Ligand Design for Site-Selective Metal Coordination: Synthesis of Transition-Metal Complexes with η6-Coordination of the Central Ring of Anthracene

Angewandte Chemie - International Edition

5 years ago

Ligand Design for Site-Selective Metal Coordination: Synthesis of Transition-Metal Complexes with η6-Coordination of the Central Ring of Anthracene

Alexandra O. Borissova, Dmitry S. Perekalin, Eduard E. Karslyan

A polycyclic aromatic ligand for site-selective metal coordination was designed by using DFT calculations. The computational prediction was confirmed by experiments: 2,3,6,7-tetramethoxy-9,10-dimethylanthracene initially reacts with [(C5H5)Ru(MeCN)3]BF4 to give the kinetic product with a [(C5H5)Ru]+ fragment coordinated at the terminal ring, which is then transformed into the thermodynamic product with coordination through the central ring. These isomeric complexes have markedly different UV/Vis spectra, which was explained by analysis of the frontier orbitals. At the same time, the calculations suggest that electrostatic interactions are mainly responsible for the site selectivity of the coordination. Moving to the center: The introduction of rationally selected substituents to anthracene ligands forces the metal to change its coordination site from the typical terminal ring to the unusual central ring. The shift leads to significant changes in the visible spectra of the complexes, which suggests potential for application of site-selective metal coordination to modify the properties of polycyclic aromatic hydrocarbons.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/anie.201700685