Aryldiazonium Tetrachloroaurate(III) Salts: Synthesis, Structure, and Fundamental Applications

Abstract

AbstractThe synthesis of aryldiazonium tetrachloroaurate(III) salts [X–4–C6H4N≡N]AuCl4 (X=F, Cl, Br, I, CN, NO2, COOH, bisaniline, triazine-based dendrimers, C8F17, C6H13) is reported by the protonation of anilines with chloroauric acid in acetonitrile followed by one-electron oxidation using nitrosonium salt [NO]X (X=tetrafluoroborate, hexafluorophosphate). X-ray crystal structure of X=CN, NO2, COOH, C8F17, C6H13 from acetonitrile or water (X=COOH) displayed [–N≡N]+ bond distance typical of a triple bond. Electrochemical reduction of the salts showed low or even positive potential values versus silver/silver chloride reference electrode. The robust gold-aryl nanoparticles, termed organometallic nanoparticles, were constructed using green and mild chemical reduction routes of the diazonium gold(III) salts for forensic, environmental, and nanomedicine engineering applications. Specifically, the salts were used in, for example, the development of latent fingerprints on copper and nickel coins, formation of gold-silver alloys, gold-aryl core-tine oxide shell structures, formation of protein and amino acid bioconjugates, and electrochemical synthesis of gold-aryl nanoparticles stabilized with polyaniline.