1
|
Lopes Jesus AJ, Nunes CM, Ferreira GA, Keyvan K, Fausto R. Photochemical Generation and Characterization of C-Aminophenyl-Nitrilimines: Insights on Their Bond-Shift Isomers by Matrix-Isolation IR Spectroscopy and Density Functional Theory Calculations. Molecules 2024; 29:3497. [PMID: 39124902 PMCID: PMC11314218 DOI: 10.3390/molecules29153497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2024] [Revised: 07/20/2024] [Accepted: 07/22/2024] [Indexed: 08/12/2024] Open
Abstract
The intriguing ability of C-phenyl-nitrilimine to co-exist as allenic and propargylic bond-shift isomers motivated us to investigate how substituents in the phenyl ring influence this behavior. Building on our previous work on the meta- and para-OH substitution, here we extended this investigation to explore the effect of the NH2 substitution. For this purpose, C-(4-aminophenyl)- and C-(3-aminophenyl)-nitrilimines were photogenerated in an argon matrix at 15 K by narrowband UV-light irradiation (λ = 230 nm) of 5-(4-aminophenyl)- and 5-(3-aminophenyl)-tetrazole, respectively. The produced nitrilimines were further photoisomerized to carbodiimides via 1H-diazirines by irradiations at longer wavelengths (λ = 380 or 330 nm). Combining IR spectroscopic measurements and DFT calculations, it was found that the para-NH2-substituted nitrilimine exists as a single isomeric structure with a predominant allenic character. In contrast, the meta-NH2-substituted nitrilimine co-exists as two bond-shift isomers characterized by propargylic and allenic structures. To gain further understanding of the effects of phenyl substitution on the bond-shift isomerism of the nitrilimine fragment, we compared geometric and charge distribution data derived from theoretical calculations performed for C-phenyl-nitrilimine with those performed for the derivatives resulting from NH2 (electron-donating group) and NO2 (electron-withdrawing group) phenyl substitutions.
Collapse
Affiliation(s)
- A. J. Lopes Jesus
- University of Coimbra, CQC-IMS, Faculty of Pharmacy, 3004-295 Coimbra, Portugal
| | - Cláudio M. Nunes
- University of Coimbra, CQC-IMS, Department of Chemistry, 3004-535 Coimbra, Portugal; (C.M.N.); (G.A.F.); (K.K.); (R.F.)
| | - Gil A. Ferreira
- University of Coimbra, CQC-IMS, Department of Chemistry, 3004-535 Coimbra, Portugal; (C.M.N.); (G.A.F.); (K.K.); (R.F.)
| | - Kiarash Keyvan
- University of Coimbra, CQC-IMS, Department of Chemistry, 3004-535 Coimbra, Portugal; (C.M.N.); (G.A.F.); (K.K.); (R.F.)
| | - R. Fausto
- University of Coimbra, CQC-IMS, Department of Chemistry, 3004-535 Coimbra, Portugal; (C.M.N.); (G.A.F.); (K.K.); (R.F.)
- Istanbul Kultur University, Faculty Sciences and Letters, Department of Physics, Bakirkoy, 34158 Istanbul, Turkey
| |
Collapse
|
2
|
Yang Y, Liang J, Li W, Yang W, Wang C, Zhang X, Fang WH, Guo Z, Chen X. Mechanistic Understanding and Reactivity Analyses for the Photochemistry of Disubstituted Tetrazoles. J Phys Chem A 2023; 127:4115-4124. [PMID: 37133205 DOI: 10.1021/acs.jpca.3c01594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The photolysis of tetrazoles has undergone extensive research. However, there are still some problems to be solved in terms of mechanistic understanding and reactivity analyses, which leaves room for theoretical calculations. Herein, multiconfiguration perturbation theory at the CASPT2//CASSCF level was employed to account for electron correction effects involved in the photolysis of four disubstituted tetrazoles. Based on calculations of vertical excitation properties and evaluations of intersystem crossing (ISC) efficiencies in the Frank-Condon region, the combination of space and electronic effects is found in maximum-absorption excitation. Two types of ISC (1ππ* → 3nπ*, 1ππ* → 3ππ*) are determined in disubstituted tetrazoles, and the obtained rates follow the El-Sayed rule. Through mapping three representative types of minimum energy profiles for the photolysis of 1,5-, and 2,5-disubstituted tetrazoles, a conclusion can be drawn that the photolysis of tetrazoles exhibits reactivity characteristic of bond-breaking selectivity. Kinetic evaluations show that the photogeneration of singlet imidoylnitrene operates predominately over that in the triplet state, which can be confirmed by a double-well model in the triplet potential energy surface of 1,5-disubstituted tetrazole. Similar mechanistic explorations and reactivity analyses were also applied to the photolysis of 2,5-disubstituted tetrazole to unveil fragmentation patterns of nitrile imine generation. All computational efforts allow us to better understand the photoreactions of disubstituted tetrazoles and to provide useful strategies for regulating their unique reactivity.
