Picosecond calorimetry: time-resolved x-ray diffraction studies of liquid CH2Cl2

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Abstract

Liquid phase time-resolved x-ray diffraction with 100 ps resolution has recently emerged as a powerful technique for probing the structural dynamics of transient photochemical species in solution. It is intrinsic to the method, however, that a structural signal is observed not only from the photochemical of interest but also from the embedding solvent matrix. To experimentally characterize the x-ray diffraction signal deriving from the solvent alone we performed time-resolved diffraction studies of a pure liquid sample over a time domain from -250 ps to 2.5 micros. Multiphoton excitation was used to rapidly heat liquid CH(2)Cl(2) using UV pulses of 100 fs duration. A significant x-ray diffraction signal is visible prior to the onset of thermal expansion, which characterizes a highly compressed superheated liquid. Liquid CH(2)Cl(2) then expands as a shock wave propagates through the sample and the temporal dependence of this phenomenon is in good agreement with theory. An unexpectedly slow initial release of energy into the liquid as heat is observed from multiphoton excited CH(2)Cl(2), revealing the presence of a metastable state of multiphoton excited CH(2)Cl(2).

Detaljer

Författare
  • Panayiotis Georgiou
  • Jonathan Vincent
  • Magnus Andersson
  • Annemarie B Wöhri
  • Pontus Gourdon
  • Jens Poulsen
  • Jan Davidsson
  • Richard Neutze
Externa organisationer
  • Uppsala universitet, Historiska institutionen
  • Chalmers University of Technology
  • Göteborgs universitet
Forskningsområden

Nyckelord

Originalspråkengelska
Artikelnummer234507
Sidor (från-till)1-9
TidskriftJournal of Chemical Physics
Volym124
Utgivningsnummer23
StatusPublished - 2006 jun 21
PublikationskategoriForskning
Peer review utfördJa
Externt publiceradJa