Polymorphism of Beryllium Oxyacetate

Abstract

WE have found a transition of beryllium oxyacetate hitherto unrecorded. The transition occurs at about 160º C., and when the temperature is raised above this point the substance assumesgradually the appearance of soft wax, though it melts snarly at 285º C. The melting point of this sub-stance is abnormally high as compared with those of other members of the homologous series, as is seen in rthe figure. It suggests that the high-temperature phase has some unusual structure in which the molecules are held together, forming a crystal lattice, but presumably with a higher order of freedom in its molecular motion, thus resembling the melt in its molecular state. This view is supported by the fact that the intensities of X-ray spectra taken with this phase fall off rapidly with increase of diffraction angles.