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

Abstract

AbstractTransitional 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.