Tris(tetraceno)triquinacenes: Synthesis and Photophysical Properties of Threefold Linearly Extended Tribenzotriquinacenes

Abstract

The linear extension of the rigid, C(3v)-symmetrical carbon framework of tribenzotriquinacene (TBTQ) along its three wings is reported. The key step of the extension procedure consists of a Diels-Alder reaction of three ortho-quinodimethane units generated in situ at the triquinacene core. The use of 1,4-naphthoquinone provides a facile and particularly efficient access to tris(tetraceno)-annellated triquinacenes. The steady-state photophysical properties of these new oligotetracenes bearing three mutually orthogonal chomophores are determined and analyzed by DFT calculations.

Versatile Syntheses of Hemi‐Cryptophanes and a Metallo‐Cryptophane from a Hexa‐Functionalized C3v‐Symmetrical Tribenzotriquinacene (TBTQ) Derivative

“…Reagents bearing a1 ,3-difunctionalized arene unit were extensively used in nucleophilic reactions and selected here as bridging entities between two indanew ings of 2a to reduce the number of reactive functionalities to three. [20] This approach was demonstrated recently by Hardie et al,w ho utilized methyl 3,benzoate as ab uilding block for spanning three bridges between the pairs of catechol units of cyclotricatechylene. [8i] In our first example, methyl 3,5-dihydroxybenzoate (6)w as selected as bridging units between the three pairs of benzene rings of hexakis(chloromethyl)-TBTQ 2a to synthesize at ricarboxylic acid ligand 8 for metal-mediated self-assembly (Scheme 1).…”

“…[18] Herein, we wish to report that the same hexakis(chloromethyl)-TBTQ compound 2a could be conveniently converted into an umber of TBTQ-based cavitands by incorporating 5-functionalized resorcinol bridges between the three indane wings. [20] In subsequent steps, ac admium-coordinating metallo-cryptophane, 9, and two TBTQ-based hemicryptophanes, 12 and 15,w ere accessiblei nt wo or three steps and good overall yields (15-32 %). Given that three different types of chemical transformation (S N 2a lkylation,r eductive amination and metal-carboxylate formation)i nvolved in the penultimate cage formation steps all proceeded in good yields, the high efficiency of these transformationsmay be attributable to the unique structural feature of the TBTQ skeleton.…”

Tribenzotriquinacene‐Based Triscyclophanes: Intra‐ and Inter‐Wing C3v‐Symmetrical Extension of the Bowl‐Shaped Tribenzotriquinacene Core

“…Sixfold chloromethylation of the aromatic nuclei of the tribenzotriquinacenes13c was found to be a key step to various C 3 v ‐symmetrical extension strategies 19,21,32. In this study, the readily accessible sixfold chloromethylated 12d‐methyl‐4b,8b,12b‐tri( n ‐propyl)tribenzotriquinacene 7 19 was used as the starting material in most cases (Schemes and ).…”

“…The C 3 v ‐symmetrical, bowl‐shaped structure11,12 and the “Cartesian” geometry1b of the TBTQ scaffold and the diverse and well controllable chemical reactivity of the TBTQ hydrocarbons [1,4,11,13,14] enables a large range of intriguing extensions, which may lead to novel applications as nanoscaled building blocks and supramolecular hosts. [1a,3a,3c,15–18] In recent years, extension of the TBTQ skeleton has mainly been focused on the elongation and enlargement of the three indane wings 19–21. For example, threefold linear extension of the three independent aromatic π‐electron systems by using various condensation [4a,13a,13c,13g,15–18,19] and Diels–Alder methodologies20,21 have been pursued to enlarge the convex‐concave surface of the TBTQ core.…”

“…[1a,3a,3c,15–18] In recent years, extension of the TBTQ skeleton has mainly been focused on the elongation and enlargement of the three indane wings 19–21. For example, threefold linear extension of the three independent aromatic π‐electron systems by using various condensation [4a,13a,13c,13g,15–18,19] and Diels–Alder methodologies20,21 have been pursued to enlarge the convex‐concave surface of the TBTQ core. Among these motifs, the globular, “all‐concave” assembly of four or eight TBTQ units, first suggested by us in 2006,1a is particularly challenging.…”