Solid‐State Pyrolysis of Polyphenylene–Metal Complexes: A Facile Approach Toward Carbon Nanoparticles

Abstract

Novel polyphenylene–metal complexes with discotic, linear, and dendritic geometries are synthesized by using a facile approach consisting of reactions between Co2(CO)8 and ethynyl functionalities in dichloromethane. Various carbon nanoparticles (CNPs), including graphitic carbon nanotubes (CNTs), graphitic carbon rods, and carbon–metal hybrid particles are obtained from the solid‐state pyrolysis of these complexes. The ultimate structures of the CNPs are found to be dependant on the structure and composition of the starting compounds. Precursors containing graphenes always result in graphitic CNTs in high yield, whereas dendritic precursors give rodlike carbon materials. Alternatively, linear oligo(arylethylene) precursors afford mostly carbon–metal hybrids with large amounts of amorphous carbon. Furthermore, the CNP structures could be controlled by adjusting the carbon/metal ratio, the type and position of the metal incorporated into the precursor, and the mode of pyrolysis. These results provide further chances toward understanding the mechanism of CNP formation.

Propellers and Planes: Phosphorescent PtII σ‐Acetylides from Polyaromatic Ligands

“…[1] Their propeller-like polyphenylene precursors have also attracted attention in dendrimer research and as supramolecular hosts to a variety of guest molecules. [2] Given the scarcity of organometallic HBC derivatives [3,4] and the well-documented improvement in the phosphorescence quantum yields of π-conjugated organic materials on incorporating heavy metal centres, [5][6][7] this article details the preparation, photophysical and electrochemical investigation of two new polyaromatic ligands and their Pt II σ-acetylide complexes. The work builds on just three known compounds that couple one HBC platform to a Pt II metal centre.…”

“…The work builds on just three known compounds that couple one HBC platform to a Pt II metal centre. [3] These exhibit enhanced singlet-triplet mixing due to the spin-orbit coupling of the metal centre and a propensity to aggregate in solution and the solid-state. The increased steric bulk and additional geometric complexity of attaching two HBC platforms to one Pt II centre was a synthetic challenge, which might enable a more in-depth study of aspects of the chemistry of HBC-related complexes.…”

Synthesis and Solid-State Pyrolysis Behavior of POSS Containing Organometallic Polymer with Dicobalt Hexacarbonyl in the Side Chain

“…In the SSP process, the pyrolysis program has a significant influence on the structure of the obtained carbon nanoparticles (CNPs) [42][43][44]. Generally, the samples would suffer a stepwise thermolysis: they were first heated to their decomposition temperature of the metal carbonyl groups and held at this temperature for several hours, then heated to a higher temperature and held there for another several hours.…”

Nanostrukturierte Kohlenstoffmaterialien aus molekularen Vorstufen

“…[190] In einer umfangreichen Studie synthetisierten Müllen und Mitarbeiter eine Vielzahl von Übergangsmetall-komplexen kohlenstoffreicher Vorstufenmoleküle -wie HBC-Derivaten, Hexaphenylbenzolderivaten, Thiophenderivaten, großen PAKs und auch linearen oder sternförmigen Oligo(phenylenethinylenen) -und variierten bei der entsprechenden Pyrolyse die Temperatur. [191] Alle mit Cobalt komplexierten PAKs bildeten unter den Pyrolysebedingungen mehrwandige CNTs, wobei sich die Ausbeute über den Cobalt-Gehalt steuern ließ. Wurden die PAKs mit einer ähnlichen Ruthenium-haltigen Verbindung komplexiert und pyrolysiert, so bildeten sich ausschließlich Kohlenstoff-Nanostäbchen.…”

“…So bildeten sich aus verzweigtem 1,3,5-Tris(phenylethinyl)benzol bei der Pyrolyse bei 700 8C kugelförmige Kohlenstoffmaterialien, während bei Erhöhung der Pyrolysetemperatur auf 850 8C Stäbchen erhalten wurden. [191] …”