Probing the Aromaticity and Stability of Metallatricycles by DFT Calculations: Toward Clar Structure in Organometallic Chemistry
Metallaaromatics have attracted considerable attention in recent years because they can display properties of both organic and organometallic species. However, it remains unclear whether Clar’s rule could be applied to organometallic chemistry despite its proposal in 1950s. Here, we investigate the relative stabilities of 49 organic and organometallic species by density functional theory (DFT) calculations. The results indicate that the nonmetal-bridged isomers are more stable than the metal-bridgehead ones, and the kinked isomers are more stable than its linear isomers, extending Clar’s rule to organometallic chemistry and aryne chemistry. Our findings provide useful information for experimental chemists to realize more metallaaromatics, as some predicted osmatricycles are thermodynamically more stable than the experimentally isolated ones.