Assembly of Dendrimers with Redox‐Active [{CpFe(μ3‐CO)}4] Clusters at the Periphery and Their Application to Oxo‐Anion and Adenosine‐5′‐Triphosphate Sensing

9, 16, or 27 [CpFe(μ3-CO)]4 clusters contain the title assemblies (see picture). The one-electron oxidation Fe4→Fe4+ of all Fe4 units appears as a single reversible cyclic voltammetry wave and was used in solution and with dendrimer-modified electrodes for oxo-anion recognition. ATP2− is selectively recognized and better than H2PO4−. The larger the dendrimer, the easier is the re-use of the modified electrode sensor.