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Curchod BFE, Sisto A, Martínez TJ. Ab Initio Multiple Spawning Photochemical Dynamics of DMABN Using GPUs. J Phys Chem A 2017; 121:265-276. [DOI: 10.1021/acs.jpca.6b09962] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Basile F. E. Curchod
- Department
of Chemistry and the PULSE Institute, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Aaron Sisto
- Department
of Chemistry and the PULSE Institute, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Todd J. Martínez
- Department
of Chemistry and the PULSE Institute, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
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2
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Georgieva I, Aquino AJA, Plasser F, Trendafilova N, Köhn A, Lischka H. Intramolecular Charge-Transfer Excited-State Processes in 4-(N,N-Dimethylamino)benzonitrile: The Role of Twisting and the πσ* State. J Phys Chem A 2015; 119:6232-43. [PMID: 25989536 PMCID: PMC4476306 DOI: 10.1021/acs.jpca.5b03282] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
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The
structural processes leading to dual fluorescence of 4-(dimethylamino)benzonitrile
in the gas phase and in acetonitrile solvent were investigated using
a combination of multireference configuration interaction (MRCI) and
the second-order algebraic diagrammatic construction (ADC(2)) methods.
Solvent effects were included on the basis of the conductor-like screening
model. The MRCI method was used for computing the nonadiabatic interaction
between the two lowest excited ππ* states (S2(La, CT) and S1(Lb, LE)) and the
corresponding minimum on the crossing seam (MXS) whereas the ADC(2)
calculations were dedicated to assessing the role of the πσ*
state. The MXS structure was found to have a twisting angle of ∼50°.
The branching space does not contain the twisting motion of the dimethylamino
group and thus is not directly involved in the deactivation process
from S2 to S1. Polar solvent effects are not
found to have a significant influence on this situation. Applying Cs symmetry restrictions, the ADC(2) calculations
show that CCN bending leads to a strong stabilization and to significant
charge transfer (CT). Nevertheless, this structure is not a minimum
but converts to the local excitation (LE) structure on releasing the
symmetry constraint. These findings suggest that the main role in
the dynamics is played by the nonadiabatic interaction of the LE and
CT states and that the main source for the dual fluorescence is the
twisted internal charge-transfer state in addition to the LE state.
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Affiliation(s)
- Ivelina Georgieva
- †Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Adélia J A Aquino
- ‡Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409-1061, United States.,§Institute for Theoretical Chemistry, University of Vienna, A-1090 Vienna, Austria
| | - Felix Plasser
- §Institute for Theoretical Chemistry, University of Vienna, A-1090 Vienna, Austria
| | - Natasha Trendafilova
- †Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Andreas Köhn
- ∥Institute for Theoretical Chemistry, University of Stuttgart, 70569 Stuttgart, Germany
| | - Hans Lischka
- ‡Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409-1061, United States.,§Institute for Theoretical Chemistry, University of Vienna, A-1090 Vienna, Austria
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3
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Perveaux A, Castro PJ, Lauvergnat D, Reguero M, Lasorne B. Intramolecular Charge Transfer in 4-Aminobenzonitrile Does Not Need the Twist and May Not Need the Bend. J Phys Chem Lett 2015; 6:1316-1320. [PMID: 26263129 DOI: 10.1021/acs.jpclett.5b00162] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A study combining accurate quantum chemistry and full-dimensional quantum dynamics is presented to confirm the existence of an ultrafast radiationless decay channel from the charge-transfer state to the locally excited state in 4-aminobenzonitrile. This intramolecular charge-transfer pathway proceeds through a newly found planar conical intersection, and it is shown to be more efficient in the presence of acetonitrile than in the gas phase. Our results are consistent with recent experimental observations.
