This book contains the formal lectures and contributed papers presented at the NATO Advanced Study Institute on. the Advances in Chemical Reaction Dynamics. The meeting convened at the city of Iraklion, Crete, Greece on 25 August 1985 and continued to 7 September 1985. The material presented describes the fundamental and recent advances in experimental and theoretical aspects of, reaction dynamics. A large section is devoted to electronically excited states, ionic species, and free radicals, relevant to chemical sys tems. In addition recent advances in gas phase polymerization, formation of clusters, and energy release processes in energetic materials were presented. Selected papers deal with topics such as the dynamics of electric field effects in low polar solutions, high electric field perturbations and relaxation of dipole equilibria, correlation in picosecond/laser pulse scattering, and applications to fast reaction dynamics. Picosecond transient Raman spectroscopy which has been used for the elucidation of reaction dynamics and structural changes occurring during the course of ultrafast chemical reactions; propagation of turbulent flames and detonations in gaseous· energetic systems are also discussed in some detail. In addition a large portion of the program was devoted to current experimental and theoretical studies of the structure of the transition state as inferred from product state distributions; translational energy release in the photodissociation of aromatic molecules; intramolecu lar and intraionic dynamic processes.

The near Infra-Red emission of the Interstellar Medium is a very puzzling subject. In the brightest regions, where spectroscopic observa tions are possible from the ground, several bands (3.3 - 3.4 - 6.2 - 7.7 - 8.6 - 11.3 ~m) have been observed since 1973. The absence of satisfying explanation was so obvious that they were called "Unidenti fied IR Emission Bands". The puzzle still increased when were known the first results of the general IR sky survey made by the satellite IRAS. On a large scale, the near IR emission of the Interstellar medium was expected to be very small but it was observed to be about one third of the total IR emission for our own galaxy ..• The situation has moved in 1984 when it was suggested that a class of stable organic molecules, the Polycyclic Aromatic Hydrocarbons (PAH's) could be at the origin of this near IR emission. Initially based on the required refractory character of particules that should be heated to high temperature without subliming, this hypothesis leads to a sugges tive spectroscopic similarity with the observed astronomical bands. This hypothesis is attractive and it has many implications, for ins tance, the PAHs would be the most abundant organic molecules in the universe. However, many points have to be clarified and the different consequences of this suggestion should be explored.

Pulse Radiolysis presents an in-depth discussion of the pulse radiolysis technique, one of the most important and powerful means for detecting transient and relaxation phenomena and following their behavior in irradiated systems. The book covers the principle of pulse radiolysis, identifies various kinds of pulse radiolysis techniques, and discusses recent advancements in the field. The text also discusses new experimental pulse radiolysis techniques (basic and applied) in broad scientific fields such as physics, chemistry, biology, and engineering. These techniques include picosecond pulse radiolysis, single particle radiolysis, and muon-induced transient phenomena. Pulse Radiolysis provides essential information for all professionals involved with pulse radiolysis research.