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Ketkov SY, Tzeng SY, Rychagova EA, Lukoyanov AN, Tzeng WB. Effect of a single methyl substituent on the electronic structure of cobaltocene studied by computationally assisted MATI spectroscopy. Phys Chem Chem Phys 2024; 26:1046-1056. [PMID: 38095021 DOI: 10.1039/d3cp05120j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2024]
Abstract
Metallocenes represent archetypical organometallic compounds playing key roles in various fields of fundamental and applied chemistry. Many of their unique properties arise from low ionization energies (IE) which can be tuned by introducing substituents into the rings. Here we report the first mass-analyzed threshold ionization (MATI) spectrum of a methylmetallocene, (Cp')(Cp)Co (Cp' = η5-C5H4Me, Cp = η5-C5H5). The presence of a single Me group allows us to study the "pure" effect of methylation without the mutual influence of substituents. The MATI technique provides an extremely high accuracy in determining the adiabatic IE of (Cp')(Cp)Co which equals 5.2097(6) eV. The effect of a Me group on the IE of cobaltocene appears to be 36% stronger than that in bis(η6-benzene)chromium. The MATI spectrum of (Cp')(Cp)Co shows a rich vibronic structure from which vibrational frequencies of the free ion are determined. This information provides a solid basis for testing the quality of quantum chemical calculations. Various levels of the DFT and coupled cluster computations are used to describe the structural and electronic transformations accompanying the detachment of an elctron from (Cp')(Cp)Co. New aspects of the methyl substituent influence on the potential energy surfaces, as well as on the inhomogeneous changes in charge density and electrostatic potential caused by ionization, are discussed.
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Affiliation(s)
- Sergey Yu Ketkov
- G. A. Razuvaev Institute of Organometallic Chemistry RAS, 49 Tropinin St., 603950 Nizhny Novgorod, Russian Federation.
| | - Sheng-Yuan Tzeng
- Institute of Atomic and Molecular Sciences, Academia Sinica, 1 Section 4, Roosevelt Road, Taipei, 10617, Taiwan.
| | - Elena A Rychagova
- G. A. Razuvaev Institute of Organometallic Chemistry RAS, 49 Tropinin St., 603950 Nizhny Novgorod, Russian Federation.
| | - Anton N Lukoyanov
- G. A. Razuvaev Institute of Organometallic Chemistry RAS, 49 Tropinin St., 603950 Nizhny Novgorod, Russian Federation.
| | - Wen-Bih Tzeng
- Institute of Atomic and Molecular Sciences, Academia Sinica, 1 Section 4, Roosevelt Road, Taipei, 10617, Taiwan.
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Li S, Zhao Y, Jiao Y, Zhao J, Li C, Jia S. Vibronic and Cationic Features of 2-Fluorobenzonitrile and 3-Fluorobenzonitrile Studied by REMPI and MATI Spectroscopy and Franck-Condon Simulations. Molecules 2023; 28:4702. [PMID: 37375257 DOI: 10.3390/molecules28124702] [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: 05/25/2023] [Revised: 06/08/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
Fluorinated organic compounds have superior physicochemical properties than general organic compounds due to the strong C-F single bond; they are widely used in medicine, biology, pesticides, and materials science. In order to gain a deeper understanding of the physicochemical properties of fluorinated organic compounds, fluorinated aromatic compounds have been investigated by various spectroscopic techniques. 2-fluorobenzonitrile and 3-fluorobenzonitrile are important fine chemical intermediates and their excited state S1 and cationic ground state D0 vibrational features remain unknown. In this paper, we used two-color resonance two photon ionization (2-color REMPI) and mass analyzed threshold ionization (MATI) spectroscopy to study S1 and D0 state vibrational features of 2-fluorobenzonitrile and 3-fluorobenzonitrile. The precise excitation energy (band origin) and adiabatic ionization energy were determined to be 36,028 ± 2 cm-1 and 78,650 ± 5 cm-1 for 2-fluorobenzonitrile and 35,989 ± 2 cm-1 and 78,873 ± 5 cm-1 for 3-fluorobenzonitrile, respectively. The density functional theory (DFT) at the levels of RB3LYP/aug-cc-pvtz, TD-B3LYP/aug-cc-pvtz, and UB3LYP/aug-cc-pvtz were used to calculate the stable structures and vibrational frequencies for the ground state S0, excited state S1, and cationic ground state D0, respectively. Franck-Condon spectral simulations for transitions of S1 ← S0 and D0 ← S1 were performed based on the above DFT calculations. The theoretical and experimental results were in good agreement. The observed vibrational features in S1 and D0 states were assigned according to the simulated spectra and the comparison with structurally similar molecules. Several experimental findings and molecular features were discussed in detail.
