Heterogeneous catalase-like activity of gold(i)–cobalt(iii) metallosupramolecular ionic crystals† †Electronic supplementary information (ESI) available: Molecular structures (Fig. S1 and S2), time profiles of O2 evolution and TOF (Fig. S3–S5 and S9–S12), solubility of [1]Xn (Tables S1 and S2), XPS (Fig. S6), PXRD (Fig. S7), NMR (Fig. S8), catalase-like activity (Table S3), microscopic photos (Fig. S13), energy profiles (Fig. S14 and S15). See DOI: 10.1039/c6sc04993a Click here for additional data file

The heterogeneous catalase-like activity of ionic crystals consisting of AuI 4CoIII 2 complex cations is studied along with their surface morphologies and oxidation states.
Unique heterogeneous catalase-like activity was observed for metallosupramolecular ionic crystals [AuI 4CoIII 2(dppe)2(d-pen)4]Xn ([1]Xn; dppe = 1,2-bis(diphenylphosphino)ethane; d-pen = d-penicillaminate; Xn = (Cl–)2, (ClO4 –)2, (NO3 –)2 or SO4 2–) consisting of AuI 4CoIII 2 complex cations, [1]2+, and inorganic anions, X– or X2–. Treatment of the ionic crystals with an aqueous H2O2 solution led to considerable O2 evolution with a high turnover frequency of 1.4 × 105 h–1 for the heterogeneous cobalt complexes, which was dependent on their size and shape as well as the arrangement of cationic and anionic species. These dependencies were rationalized by the presence of cobalt(ii) centers on the crystal surface and their efficient exposure on the (111) plane rather than the (100) plane based on morphological and theoretical studies.