Collapse
Affiliation(s)
- Yanting Yang
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Jing Liang
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Weijia Li
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Wenjing Yang
- College of Materials Science & Engineering, Taiyuan University of Technology, Taiyuan, Shanxi 030024, People's Republic of China
| | - Chu Wang
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Xiaorui Zhang
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Wei-Hai Fang
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Zhen Guo
- College of Materials Science & Engineering, Taiyuan University of Technology, Taiyuan, Shanxi 030024, People's Republic of China
| | - Xuebo Chen
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| |
Collapse
|
3
|
Rizzo R, Petelinšek N, Bonato A, Zenobi‐Wong M. From Free-Radical to Radical-Free: A Paradigm Shift in Light-Mediated Biofabrication. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2205302. [PMID: 36698304 PMCID: PMC10015869 DOI: 10.1002/advs.202205302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 12/25/2022] [Indexed: 06/17/2023]
Abstract
In recent years, the development of novel photocrosslinking strategies and photoactivatable materials has stimulated widespread use of light-mediated biofabrication techniques. However, despite great progress toward more efficient and biocompatible photochemical strategies, current photoresins still rely on photoinitiators (PIs) producing radical-initiating species to trigger the so-called free-radical crosslinking/polymerization. In the context of bioprinting, where cells are encapsulated in the bioink, the presence of radicals raises concerns of potential cytotoxicity. In this work, a universal, radical-free (RF) photocrosslinking strategy to be used for light-based technologies is presented. Leveraging RF uncaging mechanisms and Michael addition, cell-laden constructs are photocrosslinked by means of one- and two-photon excitation with high biocompatibility. A hydrophilic coumarin-based group is used to cage a universal RF photocrosslinker based on 4-arm-PEG-thiol (PEG4SH). Upon light exposure, thiols are uncaged and react with an alkene counterpart to form a hydrogel. RF photocrosslinker is shown to be highly stable, enabling potential for off-the-shelf products. While PI-based systems cause a strong upregulation of reactive oxygen species (ROS)-associated genes, ROS are not detected in RF photoresins. Finally, optimized RF photoresin is successfully exploited for high resolution two-photon stereolithography (2P-SL) using remarkably low polymer concentration (<1.5%), paving the way for a shift toward radical-free light-based bioprinting.
