Search Menu
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information
Search Scholarly Publications

Title: Ultrafast 25-fs relaxation in highly excited states of methyl azide mediated by strong nonadiabatic coupling

Abstract

Highly excited electronic states are challenging to explore experimentally and theoretically—due to the large density of states and the fact that small structural changes lead to large changes in electronic character with associated strong nonadiabatic dynamics. They can play a key role in astrophysical and ionospheric chemistry, as well as the detonation chemistry of high-energy density materials. Here, we implement ultrafast vacuum-UV (VUV)-driven electron–ion coincidence imaging spectroscopy to directly probe the reaction pathways of highly excited states of energetic molecules—in this case, methyl azide. Our data, combined with advanced theoretical simulations, show that photoexcitation of methyl azide by a 10-fs UV pulse at 8 eV drives fast structural changes and strong nonadiabatic coupling that leads to relaxation to other excited states on a surprisingly fast timescale of 25 fs. This ultrafast relaxation differs from dynamics occurring on lower excited states, where the timescale required for the wavepacket to reach a region of strong nonadiabatic coupling is typically much longer. Moreover, our theoretical calculations show that ultrafast relaxation of the wavepacket to a lower excited state occurs along one of the conical intersection seams before reaching the minimum energy conical intersection. These findings are important for understanding the unique strongly coupledmore » non-Born–Oppenheimer molecular dynamics of VUV-excited energetic molecules. Although such observations have been predicted for many years, this study represents one of the few where such strongly coupled non-Born–Oppenheimer molecular dynamics of VUV-excited energetic molecules have been conclusively observed directly, making it possible to identify the ultrafast reaction pathways.« less

Authors:
ORCiD logo [1];  [1];  [2];  [3];  [1];  [4];  [3];  [2];  [1];  [1];  [3]
+ Show Author Affiliations
  1. JILA, University of Colorado, Boulder, CO 80309,, Department of Physics, University of Colorado, Boulder, CO 80309,
  2. Theoretical Physical Chemistry, Unité de Recherche Molecular Systems (UR MOLSYS) University of Liège, B4000 Liège, Belgium,
  3. Department of Chemistry, Wayne State University, Detroit, MI 48202,
  4. Department of Chemistry and Biochemistry, Georgia Southern University, Statesboro, GA 30460
Publication Date:
Research Org.:
Wayne State Univ., Detroit, MI (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1408161
Alternate Identifier(s):
OSTI ID: 1527121
Grant/Contract Number:  
SC0012628
Resource Type:
Published Article
Journal Name:
Proceedings of the National Academy of Sciences of the United States of America
Additional Journal Information:
Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Volume: 114 Journal Issue: 52; Journal ID: ISSN 0027-8424
Publisher:
Proceedings of the National Academy of Sciences
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; conical intersection; nonadiabatic dynamics; Rydberg–valence electronic states; PEPICO

