• Palladium catalysed C-H arylation of pyrenes: access to a new class of exfoliating agents for water-based graphene dispersions.

      Just-Baringo, Xavier; orcid: 0000-0003-2182-5960; Shin, Yuyoung; orcid: 0000-0003-4359-5406; Panigrahi, Adyasha; Zarattini, Marco; Nagyte, Vaiva; orcid: 0000-0003-0835-6039; Zhao, Ling; Kostarelos, Kostas; orcid: 0000-0002-2224-6672; Casiraghi, Cinzia; orcid: 0000-0001-7185-0377; Larrosa, Igor; orcid: 0000-0002-5391-7424 (2020-01-28)
      A new and diverse family of pyrene derivatives was synthesised <i>via</i> palladium-catalysed C-H <i>ortho</i>-arylation of pyrene-1-carboxylic acid. The strategy affords easy access to a broad scope of 2-substituted and 1,2-disubstituted pyrenes. The C1-substituent can be easily transformed into carboxylic acid, iodide, alkynyl, aryl or alkyl functionalities. This approach gives access to arylated pyrene ammonium salts, which outperformed their non-arylated parent compound during aqueous Liquid Phase Exfoliation (LPE) of graphite and compare favourably to state-of-the-art sodium pyrene-1-sulfonate <b>PS1</b>. This allowed the production of concentrated and stable suspensions of graphene flakes in water.