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Abstract Within the growing family of strained carbon nanohoops and nanobelts, [10]CPP arguably offers the best compromise between synthetic accessibility and strong binding affinity for C60. In this work, we report the synthesis of two nitrogen-containing analogues of [10]CPP and we systematically compare the structure, optoelectronic properties and C60 binding affinities of this small set of structurally similar macrocycles. While Aza[10]CPP outcompetes the parent compound by approximately one order of magnitude with respect to C60 binding, we found that the reverse was true for the methylaza analogue. Transient absorption studies showed that photo-induced electron transfer occurred readily from [10]CPP and its aza-analogue to an encapsulated C60 guest. Formation of a charge-separated complex was not observed however for the N-methylated derivative. These insights will prove useful for further applications of strained nanohoops in supramolecular chemistry and organic electronics.

Abstract An electron-poor bowl-shaped naphthalimide-annulated corannulene with branched alkyl residues in the imide position was synthesized by a palladium-catalyzed cross-coupling annulation sequence. This dipolar compound exhibits strong absorption in the visible range along with a low-lying LUMO level at –3.85 eV, enabling n-type charge transport in organic thin-film transistors. Furthermore, we processed inverted bulk-heterojunction solar cells in combination with the two donor polymers PCE–10 and PM6 to achieve open-circuit voltages up to 1.04 V. By using a blend of the self-assembled naphthalimide-annulated corannulene and PCE–10, we were able to obtain a power conversion efficiency of up to 2.1%, which is to the best of our knowledge the highest reported value for a corannulene-based organic solar cell to date.

Traditional 'picket fence' porphyrin systems have been a topic of interest for their capacity to direct steric shielding effects selectively to one side of the macrocycle. Sterically overcrowded porphyrin systems that adopt macrocycle deformations have recently drawn attention for their applications in organocatalysis and sensing. Here we explore the combined benefits of nonplanar porphyrins and the old molecular design to bring new concepts to the playing field. The challenging ortho‐positions of meso‐phenyl residues in dodecasubstituted porphyrin systems led us to transition to less hindered para‐ and meta‐sites and develop selective demethylation based on the steric interplay. Isolation of the symmetrical target compound [2,3,7,8,12,13,17,18‐octaethyl‐5,10,15,20‐tetrakis(3,5‐dipivaloyloxyphenyl)porphyrin] was investigated under two synthetic pathways. The obtained insight was used to isolate unsymmetrical [2,3,7,8,12,13,17,18‐octaethyl‐5,10,15,20‐tetrakis(2‐nitro‐5‐pivaloyloxyphenyl)porphyrin]. Upon separation of the atropisomers, a detailed single‐crystal X‐ray crystallographic analysis highlighted intrinsic intermolecular interactions. The nonplanarity of these systems in combination with 'picket fence' motifs provides an important feature in the design of supramolecular ensembles. [ABSTRACT FROM AUTHOR]

The formation of discrete macrocycles wrapped around single‐walled carbon nanotubes (SWCNTs) has recently emerged as an appealing strategy to functionalize these carbon nanomaterials and modify their properties. Here, we demonstrate that the reversible disulfide exchange reaction, which proceeds under mild conditions, can install relatively large amounts of mechanically interlocked disulfide macrocycles on the one‐dimensional nanotubes. Size‐selective functionalization of a mixture of SWCNTs of different diameters were observed, presumably arising from error correction and the presence of relatively rigid, curved π‐systems in the key building blocks. A combination of UV/Vis/NIR, Raman, photoluminescence excitation, and transient absorption spectroscopy indicated that the small (6,4)‐SWCNTs were predominantly functionalized by the small macrocycles 12, whereas the larger (6,5)‐SWCNTs were an ideal match for the larger macrocycles 22. This size selectivity, which was rationalized computationally, could prove useful for the purification of nanotube mixtures, since the disulfide macrocycles can be removed quantitatively under mild reductive conditions. [ABSTRACT FROM AUTHOR]

Macrocycle ligands have three or more donor sites. Selective replacement of skeleton carbon atoms by heteroatoms and vacancies in C60 could lead to various macrocycle ligands with a cage-shaped backbone. Theoretical calculations indicate that such C60-based macrocycle ligands are as stable as C60 thermodynamically according to their similar HOMO-LUMO gaps. The synthesis of these ligands is a challenging task. Nevertheless important progresses have been reported. This concept article focuses on the structures of possible C60-based macrocycle ligands and related synthetic results. [ABSTRACT FROM AUTHOR]

Selective replacement of skeleton carbon atoms in C60 by heteroatoms and vacancies could lead to various macrocycle ligands with a cage ‐ shaped backbone. Theoretical calculations and preliminary experimental results indicate that such C60 ‐ based macrocycle ligands are as stable as C60. This Concept article focuses on their designed structures and related synthetic results, see Y. Li and L. Gan on page 10485 ff. [ABSTRACT FROM AUTHOR]