Rotaxanes and pseudorotaxanes with Fe-, Pd- and Pt-containing axles. Molecular motion in the solid state and aggregation in solution

Abstract

This article reviews our recent studies on structure and properties of rotaxanes and pseudorotaxanes with Fe-, Pd- and Pt-containing complexes as the axle component. Electrochemical oxidation of ferrocenylmethylamine in the presence of a hydrogen radical precursor induces formal protonation of the amino group and produces a pseudorotaxane of the resulting ammonium species with a crown ether. Single crystals of the ferrocene-containing pseudorotaxane undergo a thermal crystalline phase transition accompanied by changes in the optical properties of the crystals. X-Ray crystallographic studies of the low- and high-temperature phases revealed different intermolecular interactions and orientations of the aromatic rings in the crystalline state depending on the temperature. End-capping of the ferrocene-containing [2]pseudorotaxane using a cross-metathesis reaction yields [2]rotaxane under mild conditions. A rotaxane having a platinum-carboxylate complex as its axle is converted into related organic and inorganic rotaxanes by partial dissociation of the Pt-O bond. An N-alkylbipyridinium forms [3]pseudorotaxane with alpha-cyclodextrin (alpha-CD), and it reacts with platinum and palladium complexes to form the corresponding [5]rotaxanes containing four alpha-cyclodextrin moieties. Complexes without alpha-CD components form micelles in aqueous solution, while the addition of alpha-CD causes degradation of the micelles and the formation of rotaxanes.

Highly Efficient Deep Blue Phosphorescent OLEDs Based on Tetradentate Pt(II) Complexes Containing Adamantyl Spacer Groups

“…The dissolved spectra were much broader than the corresponding solid‐state spectra, which may be attributed to greater intermolecular interactions and vibronic motion of molecules in solution. [ 52 ] The largest difference between the PL spectra of the dissolved and solid states was observed with Pt‐R. This indicates that adamantyl groups suppress intermolecular interactions even in the dissolved state.…”

Strategies and Tactics for the Metal‐Directed Synthesis of Rotaxanes, Knots, Catenanes, and Higher Order Links

“…[210] Takata and co-workers have shown that 1ferrocene carboxylate is an excellent moiety for assembling [2]rotaxanes comprised of a crown ether macrocycle and alkylammonium threads. [211] Osakada et al have prepared related [2]-and [3]rotaxanes making use of cross-alkene metathesis to install the stopper groups [206,212] and Beer et al have used bulky ferrocence derivatives to prepare surfaceassembled rotaxane sensors, such as 156-Fe II (Scheme 55). [213] Axially-coordinated porphyrin-like (e.g.…”

Strategien und Taktiken für die metallgesteuerte Synthese von Rotaxanen, Knoten, Catenanen und Verschlingungen höherer Ordnung

“…[210] Takata und Mitarbeiter zeigten, dass 1-Ferrocencarboxylat ein hervorragender Baustein zum Aufbau von [2]Rotaxanen ist, die aus einen Kronenether-Makrocyclus und Alkylammoniumsträngen bestehen. [211] Osakada et al stellten ähnliche [2]-und [3]Rotaxane her, indem sie zum Einbau der Stoppergruppen Kreuzmetathesen von Alkenen einsetzten, [206,212] 56 b). [216] Die Labilität der koordinativen Metall-LigandBindungen ermçglichte die Bildung der Rotaxane unter thermodynamischer Kontrolle bei Raumtemperatur.…”

“…[210] Takata und Mitarbeiter zeigten, dass 1-Ferrocencarboxylat ein hervorragender Baustein zum Aufbau von [2]Rotaxanen ist, die aus einen Kronenether-Makrocyclus und Alkylammoniumsträngen bestehen. [211] Osakada et al stellten ähnliche [2]-und [3]Rotaxane her, indem sie zum Einbau der Stoppergruppen Kreuzmetathesen von Alkenen einsetzten, [206,212] [203] ierten Pyridinstrangs an einen Ru II -Metalloporphyrinkomplex zur Bildung des [2]Rotaxans 157-Ru II , mit dem Ziel, photochemische Ladungsübertragungen zwischen den Chromophoren zu untersuchen (Schema 56 a). [215] Die Gruppen von Gunter und Sanders verschlossen ein [2]Pseudorotaxan bestehend aus einem pyridylterminierten Naphthodiimidstrang umgeben von einem Kronenether-Makrocyclus mit verschiedenen Metalloporphyrinen und bildeten so die [2]Rotaxane 158-M (M = Zn II , Ru II und Rh III ) (Schema 56 b).…”