Ambiphilic ligands featuring Lewis basic and acidic sites have been used to modify the electronic properties of coordinated transition metals (M). Recently, our group has started to systematically explore examples of such ligands in which the Lewis acidic functionality is a carbenium ion. For example, we have reported the synthesis and structure of an ambiphilic ligand (EliPhos) in which a diphenylphosphino group and an N-methyl acridinium moiety coexist at the ortho-positions of a phenylene backbone. After observing weak metal→acridinium interactions in the gold(I) complexes formed by this ligand, we have now investigated the complexation of zero-valent Ni, Pd, and Pt centers. Our findings suggest that the resulting complexes feature a strong M→Ccarbenium interaction involving the C19 position of the central acridinium ring. Computational analysis of these complexes show that the M→Ccarbenium interactions in these complexes result from the donation of a d-electron pair from the metal into the carbenium p-orbital. Altogether, these results support the notion that carbenium ion can indeed be regarded as Z-type ligands.

Coordination chemistry of EliPhos, an acridinium-based, γ-cationic phosphine: Isolation of group 10 metal complexes with strong metal→acridinium interactions

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.