Themed collection Challenges in Aromaticity: 150 Years after Kekulé’s Benzene

Guest editors Nazario Martín and Lawrence T. Scott introduce the Challenges in Aromaticity: 150 years after Kekulé's benzene issue of Chemical Society Reviews

This review discusses recent advancements in nanographene chemistry, focusing on the bottom-up synthesis of graphene molecules and graphene nanoribbons.

Recent advances in experimental and theoretical studies of carbo-benzene derivatives, along with the proposition of a generalization of the definition of aromaticity to the two-membered π-rings of triple bonds, suggest relevance for the notion of “carbo-aromaticity”.

This review illustrates recent advances in extending aromaticity/antiaromaticity concepts to inorganic and all-metal rings in order to account for their electronic structure and stability.

A review summarizing recent advances in magnetic criteria for identification and evaluation of aromaticity.

Big, bigger, biggest. This Review puts the spotlight on the handful of PAHs with four or more rings that have been incorporated into cyclophanes. Lessons in synthesis, structure, fundamental concepts and properties abound in these remarkable molecules that feature PAHs ranging in size from pyrene to hexabenzocoronene.

Pro-aromatic and anti-aromatic π-conjugated molecules are demonstrated to have an irresistible wish to be diradicals in the ground state.

Baird's rule tells that benzene is an antiaromatic “Mr Hyde” in its lowest excited states, explaining many photoreactions of benzene derivatives.

Theoretical and experimental aspects of kekulene and its benzenoid, non-benzenoid and non-alternant type congeners are reviewed.

Aromaticity descriptors based on the quantification of electron delocalization are all-round indicators that outperform most of the classical structural- and magnetic-based indices.

Reactions that form new σ-bonds to interior carbon atoms of polycyclic aromatic hydrocarbons were unknown before the fullerene era.

In this review, we focus on the aromaticity of a particular family of organometallic compounds known as metallabenzenes, which are characterized by the formal replacement of a CH group in benzene by an isolobal transition metal fragment.

A tutorial review describing kekulene and other cycloarenes, their synthesis, and the fundamental concepts of aromaticity they taught.

A concise tutorial review on the basic concepts of π–π interactions involving fullerenes, carbon nanotubes, and graphene.

π-Expanded oligothiophene macrocycles show electronic, optical, and optoelectronic properties as well as unique supramolecular self-assembly and morphological changes.

A collection of data and discussion on the optical, electronic, and solid-state structure of [5]–[12]cycloparaphenylene.