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

• Published in: Angewandte Chemie 2017-05, Vol.129 (20), p.5676-5679
• Main Authors: Karslyan, Eduard E., Borissova, Alexandra O., Perekalin, Dmitry S.
• Format: Article
• Language: English
• Subjects: Arenliganden; Dichtefunktionalrechnungen; Ligandenentwicklung; Ruthenium; Sandwichkomplexe
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.201700685

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. Zug zur Mitte: Die Einführung ausgewählter Substituenten an Anthracenliganden erzwingt die Koordination eines Metallzentrums am zentralen Ring anstelle, wie üblich, an einem äußeren Ring. Daraus resultieren signifikante Farbänderungen der Komplexe. Die positionsselektive Metallkoordination hat Anwendungspotenzial für die Modifizierung der Eigenschaften von polycyclischen aromatischen Kohlenwasserstoffen.