energy & Materials Systems Laboratory, Department of Chemical Engineering, Indian Institute of Technology Guwahati, Assam 781039, India
| | - Amay Sanjay Redkar
- Molecular Informatics and Design Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Assam 781039, India.
| | - Venugopal T Bhat
- Organic Synthesis and Catalysis Laboratory SRM Research Institute and Department of Chemistry SRM Institute of Science and Technology, Tamil Nadu 603203, India.
| | - Vibin Ramakrishnan
- Molecular Informatics and Design Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Assam 781039, India.
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Dominikowska J, Palusiak M. Tuning Aromaticity of para-Substituted Benzene Derivatives with an External Electric Field. Chemphyschem 2018; 19:590-595. [PMID: 29372611 DOI: 10.1002/cphc.201701203] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 11/28/2017] [Indexed: 01/20/2023]
Abstract
Substituent effects are phenomena which play an important role in organic chemistry, especially when aromatic species are considered. For this class of systems, the question of the interrelation between substituent effect and aromaticity arises. The relationship between aromaticity and substituent effects appears to be of a competitive nature. This work examines changes in aromaticity in para-substituted benzene derivatives exposed to external electric fields of various intensities. Three systems with different substituent electron-accepting/donating properties are studied, namely p-aminophenol, p-nitrobenzonitrile and p-nitrophenol. In these cases, the competitive character between substituent effects and aromaticity is emphasised. It is also shown that aromaticity (and the substituent effect) can be tuned using an external electric field applied to the system.
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Affiliation(s)
- Justyna Dominikowska
- Theoretical and Structural Chemistry Group, Faculty of Chemistry, University of Łódź, Pomorska 163/165, 90-236, Łódź, Poland
| | - Marcin Palusiak
- Theoretical and Structural Chemistry Group, Faculty of Chemistry, University of Łódź, Pomorska 163/165, 90-236, Łódź, Poland
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Vamhindi BSDR, Karton A. Can DFT and ab initio methods adequately describe binding energies in strongly interacting C6X6⋯C2X π–π complexes? Chem Phys 2017. [DOI: 10.1016/j.chemphys.2017.05.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Youn IS, Kim DY, Cho WJ, Madridejos JML, Lee HM, Kołaski M, Lee J, Baig C, Shin SK, Filatov M, Kim KS. Halogen-π Interactions between Benzene and X 2/CX 4 (X = Cl, Br): Assessment of Various Density Functionals with Respect to CCSD(T). J Phys Chem A 2016; 120:9305-9314. [PMID: 27802060 DOI: 10.1021/acs.jpca.6b09395] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Various types of interactions between halogen (X) and π moiety (X-π interaction) including halogen bonding play important roles in forming the structures of biological, supramolecular, and nanomaterial systems containing halogens and aromatic rings. Furthermore, halogen molecules such as X2 and CX4 (X = Cl/Br) can be intercalated in graphite and bilayer graphene for doping and graphene functionalization/modification. Due to the X-π interactions, though recently highly studied, their structures are still hardly predictable. Here, using the coupled-cluster with single, double, and noniterative triple excitations (CCSD(T)), the Møller-Plesset second-order perturbation theory (MP2), and various flavors of density functional theory (DFT) methods, we study complexes of benzene (Bz) with halogen-containing molecules X2 and CX4 (X = Cl/Br) and analyze various components of the interaction energy using symmetry adapted perturbation theory (SAPT). As for the lowest energy conformers (S1), X2-Bz is found to have the T-shaped structure where the electropositive X atom-end of X2 is pointing to the electronegative midpoint of CC bond of the Bz ring, and CX4-Bz has the stacked structure. In addition to this CX4-Bz (S1), other low energy conformers of X2-Bz (S2/S3) and CX4-Bz (S2) are stabilized primarily by the dispersion interaction, whereas the electrostatic interaction is substantial. Most of the density functionals show noticeable deviations from the CCSD(T) complete basis set (CBS) limit binding energies, especially in the case of strongly halogen-bonded conformers of X2-Bz (S1), whereas the deviations are relatively small for CX4-Bz where the dispersion is more important. The halogen bond shows highly anisotropic electron density around halogen atoms and the DFT results are very sensitive to basis set. The unsatisfactory performance of many density functionals could be mainly due to less accurate exchange. This is evidenced from the good performance by the dispersion corrected hybrid and double hybrid functionals. B2GP-PLYP-D3 and PBE0-TS(Tkatchenko-Scheffler)/D3 are well suited to describe the X-π interactions adequately, close to the CCSD(T)/CBS binding energies (within ∼1 kJ/mol). This understanding would be useful to study diverse X-π interaction driven structures such as halogen containing compounds intercalated between 2-dimensional layers.
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Affiliation(s)
| | | | | | | | | | - Maciej Kołaski
- Department of Chemistry, Pohang University of Science and Technology , Pohang 37673, Korea.,Department of Theoretical Chemistry, Institute of Chemistry, University of Silesia , 9 Szkolna Street, 40-006 Katowice, Poland
| | - Joonho Lee
- Department of Chemistry, Pohang University of Science and Technology , Pohang 37673, Korea.,Department of Chemistry, University of California , Berkeley, California 94720-1460, United States
| | | | - Seung Koo Shin
- Department of Chemistry, Pohang University of Science and Technology , Pohang 37673, Korea
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Novák M, Foroutan-Nejad C, Marek R. Modulating Electron Sharing in Ion-π-Receptors via Substitution and External Electric Field: A Route toward Bond Strengthening. J Chem Theory Comput 2016; 12:3788-95. [DOI: 10.1021/acs.jctc.6b00586] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Martin Novák
- CEITEC −
Central European Institute of Technology, Masaryk University, Kamenice 5/A4, CZ-625 00 Brno, Czech Republic
| | - Cina Foroutan-Nejad
- CEITEC −
Central European Institute of Technology, Masaryk University, Kamenice 5/A4, CZ-625 00 Brno, Czech Republic
| | - Radek Marek
- CEITEC −
Central European Institute of Technology, Masaryk University, Kamenice 5/A4, CZ-625 00 Brno, Czech Republic
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