Coordination of 12-Electron Organometallic Fragments to the Arene Ring of Nonsymmetric Group 10 POCOP Pincer Complexes

A series of heterobimetallic complexes
have been prepared in good
yields by η6 coordination of [Cp*Ru]+,
[CpRu]+, [CpFe]+, and [Cr­(CO)3] fragments
to the aromatic ring of nonsymmetric Ni­(II), Pd­(II), and Pt­(II) naphthoresorcinate
POCOP compounds, and the molecular structures of the new compounds
have been unequivocally determined by single-crystal X-ray diffraction
crystallography. The reaction is regiospecific, and only coordination
at the noncyclometalated ring is observed. The coordination occurs
in an orthogonal fashion, and as a consequence, the heterobimetallic
species exhibit axial desymmetrization of the pincer fragment, generating
molecules with planar chirality. In addition, the electronic properties
of the metal center can be tuned by the effect of π coordination
of the second metal, as shown by electrochemical studies. The observed
specificity of the reaction is discussed and supported with theoretical
studies.