“Broken-hearted” carbon bowl via electron shuttle reaction: energetics and electron coupling

Abstract

Unprecedented one-step C=C bond cleavage leading to opening of the π-bowl, that could provide access to carbon-rich structures with previously inaccessible topologies, is reported; highlighting the possibility to implement drastically...

Tetrathienyl Corannulene Compounds with Highly Sensitive Photochromism

“…Corannulene, [24–29] known as a substructure of buckminsterfullerene C 60 , is a bowl‐like curved aromatic compound with a relatively large ϵ value in the order of 10 4 , large HOMO–LUMO gap, geometrical and electronical anisotropy, [28,30,31] characteristic bowl‐to‐bowl interconversion, [32–34] and chemical reactivity, [35–37] which are different from those of typical planar aromatic compounds. Its aromaticity has been typically explained in terms of the annulene‐within‐an‐annulene model [27] with some discussion [38] .…”

“…For example, some of the diarylethene derivatives undergo inefficient or no photocyclization possibly due to quenching through intramolecular energy transfer, [20][21][22] or decreasing the excitation density at the central hexatriene unit. [23] Corannulene, [24][25][26][27][28][29] known as a substructure of buckminsterfullerene C 60 , is a bowl-like curved aromatic compound with a relatively large ɛ value in the order of 10 4 , large HOMO-LUMO gap, geometrical and electronical anisotropy, [28,30,31] characteristic bowl-to-bowl interconversion, [32][33][34] and chemical reactivity, [35][36][37] which are different from those of typical planar aromatic compounds. Its aromaticity has been typically explained in terms of the annulene-within-an-annulene model [27] with some discussion.…”

Aromatic C–C Bond Cleavage in a Curved π-System of Aminocorannulene

“…Shustova et al recently reported the one-step C−C bond cleavage in corannulene in the solid state at 200 °C, using zinc and a redox mediator in the presence of acid (Scheme 1). 34 Herein, we report an aromatic C−C bond cleavage in corannulene under relatively mild, catalyst-free conditions that effectively planarize the π-bowl structure to an "open" corannulene analogue. The coupling of 1-aminocorannulene and hydrazonyl chloride offers a direct access to a 1,2,4triazole-linked benzo[ghi]fluoranthene derivative (Scheme 1), manifesting the possibility of the controlled metal-and oxidant-free aromatic C−C bond cleavages.…”

Modular Synthesis of a Semibuckminsterfullerene

“…3−7 The interest in these curved molecules is derived from their optoelectronic, structural, and electron transport properties. 8,9 The presence of one or more five-membered or seven-membered rings prevents the molecules from being planar and induces the strain that renders their syntheses challenging and largely in the purview of specialists. Our aim is to develop a convenient, flexible approach to the synthesis of these compounds that will render them available on scale without the need for unusual reagents or other challenging experimental conditions (e.g., flash vacuum pyrolysis (FVP)).…”

“…In 1966 Barth and Lawton reported the first synthesis and characterization of corannulene 1 , a geodesic polyaromatic hydrocarbon. , The 17-step linear synthesis marked the beginning of a field that has burgeoned and that now encompasses geodesic hydrocarbons that are cylindrical, helical, saddle-shaped, bowl-shaped, or spherical. − The interest in these curved molecules is derived from their optoelectronic, structural, and electron transport properties. , The presence of one or more five-membered or seven-membered rings prevents the molecules from being planar and induces the strain that renders their syntheses challenging and largely in the purview of specialists. Our aim is to develop a convenient, flexible approach to the synthesis of these compounds that will render them available on scale without the need for unusual reagents or other challenging experimental conditions (e.g., flash vacuum pyrolysis (FVP)).…”