Tubularenes

Abstract

We report the synthesis and characterization of conjugated, conformationally rigid, and electroactive carbon-based nanotubes that we term tubularenes. These structures are constructed from a resorcin[nb]arene base. Cyclization of the conjugated...

Conjugated Molecular Nanotubes

“…However, due to tubularene's rigidity, only four phenyl rings are able to rotate, although at a significantly high rotational barrier of ~29 kcal/mol. [85] This tubular rigidity is well observed in the 1 H NMR of 12 and 13, and also leads to larger SEs in the order of 90 and 81 kcal/mol for 12 and 13, respectively, in comparison to [8]CPP nearing 72 kcal/mol. [31] Aside from its X-ray molecular crystal structure confirming its rigid tubular structure, tubularenes 12 and 13 display rich electrochemistry with four reduction events from around À 2.0 to À 2.7 V vs Fc/Fc + .…”

“…The top rim of 12 resembles the structure of [8]CPP. However, due to tubularene's rigidity, only four phenyl rings are able to rotate, although at a significantly high rotational barrier of ∼29 kcal/mol [85] . This tubular rigidity is well observed in the 1 H NMR of 12 and 13 , and also leads to larger SEs in the order of 90 and 81 kcal/mol for 12 and 13 , respectively, in comparison to [8]CPP nearing 72 kcal/mol [31] .…”

“…Our group recently developed a general method to obtain highly strained CMTs thorugh a templated approach using resorcin[n b ]arenes. [85] These have been termed tubular[n b ,n,m,r] arenes (tubularenes for short), where n b , n, m, and r stand for the basal template (resorcin[n b ]arene parent), the CNT chiral indices (n,m), and the number of aromatic rings making up the upper nanoring (r), respectively. Tubularenes are synthesized through a bottom-up methodology in just a few steps.…”

Radially Oriented [n]Cyclo-meta-phenylenes

“…Recently, our group reported the synthesis of tubularenes by following an approach that facilitates the formation of the strained aromatic, the bottleneck step, in a one-pot eight-fold C–C bond formation via Suzuki–Miyaura cross-coupling reaction (Figure b) . The upper rim of our previous tubularenes follows an armchair CNT geometry.…”

Synthesis of Finite Molecular Nanotubes by Connecting Axially Functionalized Macrocycles

“…[9][10][11][12][13][14][15][16][17] One-dimensional hollow nanostructures feature confined tubular space and anisotropic properties, representing an emerging category of artificial materials with increasing functions and applications during the past decades. [18][19][20][21][22][23][24][25][26][27][28][29][30] With a number of noteworthy exceptions, [9][10][11][12][13][14][15][16][17][31][32][33][34][35][36][37] (metallo)organic nanotubes are mostly obtained through selfassembly via non-covalent interactions such as hydrogen bonds and/or - interactions. [38][39][40][41][42][43][44][45][46][47]…”