Comparison of π(BB)⋯M bond and luminescence behavior of group 11/12 metal π‐diborene complexes: Theoretical investigation.

Transitional metal (TM) π‐diborene complexes have similar structures to those side‐on‐bound TM‐π‐olefin complexes, while their luminescence behaviors are distinctly different. In this work, the natures of the π(BB)⋯TM bonds in π‐diborene(1)⋯MCl (M = Cu, Ag, and Au) and π‐diborene(2)⋯M′Cl2 (M′ = Zn, Cd, and Hg) have been investigated and compared based on EDA, AIM, ELF, NCI, NBO, and ETS‐NOCV analysis as well as their UV/Vis spectra have been predicted. The calculated results show that the π(BB)⋯M/M′ bonds are strong covalent bonds, the orbital interactions in π(BB)⋯M′ (M′ = Zn, Cd, and Hg) are more dominant than those in π(BB)···M (M = Cu, Ag, and Au) bonds. The π(BB)⋯M/M′ interactions belong to the Dewar–Chatt–Duncanson model, the back donations of the M′Cl2 in π‐diborene(2)⋯M′Cl2 are less than those of MCl in π‐diborene(1)⋯MCl. Both π‐diborene(1)⋯MCl and π‐diborene(2)⋯M′Cl2 can produce blue luminescence, the luminescence intensity of former complexes are stronger than the latter complexes. [ABSTRACT FROM AUTHOR]