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Das R, Linseis M, Schupp SM, Gogesch FS, Schmidt-Mende L, Winter RF. Organic binary charge-transfer compounds of 2,2' : 6',2'' : 6'',6-trioxotriphenylamine and a pyrene-annulated azaacene as donors. RSC Adv 2023; 13:3652-3660. [PMID: 36756575 PMCID: PMC9890512 DOI: 10.1039/d2ra07322f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 01/18/2023] [Indexed: 01/31/2023] Open
Abstract
Three binary charge-transfer (CT) compounds resulting from the donor 2,2' : 6',2'' : 6'',6-trioxotriphenylamine (TOTA) and the acceptors F4TCNQ and F4BQ and of a pyrene-annulated azaacene (PAA) with the acceptor F4TCNQ are reported. The identity of these CT compounds are confirmed by single-crystal X-ray diffraction as well as by IR, UV-vis-NIR and EPR spectroscopy. X-ray diffraction analysis reveals a 1 : 1 stoichiometry for TOTA·F4TCNQ, a 2 : 1 donor : acceptor ratio in (TOTA)2·F4BQ, and a rare 4 : 1 stoichiometry in (PAA)4·F4TCNQ, respectively. Metrical parameters of the donor (D) and acceptor (A) constituents as well as IR spectra indicate full CT in TOTA·F4TCNQ, partial CT in (TOTA)2·F4BQ and only a very modest one in (PAA)4·F4TCNQ. Intricate packing motifs are present in the crystal lattice with encaged, π-stacked (F4TCNQ-)2 dimers in TOTA·F4TCNQ or mixed D/A stacks in the other two compounds. Their solid-state UV-vis-NIR spectra feature CT transitions. The CT compounds with F4TCNQ are electrical insulators, while (TOTA)2·F4BQ is weakly conducting.
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Affiliation(s)
- Rajorshi Das
- Fachbereich Chemie, Universität Konstanz Universitätsstrasse 10, 78457 Konstanz Germany
| | - Michael Linseis
- Fachbereich Chemie, Universität Konstanz Universitätsstrasse 10, 78457 Konstanz Germany
| | - Stefan M Schupp
- Fachbereich Physik, Universität Konstanz Universitätsstrasse 10, 78457 Konstanz Germany
| | - Franciska S Gogesch
- Fachbereich Chemie, Universität Konstanz Universitätsstrasse 10, 78457 Konstanz Germany
| | - Lukas Schmidt-Mende
- Fachbereich Physik, Universität Konstanz Universitätsstrasse 10, 78457 Konstanz Germany
| | - Rainer F Winter
- Fachbereich Chemie, Universität Konstanz Universitätsstrasse 10, 78457 Konstanz Germany
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2
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Gao J, Guo J, Chen Y, Deng S, Lu Q, Ren Y, Wang X, Fan H, Teng F, He X, Jiang H, Hu P. The competitive role of C–H⋯X (X = F, O) and π–π interactions in contributing to the degree of charge transfer in organic cocrystals: a case study of heteroatom-free donors with p-fluoranil (FA). CrystEngComm 2022. [DOI: 10.1039/d2ce00925k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Four binary organic charge transfer cocrystals were grown by the slow cooling method. The competitive role of C–H⋯X (X = F, O) and π–π interactions in contributing to the degree of charge transfer in the cocrystals was investigated.
