Synthesis, structure and characterization of Fe6 molecular clusters with peripheral sulfur atom-capped silver nanoparticles.

There are rare reports of high-nuclear transition metal clusters with thiol groups in their periphery. In this work, a novel cluster, [Fe6O2(OH)2(O2CC6H4SCH3)10(hep)2]·CH3CN.CH2Cl2 (Fe6) has been constructed by coordinating an octahedral Fe(III) ion with 4-mercaptobenzoate and hepH (hepH = 2-(2-hydroxyethyl) pyridine). The functionalized thiomethyl groups around the periphery of the Fe6 cluster may provide binding sites for the surfaces of some specific materials, such as noble metals. Therefore, silver nanoparticle coated Fe6 (Ag@Fe6) complexes have been prepared by spontaneous self-assembly reactions. Transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM) images show that the Fe6 cluster layer is formed on the surface of the silver nanoparticles and the diameter of the Fe6 cluster is about 2 nm. In addition, powder X-ray diffraction (XRD), UV-vis spectroscopy, surface enhanced Raman spectroscopy (SERS), and cyclic voltammetry of the Fe6 and Ag@Fe6 complexes were also investigated. [ABSTRACT FROM AUTHOR]