1
|
Yong H, Xu X, Ruddock JM, Stankus B, Carrascosa AM, Zotev N, Bellshaw D, Du W, Goff N, Chang Y, Boutet S, Carbajo S, Koglin JE, Liang M, Robinson JS, Kirrander A, Minitti MP, Weber PM. Ultrafast X-ray scattering offers a structural view of excited-state charge transfer. Proc Natl Acad Sci U S A 2021; 118:e2021714118. [PMID: 33947814 PMCID: PMC8126834 DOI: 10.1073/pnas.2021714118] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Intramolecular charge transfer and the associated changes in molecular structure in N,N'-dimethylpiperazine are tracked using femtosecond gas-phase X-ray scattering. The molecules are optically excited to the 3p state at 200 nm. Following rapid relaxation to the 3s state, distinct charge-localized and charge-delocalized species related by charge transfer are observed. The experiment determines the molecular structure of the two species, with the redistribution of electron density accounted for by a scattering correction factor. The initially dominant charge-localized state has a weakened carbon-carbon bond and reorients one methyl group compared with the ground state. Subsequent charge transfer to the charge-delocalized state elongates the carbon-carbon bond further, creating an extended 1.634 Å bond, and also reorients the second methyl group. At the same time, the bond lengths between the nitrogen and the ring-carbon atoms contract from an average of 1.505 to 1.465 Å. The experiment determines the overall charge transfer time constant for approaching the equilibrium between charge-localized and charge-delocalized species to 3.0 ps.
Collapse
Affiliation(s)
- Haiwang Yong
- Department of Chemistry, Brown University, Providence, RI 02912
| | - Xuan Xu
- Department of Chemistry, Brown University, Providence, RI 02912
| | | | - Brian Stankus
- Department of Chemistry and Biochemistry, Western Connecticut State University, Danbury, CT 06810
| | | | - Nikola Zotev
- EaStCHEM, School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
- Center for Science at Extreme Conditions, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Darren Bellshaw
- EaStCHEM, School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
- Center for Science at Extreme Conditions, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Wenpeng Du
- Department of Chemistry, Brown University, Providence, RI 02912
| | - Nathan Goff
- Department of Chemistry, Brown University, Providence, RI 02912
| | - Yu Chang
- Department of Chemistry, Brown University, Providence, RI 02912
| | - Sébastien Boutet
- Linac Coherent Light Source, Stanford Linear Accelerator Center National Accelerator Laboratory, Menlo Park, CA 94025
| | - Sergio Carbajo
- Linac Coherent Light Source, Stanford Linear Accelerator Center National Accelerator Laboratory, Menlo Park, CA 94025
| | - Jason E Koglin
- Linac Coherent Light Source, Stanford Linear Accelerator Center National Accelerator Laboratory, Menlo Park, CA 94025
| | - Mengning Liang
- Linac Coherent Light Source, Stanford Linear Accelerator Center National Accelerator Laboratory, Menlo Park, CA 94025
| | - Joseph S Robinson
- Linac Coherent Light Source, Stanford Linear Accelerator Center National Accelerator Laboratory, Menlo Park, CA 94025
| | - Adam Kirrander
- EaStCHEM, School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom;
- Center for Science at Extreme Conditions, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Michael P Minitti
- Linac Coherent Light Source, Stanford Linear Accelerator Center National Accelerator Laboratory, Menlo Park, CA 94025
| | - Peter M Weber
- Department of Chemistry, Brown University, Providence, RI 02912;
| |
Collapse
|
2
|
Zotev N, Moreno Carrascosa A, Simmermacher M, Kirrander A. Excited Electronic States in Total Isotropic Scattering from Molecules. J Chem Theory Comput 2020; 16:2594-2605. [DOI: 10.1021/acs.jctc.9b00670] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nikola Zotev
- EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, U.K
| | - Andrés Moreno Carrascosa
- EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, U.K
| | - Mats Simmermacher
- EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, U.K
| | - Adam Kirrander
- EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, U.K
| |
Collapse
|
3
|
Ruddock JM, Yong H, Stankus B, Du W, Goff N, Chang Y, Odate A, Carrascosa AM, Bellshaw D, Zotev N, Liang M, Carbajo S, Koglin J, Robinson JS, Boutet S, Kirrander A, Minitti MP, Weber PM. A deep UV trigger for ground-state ring-opening dynamics of 1,3-cyclohexadiene. Sci Adv 2019; 5:eaax6625. [PMID: 31523713 PMCID: PMC6731073 DOI: 10.1126/sciadv.aax6625] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 08/03/2019] [Indexed: 05/03/2023]
Abstract
We explore the photo-induced kinetics of 1,3-cyclohexadiene upon excitation at 200 nm to the 3p state by ultrafast time-resolved, gas-phase x-ray scattering using the Linac Coherent Light Source. Analysis of the scattering anisotropy reveals that the excitation leads to the 3px and 3py Rydberg electronic states, which relax to the ground state with a time constant of 208 ± 11 fs. In contrast to the well-studied 266 nm excitation, at 200 nm the majority of the molecules (76 ± 3%) relax to vibrationally hot cyclohexadiene in the ground electronic state. A subsequent reaction on the ground electronic state surface leads from the hot cyclohexadiene to 1,3,5-hexatriene, with rates for the forward and backward reactions of 174 ± 13 and 355 ± 45 ps, respectively. The scattering pattern of the final hexatriene product reveals a thermal distribution of rotamers about the carbon-carbon single bonds.