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Affiliation(s)
- Jiaoyang Gao
- School of Physics, Northwest University, Xi'an 710069, P.R. China
| | - Jinjia Guo
- School of Physics, Northwest University, Xi'an 710069, P.R. China
| | - Yi Chen
- School of Materials Science and Engineering, Shaanxi Normal University, Xi'an 710119, P.R. China
| | - Shunlan Deng
- School of Materials Science and Engineering, Shaanxi Normal University, Xi'an 710119, P.R. China
| | - Qidong Lu
- School of Physics, Northwest University, Xi'an 710069, P.R. China
| | - Yuxin Ren
- School of Physics, Northwest University, Xi'an 710069, P.R. China
| | - Xiaoming Wang
- School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi’an 710062, China
| | - Haibo Fan
- School of Physics, Northwest University, Xi'an 710069, P.R. China
| | - Feng Teng
- School of Physics, Northwest University, Xi'an 710069, P.R. China
| | - Xuexia He
- School of Materials Science and Engineering, Shaanxi Normal University, Xi'an 710119, P.R. China
| | - Hui Jiang
- School of Materials Science and Engineering, Tianjin University, Tianjin 300072, P.R. China
| | - Peng Hu
- School of Physics, Northwest University, Xi'an 710069, P.R. China
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Pereira-da-Silva J, Mendes M, Kossoski F, Lozano AI, Rodrigues R, Jones NC, Hoffmann SV, Ferreira da Silva F. Perfluoro effect on the electronic excited states of para-benzoquinone revealed by experiment and theory. Phys Chem Chem Phys 2021; 23:2141-2153. [PMID: 33437976 DOI: 10.1039/d0cp05626j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report a comprehensive study on the electronic excited states of tetrafluoro-1,4-benzoquinone, through high-resolution vacuum ultraviolet photoabsorption spectroscopy and time-dependent density functional theory calculations performed within the nuclear ensemble approach. Absolute cross section values were experimentally determined in the 3.8-10.8 eV energy range. The present experimental results represent the highest resolution data yet reported for this molecule and reveal previously unresolved spectral structures. The interpretation of the results was made in close comparison with the available data for para-benzoquinone [Jones et al., J. Chem. Phys., 2017, 146, 184303]. While the dominant absorption features for both molecules arise from analogous π* ← π transitions, some remarkable differences have been identified. The perfluoro effect manifests in different ways: shifts in band positions and cross sections, appearance of features associated with excitations to σCF* orbitals, and spectrum broadening by quenching of either vibrational or Rydberg progressions. The level of agreement between experiment and theory is very satisfactory, yet that required the inclusion of nuclear quantum effects in the calculations. We have also discussed the role of temperature on the absorption spectrum, as well as the involvement of core-excited resonances in promoting dissociative electron attachment reactions in the 3-5 eV range.
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Affiliation(s)
- J Pereira-da-Silva
- Atomic and Molecular Collisions Laboratory, CEFITEC, Department of Physics, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal.
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Ravi Kumar V, Ariese F, Umapathy S. Triplet excited electronic state switching induced by hydrogen bonding: A transient absorption spectroscopy and time-dependent DFT study. J Chem Phys 2016; 144:114301. [PMID: 27004870 DOI: 10.1063/1.4943514] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The solvent plays a decisive role in the photochemistry and photophysics of aromatic ketones. Xanthone (XT) is one such aromatic ketone and its triplet-triplet (T-T) absorption spectra show intriguing solvatochromic behavior. Also, the reactivity of XT towards H-atom abstraction shows an unprecedented decrease in protic solvents relative to aprotic solvents. Therefore, a comprehensive solvatochromic analysis of the triplet-triplet absorption spectra of XT was carried out in conjunction with time dependent density functional theory using the ad hoc explicit solvent model approach. A detailed solvatochromic analysis of the T-T absorption bands of XT suggests that the hydrogen bonding interactions are different in the corresponding triplet excited states. Furthermore, the contributions of non-specific and hydrogen bonding interactions towards differential solvation of the triplet states in protic solvents were found to be of equal magnitude. The frontier molecular orbital and electron density difference analysis of the T1 and T2 states of XT indicates that the charge redistribution in these states leads to intermolecular hydrogen bond strengthening and weakening, respectively, relative to the S0 state. This is further supported by the vertical excitation energy calculations of the XT-methanol supra-molecular complex. The intermolecular hydrogen bonding potential energy curves obtained for this complex in the S0, T1, and T2 states support the model. In summary, we propose that the different hydrogen bonding mechanisms exhibited by the two lowest triplet excited states of XT result in a decreasing role of the nπ(∗) triplet state, and are thus responsible for its reduced reactivity towards H-atom abstraction in protic solvents.
