 The complex indeed contains ethylene.Attempts to establish the correct structure and composition of Zeise's salt drove much basic research during the second half of the 19th century and led to a greater sophistication in organometallic chemistry.The structure of Zeise's salt was definitively resolved only with the advent of X-ray crystallography and the nature of its platinum to ethylene bond was not understood until the development of the Dewar–Chatt–Duncanson model in the 1950s.