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Affiliation(s)
- Aurelie Perveaux
- †Laboratoire de Chimie Physique (UMR 8000), CNRS, Université Paris-Sud, 91405 Orsay, France
- ‡Institut Charles Gerhardt (UMR 5253), CNRS, Université de Montpellier, 34095 Montpellier, France
| | - Pedro J Castro
- §Departament de Quı́mica Fı́sica i Inorgànica, Universitat Rovira i Virgili, 43007 Tarragona, Spain
| | - David Lauvergnat
- †Laboratoire de Chimie Physique (UMR 8000), CNRS, Université Paris-Sud, 91405 Orsay, France
| | - Mar Reguero
- §Departament de Quı́mica Fı́sica i Inorgànica, Universitat Rovira i Virgili, 43007 Tarragona, Spain
| | - Benjamin Lasorne
- ‡Institut Charles Gerhardt (UMR 5253), CNRS, Université de Montpellier, 34095 Montpellier, France
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4
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Gómez I, Castro PJ, Reguero M. Insight into the Mechanisms of Luminescence of Aminobenzonitrile and Dimethylaminobenzonitrile in Polar Solvents. An ab Initio Study. J Phys Chem A 2015; 119:1983-95. [DOI: 10.1021/acs.jpca.5b01421] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Isabel Gómez
- Departament
de Química
Física i Inorgànica, Universitat Rovira i Virgili, C.
Marcel·lí Domingo 1, 43007, Tarragona , Spain
| | - Pedro J. Castro
- Departament
de Química
Física i Inorgànica, Universitat Rovira i Virgili, C.
Marcel·lí Domingo 1, 43007, Tarragona , Spain
| | - Mar Reguero
- Departament
de Química
Física i Inorgànica, Universitat Rovira i Virgili, C.
Marcel·lí Domingo 1, 43007, Tarragona , Spain
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5
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Kochman MA, Tajti A, Morrison CA, Miller RJD. Early Events in the Nonadiabatic Relaxation Dynamics of 4-(N,N-Dimethylamino)benzonitrile. J Chem Theory Comput 2015; 11:1118-28. [DOI: 10.1021/ct5010609] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Michał A. Kochman
- Max Planck Institute
for the Structure and Dynamics of Matter, Building 99 (CFEL), Luruper Chaussee 149, 22761 Hamburg, Hamburg, Germany
| | - Attila Tajti
- Institute
of Chemistry, Eötvös Loránd University, Budapest 1053, Hungary
| | - Carole A. Morrison
- School
of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster
Road, Edinburgh, Scotland EH9 3FJ
| | - R. J. Dwayne Miller
- Max Planck Institute
for the Structure and Dynamics of Matter, Building 99 (CFEL), Luruper Chaussee 149, 22761 Hamburg, Hamburg, Germany
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6
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Mao M, Ren MG, Song QH. Thermodynamics and Conformations in the Formation of Excited States and Their Interconversions for Twisted Donor-Substituted Tridurylboranes. Chemistry 2012; 18:15512-22. [DOI: 10.1002/chem.201201719] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Indexed: 11/10/2022]
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7
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Chan CTL, Cheng CCW, Ho KYF, Kwok WM. Femtosecond broadband time-resolved fluorescence and transient absorption study of the intramolecular charge transfer state of methyl 4-dimethylaminobenzoate. Phys Chem Chem Phys 2011; 13:16306-13. [DOI: 10.1039/c1cp21627a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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9
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Galván IF, Martín ME, Aguilar MA. Theoretical Study of the Dual Fluorescence of 4-(N,N-Dimethylamino)benzonitrile in Solution. J Chem Theory Comput 2010; 6:2445-54. [DOI: 10.1021/ct9006713] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ignacio Fdez. Galván
- Química Física, Edif. José María Viguera Lobo, Universidad de Extremadura, Avda. de Elvas s/n, 06071 Badajoz, Spain
| | - M. Elena Martín
- Química Física, Edif. José María Viguera Lobo, Universidad de Extremadura, Avda. de Elvas s/n, 06071 Badajoz, Spain
| | - Manuel A. Aguilar
- Química Física, Edif. José María Viguera Lobo, Universidad de Extremadura, Avda. de Elvas s/n, 06071 Badajoz, Spain
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10
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Druzhinin SI, Mayer P, Stalke D, von Bülow R, Noltemeyer M, Zachariasse KA. Intramolecular Charge Transfer with 1-tert-Butyl-6-cyano-1,2,3,4-tetrahydroquinoline (NTC6) and Other Aminobenzonitriles. A Comparison of Experimental Vapor Phase Spectra and Crystal Structures with Calculations. J Am Chem Soc 2010; 132:7730-44. [DOI: 10.1021/ja101336n] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sergey I. Druzhinin
