Redox-controlled potassium intercalation into two polyaromatic hydrocarbon solids



Denis Romero, F, Pitcher, MJ ORCID: 0000-0003-2044-6774, Hiley, CI, Whitehead, GFS, Kar, S, Ganin, AY, Antypov, D ORCID: 0000-0003-1893-7785, Collins, C ORCID: 0000-0002-0101-4426, Dyer, MS ORCID: 0000-0002-4923-3003, Klupp, G
et al (show 3 more authors) (2017) Redox-controlled potassium intercalation into two polyaromatic hydrocarbon solids. Nature Chemistry, 9 (7). pp. 644-652.

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Abstract

Alkali metal intercalation into polyaromatic hydrocarbons (PAHs) has been studied intensely after reports of superconductivity in a number of potassium- and rubidium-intercalated materials. There are, however, no reported crystal structures to inform our understanding of the chemistry and physics because of the complex reactivity of PAHs with strong reducing agents at high temperature. Here we present the synthesis of crystalline K2Pentacene and K2Picene by a solid–solid insertion protocol that uses potassium hydride as a redox-controlled reducing agent to access the PAH dianions, and so enables the determination of their crystal structures. In both cases, the inserted cations expand the parent herringbone packings by reorienting the molecular anions to create multiple potassium sites within initially dense molecular layers, and thus interact with the PAH anion π systems. The synthetic and crystal chemistry of alkali metal intercalation into PAHs differs from that into fullerenes and graphite, in which the cation sites are pre-defined by the host structure.

Item Type: Article
Additional Information: Alkali metal intercalation into polyaromatic hydrocarbons (PAHs) has been studied intensely after reports of superconductivity in a number of potassium- and rubidium-intercalated materials. There are, however, no reported crystal structures to inform our understanding of the chemistry and physics because of the complex reactivity of PAHs with strong reducing agents at high temperature. Here we present the synthesis of crystalline K2Pentacene and K2Picene by a solid–solid insertion protocol that uses potassium hydride as a redox-controlled reducing agent to access the PAH dianions, and so enables the determination of their crystal structures. In both cases, the inserted cations expand the parent herringbone packings by reorienting the molecular anions to create multiple potassium sites within initially dense molecular layers, and thus interact with the PAH anion π systems. The synthetic and crystal chemistry of alkali metal intercalation into PAHs differs from that into fullerenes and graphite, in which the cation sites are pre-defined by the host structure.
Depositing User: Symplectic Admin
Date Deposited: 15 May 2017 08:31
Last Modified: 19 Jan 2023 07:04
DOI: 10.1038/NCHEM.2765
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3007460