Studies in polymerization - XV. The photosensitized initiation of vinyl polymerization by manganese carbonyl

Abstract
Single crystals of naturally occurring graphite which had been treated with bromine vapour have been examined by electron and X-ray diffraction and also by electron microscopy. The intercalated bromine is in the form of layers, interleaved between the graphite layers in a sequence which is dependent upon the concentration of bromine. The structure within a bromine layer is relatively highly ordered and has been shown to take on two forms, one which occurs at concentrations in excess of 47 (wt.) %, the other occurs at lower concentrations. Detailed analysis of the diffraction patterns given by the lower concentration form suggest that it is composed of chains of Br$_2$ molecules, in which the interatomic distances are virtually identical with those of solid bromine.