- Max-Planck-Institut für biophysikalische Chemie, Spektroskopie und Photochemische Kinetik, 37070 Göttingen, Germany, Department Chemie und Biochemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, Haus F, 81377 München, Germany, and Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany
| | - Peter Mayer
- Max-Planck-Institut für biophysikalische Chemie, Spektroskopie und Photochemische Kinetik, 37070 Göttingen, Germany, Department Chemie und Biochemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, Haus F, 81377 München, Germany, and Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany
| | - Dietmar Stalke
- Max-Planck-Institut für biophysikalische Chemie, Spektroskopie und Photochemische Kinetik, 37070 Göttingen, Germany, Department Chemie und Biochemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, Haus F, 81377 München, Germany, and Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany
| | - Rixa von Bülow
- Max-Planck-Institut für biophysikalische Chemie, Spektroskopie und Photochemische Kinetik, 37070 Göttingen, Germany, Department Chemie und Biochemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, Haus F, 81377 München, Germany, and Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany
| | - Mathias Noltemeyer
- Max-Planck-Institut für biophysikalische Chemie, Spektroskopie und Photochemische Kinetik, 37070 Göttingen, Germany, Department Chemie und Biochemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, Haus F, 81377 München, Germany, and Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany
| | - Klaas A. Zachariasse
- Max-Planck-Institut für biophysikalische Chemie, Spektroskopie und Photochemische Kinetik, 37070 Göttingen, Germany, Department Chemie und Biochemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, Haus F, 81377 München, Germany, and Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany
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11
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Druzhinin SI, Kovalenko SA, Senyushkina TA, Demeter A, Zachariasse KA. Intramolecular Charge Transfer with Fluorazene and N-Phenylpyrrole. J Phys Chem A 2009; 114:1621-32. [DOI: 10.1021/jp909682p] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Sergey I. Druzhinin
- Max-Planck-Institut für biophysikalische Chemie, Spektroskopie und Photochemische Kinetik, 37070 Göttingen, Germany, Institut für Chemie, Humboldt Universität zu Berlin, Brook-Taylor Strasse 2, 12489 Berlin, Germany, and Institute of Materials and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sciences. P. O. Box 17, 1525 Budapest, Hungary
| | - Sergey A. Kovalenko
- Max-Planck-Institut für biophysikalische Chemie, Spektroskopie und Photochemische Kinetik, 37070 Göttingen, Germany, Institut für Chemie, Humboldt Universität zu Berlin, Brook-Taylor Strasse 2, 12489 Berlin, Germany, and Institute of Materials and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sciences. P. O. Box 17, 1525 Budapest, Hungary
| | - Tamara A. Senyushkina
- Max-Planck-Institut für biophysikalische Chemie, Spektroskopie und Photochemische Kinetik, 37070 Göttingen, Germany, Institut für Chemie, Humboldt Universität zu Berlin, Brook-Taylor Strasse 2, 12489 Berlin, Germany, and Institute of Materials and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sciences. P. O. Box 17, 1525 Budapest, Hungary
| | - Attila Demeter
- Max-Planck-Institut für biophysikalische Chemie, Spektroskopie und Photochemische Kinetik, 37070 Göttingen, Germany, Institut für Chemie, Humboldt Universität zu Berlin, Brook-Taylor Strasse 2, 12489 Berlin, Germany, and Institute of Materials and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sciences. P. O. Box 17, 1525 Budapest, Hungary
| | - Klaas A. Zachariasse
- Max-Planck-Institut für biophysikalische Chemie, Spektroskopie und Photochemische Kinetik, 37070 Göttingen, Germany, Institut für Chemie, Humboldt Universität zu Berlin, Brook-Taylor Strasse 2, 12489 Berlin, Germany, and Institute of Materials and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sciences. P. O. Box 17, 1525 Budapest, Hungary
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12
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Druzhinin SI, Kovalenko SA, Senyushkina TA, Demeter A, Machinek R, Noltemeyer M, Zachariasse KA. Intramolecular Charge Transfer with the Planarized 4-Cyanofluorazene and Its Flexible Counterpart 4-Cyano-N-phenylpyrrole. Picosecond Fluorescence Decays and Femtosecond Excited-State Absorption. J Phys Chem A 2008; 112:8238-53. [DOI: 10.1021/jp8037413] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sergey I. Druzhinin