Collapse
Affiliation(s)
- Riccardo Rizzo
- Tissue Engineering + Biofabrication LaboratoryDepartment of Health Sciences & TechnologyETH ZürichOtto‐Stern‐Weg 7Zürich8093Switzerland
| | - Nika Petelinšek
- Tissue Engineering + Biofabrication LaboratoryDepartment of Health Sciences & TechnologyETH ZürichOtto‐Stern‐Weg 7Zürich8093Switzerland
| | - Angela Bonato
- Tissue Engineering + Biofabrication LaboratoryDepartment of Health Sciences & TechnologyETH ZürichOtto‐Stern‐Weg 7Zürich8093Switzerland
| | - Marcy Zenobi‐Wong
- Tissue Engineering + Biofabrication LaboratoryDepartment of Health Sciences & TechnologyETH ZürichOtto‐Stern‐Weg 7Zürich8093Switzerland
| |
Collapse
|
4
|
Roque JPL, Nunes CM, Fausto R. Matrix Isolation in Heterocyclic Chemistry. HETEROCYCLES 2022. [DOI: 10.1002/9783527832002.ch12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
5
|
Secrieru A, Oumeddour R, Cristiano MLS. Substituent Effects on EI-MS Fragmentation Patterns of 5-Allyloxy-1-aryl-tetrazoles and 4-Allyl-1-aryl-tetrazole-5-ones; Correlation with UV-Induced Fragmentation Channels. Molecules 2021; 26:molecules26113282. [PMID: 34072370 PMCID: PMC8199304 DOI: 10.3390/molecules26113282] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 05/26/2021] [Accepted: 05/27/2021] [Indexed: 01/29/2023] Open
Abstract
1,4- and 1,5-disubstituted tetrazoles possess enriched structures and versatile chemistry, representing a challenge for chemists. In the present work, we unravel the fragmentation patterns of a chemically diverse range of 5-allyloxy-1-aryl-tetrazoles and 4-allyl-1-aryl-tetrazolole-5-ones when subjected to electron impact mass spectrometry (EI-MS) and investigate the correlation with the UV-induced fragmentation channels of the matrix-isolated tetrazole derivatives. Our results indicate that the fragmentation pathways of the selected tetrazoles in EI-MS are highly influenced by the electronic effects induced by substitution. Multiple pathways can be envisaged to explain the mechanisms of fragmentation, frequently awarding common final species, namely arylisocyanate, arylazide, arylnitrene, isocyanic acid and hydrogen azide radical cations, as well as allyl/aryl cations. The identified fragments are consistent with those found in previous investigations concerning the photochemical stability of the same class of molecules. This parallelism showcases a similarity in the behaviour of tetrazoles under EI-MS and UV-irradiation in the inert environment of cryogenic matrices of noble gases, providing efficient tools for reactivity predictions, whether for analytical ends or more in-depth studies. Theoretical calculations provide complementary information to articulate predictions of resulting products.
Collapse
Affiliation(s)
- Alina Secrieru
- CCMAR and Department of Chemistry and Pharmacy, FCT, Campus de Gambelas, University of Algarve, 8005-039 Faro, Portugal; (A.S.); (R.O.)
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, UK
| | - Rabah Oumeddour
- CCMAR and Department of Chemistry and Pharmacy, FCT, Campus de Gambelas, University of Algarve, 8005-039 Faro, Portugal; (A.S.); (R.O.)
- Laboratory of Industrial Analysis and Materials Science, Faculty MISM, University 8 Mai 1945, Guelma 24000, Algeria
| | - Maria L. S. Cristiano
- CCMAR and Department of Chemistry and Pharmacy, FCT, Campus de Gambelas, University of Algarve, 8005-039 Faro, Portugal; (A.S.); (R.O.)
- Correspondence: ; Tel.: +351-289-800-953
| |
Collapse
|
6
|
Halasz A, Hawari J, Perreault NN. Photodegradation of bis(1H-tetrazol-5-yl)amine (H 2BTA), a high nitrogen content tetrazole-based energetic compound in water. CHEMOSPHERE 2020; 241:125008. [PMID: 31604194 DOI: 10.1016/j.chemosphere.2019.125008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 08/08/2019] [Accepted: 09/28/2019] [Indexed: 06/10/2023]
Abstract
Tetrazoles have wide industrial applications, notably in the pharmaceutical industry. Tetrazole derivatives such as bis(1H-tetrazol-5-yl)amine (H2BTA) have recently been considered by the defense industry as high nitrogen composite propellants. Photodegradation studies under solar simulating conditions showed that H2BTA was partially degraded in water, while it was completely degraded under UV light at 254 nm. When H2BTA (0.35 mM) was irradiated with simulated sunlight at pH 3.65, there was a 1-day lag phase before the chemical started to degrade, reaching 43.5% degradation after 7 d. However, when pH increased to 5.76, it degraded without lag phase, suggesting that an HBTA- anion was involved in the initial degradation of the chemical. 5-Aminotetrazole (5-AT) was identified as a final degradation product and N-(1H-tetrazol-5-yl)formamide(T(5 yl)FA) and 1H-tetrazol-5-ylcarbamic acid (T(5 yl)CA) as intermediate products. At λ = 254 nm, H2BTA disappeared rapidly, resulting in the loss of 94% after 65 min. 5-AT was detected together with several transient products including N-(1H-tetrazol-5-yl)carbamohydrazonic acid (T(5 yl)CHA) and T(5 yl)FA. Kinetic studies and products analysis revealed that H2BTA photodegraded via two initial routes. One route (a) marked by the initial loss of HN3 and another (b) marked by the initial loss of N2. Route a) was characteristics for irradiation with simulated sunlight; however, routes a) and b) proceeded simultaneously under UV light. 5-AT eventually degraded to presumably give N2 and/or HN3 under UV light. Understanding the photodegradation pathway of H2BTA under simulated sunlight can help in providing the basis for natural attenuation assessment of the chemical in contaminated aquatic environments.
