Zeise's Salt - History

History

Zeise's salt was one of the first organometallic compounds to be reported. Its inventor W. C. Zeise, a professor at the University of Copenhagen, prepared this compound in 1820s while investigating the reaction of PtCl₄ with boiling ethanol, and proposed that the resulting compound contained ethylene. Justus von Liebig, an influential chemist of that era, often criticised Zeise's proposal, but Zeise's theories were decisively supported in 1868 when Birnbaum prepared the complex using ethylene.

Zeise's salt received a great deal of attention during the second half of the 19th century because chemists could not properly explain the molecular structure of the salt. This question remained unanswered until the advent of x-ray diffraction in the 20th century.

Zeise's salt stimulated much scientific research in the field of organometallic chemistry, and would be key in defining new concepts in chemistry such as Hapticity. The Dewar-Chatt-Duncanson model explains how the metal is coordinated to the double bond.