- Max-Planck-Institut für biophysikalische Chemie, Spektroskopie and Photochemische Kinetik, 37070 Göttingen, Germany, Institut für Chemie, Humboldt Universität zu Berlin, Brook-Taylor Strasse 2, 12489 Berlin, Germany, Institute of Materials and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sciences. P. O. Box 17, 1525 Budapest, Hungary, Institut für Organische Chemie, Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany, and Institut für Anorganische Chemie,
| | - Sergey A. Kovalenko
- Max-Planck-Institut für biophysikalische Chemie, Spektroskopie and Photochemische Kinetik, 37070 Göttingen, Germany, Institut für Chemie, Humboldt Universität zu Berlin, Brook-Taylor Strasse 2, 12489 Berlin, Germany, Institute of Materials and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sciences. P. O. Box 17, 1525 Budapest, Hungary, Institut für Organische Chemie, Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany, and Institut für Anorganische Chemie,
| | - Tamara A. Senyushkina
- Max-Planck-Institut für biophysikalische Chemie, Spektroskopie and Photochemische Kinetik, 37070 Göttingen, Germany, Institut für Chemie, Humboldt Universität zu Berlin, Brook-Taylor Strasse 2, 12489 Berlin, Germany, Institute of Materials and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sciences. P. O. Box 17, 1525 Budapest, Hungary, Institut für Organische Chemie, Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany, and Institut für Anorganische Chemie,
| | - Attila Demeter
- Max-Planck-Institut für biophysikalische Chemie, Spektroskopie and Photochemische Kinetik, 37070 Göttingen, Germany, Institut für Chemie, Humboldt Universität zu Berlin, Brook-Taylor Strasse 2, 12489 Berlin, Germany, Institute of Materials and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sciences. P. O. Box 17, 1525 Budapest, Hungary, Institut für Organische Chemie, Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany, and Institut für Anorganische Chemie,
| | - Reinhard Machinek
- Max-Planck-Institut für biophysikalische Chemie, Spektroskopie and Photochemische Kinetik, 37070 Göttingen, Germany, Institut für Chemie, Humboldt Universität zu Berlin, Brook-Taylor Strasse 2, 12489 Berlin, Germany, Institute of Materials and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sciences. P. O. Box 17, 1525 Budapest, Hungary, Institut für Organische Chemie, Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany, and Institut für Anorganische Chemie,
| | - Mathias Noltemeyer
- Max-Planck-Institut für biophysikalische Chemie, Spektroskopie and Photochemische Kinetik, 37070 Göttingen, Germany, Institut für Chemie, Humboldt Universität zu Berlin, Brook-Taylor Strasse 2, 12489 Berlin, Germany, Institute of Materials and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sciences. P. O. Box 17, 1525 Budapest, Hungary, Institut für Organische Chemie, Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany, and Institut für Anorganische Chemie,
| | - Klaas A. Zachariasse
- Max-Planck-Institut für biophysikalische Chemie, Spektroskopie and Photochemische Kinetik, 37070 Göttingen, Germany, Institut für Chemie, Humboldt Universität zu Berlin, Brook-Taylor Strasse 2, 12489 Berlin, Germany, Institute of Materials and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sciences. P. O. Box 17, 1525 Budapest, Hungary, Institut für Organische Chemie, Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany, and Institut für Anorganische Chemie,
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13
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Druzhinin SI, Kovalenko SA, Senyushkina T, Zachariasse KA. Dynamics of Ultrafast Intramolecular Charge Transfer with 1-tert-Butyl-6-cyano-1,2,3,4-tetrahydroquinoline (NTC6) in n-Hexane and Acetonitrile. J Phys Chem A 2007; 111:12878-90. [DOI: 10.1021/jp074983z] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Sergey I. Druzhinin
- Spektroskopie und Photochemische Kinetik, Max-Planck-Institut für biophysikalische Chemie, 37070 Göttingen, Germany, and Institut für Chemie, Humboldt Universität zu Berlin, Brook-Taylor Strasse 2, 12489 Berlin, Germany
| | - Sergey A. Kovalenko
- Spektroskopie und Photochemische Kinetik, Max-Planck-Institut für biophysikalische Chemie, 37070 Göttingen, Germany, and Institut für Chemie, Humboldt Universität zu Berlin, Brook-Taylor Strasse 2, 12489 Berlin, Germany
| | - Tamara Senyushkina
- Spektroskopie und Photochemische Kinetik, Max-Planck-Institut für biophysikalische Chemie, 37070 Göttingen, Germany, and Institut für Chemie, Humboldt Universität zu Berlin, Brook-Taylor Strasse 2, 12489 Berlin, Germany
| | - Klaas A. Zachariasse