Collapse
Affiliation(s)
- Annamaria Halasz
- National Research Council Canada, 6100 Royalmount Ave, Montreal, Quebec, H4P 2R2, Canada
| | - Jalal Hawari
- Department of Civil, Geological and Mining Engineering, Ecole Polytechnique de Montréal, Montreal, Quebec, H3C 3A7, Canada
| | - Nancy N Perreault
- National Research Council Canada, 6100 Royalmount Ave, Montreal, Quebec, H4P 2R2, Canada.
| |
Collapse
|
7
|
Ismael A, Abe M, Fausto R, Cristiano MLS. Insights into the photochemistry of 5-aminotetrazole derivatives with applications in coordination chemistry. Effect of the saccharyl moiety on the photostability. PURE APPL CHEM 2020. [DOI: 10.1515/pac-2019-0402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The properties and applications of 2-methyl-(2H)-tetrazole-5-amino-saccharinate (2MTS) in catalysis and chelant-based chemotherapy stimulated investigations on its photostability. The photochemistry of monomeric 2MTS in solid argon (15 K) was compared with those of 2-methyl-(2H)-tetrazole-5-amine (2MT) and 1-methyl-(2H)-tetrazole-5-amine (1MT). Compounds were subjected to in situ narrowband UV-irradiation at different wavelengths. Reactions were followed by infrared spectroscopy, supported by B3LYP/6-311++G(d,p) calculations. Photochemical pathways for 2MT and 2MTS proved similar but photodegradation of 2MTS was 20× slower, unraveling the photostabilizing effect of the saccharyl moiety that extends into the nitrilimine formed from 2MTS and its antiaromatic 1H-diazirene isomer, which proved photostable at 290 nm, unlike the 1H-diazirene formed from 2MT. Analysis of the photochemistries of 2MTS/2MT (250 nm) and 1MT (222 nm), including energy trends calculated for the isomeric C2H5N3 species postulated/observed from photolysis and EPR results, enabled a deeper insight into the photodegradation mechanisms of 1,5-substituted and 2,5-substituted tetrazoles. We postulate a pivotal singlet state imidoylnitrene species,
sN1, as common intermediate, which undergoes a Wolff-type isomerization to a stable carbodiimide. Photo-extrusion of N2 from 1,5-substituted tetrazoles generates
sN1 directly but from 2,5-substituted tetrazoles it originates a nitrilimine, then a diazirene, which finally leads to
sN1. Selective formation of cyanamide from 1MT requires photoisomerization between
sN1 and
sN2, accessible at 222 nm. EPR studies enabled the detection of methyl nitrene, arising from photolysis of 1H-diazirene intermediate.