Collapse
Affiliation(s)
- Jennifer M. Ruddock
- Department of Chemistry, Brown University, 324 Brook St., Providence, RI 02912, USA
- SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, CA 94025, USA
| | - Haiwang Yong
- Department of Chemistry, Brown University, 324 Brook St., Providence, RI 02912, USA
| | - Brian Stankus
- Department of Chemistry, Brown University, 324 Brook St., Providence, RI 02912, USA
| | - Wenpeng Du
- Department of Chemistry, Brown University, 324 Brook St., Providence, RI 02912, USA
| | - Nathan Goff
- Department of Chemistry, Brown University, 324 Brook St., Providence, RI 02912, USA
| | - Yu Chang
- Department of Chemistry, Brown University, 324 Brook St., Providence, RI 02912, USA
| | - Asami Odate
- Department of Chemistry, Brown University, 324 Brook St., Providence, RI 02912, USA
| | - Andrés Moreno Carrascosa
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, UK
| | - Darren Bellshaw
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, UK
| | - Nikola Zotev
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, UK
| | - Mengning Liang
- SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, CA 94025, USA
| | - Sergio Carbajo
- SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, CA 94025, USA
| | - Jason Koglin
- SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, CA 94025, USA
| | - Joseph S. Robinson
- SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, CA 94025, USA
| | - Sébastien Boutet
- SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, CA 94025, USA
| | - Adam Kirrander
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, UK
| | - Michael P. Minitti
- SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, CA 94025, USA
- Corresponding author. (P.M.W.); (M.P.M.)
| | - Peter M. Weber
- Department of Chemistry, Brown University, 324 Brook St., Providence, RI 02912, USA
- Corresponding author. (P.M.W.); (M.P.M.)
| |
Collapse
|
4
|
Yong H, Ruddock JM, Stankus B, Ma L, Du W, Goff N, Chang Y, Zotev N, Bellshaw D, Boutet S, Carbajo S, Koglin JE, Liang M, Robinson JS, Kirrander A, Minitti MP, Weber PM. Scattering off molecules far from equilibrium. J Chem Phys 2019; 151:084301. [PMID: 31470697 DOI: 10.1063/1.5111979] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Pump-probe gas phase X-ray scattering experiments, enabled by the development of X-ray free electron lasers, have advanced to reveal scattering patterns of molecules far from their equilibrium geometry. While dynamic displacements reflecting the motion of wavepackets can probe deeply into the reaction dynamics, in many systems, the thermal excitation embedded in the molecules upon optical excitation and energy randomization can create systems that encompass structures far from the ground state geometry. For polyatomic molecular systems, large amplitude vibrational motions are associated with anharmonicity and shifts of interatomic distances, making analytical solutions using traditional harmonic approximations inapplicable. More generally, the interatomic distances in a polyatomic molecule are not independent and the traditional equations commonly used to interpret the data may give unphysical results. Here, we introduce a novel method based on molecular dynamic trajectories and illustrate it on two examples of hot, vibrating molecules at thermal equilibrium. When excited at 200 nm, 1,3-cyclohexadiene (CHD) relaxes on a subpicosecond time scale back to the reactant molecule, the dominant pathway, and to various forms of 1,3,5-hexatriene (HT). With internal energies of about 6 eV, the energy thermalizes quickly, leading to structure distributions that deviate significantly from their vibrationless equilibrium. The experimental and theoretical results are in excellent agreement and reveal that a significant contribution to the scattering signal arises from transition state structures near the inversion barrier of CHD. In HT, our analysis clarifies that previous inconsistent structural parameters determined by electron diffraction were artifacts that might have resulted from the use of inapplicable analytical equations.