Citation Formats

Peters, William K., Couch, David E., Mignolet, Benoit, Shi, Xuetao, Nguyen, Quynh L., Fortenberry, Ryan C., Schlegel, H. Bernhard, Remacle, Françoise, Kapteyn, Henry C., Murnane, Margaret M., and Li, Wen. Ultrafast 25-fs relaxation in highly excited states of methyl azide mediated by strong nonadiabatic coupling. United States: N. p., 2017. Web. doi:10.1073/pnas.1712566114.
Copy to clipboard
Peters, William K., Couch, David E., Mignolet, Benoit, Shi, Xuetao, Nguyen, Quynh L., Fortenberry, Ryan C., Schlegel, H. Bernhard, Remacle, Françoise, Kapteyn, Henry C., Murnane, Margaret M., & Li, Wen. Ultrafast 25-fs relaxation in highly excited states of methyl azide mediated by strong nonadiabatic coupling. United States. https://doi.org/10.1073/pnas.1712566114
Copy to clipboard
Peters, William K., Couch, David E., Mignolet, Benoit, Shi, Xuetao, Nguyen, Quynh L., Fortenberry, Ryan C., Schlegel, H. Bernhard, Remacle, Françoise, Kapteyn, Henry C., Murnane, Margaret M., and Li, Wen. Mon . "Ultrafast 25-fs relaxation in highly excited states of methyl azide mediated by strong nonadiabatic coupling". United States. https://doi.org/10.1073/pnas.1712566114.
Copy to clipboard
@article{osti_1408161,
title = {Ultrafast 25-fs relaxation in highly excited states of methyl azide mediated by strong nonadiabatic coupling},
author = {Peters, William K. and Couch, David E. and Mignolet, Benoit and Shi, Xuetao and Nguyen, Quynh L. and Fortenberry, Ryan C. and Schlegel, H. Bernhard and Remacle, Françoise and Kapteyn, Henry C. and Murnane, Margaret M. and Li, Wen},
abstractNote = {Highly excited electronic states are challenging to explore experimentally and theoretically—due to the large density of states and the fact that small structural changes lead to large changes in electronic character with associated strong nonadiabatic dynamics. They can play a key role in astrophysical and ionospheric chemistry, as well as the detonation chemistry of high-energy density materials. Here, we implement ultrafast vacuum-UV (VUV)-driven electron–ion coincidence imaging spectroscopy to directly probe the reaction pathways of highly excited states of energetic molecules—in this case, methyl azide. Our data, combined with advanced theoretical simulations, show that photoexcitation of methyl azide by a 10-fs UV pulse at 8 eV drives fast structural changes and strong nonadiabatic coupling that leads to relaxation to other excited states on a surprisingly fast timescale of 25 fs. This ultrafast relaxation differs from dynamics occurring on lower excited states, where the timescale required for the wavepacket to reach a region of strong nonadiabatic coupling is typically much longer. Moreover, our theoretical calculations show that ultrafast relaxation of the wavepacket to a lower excited state occurs along one of the conical intersection seams before reaching the minimum energy conical intersection. These findings are important for understanding the unique strongly coupled non-Born–Oppenheimer molecular dynamics of VUV-excited energetic molecules. Although such observations have been predicted for many years, this study represents one of the few where such strongly coupled non-Born–Oppenheimer molecular dynamics of VUV-excited energetic molecules have been conclusively observed directly, making it possible to identify the ultrafast reaction pathways.},
doi = {10.1073/pnas.1712566114},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
number = 52,
volume = 114,
place = {United States},
year = {Mon Nov 06 00:00:00 EST 2017},
month = {Mon Nov 06 00:00:00 EST 2017}
}
Copy to clipboard
Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
https://doi.org/10.1073/pnas.1712566114
Copyright Statement
Other availability
Search WorldCat Search WorldCat to find libraries that may hold this journal
Citation Metrics:
Cited by: 14 works
Citation information provided by
Web of Science

Figures / Tables:

Fig. 1 Fig. 1: Femtosecond PEPICO spectroscopy of methyl azide Rydberg–valence states. A shows two laser pulses which interact with an effusive molecular beam; the pump pulse prepares an excited state, which is then ionized by the probe pulse. Ionized fragments and their coincident electrons are detected with timeand position-sensitive detectors. Bmore » shows a schematic of the dynamics in the electronic states. The pump pulse excites a wavepacket on a highly excited state (S8). If the second pulse probes the dynamics at time t = 0 (B, i), it ionizes the molecule to both the cation ground and first excited states. For pump–probe delay before 25 fs (B, ii), the wavepacket has time to evolve on the excited-state potential energy surface. Due to the corresponding increase in vibrational energy, the probe pulse can only ionize to the cation ground state. For longer pump–probe delays (B, iii), the wavepacket has completely relaxed to the dark S4 state, due to strong nonadiabatic coupling, and the ion yield drops to zero. C shows a schematic representation of the potential energy surfaces of the mixed Rydberg–valence state accessed by the pulse and the dark valence state, as well as the conical intersection seam through which the population transfer occurs. The motion of the initial wavepacket on these surfaces is also shown with a white line, as well as points corresponding to the dynamics described in B. D shows excitation orbitals computed with EOM-CCSD for the initially prepared excited state, S8, and the dark state, S4. The initial S8 state has mixed HOMO-excited and (HOMO-1) –excited character, with each component displaying mixed Rydberg and valence character. The dark S4 state is a (HOMO-1) –excited valence state. Isocontours are 0.03 |e|/Å3 for the mixed Rydberg–valence orbitals and 0.07 |e|/Å3 for the pure valence orbitals.« less
All figures and tables (6 total)
Save / Share:
Export Metadata
Save to My Library
You must Sign In or Create an Account in order to save documents to your library.

