Bonding analysis and electronic structure of transition metal–benzoquinoline complexes: A theoretical study

The geometric and electronic structures of a series of hypothetical compounds of the types CpM(C13H9N) and (CO)3M(C13H9N) (M = first row transition metal and C13H9N = 7,8-benzoquinoline) have been investigated by means of density functional theory (DFT). The benzoquinoline ligand can bind to the metal through η1–η6 coordination modes, adopting structures of types a, b and c, in agreement with the electron count and the nature of the metal. In the investigated species, the most favored closed-shell count is 18-MVE, except for the Ti and V models which prefer the open-shell 16-MVE configuration. This study has shown the difference in the coordination ability of this heteropolycyclic ligand and coordination of the inner C6 ring is less favored than the outer C6 and C5N rings, in agreement with the π-electron density localization.

A DFT study has shown the different coordination abilities of the benzoquinoline ligand. The coordination of the inner C6 ring is less favored compared to the outer C6 and C5N rings, in agreement with the π-electron density localization. The coordination decreases in accordance with the increasing number of the metal electrons.Figure optionsDownload as PowerPoint slideHighlights
► This study predicts the richness of the benzoquinoline in organometallic chemistry.
► The C6 ring acts as a π donor and the C5N can be considered as a π acceptor.
► Coordination modes from η1 to η6 are adopted by the C6 and the C5N rings.
► The most favored closed-shell count is 18-MVE configuration
► The investigated compounds should be enough stable for being isolated.