Self-assembly of cyclometallated Pd(II) compounds directed by C–H⋅⋅⋅π interactions: A structural evidence for metalloaromaticity in a cyclopalladated ring

Structural studies on the two binuclear cyclometallated compounds [Pd(C2,N-bzan)(μ-N3)]2 (1) and [Pd(C2,N-bzan)(μ-Pz)]2 (2) (bzan = N-benzylideneaniline) have been carried out in this work. In both compounds, C–H⋅⋅⋅π interactions play an important role in the molecular self-assembly. In complex 1, ortho-CH bonds from bzan moiety interact with the cyclopalladated ring at a distance of Cbzan⋅⋅⋅Cg 3.448(6) Å, providing a new structural evidence for the metalloaromaticity of the cyclometallated ring.

Graphical AbstractStructural studies on the cyclometallated [Pd(C2,N-bzan)(μ-N3)]2 (1) and [Pd(C2,N-bzan)(μ-Pz)]2 (2) (bzan = N-benzylideneaniline, Pz = pyrazolato) revealed that C–H⋅⋅⋅π interactions are responsible for the stabilization of their crystal structures. In complex 1, ortho-CH bonds interact with the metal chelate ring, providing a new structural evidence for the metalloaromaticity of a cyclometallated ring.Figure optionsDownload full-size imageDownload as PowerPoint slide