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Affiliation(s)
- Venkatraman Ravi Kumar
- Inorganic and Physical Chemistry Department, Indian Institute of Science, Bangalore 560012, India
| | - Freek Ariese
- Inorganic and Physical Chemistry Department, Indian Institute of Science, Bangalore 560012, India
| | - Siva Umapathy
- Inorganic and Physical Chemistry Department, Indian Institute of Science, Bangalore 560012, India
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Ravi Kumar V, Verma C, Umapathy S. Molecular dynamics and simulations study on the vibrational and electronic solvatochromism of benzophenone. J Chem Phys 2016; 144:064302. [DOI: 10.1063/1.4941058] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Kumar VR, Rajkumar N, Ariese F, Umapathy S. Direct Observation of Thermal Equilibrium of Excited Triplet States of 9,10-Phenanthrenequinone. A Time-Resolved Resonance Raman Study. J Phys Chem A 2015; 119:10147-57. [PMID: 26381591 DOI: 10.1021/acs.jpca.5b07972] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The photochemistry of aromatic ketones plays a key role in various physicochemical and biological processes, and solvent polarity can be used to tune their triplet state properties. Therefore, a comprehensive analysis of the conformational structure and the solvent polarity induced energy level reordering of the two lowest triplet states of 9,10-phenanthrenequinone (PQ) was carried out using nanosecond-time-resolved absorption (ns-TRA), time-resolved resonance Raman (TR(3)) spectroscopy, and time dependent-density functional theory (TD-DFT) studies. The ns-TRA of PQ in acetonitrile displays two bands in the visible range, and these two bands decay with similar lifetime at least at longer time scales (μs). Interestingly, TR(3) spectra of these two bands indicate that the kinetics are different at shorter time scales (ns), while at longer time scales they followed the kinetics of ns-TRA spectra. Therefore, we report a real-time observation of the thermal equilibrium between the two lowest triplet excited states of PQ, assigned to nπ* and ππ* of which the ππ* triplet state is formed first through intersystem crossing. Despite the fact that these two states are energetically close and have a similar conformational structure supported by TD-DFT studies, the slow internal conversion (∼2 ns) between the T(2)(1(3)nπ*) and T(1)(1(3)ππ*) triplet states indicates a barrier. Insights from the singlet excited states of PQ in protic solvents [ J. Chem. Phys. 2015 , 142 , 24305 ] suggest that the lowest nπ* and ππ* triplet states should undergo hydrogen bond weakening and strengthening, respectively, relative to the ground state, and these mechanisms are substantiated by TD-DFT calculations. We also hypothesize that the different hydrogen bonding mechanisms exhibited by the two lowest singlet and triplet excited states of PQ could influence its ISC mechanism.
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Affiliation(s)
- Venkatraman Ravi Kumar
- Inorganic and Physical Chemistry Department, Indian Institute of Science , Bangalore 560012, India
| | - Nagappan Rajkumar
- Inorganic and Physical Chemistry Department, Indian Institute of Science , Bangalore 560012, India
| | - Freek Ariese
- Inorganic and Physical Chemistry Department, Indian Institute of Science , Bangalore 560012, India
| | - Siva Umapathy
- Inorganic and Physical Chemistry Department, Indian Institute of Science , Bangalore 560012, India
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Ravi Kumar V, Rajkumar N, Umapathy S. Solvatochromism of 9,10-phenanthrenequinone: An electronic and resonance Raman spectroscopic study. J Chem Phys 2015; 142:024305. [DOI: 10.1063/1.4905126] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
| | - Nagappan Rajkumar
- Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - Siva Umapathy
- Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
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Sil S, Chaturvedi D, Krishnappa KB, Kumar S, Asthana SN, Umapathy S. Density Functional Theoretical Modeling, Electrostatic Surface Potential and Surface Enhanced Raman Spectroscopic Studies on Biosynthesized Silver Nanoparticles: Observation of 400 pM Sensitivity to Explosives. J Phys Chem A 2014; 118:2904-14. [DOI: 10.1021/jp4090266] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sanchita Sil
- Department of Inorganic & Physical Chemistry Indian Institute of Science, Bangalore 560012, India
- High Energy Materials Research Laboratory, Sutarwadi, Pune 411021, India
| | - Deepika Chaturvedi
- Department of Inorganic & Physical Chemistry Indian Institute of Science, Bangalore 560012, India
| | - Keerthi B. Krishnappa
- Department of Inorganic & Physical Chemistry Indian Institute of Science, Bangalore 560012, India
| | - Srividya Kumar
- Department of Inorganic & Physical Chemistry Indian Institute of Science, Bangalore 560012, India
| | - S. N. Asthana
- High Energy Materials Research Laboratory, Sutarwadi, Pune 411021, India
| | - Siva Umapathy
- Department of Inorganic & Physical Chemistry Indian Institute of Science, Bangalore 560012, India
- Department
of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore-560012, India
