text: Studying the decomposition of double salts of aryldiazonium halides with mercury halides by copper powder, in 1929 Nesmeyanov proposed a new method for obtaining arylmercury halides. Later, the diazo method was extended to the synthesis of organometallic compounds of thallium, germanium, tin, lead, arsenic, antimony, and bismuth. The features of the diazo method, which distinguish it from direct metalation methods, are the possibility of obtaining organometallic compounds with different functional groups in the carbon radical and the possibility of selectively introducing a metal atom into a certain position. In 1935 – 1948, Nesmeyanov, together with K. A. Kocheshkov, obtained organic derivatives of tin, lead, antimony and other metals. Due to mutual transitions from organic derivatives of some elements to organic compounds of other elements, organometallic compounds obtained by the diazo method have found new applications in synthesis.