Works referenced in this record:

Exploring photochemistry of p-bromophenylsulfonyl, p-tolylsulfonyl and methylsulfonyl azides by ultrafast UV-pump–IR-probe spectroscopy and computations
journal, January 2016

  • Kuzmin, A. V.; Neumann, C.; van Wilderen, L. J. G. W.
  • Physical Chemistry Chemical Physics, Vol. 18, Issue 12
  • DOI: 10.1039/C5CP07636F

Rich Athermal Ground-State Chemistry Triggered by Dynamics through a Conical Intersection
journal, October 2016

  • Mignolet, Benoit; Curchod, Basile F. E.; Martínez, Todd J.
  • Angewandte Chemie International Edition, Vol. 55, Issue 48
  • DOI: 10.1002/anie.201607633

Excited state non-adiabatic dynamics of pyrrole: A time-resolved photoelectron spectroscopy and quantum dynamics study
journal, February 2015

  • Wu, Guorong; Neville, Simon P.; Schalk, Oliver
  • The Journal of Chemical Physics, Vol. 142, Issue 7
  • DOI: 10.1063/1.4907529

Quadratic configuration interaction. A general technique for determining electron correlation energies
journal, November 1987

  • Pople, John A.; Head‐Gordon, Martin; Raghavachari, Krishnan
  • The Journal of Chemical Physics, Vol. 87, Issue 10
  • DOI: 10.1063/1.453520

Direct Observation of Acyl Azide Excited States and Their Decay Processes by Ultrafast Time Resolved Infrared Spectroscopy
journal, April 2009

  • Kubicki, Jacek; Zhang, Yunlong; Wang, Jin
  • Journal of the American Chemical Society, Vol. 131, Issue 12
  • DOI: 10.1021/ja9002102

Nonadiabatic Reaction of Energetic Molecules
journal, December 2010

  • Bhattacharya, Atanu; Guo, Yuanqing; Bernstein, Elliot R.
  • Accounts of Chemical Research, Vol. 43, Issue 12
  • DOI: 10.1021/ar100067f

On the initiation of chemical reactions by electronic excitations in molecular solids
journal, March 2003

Molpro: a general-purpose quantum chemistry program package: Molpro
journal, July 2011

  • Werner, Hans-Joachim; Knowles, Peter J.; Knizia, Gerald
  • Wiley Interdisciplinary Reviews: Computational Molecular Science, Vol. 2, Issue 2
  • DOI: 10.1002/wcms.82

Can Diarylethene Photochromism Be Explained by a Reaction Path Alone? A CASSCF Study with Model MMVB Dynamics
journal, December 2003

  • Boggio-Pasqua, Martial; Ravaglia, Marcella; Bearpark, Michael J.
  • The Journal of Physical Chemistry A, Vol. 107, Issue 50
  • DOI: 10.1021/jp036862e

Role of Conical Intersections in Molecular Spectroscopy and Photoinduced Chemical Dynamics
journal, May 2012

Many – Body Methods in Chemistry and Physics
book, January 2009

Multiply-charged ions and interstellar chemistry
journal, January 2011

  • Böhme, Diethard Kurt
  • Physical Chemistry Chemical Physics, Vol. 13, Issue 41
  • DOI: 10.1039/c1cp21814j

Collision-free photochemistry of methylazide: Observation of unimolecular decomposition of singlet methylnitrene
journal, October 2006

  • Larson, Christopher; Ji, Yuanyuan; Samartzis, Petros
  • The Journal of Chemical Physics, Vol. 125, Issue 13
  • DOI: 10.1063/1.2215598

Multi-Electronic-State Molecular Dynamics:  A Wave Function Approach with Applications
journal, January 1996

