Large molecules, small radicals and the diffuse interstellar bands

Abstract

A theory is investigated in which the carriers of the diffuse interstellar bands are fullerane molecules and their ions, such as the series C 60 H m , m = 1, 2,...,60. No suitable spectra are available for these molecules, so certain small hydrocarbons are studied instead which have electronic systems similar to those found in some of the fulleranes. The properties of these analogues are reviewed and assessed, not only for the presence of transitions at wavelengths close to those of interstellar features, but also for the absence of transitions at wavelengths where no interstellar features are known, and the allyl radical .C 3 H 5 is found to be worthy of note. It has a transition whose origin is at 4083 A, not far from the diffuse band at 4430 A, and another close to the interstellar absorption feature at 2175 A