The aromaticity of tungstenacyclobutadiene, Cl3W(–ButC–CMe–CMe–): A DFT/NICS study

B3LYP and MP2 are used to investigate the geometry and aromaticity of tungstenacyclobutadiene, Cl3W(–ButC–CMe–CMe–). Nucleus-independent chemical shift is used as an index of aromaticity for this experimentally observed metallacyclobutadiene. Additionally, charge effects are explored by characterizing the aromaticity of the tungstenacyclobutadiene fragment ions, WC3H3+3 and WC3H3+1. CMO-NICS analysis provides the contribution of each B3LYP orbital to the aromaticity and allows differentiation between orbitals of σ and π symmetries.

B3LYP and MP2 are used to investigate the geometry and aromaticity of tungstenacyclobutadiene, W[C-t-BuCMeCMe]Cl3. Nucleus-independent chemical shift is used as an index of aromaticity for this experimentally observed metallacyclobutadiene. Additionally, charge effects are explored by characterizing the aromaticity of the tungstenacyclobutadiene fragment ions, WC3H3+3 and WC3H3+1. CMO-NICS analysis provides the contribution of each B3LYP orbital to the aromaticity and allows differentiation between orbitals of σ and π symmetries.Figure optionsDownload as PowerPoint slide