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Ómarsson B, Ingólfsson O. Stabilization, fragmentation and rearrangement reactions in low-energy electron interaction with tetrafluoro-para-benzoquinone: a combined theoretical and experimental study. Phys Chem Chem Phys 2013; 15:16758-67. [DOI: 10.1039/c3cp52397g] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Sahoo SK, Umapathy S, Parker AW. Time-resolved resonance Raman spectroscopy: exploring reactive intermediates. APPLIED SPECTROSCOPY 2011; 65:1087-115. [PMID: 21986070 DOI: 10.1366/11-06406] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The study of reaction mechanisms involves systematic investigations of the correlation between structure, reactivity, and time. The challenge is to be able to observe the chemical changes undergone by reactants as they change into products via one or several intermediates such as electronic excited states (singlet and triplet), radicals, radical ions, carbocations, carbanions, carbenes, nitrenes, nitrinium ions, etc. The vast array of intermediates and timescales means there is no single "do-it-all" technique. The simultaneous advances in contemporary time-resolved Raman spectroscopic techniques and computational methods have done much towards visualizing molecular fingerprint snapshots of the reactive intermediates in the microsecond to femtosecond time domain. Raman spectroscopy and its sensitive counterpart resonance Raman spectroscopy have been well proven as means for determining molecular structure, chemical bonding, reactivity, and dynamics of short-lived intermediates in solution phase and are advantageous in comparison to commonly used time-resolved absorption and emission spectroscopy. Today time-resolved Raman spectroscopy is a mature technique; its development owes much to the advent of pulsed tunable lasers, highly efficient spectrometers, and high speed, highly sensitive multichannel detectors able to collect a complete spectrum. This review article will provide a brief chronological development of the experimental setup and demonstrate how experimentalists have conquered numerous challenges to obtain background-free (removing fluorescence), intense, and highly spectrally resolved Raman spectra in the nanosecond to microsecond (ns-μs) and picosecond (ps) time domains and, perhaps surprisingly, laid the foundations for new techniques such as spatially offset Raman spectroscopy.
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Affiliation(s)
- Sangram Keshari Sahoo
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore-560012, India
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11
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Mohapatra H, Umapathy S. Time-Resolved Resonance Raman Studies on Proton-Induced Electron-Transfer Reaction from Triplet Excited State of 2-Methoxynaphthalene to Decafluorobenzophenone. J Phys Chem A 2010; 114:12447-51. [DOI: 10.1021/jp109821r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Himansu Mohapatra
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - S. Umapathy
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
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12
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Unravelling the Reaction Mechanism for the Fast Photocyclisation of 2-Benzoylpyridine in Aqueous Solvent by Time-Resolved Spectroscopy and Density Functional Theory Calculations. Chemistry 2010; 16:6961-72. [DOI: 10.1002/chem.200903073] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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13
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Balakrishnan G, Sahoo SK, Chowdhury BK, Umapathy S. Understanding solvent effects on structure and reactivity of organic intermediates: a Raman study. Faraday Discuss 2010. [DOI: 10.1039/b908146a] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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14
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Mohapatra H, Umapathy S. Influence of Solvent on Photoinduced Electron-Transfer Reaction: Time-Resolved Resonance Raman Study. J Phys Chem A 2009; 113:6904-9. [DOI: 10.1021/jp903973q] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Himansu Mohapatra
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore-560012, India
| | - Siva Umapathy
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore-560012, India
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Mohammed A, Ågren H, Norman P. Resonance enhanced Raman scattering from the complex electric-dipole polarizability: A theoretical study on N2. Chem Phys Lett 2009. [DOI: 10.1016/j.cplett.2008.11.063] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Shi M, Yang WG, Wu S. Wavelength-dependent photolyses of 2,5-dichloro-3,6-bis(dialkylamino)-[1,4]benzoquinone. J Photochem Photobiol A Chem 2007. [DOI: 10.1016/j.jphotochem.2006.05.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Puranik M, Umapathy S. Excited State Structure and Dynamics ofp-Benzoquinone and Bromanil from Time-Resolved Resonance Raman Spectra and Simulation. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2002. [DOI: 10.1246/bcsj.75.1057] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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