Charge-Transfer Salts of Electron-Rich Diruthenium and Macrocyclic Tetraruthenium Complexes
Final Report Abstract
The research project focused on ligand-bridged, electron-rich diruthenium complexes with π-conjugated bridging ligands. These were to be tested for their suitability as organometallic donors for charge transfer compounds in concert with planar organic electron acceptors. For this purpose, the bridging ligands were designed so as to offer a sufficiently large lateral extension to be able to interact with the acceptors via π stacking interactions. This structural motif is known to often lead to high electrical conductivity. The bridging motifs used in this work include 1,4-anthrylene, pyrene-fused azaacenes, dibenzo(tetrathiafulvalene), an oligophenylene vinylene or an oligophenylene vinylene/oligophenylene ethynylene blend with three repeat units, as well as a linker of the latter type in which the central phenylene building block is replaced by a 2,7-pyrenyl unit. The donor complexes were all examined with regard to their electrochemical properties. Without exception, they proved to be easily oxidized and form sufficiently stable radical cations and dications to allow them to be examined spectroscopically. Here we encountered different constellations: stepwise oxidations of the particularly electron-rich end groups with a variable degree of electronic coupling up to an oxidation largely centered on the bridging ligand. In one case, we were able to demonstrate that the extent of electronic coupling was significantly reduced in the presence of an electrolyte. We further found an example in which electronic decoupling of the central pyrenyl moiety from the electron-rich end groups preserves pyrene luminescence. All organometallic donors used readily form charge transfer compounds with organic acceptors with a variable extent of charge transfer (ionicity). We were able to obtain three CT compounds with ligand precursors as donors in single-crystalline form. Unfortunately, all CT compounds with organometallic donors were found to be highly amorphous and electrical insulators. It remains unclear whether this is primarily due to inherently poor conductor properties or to high contact resistances between spherical nanoparticles. The results we achieved as part of this project have led to a total of seven original publications in peer-reviewed journals.
Publications
-
Electron‐Rich Diruthenium Complexes with π‐Extended Alkenyl Ligands and Their F4TCNQ Charge‐Transfer Salts**. Chemistry – A European Journal, 28(23).
Das, Rajorshi; Linseis, Michael; Schupp, Stefan M.; Schmidt‐Mende, Lukas & Winter, Rainer F.
-
Reversible Multielectron Release from Redox-Active Three-Dimensional Molecular Barrels with Ruthenium-Alkenyl Moieties. Inorganic Chemistry, 61(32), 12662-12677.
Das, Rajorshi; Linseis, Michael; Scheerer, Stefan; Zoller, Katrin; Senft, Laura; Ivanović-Burmazović, Ivana & Winter, Rainer F.
-
Tetraruthenium Macrocycles with Laterally Extended Bis(alkenyl)quinoxaline Ligands and Their F4TCNQ•− Salts. Inorganics, 10(6), 82.
Das, Rajorshi; Linseis, Michael; Senft, Laura; Ivanović-Burmazović, Ivana & Winter, Rainer F.
-
A Dibenzotetrathiafulvalene-Bridged Bis(alkenylruthenium) Complex and Its One-and Two-Electron-Oxidized Forms. Inorganic Chemistry, 62(46), 18789-18803.
Gogesch, Franciska S.; Laininger, Lukas S.; Sokov, Nick; Schupp, Stefan M.; Senft, Laura; Moura, Hipassia M.; Linseis, Michael; Schmidt-Mende, Lukas; Ivanović-Burmazović, Ivana; Unterlass, Miriam M. & Winter, Rainer F.
-
Diruthenium Complexes with π-Extended Bridging Bis(alkenyl)arylene Ligands, A Derived Metallamacrocycle, and Their Oxidized Forms. Organometallics, 42(21), 3085-3098.
Gogesch, Franciska S.; Schwab, Sebastian; Rehse, Anja; Linseis, Michael; Baksi, Ananya; Clever, Guido H. & Winter, Rainer F.
-
Organic binary charge-transfer compounds of 2,2′ : 6′,2′′ : 6′′,6-trioxotriphenylamine and a pyrene-annulated azaacene as donors. RSC Advances, 13(6), 3652-3660.
Das, Rajorshi; Linseis, Michael; Schupp, Stefan M.; Gogesch, Franciska S.; Schmidt-Mende, Lukas & Winter, Rainer F.
-
Pyrene fluorescence in 2,7-di(4-phenylethynyl)pyrene-bridged bis(alkenylruthenium) complexes. Dalton Transactions, 53(1), 251-259.
Gogesch, Franciska S.; Bauer, Lea; Vollstädt, Florian D.; Linseis, Michael; Senft, Laura; Ivanović-Burmazović, Ivana & Winter, Rainer F.