  • Martinez, Todd J.; Ben-Nun, M.; Levine, R. D.
  • The Journal of Physical Chemistry, Vol. 100, Issue 19
  • DOI: 10.1021/jp953105a

Photoionization of CH 3 N 3 Produces 3 B 2 N 3 – : A Theoretical and Experimental Study of the Ion-Pair Channel
journal, August 2011

  • Quinto-Hernandez, Alfredo; Lee, Yin Yu; Huang, Tzu-Ping
  • The Journal of Physical Chemistry Letters, Vol. 2, Issue 18
  • DOI: 10.1021/jz200914g

Gaussian basis sets for use in correlated molecular calculations. I. The atoms boron through neon and hydrogen
journal, January 1989

  • Dunning, Thom H.
  • The Journal of Chemical Physics, Vol. 90, Issue 2
  • DOI: 10.1063/1.456153

Photofragmentation Translational Spectroscopy of Methyl Azide (CH 3 N 3 ) Photolysis at 193 nm: Molecular and Radical Channel Product Branching Ratio
journal, April 2012

  • Quinto-Hernandez, Alfredo; Doehla, Jeremie; Huang, Wen-Tsung
  • The Journal of Physical Chemistry A, Vol. 116, Issue 19
  • DOI: 10.1021/jp301562c

Isomerization Through Conical Intersections
journal, May 2007

Probing Rapidly-Ionizing Super-Atom Molecular Orbitals in C 60 : A Computational and Femtosecond Photoelectron Spectroscopy Study
journal, August 2013

  • Mignolet, Benoît; Johansson, J. Olof; Campbell, Eleanor E. B.
  • ChemPhysChem, Vol. 14, Issue 14
  • DOI: 10.1002/cphc.201300585

Ab Initio Classical Trajectory Study of the Dissociation of Neutral and Positively Charged Methanimine (CH 2 NH n + n = 0−2)
journal, September 2009

  • Zhou, Jia; Schlegel, H. Bernhard
  • The Journal of Physical Chemistry A, Vol. 113, Issue 37
  • DOI: 10.1021/jp905420v

A new mixing of Hartree–Fock and local density‐functional theories
journal, January 1993

  • Becke, Axel D.
  • The Journal of Chemical Physics, Vol. 98, Issue 2
  • DOI: 10.1063/1.464304

On the Interaction of Methyl Azide (CH 3 N 3 ) Ices with Ionizing Radiation: Formation of Methanimine (CH 2 NH), Hydrogen Cyanide (HCN), and Hydrogen Isocyanide (HNC) †
journal, January 2011

  • Quinto-Hernandez, Alfredo; Wodtke, Alec M.; Bennett, Chris J.
  • The Journal of Physical Chemistry A, Vol. 115, Issue 3
  • DOI: 10.1021/jp103028v

Ionization and Dissociation of Hydrazoic Acid and Methyl Azide by Electron Impact
journal, January 1958

  • Franklin, J. L.; Dibeler, Vernon H.; Reese, Robert M.
  • Journal of the American Chemical Society, Vol. 80, Issue 2
  • DOI: 10.1021/ja01535a012

Self‐consistent molecular orbital methods. XVIII. Constraints and stability in Hartree–Fock theory
journal, April 1977

  • Seeger, Rolf; Pople, John A.
  • The Journal of Chemical Physics, Vol. 66, Issue 7
  • DOI: 10.1063/1.434318

Psi4: an open-source ab initio electronic structure program : Psi4: an electronic structure program
journal, October 2011

  • Turney, Justin M.; Simmonett, Andrew C.; Parrish, Robert M.
  • Wiley Interdisciplinary Reviews: Computational Molecular Science, Vol. 2, Issue 4
  • DOI: 10.1002/wcms.93

Time-resolved photoelectron imaging of ultrafast S2→S1 internal conversion through conical intersection in pyrazine
journal, May 2010

  • Suzuki, Yoshi-Ichi; Fuji, Takao; Horio, Takuya
  • The Journal of Chemical Physics, Vol. 132, Issue 17
  • DOI: 10.1063/1.3395206