- Spektroskopie und Photochemische Kinetik, Max-Planck-Institut für biophysikalische Chemie, 37070 Göttingen, Germany, and Institut für Chemie, Humboldt Universität zu Berlin, Brook-Taylor Strasse 2, 12489 Berlin, Germany
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Amatatsu Y, Komura Y. Reaction coordinate analysis of the S1-S0 internal conversion of azulene. J Chem Phys 2007; 125:174311. [PMID: 17100443 DOI: 10.1063/1.2364891] [Citation(s) in RCA: 15] [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 reaction coordinate of the S(1)-S(0) internal conversion of azulene has been analyzed using ab initio complete active space self-consistent field method. The stable geometry in S(0) (S(0) geometry) takes a bond-equalized structure where all the peripheral skeletal bond distances are similar to an aromatic CC bond distance. The transannular bond is similar to a normal C-C single bond. The first event upon electronic excitation into S(1) at S(0) geometry is characterized by the following two simultaneous changes in the skeletal bonds; the transannular bond in S(1) increases its double bond character and the aromaticity of the peripheral bonds disappears. In consequence, the most stable azulene in S(1) (S(1) geometry) has a biradical character. To reach the conical intersection between S(1) and S(0) (S(1)S(0)-CIX) where radiationless relaxation takes place, the seven-membered ring greatly deviates from a planar structure. After a transition into S(0) at S(1)S(0)-CIX, the bond-equalized structure is recovered immediately and then the nonplanarity decreases so that azulene again takes the stable planar S(0) geometry. In order to deepen the understanding of the S(1)-S(0) internal conversion, the dipole moments along the reaction coordinate have been analyzed.
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Affiliation(s)
- Yoshiaki Amatatsu
- Faculty of Engineering and Resource Science, Akita University, Tegata Gakuen-cho, Akita 010-8502, Japan.
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15
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Fuss W, Schmid WE, Kuttan Pushpa K, Trushin SA, Yatsuhashi T. Ultrafast relaxation and coherent oscillations in aminobenzonitriles in the gas phase probed by intense-field ionization. Phys Chem Chem Phys 2007; 9:1151-69. [PMID: 17325762 DOI: 10.1039/b611877a] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
4-Aminobenzonitrile derivatives have two excited states of similar energy: besides the benzene-like L(b) state (also termed "locally excited" or LE state) one with charge-transfer (CT) character that is slightly higher in the isolated molecules. The CT state can be lowered by solvents of suitable polarity, so that dual fluorescence can be observed in them. It is controversial along which coordinate this state is displaced, although the amino-group twist is a wide-spread assumption. We investigated a number of such compounds by transient ionization in the gas phase, initially exciting the higher-lying L(a) state (S(2)). Here we briefly review the previous results on 4-(dimethylamino)benzonitrile (the prototype of this class of molecules), 4-piperidino-, pyrrolidino- and pyrrolyl-benzonitrile and compare them with new results on 4-aminobenzonitrile and on the bridged derivative N-methyl-6-cyano-1,2,3,4-tetrahydroquinoline (NMC6). Although in the latter two molecules the CT state has never been detected before, we find the same relaxation path for all compounds: From S(2), the wave packet passes through a conical intersection (CI); from there part of it reaches the S(1) (L(b)) state directly, whereas another part temporarily populates the CT state (also in NMC6), from where it goes around the CI also to the L(b) well. The wave packet directly reaching the L(b) well oscillates there along coordinates involving amino-group twist and wagging or molecular arching and a quinoidal distortion. These coordinates must be components of the CI displacement vector. A vibration involving bond-length alternation of the benzene ring is ascribed to a momentum caused by the electronic symmetry change in the CI, i.e., to the nonadiabatic coupling vector. Also the CT state involves amino-group twist, as to conclude from the anisotropy of the corresponding signal. The six-membered aliphatic ring in NMC6 hinders the twist and raises the CT state to an energy that is, however, still below the L(a) state, so that it can be temporarily populated in a barrierless process. Also in aminobenzonitrile the CT state is between L(a) and L(b) and is reached from L(a) without a barrier. The twist is rationalized by vibronic interaction with a higher state that is pi-antibonding between the amino group and the aromatic ring.