Collapse
Affiliation(s)
- Amin Ismael
- CCMAR and Department of Chemistry and Pharmacy, F.C.T. , University of Algarve , P-8005-039 Faro , Portugal
| | - Manabu Abe
- Department of Chemistry, Graduate School of Science , Hiroshima University , Hiroshima , Japan
| | - Rui Fausto
- Departmento de Química , Faculdade de Ciências e Tecnologia Universidade de Coimbra, Rua Larga , P-3004-535 Coimbra , Portugal
- CQC, Department of Chemistry , University of Coimbra , P-3004-535 Coimbra , Portugal
| | - Maria L. S. Cristiano
- Departamento de Química e Farmácia, Faculdade de Ciências e Tecnologia , Campus de Gambelas, Universidade do Algarve , P-8005-039 Faro , Portugal
- CCMAR, F.C.T. , University of Algarve , P-8005-039 Faro , Portugal
| |
Collapse
|
8
|
Wang Y, Pan JA, Wu H, Talapin DV. Direct Wavelength-Selective Optical and Electron-Beam Lithography of Functional Inorganic Nanomaterials. ACS NANO 2019; 13:13917-13931. [PMID: 31609104 DOI: 10.1021/acsnano.9b05491] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Direct optical lithography of functional inorganic nanomaterials (DOLFIN) is a photoresist-free method for high-resolution patterning of inorganic nanocrystals (NCs) that has been demonstrated using deep UV (DUV, 254 nm) photons. Here, we expand the versatility of DOLFIN by designing a series of photochemically active NC surface ligands for direct patterning using various photon energies including DUV, near-UV (i-line, 365 nm), blue (h-line, 405 nm), and visible (450 nm) light. We show that the exposure dose for DOLFIN can be ∼30 mJ/cm2, which is small compared to most commercial photopolymer resists. Patterned nanomaterials can serve as highly robust optical diffraction gratings. We also introduce a general approach for resist-free direct electron-beam lithography of functional inorganic nanomaterials (DELFIN) which enables all-inorganic NC patterns with feature size down to 30 nm, while preserving the optical and electronic properties of patterned NCs. The designed ligand chemistries and patterning techniques offer a versatile platform for nano- and micron-scale additive manufacturing, complementing the existing toolbox for device fabrication.
Collapse
Affiliation(s)
- Yuanyuan Wang
- Department of Chemistry and James Franck Institute , University of Chicago , Chicago , Illinois 60637 , United States
| | - Jia-Ahn Pan
- Department of Chemistry and James Franck Institute , University of Chicago , Chicago , Illinois 60637 , United States
| | - Haoqi Wu
- Department of Chemistry and James Franck Institute , University of Chicago , Chicago , Illinois 60637 , United States
| | - Dmitri V Talapin
- Department of Chemistry and James Franck Institute , University of Chicago , Chicago , Illinois 60637 , United States
- Center for Nanoscale Materials , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| |
Collapse
|
9
|
Pagacz-Kostrzewa M, Sałdyka M, Bil A, Gul W, Wierzejewska M, Khomenko DM, Doroschuk RO. Phototransformations of 2-(1,2,4-Triazol-3-yl)benzoic Acid in Low Temperature Matrices. J Phys Chem A 2019; 123:841-850. [DOI: 10.1021/acs.jpca.8b10762] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- M. Pagacz-Kostrzewa
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
| | - M. Sałdyka
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
| | - A. Bil
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
| | - W. Gul
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
| | - M. Wierzejewska
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
| | - D. M. Khomenko
- Department of Chemistry, Taras Shevchenko National University of Kyiv, Volodymyrska Street, 64/13, Kyiv 01601, Ukraine
| | - R. O. Doroschuk
