History of organometallics

In 1760 in a Parisian military pharmacy a french chemist L.C. Cadet attempted to make invisible ink. He used cobalt minerals which contained arsine salts. Unintentionally he produced a vile smelling liquid which was later to be named dicacodyl.

This was in fact the first ever synthesised organometallic compound. The investigation and identification of cacodyl by Bunsen in 1848 was to mark the beginning of the era of organometallic chemistry. R.W. Bunsen(better known for his invention of the bunsen burner)continued investigating what he called alkarsines and produced many derivatives of R₂As-AsR₂ such as (CH₃)2AsCN (which bunsen supposedly tasted). The true founder of organometallic as a branch of chemistry was one of Bunsen's student Edward Frankland. Edward first synthesised organo zinc compounds by treating organo halides with zinc metal. He was actually attempting to prepare ethyl radical but instead prepared diethylzinc.

In 1852 after further research Edward Frankland prepares alkyl mercury compounds.

This was followed by (C₂H₅)Sn and (CH₃)₃CrCo. Such compounds were important in organic chemistry synthesis until their replacement by Grignard reagents in 1900. From these discovery's the term "Organometallic" was coined for compounds containing direct carbon-metal bonds and Frankland realised the importance of the valency of elements(combining power). This was pursued by Kekule who laid the foundation of modern theory structural chemistry.

Although Cadet had discovered Cacodyl in 1760. It was William Zeise who in 1830 made the first report of preparing an organometallic now known as a Zeise salt K[PtCl₃(C₂H₄)].H₂O. This was to be the first synthesised pie-bonded organometallic. although Pope and Peachly isolated the first organotransition metal compound (Me3PtCl). It was not until 1951 thanks to the Germans Hein, Hieber and Reppe and of course the discovery of Ferrocene, laid the foundations of modern day organometallics.

Such compounds were to revolutionise catalysis in the chemical industry such as the Ziegler-Natta polymerisation 1955, Waker process 1959, Olefin metathesis 1964 and Rhodium carbonylation of methanol 1970. Organometallics predates organic chemistry and has become one of the largest forms of chemistry especially in the petrochemical industry. Such chemistry breaks down the barriers between organic and inorganic chemistry.