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Affiliation(s)
- Werner Fuss
- Max-Planck-Institut für Quantenoptik, D-85741 Garching, Germany
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16
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Hättig C, Hellweg A, Köhn A. Intramolecular Charge-Transfer Mechanism in Quinolidines: The Role of the Amino Twist Angle. J Am Chem Soc 2006; 128:15672-82. [PMID: 17147377 DOI: 10.1021/ja0642010] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Quantum-chemical calculations with the approximate coupled-cluster singles-and-doubles model CC2 have been carried out for 1-tert-butyl-6-cyano-1,2,3,4-tetrahydroquinoline (NTC6). For this molecule dual fluorescence was experimentally observed, raising the discussion about the importance of the amino twist angle for this process. The calculations suggest that both the ground state and the normal fluorescent state are significantly twisted by 30 degrees -40 degrees and that the molecule is flexible enough to move into an even stronger twisted conformation (60 degrees -70 degrees ) in its intramolecular charge-transfer (ICT) state which is responsible for the anomalous fluorescence band. Such a conformation both minimizes the total energy in the S1 state and maximizes the dipole moment. The barrier from the normal fluorescent state to the ICT state region is very small. Comparison to the situation in the 1-methyl-derivative NMC6 suggests that a large alkyl substituent makes the preferably planar normal fluorescent state energetically unfavorable compared to the ICT state and thus promotes the occurrence of dual fluorescence.
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Affiliation(s)
- Christof Hättig
- Forschungszentrum Karlsruhe, Institute of Nanotechnology, D-76021 Karlsruhe, Germany
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Pigliucci A, Nikolov P, Rehaman A, Gagliardi L, Cramer CJ, Vauthey E. Early Excited State Dynamics of 6-Styryl-Substituted Pyrylium Salts Exhibiting Dual Fluorescence. J Phys Chem A 2006; 110:9988-94. [PMID: 16913670 DOI: 10.1021/jp063214x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A series of 6-styryl-2,4-diphenylpyrylium salts exhibiting dual fluorescence has been investigated by fluorescence up-conversion in conjunction with quantum chemical calculations. The short-wavelength emission is due to an excited state localized on the pyrylium fragment and the long-wavelength emission arises from a charge-transfer state delocalized over the whole molecule. The two fluorescing states do not exhibit a precursor-successor relationship. The rise time of the short-wavelength fluorescence is smaller than 200 fs, and that of the long-wavelength emission depends on the electron-donating property of the styryl group substituent. The rise is almost prompt with the weaker donors but is slower, wavelength and viscosity dependent with the strongest electron-donating group. A model involving a S(2)/S(1) conical intersection is proposed to account for these observations.
