A 3:1 site-differentiated [4Fe-4S] cluster is immobilized on a thiol-functionalized self-assembled monolayer (SAM) on Au(111) by thiol−thiolate exchange chemistry. Fe 2p signals observed by X-ray photoelectron spectroscopy support the presence of [4Fe-4S] clusters at the SAM surface; further evidence comes from the detection of n-Bu4N+ and cluster-derived species by secondary-ion mass spectrometry. The immobilizing interaction is sufficiently strong to allow the study of [4Fe-4S] clusters at solid−liquid interfaces.