Collapse
Affiliation(s)
- Haiwang Yong
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Jennifer M Ruddock
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Brian Stankus
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Lingyu Ma
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Wenpeng Du
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Nathan Goff
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Yu Chang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Nikola Zotev
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Darren Bellshaw
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Sébastien Boutet
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Sergio Carbajo
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Jason E Koglin
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Mengning Liang
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Joseph S Robinson
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Adam Kirrander
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Michael P Minitti
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Peter M Weber
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| |
Collapse
|
5
|
Ruddock JM, Zotev N, Stankus B, Yong H, Bellshaw D, Boutet S, Lane TJ, Liang M, Carbajo S, Du W, Kirrander A, Minitti M, Weber PM. Simplicity Beneath Complexity: Counting Molecular Electrons Reveals Transients and Kinetics of Photodissociation Reactions. Angew Chem Int Ed Engl 2019; 58:6371-6375. [PMID: 30866169 DOI: 10.1002/anie.201902228] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Indexed: 11/11/2022]
Abstract
Time-resolved pump-probe gas-phase X-ray scattering signals, extrapolated to zero momentum transfer, provide a measure of the number of electrons in a system, an effect that arises from the coherent addition of elastic scattering from the electrons. This allows to identify reactive transients and determine the chemical reaction kinetics without the need for extensive scattering simulations or complicated inversion of scattering data. We examine the photodissociation reaction of trimethylamine and identify two reaction paths upon excitation to the 3p state at 200 nm: a fast dissociation path out of the 3p state to the dimethyl amine radical (16.6±1.2 %) and a slower dissociation via internal conversion to the 3s state (83.4±1.2 %). The time constants for the two reactions are 640±130 fs and 74±6 ps, respectively. Additionally, it is found that the transient dimethyl amine radical has a N-C bond length of 1.45±0.02 Å and a C-N-C bond angle of 118°±4°.
Collapse
Affiliation(s)
- Jennifer M Ruddock
- Department of Chemistry, Brown University, 324 Brook St, Providence, RI, 02912, USA.,SLAC National Accelerator Laboratory, 2575 Sandhill Rd, Menlo Park, CA, 94025, USA
| | - Nikola Zotev
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh, EH9 3FJ, UK
| | - Brian Stankus
- Department of Chemistry, Brown University, 324 Brook St, Providence, RI, 02912, USA
| | - Haiwang Yong
- Department of Chemistry, Brown University, 324 Brook St, Providence, RI, 02912, USA
| | - Darren Bellshaw
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh, EH9 3FJ, UK
| | - Sébastien Boutet
- SLAC National Accelerator Laboratory, 2575 Sandhill Rd, Menlo Park, CA, 94025, USA
| | - Thomas J Lane
- SLAC National Accelerator Laboratory, 2575 Sandhill Rd, Menlo Park, CA, 94025, USA
| | - Mengning Liang
- SLAC National Accelerator Laboratory, 2575 Sandhill Rd, Menlo Park, CA, 94025, USA
| | - Sergio Carbajo
- SLAC National Accelerator Laboratory, 2575 Sandhill Rd, Menlo Park, CA, 94025, USA
| | - Wenpeng Du
- Department of Chemistry, Brown University, 324 Brook St, Providence, RI, 02912, USA
| | - Adam Kirrander
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh, EH9 3FJ, UK
| | - Michael Minitti
- SLAC National Accelerator Laboratory, 2575 Sandhill Rd, Menlo Park, CA, 94025, USA
| | - Peter M Weber
- Department of Chemistry, Brown University, 324 Brook St, Providence, RI, 02912, USA
| |
Collapse
|
6
|
Ruddock JM, Zotev N, Stankus B, Yong H, Bellshaw D, Boutet S, Lane TJ, Liang M, Carbajo S, Du W, Kirrander A, Minitti M, Weber PM. Simplicity Beneath Complexity: Counting Molecular Electrons Reveals Transients and Kinetics of Photodissociation Reactions. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201902228] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Jennifer M. Ruddock
- Department of Chemistry Brown University 324 Brook St Providence RI 02912 USA
- SLAC National Accelerator Laboratory 2575 Sandhill Rd Menlo Park CA 94025 USA
| | - Nikola Zotev
- EaStCHEM School of Chemistry University of Edinburgh David Brewster Road Edinburgh EH9 3FJ UK
| | - Brian Stankus
- Department of Chemistry Brown University 324 Brook St Providence RI 02912 USA
| | - Haiwang Yong
- Department of Chemistry Brown University 324 Brook St Providence RI 02912 USA
| | - Darren Bellshaw
- EaStCHEM School of Chemistry University of Edinburgh David Brewster Road Edinburgh EH9 3FJ UK
| | - Sébastien Boutet
- SLAC National Accelerator Laboratory 2575 Sandhill Rd Menlo Park CA 94025 USA
| | - Thomas J. Lane
- SLAC National Accelerator Laboratory 2575 Sandhill Rd Menlo Park CA 94025 USA
| | - Mengning Liang
- SLAC National Accelerator Laboratory 2575 Sandhill Rd Menlo Park CA 94025 USA
| | - Sergio Carbajo
- SLAC National Accelerator Laboratory 2575 Sandhill Rd Menlo Park CA 94025 USA