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Affiliation(s)
- Anatolio Pigliucci
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, CH-1211 Geneva, Switzerland
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Amatatsu Y. Skeletal Relaxation Effect on the Charge Transfer State Formation of 4-Dimethylamino,4‘-cyanostilbene. J Phys Chem A 2006; 110:8736-43. [PMID: 16836435 DOI: 10.1021/jp061310s] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ab initio complete active space self-consistent field (CASSCF) calculations combined with polarized continuum model (PCM) have been performed to examine the charge transfer (CT) state formation of trans-4-dimethylamino,4'-cyanostilbene (DCS) in a solvent. In a polar solvent, the globally stable geometry in S1 takes a twisted conformation where the electron-donating dimethylanilino group is highly twisted against the other part of the electron-withdrawing 4-cyanostyryl group. In addition, skeletal relaxation where the aromatic benzene rings turn to be a nonaromatic quinoid structure is essential to stabilize the CT state. In a nonpolar solvent, the stable geometry in S1 takes a nontwisted conformation, though the skeletal relaxation is also an essential factor. By means of the free energy decomposition analysis, it is found that the stable CT geometry which depends on solvent polarity mainly comes from two factors: the linkage bond between the dimethylanilino and the 4-cyanostyryl group and the electrostatic interaction. In a polar solvent, the linkage bond has a single bond character to slightly prevent the torsional motion. This twist geometrically assists the charge separation so as to reinforce the electrostatic interaction. In consequence, the twisted internal CT (TICT) conformation is stable. In a nonpolar solvent, on the other hand, a nontwisted CT state is stable because the linkage bonds greatly increase a double bond character so as to prevent the torsional motion, while the electrostatic interaction is not so enhanced even by the geometrical twist.
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Affiliation(s)
- Yoshiaki Amatatsu
- Faculty of Engineering and Resource Science, Akita University, Tegata Gakuen-cho, Akita 010-8502, Japan.
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Yang JS, Liau KL, Hwang CY, Wang CM. Photoinduced Single- versus Double-Bond Torsion in Donor−Acceptor−Substituted trans-Stilbenes. J Phys Chem A 2006; 110:8003-10. [PMID: 16805484 DOI: 10.1021/jp060296g] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The electronic absorption and fluorescence spectra, quantum yields for fluorescence (Phi(f)) and trans --> cis photoisomerization (Phi(tc)), and fluorescence lifetimes of trans-4-(N-arylamino)-4'-cyanostilbenes (2H, 2Me, 2OM, 2CN, and 2Xy with aryl = phenyl, 4-methylphenyl, 4-methoxyphenyl, 4-cyanophenyl, and 2,5-dimethylphenyl, respectively), trans-4-(N-methyl-N-phenylamino)-4'-cyanostilbene (2MP), trans-4-(N,N-diphenylamino)-4'-cyanostilbene (2PP), trans-4-(N-methyl-N-phenylamino)-4'-nitrostilbene (3MP), and three ring-bridged analogues 2OMB, 2MPB, and 3MPB are reported. Whereas fluorescence and torsion of the central double bond account for the excited decay of the majority of these donor-acceptor substituted stilbenes in both nonpolar and polar solvents (i.e., Phi(f) + 2Phi(tc) approximately 1), exceptions are observed for 2OM, 3MP, and 3MPB in solvents more polar than THF and for 2Me and 2MP in acetonitrile as a result of the formation of a weakly fluorescent and isomerization-free twisted intramolecular charge transfer (TICT) state (i.e., Phi(f) + 2Phi(tc) << 1). The TICT state for 2OM, 2Me, and 2MP results from the torsion of the stilbenyl-anilino C-N single bond, but the torsion of the styryl-anilino C-C bond is more likely to be responsible for the TICT state formation of 3MP and 3MPB. In conjunction with the behavior of aminostilbenes 1, a guideline based on the values of Phi(f) and Phi(tc) for judging the importance of a TICT state for trans-stilbenes is provided. Accordingly, the TICT state formation is unimportant for the excited decay of trans-4-(N,N-dimethylamino)-4'-cyanostilbene (DCS). In contrast, our results support the previously proposed TICT state for trans-4-(N,N-dimethylamino)-4'-nitrostilbene (DNS).
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Affiliation(s)
- Jye-Shane Yang
- Department of Chemistry, National Taiwan University, Taipei, Taiwan 10617.
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