Development of X-ray Crystallography Research in India

Abstract

X-ray crystallography began in India with the successful determination of the structures of naphthalene and anthracene crystals in 1929 by the method of trial and error. The results of these determinations were published in 1930. This beginning however, has an interesting background. C.V. Raman and his students at the Indian Association for the Cultivation of Science in Calcutta were greatly interested in the study of optical anisotropy of molecules from scattering of light. He and Ramanathan extended the optical theory of scattering to X-ray diffraction by liquids and attempts were started in this laboratory by Sogani and others to compare the theory with experimental results. It became clear from these experiments that the shapes of the molecules and the intermolecular forces had profound influence on the diffraction patterns. I found at about the same time that phase changes in the liquid alloys of sodium and potassium could be studied by X-ray diffraction in a way similar to that possible in the case of solid alloys. All these studies led to the idea that the shapes of molecules and the intermolecular forces correspond to some degree in the solid and the liquid states.