Synthesis, Structural Analysis, and Properties of [8]Circulenes

Feng, Chieh Ning; Kuo, Ming Yu; Wu, Yao Ting

doi:10.1002/anie.201303875

Cited by 199 publications

(133 citation statements)

References 37 publications

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“…[8]circulene ([8]C) 30 , tetraoxa [8]circulene (4O [8]C) 31 and tetrathio [8]circulenes 20 have been synthesized and their X-ray structural data are available in literature. Several theoretical research groups reported 14-18, 20, 22, 32 structures and properties of these [8]circulenes using the B3LYP functional and similar basis sets considered herein and results are in accordance with experimental findings.…”

Section: Resultsmentioning

confidence: 99%

Structure and Properties of [8]BN-Circulenes: Inorganic Analogues of [8]Circulenes

2015

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Structure and properties of [8]BN-circulenes are calculated using density functional theory (DFT) and time-dependent DFT (TD-DFT). Structurally they are similar to [8]circulenes, but exhibit different electronic and optical properties. For example, carbon circulenes emit in the visible region while BN-circulenes exhibit higher emission energies which fall in the UV-region. Tuning of molecular properties was examined by derivatization of [8]BN-circulenes, analogous to that in tetraoxa-and tetrathioderivatives. Such materials may be used in optical devices and serve as an alternative to organic light emitting devices (OLEDs). Absorption in the UV-region by [8]BNcirculenes suggests that such compounds may be an excellent candidate for UV-light protection.

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Section: Resultsmentioning

confidence: 99%

Structure and Properties of [8]BN-Circulenes: Inorganic Analogues of [8]Circulenes

2015

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“…10). 132 Octaaryl- [8]circulene 44 could be obtained in remarkable 60-75% yields, corresponding to B88-93% for each annulation step, allowing the preparation of several hundred milligrams of 44.…”

Section: Synthesis Of Graphene Moleculesmentioning

confidence: 99%

New advances in nanographene chemistry

et al. 2015

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Nanographenes, or extended polycyclic aromatic hydrocarbons, have been attracting renewed and more widespread attention since the first experimental demonstration of graphene in 2004. However, the atomically precise fabrication of nanographenes has thus far been achieved only through synthetic organic chemistry. The precise synthesis of quasi-zero-dimensional nanographenes, i.e. graphene molecules, has witnessed rapid developments over the past few years, and these developments can be summarized in four categories: (1) non-conventional methods, (2) structures incorporating seven- or eight-membered rings, (3) selective heteroatom doping, and (4) direct edge functionalization. On the other hand, one-dimensional extension of the graphene molecules leads to the formation of graphene nanoribbons (GNRs) with high aspect ratios. The synthesis of structurally well-defined GNRs has been achieved by extending nanographene synthesis to longitudinally extended polymeric systems. Access to GNRs thus becomes possible through the solution-mediated or surface-assisted cyclodehydrogenation, or "graphitization," of tailor-made polyphenylene precursors. In this review, we describe recent progress in the "bottom-up" chemical syntheses of structurally well-defined nanographenes, namely graphene molecules and GNRs.

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“…For instance, [8]circulene 5 H , which was synthesized as late as in 2013, 9 was studied in detail by quantum chemical methods at different levels of theory 40 ± 42 10 years prior to its successful synthesis, and the calculated shape and structural parameters proved to be consistent with the X-ray diffraction data 9 (circulene 5 H is a simpler analogue of compounds 5 containing no methyl and aryl substituents, the cyclic structure of which was correctly predicted to have a saddle-shaped form with D 2d symmetry). 40 ± 42 The structure and some energy properties of quadrannulene 4 were also predicted 43 shortly before the first synthesis 8 of this bowl-shaped representative of benzocirculenes in 2010.…”

Section: Iv1 Hypothetical Heterocirculenesmentioning

confidence: 99%