biostudies-literatureUnknown14(2)Liu WCWe describe a novel gold chloride complex supported by an ambiphilic phosphine/xanthylium ligand in which the AuCl moiety interacts with the π⁺ surface of the xanthylium unit as indicated by structural studies. Energy decomposition analyses carried out on a model system indicates the prevalence of non-covalent interactions in which the electrostatic and dispersion terms cumulatively dominate. The presence of these AuCl-π⁺ interactions correlates with the high catalytic activity of this complex in the cyclisation of 2-(phenylethynyl)phenylboronic acid, <i>N</i>-propargyl-<i>t</i>-butylamide, and 2-allyl-2-(2-propynyl)malonate. Comparison with the significantly less active acridinium and the 9-oxa-10-boraanthracene analogues reinforces this conclusion.Chemical science277-283https://www.ebi.ac.uk/biostudies/studies/S-EPMC9811580biostudies-literaturePlacing gold on a π⁺-surface: ligand design and impact on reactivity.PMC9811580Liu WCGabbai FPfalsePlacing gold on a π⁺-surface: ligand design and impact on reactivity.We describe a novel gold chloride complex supported by an ambiphilic phosphine/xanthylium ligand in which the AuCl moiety interacts with the π⁺ surface of the xanthylium unit as indicated by structural studies. Energy decomposition analyses carried out on a model system indicates the prevalence of non-covalent interactions in which the electrostatic and dispersion terms cumulatively dominate. The presence of these AuCl-π⁺ interactions correlates with the high catalytic activity of this complex in the cyclisation of 2-(phenylethynyl)phenylboronic acid, <i>N</i>-propargyl-<i>t</i>-butylamide, and 2-allyl-2-(2-propynyl)malonate. Comparison with the significantly less active acridinium and the 9-oxa-10-boraanthracene analogues reinforces this conclusion.2023-01-01T00:00:00Z2023 Jan2025-04-04T14:27:21.174Z2025-04-04T14:27:21.174ZS-EPMC98115803668735810.1039/d2sc05574k