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Affiliation(s)
- Shuxian Li
- State Key Laboratory of Quantum Optics and Quantum Optic Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China
| | - Yan Zhao
- Department of Physics and Electronics Engineering, Jinzhong University, Jinzhong 030619, China
| | - Yuechun Jiao
- State Key Laboratory of Quantum Optics and Quantum Optic Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
| | - Jianming Zhao
- State Key Laboratory of Quantum Optics and Quantum Optic Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
| | - Changyong Li
- State Key Laboratory of Quantum Optics and Quantum Optic Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
| | - Suotang Jia
- State Key Laboratory of Quantum Optics and Quantum Optic Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
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Ketkov SY, Rychagova EA. Influence of Ionization and Spin Transitions on Electron Delocalization in the Molecules of Transition Metal Sandwich Complexes. HIGH ENERGY CHEMISTRY 2023. [DOI: 10.1134/s0018143923010071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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Ketkov S, Tzeng SY, Rychagova E, Tzeng WB. Ionization of Decamethylmanganocene: Insights from the DFT-Assisted Laser Spectroscopy. Molecules 2022; 27:molecules27196226. [PMID: 36234763 PMCID: PMC9573365 DOI: 10.3390/molecules27196226] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 09/15/2022] [Accepted: 09/17/2022] [Indexed: 11/24/2022] Open
Abstract
Metallocenes represent one of the most important classes of organometallics with wide prospects for practical use in various fields of chemistry, materials science, molecular electronics, and biomedicine. Many applications of these metal complexes are based on their ability to form molecular ions. We report the first results concerning the changes in the molecular and electronic structure of decamethylmanganocene, Cp*2Mn, upon ionization provided by the high-resolution mass-analyzed threshold ionization (MATI) spectroscopy supported by DFT calculations. The precise ionization energy of Cp*2Mn is determined as 5.349 ± 0.001 eV. The DFT modeling of the MATI spectrum shows that the main structural deformations accompanying the detachment of an electron consist in the elongation of the Mn-C bonds and a change in the Me out-of-plane bending angles. Surprisingly, the DFT calculations predict that most of the reduction in electron density (ED) upon ionization is associated with the hydrogen atoms of the substituents, despite the metal character of the ionized orbital. However, the ED difference isosurfaces reveal a complex mechanism of the charge redistribution involving also the carbon atoms of the molecule.
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Affiliation(s)
- Sergey Ketkov
- G.A. Razuvaev Institute of Organometallic Chemistry of the Russian Academy of Sciences, 49 Tropinin St., 603950 Nizhny Novgorod, Russia
- Correspondence: (S.K.); (W.-B.T.)
| | - Sheng-Yuan Tzeng
- Institute of Atomic and Molecular Sciences, Academia Sinica, 1 Section 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Elena Rychagova
- G.A. Razuvaev Institute of Organometallic Chemistry of the Russian Academy of Sciences, 49 Tropinin St., 603950 Nizhny Novgorod, Russia
| | - Wen-Bih Tzeng
- Institute of Atomic and Molecular Sciences, Academia Sinica, 1 Section 4, Roosevelt Road, Taipei 10617, Taiwan
- Correspondence: (S.K.); (W.-B.T.)
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Valiev RR, Kurten T, Valiulina LI, Ketkov SY, Cherepanov VN, Dimitrova M, Sundholm D. Magnetically induced ring currents in metallocenothiaporphyrins. Phys Chem Chem Phys 2022; 24:1666-1674. [PMID: 34981802 DOI: 10.1039/d1cp04779e] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The magnetically induced current-density susceptibility tensor (CDT) of the lowest singlet and triplet states of the metallocenothiaporphyrins, where the metal is V, Cr, Mn, Fe, Co, Ni, Mo, Tc, Ru, or Rh, have been studied with the gauge-including magnetically induced currents (GIMIC) method. The compounds containing V, Mn, Co, Tc or Rh were studied as cations because the neutral molecules have an odd number of electrons. The calculations show that the aromatic nature of most of the studied molecules follows the Hückel and Baird rules of aromaticity. CDT calculations on the high-spin states of the neutral metallocenothiaporphyrins with V, Mn, Co, Tc or Rh also shows that these molecules follow a unified extended Hückel and Baird aromaticity orbital-count rule stating that molecules with an odd number of occupied conjugated valence orbitals are aromatic, whereas molecules with an even number of occupied conjugated orbitals are antiaromatic.
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Affiliation(s)
- Rashid R Valiev
- Department of Optics and Spectroscopy, Tomsk State University, Tomsk, 634050, Russia.,Department of Chemistry, Faculty of Science, University of Helsinki, FIN-00014, Helsinki, Finland.
| | - Theo Kurten
- Department of Chemistry, Faculty of Science, University of Helsinki, FIN-00014, Helsinki, Finland.
| | - Lenara I Valiulina
- Department of Optics and Spectroscopy, Tomsk State University, Tomsk, 634050, Russia
| | - Sergey Yu Ketkov
- Laboratory of Structures of Organometallic and Coordination Compounds, G. A. Razuvaev Institute of Organometallic Chemistry RAS, 49 Tropinin St., Nizhny Novgorod 603950, Russia
| | - Viktor N Cherepanov
- Department of Optics and Spectroscopy, Tomsk State University, Tomsk, 634050, Russia
| | - Maria Dimitrova
- Department of Chemistry, Faculty of Science, University of Helsinki, FIN-00014, Helsinki, Finland.
| | - Dage Sundholm
- Department of Chemistry, Faculty of Science, University of Helsinki, FIN-00014, Helsinki, Finland.
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