- Department of Chemistry, Taras Shevchenko National University of Kyiv, Volodymyrska Street, 64/13, Kyiv 01601, Ukraine
| |
Collapse
|
10
|
Bégué D, Santos-Silva H, Dargelos A, Wentrup C. Imidoylnitrenes R′C(═NR)–N, Nitrile Imines, 1H-Diazirines, and Carbodiimides: Interconversions and Rearrangements, Structures, and Energies at DFT and CASPT2 Levels of Theory. J Phys Chem A 2017; 121:8227-8235. [DOI: 10.1021/acs.jpca.7b08445] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Didier Bégué
- Institut
Pluridisciplinaire de Recherche sur l’Environnement et les
Matériaux, Université de Pau et des Pays de l’Adour, 64000 Pau, France
| | - Hugo Santos-Silva
- Institut
Pluridisciplinaire de Recherche sur l’Environnement et les
Matériaux, Université de Pau et des Pays de l’Adour, 64000 Pau, France
| | - Alain Dargelos
- Institut
Pluridisciplinaire de Recherche sur l’Environnement et les
Matériaux, Université de Pau et des Pays de l’Adour, 64000 Pau, France
| | - Curt Wentrup
- School
of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| |
Collapse
|
11
|
Yan J, Ni JC, Zhao JX, Sun LX, Bai FY, Shi Z, Xing YH. The nitro aromatic compounds detection by triazole carboxylic acid and its complex with the fluorescent property. Tetrahedron 2017. [DOI: 10.1016/j.tet.2017.03.057] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
|
12
|
Toyota A, Muramatsu T, Koseki S. Multiconfiguration Self-Consistent Field Study on Formonitrile Imine and N-Substituted Nitrile Imines HCN 2-R: Energy Component Analysis of the Pseudo-Jahn-Teller Effect. J Phys Chem A 2017; 121:2298-2310. [PMID: 28252299 DOI: 10.1021/acs.jpca.7b01718] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Stable geometrical structures for formonitrile imine (1) and N-substituted nitrile imines HCN2-R (R = Li, BeH, BH2, CH3, CN, CCH, C6H5, NH2, OH, and F) (2-11) were examined by using the multiconfiguration self-consistent-field (MCSCF) method followed by second-order configuration interaction (SOCI) calculations and second-order multiconfiguration quasi-degenerate perturbation theory (MCQDPT2) calculations, together with the aug-cc-pVTZ basis sets. The results show that 1 suffers a pseudo-Jahn-Teller (JT) distortion from a linear C∞v structure to a C1 structure via a planar bent Cs structure. Each of the others is found to undergo pseudo-JT distortion from a symmetrical structure to a planar bent Cs structure for 2, 3, and 7 and to a C1 structure for 4, 5, 6, 8, 9, 10, and 11. At the stationary structures of 1-11, the structural characteristics were briefly discussed in terms of allenic and propargylic. To elucidate the nature of pseudo-JT distortions, energy component analyses were carried out at the MCSCF+SOCI level of theory at all of the stationary structures for the relevant molecules. In most of the molecules examined, pseudo-JT stabilizations were classified into two groups, one in which the stability arises from a lowering of the energy of the attractive term Ven and the other in which the stability results from a lowering of the energy of the repulsive terms Vnn and Vee. In addition to the above two groups, it was also found that the following three groups are responsible for the pseudo-JT stabilizations in a certain stage of the structural changes. Namely, one is a lowering of the energy of the term Vee observed in 6, another is a lowering of the energy of the terms Vee and Ven observed in 9-11, and the other is a lowering of the energy of the terms Ven and Vnn observed in 10. These energetic behaviors were accounted in terms of an elongation or a contraction of the molecular skeleton, a migration of electrons from one part of the molecule to other parts, and the combined effects arising from these two factors.
