Synthesis and Molecular Structures of the Cationic Silver Complexes of the Polycondensed Aromatics Fluorene, Pseudorubrene, and Truxene

• Published in: European journal of inorganic chemistry 2016-11, Vol.2016 (32), p.5152-5160
• Main Authors: Wombacher, Tobias, Foro, Sabine, Schneider, Jörg J.
• Format: Article
• Language: English
• Subjects: Aromaticity; Binding sites; Cationic; Coordination chemistry; Crystal structure; Crystals; Derivatives; Fused-ring systems; Hydrocarbons; Molecular structure; Polyallylamine hydrochloride; Silver; Synthesis (chemistry)
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.201600901

We investigated the coordination behavior of AgI towards three polycondensed aromatic hydrocarbons (PAHs) in solution, in the solid state, and theoretically. Silver(I) trifluoromethanesulfonate (AgTfl) coordinates to fluorene to yield crystals of the composition {[(µ‐η2:η2‐fluorene)Ag2(Tfl)2]}n (1), the fluorene derivative 5,12‐diphenyl‐5,6;11,12‐di‐o‐phenylene‐5,12‐dihydrotetracene (pseudorubrene) reacts with silver(I) perchlorate to yield crystals of the composition bis[(η2‐pseudorubrene)(η2‐toluene)AgClO4]·toluenesolv (2), and the formation of the crystalline dimeric AgI sandwich compound [(µ‐η2:η2‐truxene)2(η1‐toluene)(µ‐H2O)Ag2(ClO4)2] (3) is accomplished by π‐coordination of the PAH truxene. In complexes 1–3, it is eminent from their crystal structures that the anionic silver moieties act as linking units between the PAH molecules. Theoretical calculations based on DFT methods of the aromatic bridging ring ligands substantiate the experimentally observed selective AgI coordination for each of the three PAH molecules fluorene, pseudorubrene, and truxene. Coordination of silver(I) salts to the extended polycyclic aromatic hydrocarbon (PAH) frameworks of fluorene, truxene, and pseudorubrene (LPsrub) may occur on binding sites of local highest electron density. Clar's π‐aromatic sextet rule allows the preferential coordination of AgI to these PAH molecules to be understood.