| | - Wenpeng Du
- Department of Chemistry Brown University 324 Brook St Providence RI 02912 USA
| | - Adam Kirrander
- EaStCHEM School of Chemistry University of Edinburgh David Brewster Road Edinburgh EH9 3FJ UK
| | - Michael Minitti
- SLAC National Accelerator Laboratory 2575 Sandhill Rd Menlo Park CA 94025 USA
| | - Peter M. Weber
- Department of Chemistry Brown University 324 Brook St Providence RI 02912 USA
| |
Collapse
|
7
|
Yong H, Zotev N, Stankus B, Ruddock JM, Bellshaw D, Boutet S, Lane TJ, Liang M, Carbajo S, Robinson JS, Du W, Goff N, Chang Y, Koglin JE, Waters MDJ, Sølling TI, Minitti MP, Kirrander A, Weber PM. Determining Orientations of Optical Transition Dipole Moments Using Ultrafast X-ray Scattering. J Phys Chem Lett 2018; 9:6556-6562. [PMID: 30380873 DOI: 10.1021/acs.jpclett.8b02773] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Identification of the initially prepared, optically active state remains a challenging problem in many studies of ultrafast photoinduced processes. We show that the initially excited electronic state can be determined using the anisotropic component of ultrafast time-resolved X-ray scattering signals. The concept is demonstrated using the time-dependent X-ray scattering of N-methyl morpholine in the gas phase upon excitation by a 200 nm linearly polarized optical pulse. Analysis of the angular dependence of the scattering signal near time zero renders the orientation of the transition dipole moment in the molecular frame and identifies the initially excited state as the 3p z Rydberg state, thus bypassing the need for further experimental studies to determine the starting point of the photoinduced dynamics and clarifying inconsistent computational results.
Collapse
Affiliation(s)
- Haiwang Yong
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Nikola Zotev
- School of Chemistry , University of Edinburgh , Edinburgh EH9 3FJ , United Kingdom
| | - Brian Stankus
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Jennifer M Ruddock
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Darren Bellshaw
- School of Chemistry , University of Edinburgh , Edinburgh EH9 3FJ , United Kingdom
| | - Sébastien Boutet
- SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| | - Thomas J Lane
- SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| | - Mengning Liang
- SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| | - Sergio Carbajo
- SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| | - Joseph S Robinson
- SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| | - Wenpeng Du
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Nathan Goff
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Yu Chang
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Jason E Koglin
- SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| | - Max D J Waters
- Department of Chemistry , University of Copenhagen , Universitetsparken 5 , 2100 Copenhagen , Denmark
| | - Theis I Sølling
- Department of Chemistry , University of Copenhagen , Universitetsparken 5 , 2100 Copenhagen , Denmark
| | - Michael P Minitti
- SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| | - Adam Kirrander
- School of Chemistry , University of Edinburgh , Edinburgh EH9 3FJ , United Kingdom
| | - Peter M Weber
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| |
Collapse
|
8
|
Stankus B, Zotev N, Rogers DM, Gao Y, Odate A, Kirrander A, Weber PM. Ultrafast photodissociation dynamics of 1,4-diiodobenzene. J Chem Phys 2018; 148:194306. [DOI: 10.1063/1.5031787] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Affiliation(s)
- Brian Stankus
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Nikola Zotev
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, United Kingdom
| | - David M. Rogers
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, United Kingdom
| | - Yan Gao
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Asami Odate
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Adam Kirrander
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, United Kingdom
| | - Peter M. Weber
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| |
Collapse
|
9
|
Abstract
We discuss the application of ab initio X-ray diffraction (AIXRD) to the interpretation of time-resolved and static X-ray diffraction. In our approach, elastic X-ray scattering is calculated directly from the ab initio multiconfigurational wave function via a Fourier transform of the electron density, using the first Born approximation for elastic scattering. Significant gains in efficiency can be obtained by performing the required Fourier transforms analytically, making it possible to combine the calculation of ab initio X-ray diffraction with expensive quantum dynamics simulations. We show that time-resolved X-ray diffraction can detect not only changes in molecular geometry but also changes in the electronic state of a molecule. Calculations for cis-, trans-, and cyclo-butadiene, as well as benzene and 1,3-cyclohexadiene are included.
Collapse
Affiliation(s)
- Thomas Northey
- School of Chemistry, University of Edinburgh , West Mains Road, Edinburgh EH9 3JJ, United Kingdom
| | - Nikola Zotev
- School of Chemistry, University of Edinburgh , West Mains Road, Edinburgh EH9 3JJ, United Kingdom
| | - Adam Kirrander
- School of Chemistry, University of Edinburgh , West Mains Road, Edinburgh EH9 3JJ, United Kingdom
| |
Collapse
|