C_3v-Symmetrical Tribenzotriquinacenes as Hosts for C₆₀ and C₇₀ in Solution and in the Solid State

Abstract

Various tribenzotriquinacenes (TBTQs), most of which incorporate six functional groups at the periphery of their C3v-symmetrical, rigid and convex-concave molecular framework, have been studied with respect to their ability to form supramolecular complexes with the C60 and C70 fullerenes, either in the solid state or in solution. The hexabromo derivative Br6-TBTQ was cocrystallized with C60 as [Br6-TBTQ<C60 x toluene] but, as studied by UV/vis and (1)H NMR spectroscopy, aggregation in benzene, toluene, or carbon disulfide solutions was not observed. Likewise, in contrast to the related C5v-symmetrical decakis(alkylthio)corannulenes, neither the parent hydrocarbon, nor a related hexamethoxy, or two hexakis(alkylthio) derivatives exhibited color, or complexation-induced chemical shift (CIS) changes with C60 or C70. The novel tris(2,3-thianthreno)triquinacene (o-S2C6H4)3-TBTQ, a TBTQ derivative extended by three 1,2-benzodithiino wings, and synthesized from Br6-TBTQ, was found to form 1:1 complexes with C60 and C70 in both benzene and toluene solutions. Association constants were determined for the respective complexes, viz. (o-S2C6H4)3-TBTQ<C60 (K(assoc) = 977 +/- 56) and (o-S2C6H4)3-TBTQ<C70 (463 +/- 49, both in benzene). The X-ray single crystal and molecular structures of the pure host and of the aggregates [(o-S2C6H4)3-TBTQ<2 C60 x 2.5 chlorobenzene] were also determined.

Enantiomerically Pure Tribenzotriquinacenes through Stereoselective Synthesis

“…[4][5][6][7] Chemically,t he four bridgehead positions and the six outer positions of the aromatic periphery can be functionalized independently and in various ways and the electronic interaction of the three benzene units is negligible.…”

Tribenzotriquinacenes that Bear Three Peripheral Pentaphenylphenyl Residues: Steric Crowding at a Bowl‐Shaped Core

“…The bowl-shaped polycyclic structure of tribenzotriquinacene [1][2][3] (TBTQ; 1, Figure 1) is an inspiring all-carbon motif that has motivated a number of researchers [4][5][6][7][8][9][10][11][12][13][14][15] since the publication of the first congener, the 12d-methyl-substituted derivative, in 1984. [16] One of the fascinating features of the conformationally rigid, C 3v -symmetrical TBTQ framework [17,18] is the suitability of the three three-dimensional bays for bridging by C 2 -units, such as 1,2-vinylidene and 1,2-phenylene groups (e.g.…”

Tribenzotriquinacenes Based on Regioselective Bis‐formylation: Optical Resolution and Absolute Configuration of Inherently Chiral Derivatives and Synthesis of the First Cyclophane‐Type Tribenzotriquinacene Dimers

“…[4,6] Combined with the large chemical versatility offered by the multiple functionalization of the peripheral positions of their three benzene nuclei, the supramolecular chemistry of TBTQ-based compounds promises to be a rich field of research. Thus, complexes with the C 60 and C 70 fullerenes [8,9] and the introduction of three mutually orthogonally oriented chromophoric groups have been reported recently. [10] In fact, both peripheral three-fold functionalization of the TBTQs, such as in the trinitro derivatives 2 and 3, [11] and six-fold functionalization, such as in Abstract: Enantiomerically pure tribenzotriquinacenes (TBTQs) bearing two monofunctionalized aromatic nuclei were synthesized for the first time and their optical properties and absolute configuration determined.…”