Synthesis and Properties of Carbon Nanostructures

Carbon nanostructures encompass a diverse family of molecular and supramolecular architectures built from sp²-hybridised carbon units. Their synthesis often relies on precise bottom-up organic methodologies, including metal-mediated couplings, Z-selective Wittig reactions and macrocyclisation strategies, to overcome ring strain and achieve defined topologies. Representative targets range from cyclic nanohoops and nanobelts to atomically precise nanotube segments and heteroatom-bridged belts. These constructs display remarkable electronic delocalisation arising from extensive π-conjugation, imparting tunable optical absorption, redox behaviour and charge-transport characteristics. Topological variations—such as Möbius twists or catenation—add chiral properties and dynamic conformational behaviour. Functional modifications, including peripheral substituents or heteroatom doping, tailor host–guest recognition, adsorption phenomena and catalytic activity. Collectively, advances in precision synthesis have unlocked bespoke carbon scaffolds for applications in molecular electronics, energy conversion, sensing and nanomechanical systems, underscoring their global significance in materials science.

Research from Nature Portfolio

Recent studies have demonstrated the synthesis of highly strained cyclic conjugated systems through innovative macrocyclic precursors. A dodecamethoxy[6]cycloparaphenylene derivative was prepared via a gold-templated coupling strategy, revealing enhanced oxidation potentials and the emergence of in-plane aromaticity upon two-electron oxidation. This work enabled the first rotaxane assembly exploiting the cyclic cavity, highlighting mechanical interlocking as a tool to probe aromatic currents. Building on this, the first Möbius carbon nanobelt was isolated through an odd-unit macrocycle design followed by nickel-mediated homocoupling. The resulting band exhibited rapid topological twist motion in solution and manifested chiral separation by circular dichroism, marking a milestone in translating mathematical topology into stable molecular form. Complementing these reports, atomically precise nitrogen-doped nanotube molecules have been synthesised by coupling pyridine and benzene building blocks within a geodesic framework. Crystallographic and multipole analyses revealed discrete atom‐vacancy defects and electronically distinct surfaces that lower unoccupied orbital levels, offering potential sites for selective electron injection in nanoelectronic devices.

Synthesis and Properties of Carbon Nanostructures publication trend

The graph below shows the total number of articles in synthesis and properties of carbon nanostructures across all publications each year (not limited to Nature Index journals).

Technical terms

Cycloparaphenylenes (CPPs): Radial π-conjugated macrocycles composed of para-linked phenylene units.

π-Conjugation: Delocalisation of π-electrons across adjacent sp² carbons, enhancing electronic and optical properties.

Möbius topology: A single-sided twist in a cyclic π-system imparting topological chirality and dynamic conformations.

Carbon nanobelt: A belt-shaped aromatic macrocycle with a closed ribbon of fused aromatic rings.

Nitrogen doping: Incorporation of pyridinic nitrogen atoms into the carbon framework to modulate electronic energy levels and reactivity.

References

1. A dodecamethoxy[6]cycloparaphenylene consisting entirely of hydroquinone ethers: unveiling in-plane aromaticity through a rotaxane structure. Nature Communications (2023).
2. Synthesis of a Möbius carbon nanobelt. Nature Synthesis (2022).
3. A nitrogen-doped nanotube molecule with atom vacancy defects. Nature Communications (2020).
4. Photoinduced Electron Transfer in Inclusion Complexes of Carbon Nanohoops. Accounts of Chemical Research (2023).
5. Towards pi-extended cycloparaphenylenes as seeds for CNT growth: investigating strain relieving ring-openings and rearrangements. Chemical Science (2016).
6. Cycloparaphenylene as a molecular porous carbon solid with uniform pores exhibiting adsorption-induced softness. Chemical Science (2016).