Collapse
Affiliation(s)
- Azumao Toyota
- Environmental Education Center, Miyagi University of Education , Sendai 980-0845, Japan
| | - Takashi Muramatsu
- Environmental Education Center, Miyagi University of Education , Sendai 980-0845, Japan
| | - Shiro Koseki
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University , 1-1 Gakuen-cho, Sakai, Osaka 599-8531, Japan.,The Research Institute for Molecular Electronic Devices (RIMED), Osaka Prefecture University , 1-1 Gakuen-cho, Naka-ku, Sakai 599-8531, Japan
| |
Collapse
|
13
|
Affiliation(s)
- Curt Wentrup
- School of Chemistry and Molecular
Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| |
Collapse
|
14
|
Ismael A, Fausto R, Cristiano MLS. Photochemistry of 1- and 2-Methyl-5-aminotetrazoles: Structural Effects on Reaction Pathways. J Org Chem 2016; 81:11656-11663. [PMID: 27809524 DOI: 10.1021/acs.joc.6b02023] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The influence of the position of the methyl substituent in 1- and 2-methyl-substituted 5-aminotetrazoles on the photochemistry of these molecules is evaluated. The two compounds were isolated in an argon matrix (15 K) and the matrix was subjected to in situ narrowband UV excitation at different wavelengths, which induce selectively photochemical transformations of different species (reactants and initially formed photoproducts). The progress of the reactions was followed by infrared spectroscopy, supported by quantum chemical calculations. It is shown that the photochemistries of the two isomers, 1-methyl-(1H)-tetrazole-5-amine (1a) and 2-methyl-(2H)-tetrazole-5-amine (1b), although resulting in a common intermediate diazirine 3, which undergoes subsequent photoconversion into 1-amino-3-methylcarbodiimide (H2N-N═C═N-CH3), show marked differences: formation of the amino cyanamide 4 (H2N-N(CH3)-C≡N) is only observed from the photocleavage of the isomer 1a, whereas formation of the nitrile imine 2 (H2N-C-═N+═N-CH3) is only obtained from photolysis of 1b. The exclusive formation of nitrile imine from the isomer 1b points to the possibility that only the 2H-tetrazoles forms can give a direct access to nitrile imines, while observation of the amino cyanamide 4 represents a novel reaction pathway in the photochemistry of tetrazoles and seems to be characteristic of 1H-tetrazoles. The structural and vibrational characterization of both reactants and photoproducts has been undertaken.
Collapse
Affiliation(s)
- A Ismael
- CCMAR and Department of Chemistry and Pharmacy, F.C.T., University of Algarve , P-8005-039 Faro, Portugal.,CQC, Department of Chemistry, University of Coimbra , P-3004-535 Coimbra, Portugal
| | - R Fausto
- CQC, Department of Chemistry, University of Coimbra , P-3004-535 Coimbra, Portugal
| | - M L S Cristiano
- CCMAR and Department of Chemistry and Pharmacy, F.C.T., University of Algarve , P-8005-039 Faro, Portugal
| |
Collapse
|
15
|
Billes F, Ziegler I, Mikosch H. Application of quantum chemistry for the interpretation of vibrational spectra. Struct Chem 2015. [DOI: 10.1007/s11224-015-0683-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
16
|
Puzzarini C, Gambi A. The energetics and structural properties of diazomethyl (HCNN) and cyanomidyl (HNCN) radicals and their related cations and anions from ab initio calculations. J Chem Phys 2005; 122:064316. [PMID: 15740381 DOI: 10.1063/1.1844314] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The molecular structures and energetics of diazomethyl (HCNN) and cyanomidyl (HNCN) radicals and their related cations (HCNN(+),HNCN(+)) and anions (HCNN(-),HNCN(-)) are reported at a high level of accuracy. The singles and doubles coupled-cluster method including a perturbational correction for connected triple excitations with systematic sequences of correlation consistent basis sets have been employed. Extrapolation to the complete basis set limit has been used with accurate treatments of core-valence correlation effects in order to accurately predict molecular properties, ionization potentials, electron affinities as well as C-H and N-H bond dissociation energies. For all the species studied, harmonic vibrational frequencies have also been evaluated in order to obtain zero-point corrections to ionization potentials, electron affinities, and dissociation energies.
Collapse
Affiliation(s)
- Cristina Puzzarini
- Dipartimento di Chimica G. Ciamician, Università di Bologna, Via Selmi 2, I-40126 Bologna, Italy.
| | | |
Collapse
|
17
|
Maier G, Bothur A. The Thermally and Photochemically Induced Ring Opening ofcis-3,4-Dichlorocyclobutene andtrans-3,4-Dichlorocyclobutene: New Insights from a Matrix-Spectroscopic Study. European J Org Chem 1998. [DOI: 10.1002/(sici)1099-0690(199810)1998:10<2063::aid-ejoc2063>3.0.co;2-f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
18
|
Maier G, Bothur A, Eckwert J, Reisenauer HP, Stumpf T. Isofulminic Acid – Phantom or Reality? ACTA ACUST UNITED AC 1997. [DOI: 10.1002/jlac.199719971213] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|