Real-time observation of X-ray-induced intramolecular and interatomic electronic decay in CH2I2

H Fukuzawa ,Syuhei Yamada ,Hikaru Sotome ,Hirohiko Kono ,Kazuhiko Ogawa ,K Nagaya ,Takayuki Umemoto ,Tsukasa Sakai ,K Matsunami ,Catalin Miron ,Kuno Kooser ,Alexander I Kuleff ,Aryya Ghosh ,Tetsuo Katayama ,Lorenz S Cederbaum ,E Kukk ,Theodor Asavei ,Per Johnsson ,Liviu Neagu ,Artem Rudenko ,Tadashi Togashi ,Yuta Sakakibara ,Gregor Kastirke ,Shinji Kajimoto ,С Л Молодцов ,Christophe Nicolas ,Denys Iablonskyi ,Yuta Ito ,Yoshiaki Kumagai ,Tsukasa Takanashi ,Takehiko Tachibana ,Kensuke Tono ,Shigeki Owada ,Daehyun You ,Kohei Ochiai ,Subhendu Mondal ,Xiao Jing Liu ,Kango Kariyazono ,Makina Yabashi ,Yoshibumi Sato ,Toshiyuki Nishiyama ,Naoki Kishimoto ,Kirill Gokhberg ,Kazuki Asa ,Kaoru Yamazaki ,Manabu Kanno ,Hiroshi Fukumura ,M S Schöffler ,S Wada ,K Motomura ,Kiyoshi Ueda

doi:10.1038/s41467-019-10060-z

Abstract

The increasing availability of X-ray free-electron lasers (XFELs) has catalyzed the development of single-object structural determination and of structural dynamics tracking in real-time. Disentangling the molecular-level reactions triggered by the interaction with an XFEL pulse is a fundamental step towards developing such applications. Here we report real-time observations of XFEL-induced electronic decay via short-lived transient electronic states in the diiodomethane molecule, using a femtosecond near-infrared probe laser. We determine the lifetimes of the transient states populated during the XFEL-induced Auger cascades and find that multiply charged iodine ions are issued from short-lived (∼20 fs) transient states, whereas the singly charged ones originate from significantly longer-lived states (∼100 fs). We identify the mechanisms behind these different time scales: contrary to the short-lived transient states which relax by molecular Auger decay, the long-lived ones decay by an interatomic Coulombic decay between two iodine atoms, during the molecular fragmentation.

Highlights

The increasing availability of X-ray free-electron lasers (XFELs) has catalyzed the development of single-object structural determination and of structural dynamics tracking in realtime
Understanding the details of the interaction between intense X-ray free-electron laser (XFEL) pulses[1,2] and matter is of paramount importance for its numerous applications, including single-particle structural determination by coherent X-ray imaging[3,4,5] and structural dynamics tracking in molecules by time-resolved X-ray spectroscopy and diffraction[6,7,8,9,10,11,12]
We experimentally determine the lifetimes of the transient states populated during the XFEL-induced Auger cascades and find that multiply charged iodine ions are issued from short-lived (∼20 fs) transient states, whereas the singly charged ones originate from significantly longer-lived states (∼100 fs)

Summary

Introduction

The increasing availability of X-ray free-electron lasers (XFELs) has catalyzed the development of single-object structural determination and of structural dynamics tracking in realtime. Understanding the details of the interaction between intense X-ray free-electron laser (XFEL) pulses[1,2] and matter is of paramount importance for its numerous applications, including single-particle structural determination by coherent X-ray imaging[3,4,5] and structural dynamics tracking in molecules by time-resolved X-ray spectroscopy and diffraction[6,7,8,9,10,11,12] Another powerful method made available by the new XFELs is serial femtosecond crystallography[13,14,15]. Our investigation allows us to identify the driving mechanisms behind: contrary to the shortlived transient states which relax by molecular Auger decay, the long-lived ones decay, during the molecular fragmentation process, by an interatomic Coulombic decay (ICD) process involving two iodine atoms

Methods

Results

Conclusion