Ultrafast x-ray scattering of photodissociation dynamics in 2-iodothiophene

W Weronika O. Razmus I Ian Gabalski F Felix Allum (Stanford PULSE Institute) G Grite L. Abma (Institute for Molecules and Materials, Radboud University 4 , Heijendaalseweg 135, 6525 AJ Nijmegen,) M Mathew Britton S Sébastien Boutet P Philip H. Bucksbaum X Xinxin Cheng S Stuart W. Crane (Department of Chemistry, Brown University 6 , Providence, Rhode Island 02912,) G Gregory Gate (Linac Coherent Light Source, SLAC National Accelerator Laboratory 5 , 2575 Sand Hill Road, Menlo Park, California 94025,) A Aaron Ghrist (PULSE Institute, SLAC National Accelerator Laboratory 2 , 2575 Sand Hill Road, Menlo Park, California 94025,) M Martin Graßl (PULSE Institute, SLAC National Accelerator Laboratory 2 , 2575 Sand Hill Road, Menlo Park, California 94025,) A Alice E. Green (EaStCHEM School of Chemistry) N Nathan Goff (Department of Chemistry, Brown University 6 , Providence, Rhode Island 02912,) D Daniel A. Horke (Institute for Molecules and Materials, Radboud University 4 , Heijendaalseweg 135, 6525 AJ Nijmegen,) L Lisa Huang (Department of Chemistry, Brown University 6 , Providence, Rhode Island 02912,) M Mengning Liang (Linac Coherent Light Source, SLAC National Accelerator Laboratory 5 , 2575 Sand Hill Road, Menlo Park, California 94025,) Y Yusong Liu L Lingyu Ma M Michael P. Minitti (Linac Coherent Light Source, SLAC National Accelerator Laboratory 5 , 2575 Sand Hill Road, Menlo Park, California 94025,) T Thomas Northey (Department of Chemistry, Brown University 6 , Providence, Rhode Island 02912,) A Asami Odate (Department of Chemistry, Brown University 6 , Providence, Rhode Island 02912,) J Joseph Robinson (Linac Coherent Light Source, SLAC National Accelerator Laboratory 5 , 2575 Sand Hill Road, Menlo Park, California 94025,) P Peter M. Weber (Department of Chemistry) T Thomas Wolf (Linac Coherent Light Source, SLAC National Accelerator Laboratory 5 , 2575 Sand Hill Road, Menlo Park, California 94025,) B Basile F. E. Curchod (School of Chemistry, Cantock’s Close) M Michael N. R. Ashfold (School of Chemistry, Cantock’s Close) R Russell S. Minns (School of Chemistry and Chemical Engineering) R Ruaridh Forbes (Linac Coherent Light Source)

Abstract

A time-resolved x-ray scattering (TRXS) investigation of the photodissociation dynamics of gas-phase 2-iodothiophene molecules following 252 nm excitation is presented. Structural evolution of the molecule and dynamical information on the resulting photofragments were captured using femtosecond x-ray free-electron laser pulses. Two dissociation pathways were identified, arising via excitation to ππ* and (n/π)σ* states, respectively, yielding distinct interfragment recoil velocities of ∼6.4 Åps−1 and 17.0 Åps−1. A comparison of asymptotic scattering data with simulated patterns indicates that the thiophene ring remains closed following dissociation at this wavelength. Modeling the experimental data yields a branching ratio of ∼3:1 in favor of the high velocity channel. These findings demonstrate the capability of TRXS to disentangle concurrent ultrafast reaction pathways and provide detailed structural insight into energy redistribution during photoinduced bond fission in complex molecular systems.

Article Details

Volume / Issue Vol. 164, Issue 2
Published January 14, 2026
ISSN 0021-9606
Publisher American Institute of Physics

Journal Info

The Journal of Chemical Physics

American Institute of Physics

ISSN: 0021-9606 Physical Sciences

Authors (29)

W

Weronika O. Razmus

I

Ian Gabalski

F

Felix Allum

Stanford PULSE Institute

G

Grite L. Abma

Institute for Molecules and Materials, Radboud University 4 , Heijendaalseweg 135, 6525 AJ Nijmegen,

M

Mathew Britton

S

Sébastien Boutet

P

Philip H. Bucksbaum

X

Xinxin Cheng

S

Stuart W. Crane

Department of Chemistry, Brown University 6 , Providence, Rhode Island 02912,

G

Gregory Gate

Linac Coherent Light Source, SLAC National Accelerator Laboratory 5 , 2575 Sand Hill Road, Menlo Park, California 94025,

A

Aaron Ghrist

PULSE Institute, SLAC National Accelerator Laboratory 2 , 2575 Sand Hill Road, Menlo Park, California 94025,

M

Martin Graßl

PULSE Institute, SLAC National Accelerator Laboratory 2 , 2575 Sand Hill Road, Menlo Park, California 94025,

A

Alice E. Green

EaStCHEM School of Chemistry

N

Nathan Goff

Department of Chemistry, Brown University 6 , Providence, Rhode Island 02912,

D

Daniel A. Horke

Institute for Molecules and Materials, Radboud University 4 , Heijendaalseweg 135, 6525 AJ Nijmegen,

L

Lisa Huang

Department of Chemistry, Brown University 6 , Providence, Rhode Island 02912,

M

Mengning Liang

Linac Coherent Light Source, SLAC National Accelerator Laboratory 5 , 2575 Sand Hill Road, Menlo Park, California 94025,

Y

Yusong Liu

L

Lingyu Ma

M

Michael P. Minitti

Linac Coherent Light Source, SLAC National Accelerator Laboratory 5 , 2575 Sand Hill Road, Menlo Park, California 94025,

T

Thomas Northey

Department of Chemistry, Brown University 6 , Providence, Rhode Island 02912,

A

Asami Odate

Department of Chemistry, Brown University 6 , Providence, Rhode Island 02912,

J

Joseph Robinson

Linac Coherent Light Source, SLAC National Accelerator Laboratory 5 , 2575 Sand Hill Road, Menlo Park, California 94025,

P

Peter M. Weber

Department of Chemistry

T

Thomas Wolf

Linac Coherent Light Source, SLAC National Accelerator Laboratory 5 , 2575 Sand Hill Road, Menlo Park, California 94025,

B

Basile F. E. Curchod

School of Chemistry, Cantock’s Close

M

Michael N. R. Ashfold

School of Chemistry, Cantock’s Close

R

Russell S. Minns

School of Chemistry and Chemical Engineering

R

Ruaridh Forbes

Linac Coherent Light Source