Synthesis of a Giant 222 Carbon Graphite Sheet

Simpson, Christopher D.; Brand, J. D.; Berresheim, Alexander J.; Przybilla, Laurence; Räder, Hans Joachim; Müllen, Kläus

doi:10.1002/1521-3765(20020315)8:6<1424::aid-chem1424>3.0.co;2-z

Cited by 359 publications

(231 citation statements)

References 28 publications

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“…Elemental analysis of 2 could not be obtained, due to incomplete combustion, an artifact of the extremely high thermal stability of the aromatic core of 1. 14 Confirmation of the bidentate nature of the coordination was obtained by comparing the 1 H NMR spectrum of 2 in CDCl 3 with that of the free ligand. The atom-labeling scheme is shown in Scheme 1.…”

Section: Resultsmentioning

confidence: 97%

Complexed Nitrogen Heterosuperbenzene: The Coordinating Properties of a Remarkable Ligand

et al. 2004

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Tetra-peri-(tert-butyl-benzo)-di-peri-(pyrimidino)-coronene 1, the parent compound of the nitrogen heterosuperbenzene family N-HSB, is employed as a novel monotopic ligand in the formation of [Pd(η 3 -C3H5)(1)]PF6 2 and [Ru(bpy)2(1)](PF6)2 (where bpy ) 2,2′-bipyridine 3a and d8-2,2′-bipyridine 3b). These N-coordinated complexes are fully characterized by 1 H NMR and IR spectroscopy and ESI-MS. Metal coordination has a profound effect on both the absorption and the emission properties of 1. Pd(II) coordination causes a red-shift in the low-energy absorptions, a decrease in the intensity of the n-π* absorptions, and a quenching of the emission. Ru(II) coordination causes absorption throughout the visible region and creates two new complexes that join an elite group of compounds known as "black" absorbers. 3a and 3b possess two discernible 1 MLCT bands. The one of exceptionally low energy (λmax ) 615 nm) has an associated 3 MLCT emission (λmax ) 880 nm) due to the unprecedented electron delocalization and acceptor properties of the rigid aromatic N-HSB 1. Both Ru(II) complexes are near-IR emitters with unusually protracted emission lifetimes of 320 ns at 77 K. They are photochemically inert, and their electrochemical properties are consistent with the presence of a low-lying π* orbital on 1. The first two reversible reductions (E1/2 (CH3CN), -0.54 V, -1.01 V vs SCE) are due to the stepwise reduction of 1 and are anodically shifted as compared to [Ru(bpy)3] 2+ . Temperature-and concentration-dependent NMR studies on 2 and 3a suggest extensive aggregation is occurring in solution.

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Section: Resultsmentioning

confidence: 97%

Complexed Nitrogen Heterosuperbenzene: The Coordinating Properties of a Remarkable Ligand

et al. 2004

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“…Bottom-up, solution-based synthetic routes for graphene quantum dots (GQDs) are based on Diels-Alder, cyclotrimerization and/or cyclodehydrogenation reactions 12 to control the GN size 13,14 . However, these chemistries fail for more than 100 ringed GQDs [13][14][15][16][17] . This is attributed to the challenge in the synthesis/stabilization of precursors, and to the decrease in solubility of the poly-aromatics in the synthesis solvents 12,18 .…”

mentioning

confidence: 99%

Nanotomy-based production of transferable and dispersible graphene nanostructures of controlled shape and size

et al. 2012

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Because of the edge states and quantum confinement, the shape and size of graphene nanostructures dictate their electrical, optical, magnetic and chemical properties. The current synthesis methods for graphene nanostructures do not produce large quantities of graphene nanostructures that are easily transferable to different substrates/solvents, do not produce graphene nanostructures of different and controlled shapes, or do not allow control of Gn dimensions over a wide range (up to 100 nm). Here we report the production of graphene nanostructures with predetermined shapes (square, rectangle, triangle and ribbon) and controlled dimensions. This is achieved by diamond-edge-induced nanotomy (nanoscalecutting) of graphite into graphite nanoblocks, which are then exfoliated. our results show that the edges of the produced graphene nanostructures are straight and relatively smooth with an I D /I G of 0.22-0.28 and roughness < 1 nm. Further, thin films of Gn-ribbons exhibit a bandgap evolution with width reduction (0, 10 and ~35 meV for 50, 25 and 15 nm, respectively).

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“…68 Nanographene composed of 222 carbon atoms (37 fused benzene rings, Figure 6a), without solubilizing substituents was prepared by oxidation of the precursor polyphenylene using Cu(OTf) 2 and AlCl 3 at 30 1C for 1 day. 69 The product was insoluble due to the lack of side chains, but its structure was confirmed by solid state 13 C NMR and MALDI-TOF.…”

Section: Nanoscale Assembly T Emrick and E Pentzermentioning

confidence: 99%

Nanoscale assembly into extended and continuous structures and hybrid materials

Emrick

Pentzer

2013

NPG Asia Mater

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Harnessing synthetic power to create novel materials with unique assembly properties is of fundamental interest for pushing the limits of molecular and macromolecular assembly, while further holding the potential for improving electronic and medical device performance. Controlling the assembly of aromatic molecules into nanostructures provides routes towards continuous and extended structures with performance that is improved markedly over that of their individual molecular components, opening possibilities for the formation of composites that have tailored interactions with other materials and thus improved applications. This review covers recent advances in the synthesis of conjugated materials, their controlled assembly into nanoscale architectures and implementation into devices. Specifically, we discuss the solution-based assembly of polythiophene into nanowire fibrils, the formation of columnar stacks of hexabenzocoronene liquid crystals and the preparation of functionalized solution processible graphene for nanocomposite formation.

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Synthesis of a Giant 222 Carbon Graphite Sheet

Cited by 359 publications

References 28 publications

Complexed Nitrogen Heterosuperbenzene: The Coordinating Properties of a Remarkable Ligand

Complexed Nitrogen Heterosuperbenzene: The Coordinating Properties of a Remarkable Ligand

Nanotomy-based production of transferable and dispersible graphene nanostructures of controlled shape and size

Nanoscale assembly into extended and continuous structures and hybrid materials

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