Picosecond infrared spectroscopy as probe for photochemical or thermal reactions in solid matrices

Technical Report · Sat Aug 01 04:00:00 EDT 1998

DOI:https://doi.org/10.2172/638215· OSTI ID:638215

Lippert, T; Funk, D J; Strauss, C E.M.; Stoutland, P O

Spectroscopy in the mid-IR on timescales from pico to milliseconds has been developed for the study of laser-material interactions over broad timescales. To reach these timescales the authors have employed two configurations: (1) for the ps to ns timescale a one and a two stage difference frequency mixing setup is employed, (2) for the longer timescale, CW mid-IR laser diodes have been used. In general, they excite the sample with one pulse at 1064/266/355 nm and probe some time later in the mid IR (2900--800 cm{sup {minus}1}). In the case of photochemical reaction, they excite the sample directly in the UV. Alternatively, they initiate thermal reactions by pumping a heater dye at 1.064 {micro}m, which quickly converts the photon energy into heat. The potential of this technique to study reactions in the solid state was demonstrated for a photochemically induced (266 nm) reaction (Wolff rearrangement of a {alpha}-diazo-ketone to {alpha}-keto-ketene) in a polymer matrix. Thermal initiation resulted in a similar reaction. The position, amplitude and width of the product bands changed, they believe due to additional side reactions and temperature effects.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 638215
• Report Number(s): LA-UR--98-771; CONF-971232--; ON: DE98003714
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
CHEMICAL EXPLOSIVES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
EXPERIMENTAL DATA
INFRARED SPECTRA
LASER SPECTROSCOPY