Time-resolved photoelectron spectroscopy: from wavepackets to observables
journal, January 2011

  • Wu, Guorong; Hockett, Paul; Stolow, Albert
  • Physical Chemistry Chemical Physics, Vol. 13, Issue 41
  • DOI: 10.1039/c1cp22031d

A new hybrid exchange–correlation functional using the Coulomb-attenuating method (CAM-B3LYP)
journal, July 2004

  • Yanai, Takeshi; Tew, David P.; Handy, Nicholas C.
  • Chemical Physics Letters, Vol. 393, Issue 1-3, p. 51-57
  • DOI: 10.1016/j.cplett.2004.06.011

Photoionization of excited states of molecules
journal, May 2004

Nonadiabatic Events and Conical Intersections
journal, May 2011

A benchmark study of the vertical electronic spectra of the linear chain radicals C2H and C4H
journal, April 2010

  • Fortenberry, Ryan C.; King, Rollin A.; Stanton, John F.
  • The Journal of Chemical Physics, Vol. 132, Issue 14
  • DOI: 10.1063/1.3376073

Photochemistry of 2-Naphthoyl Azide. An Ultrafast Time-Resolved UV–Vis and IR Spectroscopic and Computational Study
journal, June 2011

  • Kubicki, Jacek; Zhang, Yunlong; Vyas, Shubham
  • Journal of the American Chemical Society, Vol. 133, Issue 25
  • DOI: 10.1021/ja109098w

Density‐functional thermochemistry. III. The role of exact exchange
journal, April 1993

  • Becke, Axel D.
  • The Journal of Chemical Physics, Vol. 98, Issue 7, p. 5648-5652
  • DOI: 10.1063/1.464913

The collision-free photochemistry of methyl azide at 157 nm: Mechanism and energy release
journal, August 2017

  • Quinto-Hernandez, Alfredo; Lee, Shih-Huang; Wodtke, Alec M.
  • The Journal of Chemical Physics, Vol. 147, Issue 6
  • DOI: 10.1063/1.4997783

Time-resolved momentum imaging system for molecular dynamics studies using a tabletop ultrafast extreme-ultraviolet light source
journal, June 2008

  • Gagnon, Etienne; Sandhu, Arvinder S.; Paul, Ariel
  • Review of Scientific Instruments, Vol. 79, Issue 6
  • DOI: 10.1063/1.2930869

Characterization of electronic transitions in complex molecules
journal, January 1950

Excited Electronic States and Nonadiabatic Effects in Contemporary Chemical Dynamics
journal, August 2009

  • Mahapatra, Susanta
  • Accounts of Chemical Research, Vol. 42, Issue 8
  • DOI: 10.1021/ar800186s

Ultrafast electronic dynamics in polyatomic molecules studied using femtosecond vacuum ultraviolet and x-ray pulses
journal, June 2014

Femtosecond Time-Resolved Photoelectron Spectroscopy
journal, April 2004

  • Stolow, Albert; Bragg, Arthur E.; Neumark, Daniel M.
  • Chemical Reviews, Vol. 104, Issue 4
  • DOI: 10.1021/cr020683w

Interacting Rydberg and valence states in radicals and molecules: experimental and theoretical studies
journal, April 2009

  • Reisler, Hanna; Krylov, Anna I.
  • International Reviews in Physical Chemistry, Vol. 28, Issue 2
  • DOI: 10.1080/01442350902989170

Conical Intersections: Theory, Computation and Experiment
book, November 2011

  • Domcke, Wolfgang; Yarkony, David R.; Köppel, Horst
  • Advanced Series in Physical Chemistry
  • DOI: 10.1142/7803

Many-body effects in the ionization spectra of azides
journal, January 1989

Additional diffuse functions in basis sets for dipole-bound excited states of anions
journal, April 2015

Direct Observation of Electronic Relaxation Dynamics in Adenine via Time-Resolved Photoelectron Spectroscopy
journal, March 2004

  • Ullrich, Susanne; Schultz, Thomas; Zgierski, Marek Z.
  • Journal of the American Chemical Society, Vol. 126, Issue 8
  • DOI: 10.1021/ja030532q

Early Events in the Photochemistry of Aryl Azides from Femtosecond UV/Vis Spectroscopy and Quantum Chemical Calculations
journal, October 2006

  • Burdzinski, Gotard; Hackett, John C.; Wang, Jin
  • Journal of the American Chemical Society, Vol. 128, Issue 41
  • DOI: 10.1021/ja061520i

Ab Initio Quantum Molecular Dynamics
book, January 2002

An Introduction to Coupled Cluster Theory for Computational Chemists
book, January 2000

  • Crawford, T. Daniel; Schaefer, Henry F.; Lipkowitz, Kenny B.
  • Reviews in Computational Chemistry: Lipkowitz/Reviews
  • DOI: 10.1002/9780470125915.ch2

Dissociative photoionization dynamics in ethane studied by velocity map imaging
journal, June 2003

Implementation of ab initio multiple spawning in the Molpro quantum chemistry package
journal, May 2008

Photoelectron spectra of some group 4 pseudohalides and related compounds
journal, January 1972

  • Cradock, S.; Ebsworth, E. A. V.; Murdoch, J. D.
  • Journal of the Chemical Society, Faraday Transactions 2, Vol. 68
  • DOI: 10.1039/f29726800086

Soft-x-ray wavelength shift induced by ionization effects in a capillary
journal, January 2006

  • Froud, Christopher A.; Rogers, Edward T.; Hanna, David C.
  • Optics Letters, Vol. 31, Issue 3
  • DOI: 10.1364/OL.31.000374

Phase Matching of High-Order Harmonics in Hollow Waveguides
journal, September 1999

Note on an Approximation Treatment for Many-Electron Systems
journal, October 1934

Electronically excited states of PANH anions
journal, January 2015

  • Theis, Mallory L.; Candian, Alessandra; Tielens, Alexander G. G. M.
  • Physical Chemistry Chemical Physics, Vol. 17, Issue 22
  • DOI: 10.1039/C5CP01354B

Discerning vibronic molecular dynamics using time-resolved photoelectron spectroscopy
journal, September 1999

  • Blanchet, Valérie; Zgierski, Marek Z.; Seideman, Tamar
  • Nature, Vol. 401, Issue 6748
  • DOI: 10.1038/43410

A complete basis set model chemistry. IV. An improved atomic pair natural orbital method
journal, October 1994

  • Montgomery, J. A.; Ochterski, J. W.; Petersson, G. A.
  • The Journal of Chemical Physics, Vol. 101, Issue 7
  • DOI: 10.1063/1.467306

Nonadiabatic blueshift of high-order harmonics from Ar and Ne atoms in an intense femtosecond laser field
journal, April 2001

Time-resolved imaging of purely valence-electron dynamics during a chemical reaction
journal, April 2011

  • Hockett, Paul; Bisgaard, Christer Z.; Clarkin, Owen J.
  • Nature Physics, Vol. 7, Issue 8
  • DOI: 10.1038/nphys1980

An ultrafast time-resolved infrared and UV-vis spectroscopic and computational study of the photochemistry of acyl azides: ULTRAFAST PHOTOCHEMISTRY OF ACYL AZIDES
journal, January 2012

  • Vyas, Shubham; Kubicki, Jacek; Luk, Hoi Ling
  • Journal of Physical Organic Chemistry, Vol. 25, Issue 8
  • DOI: 10.1002/poc.2903

Conical intersection dynamics of the primary photoisomerization event in vision
journal, September 2010

  • Polli, Dario; Altoè, Piero; Weingart, Oliver
  • Nature, Vol. 467, Issue 7314
  • DOI: 10.1038/nature09346
    Sort by:
    [ × clear filter / sort ]

    Figures / Tables found in this record:

    Fig. 1 (p. 3)figure
    Fig. 2 (p. 5)figure
    Fig. 3 (p. 6)figure
    Table 1 (p. 6)table
    Fig. 4 (p. 7)figure
    Fig. 5 (p. 8)figure
      [ × clear filter / sort ]
      Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.

      Similar Records in DOE PAGES and OSTI.GOV collections: