1. Synthesis, characterization, and SAMs electroactivity of ruthenium complexes with sulfur containing ligands
- Author
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de Sousa, Jackson R., Diógenes, Izaura C.N., Temperini, Márcia L.A., Sales, Francisco A.M., Pinheiro, Solange de O., Costa Filho, Raimundo N., de Andrade Júnior, José S., and Moreira, Ícaro de S.
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CONDUCTING polymers , *RUTHENIUM , *LIGANDS (Chemistry) , *SULFUR - Abstract
Abstract: The vibrational and 1H NMR data hints that the coordination of the 2,2′-dithiodipyridine (2-pySS) ligand to the [Ru(CN)5]3− metal center occurs through the sulfur atom instead of the nitrogen atoms which is usually observed for N-heterocyclic ligands. Electrochemical results show that this coordination mode implies an additional thermodynamic stabilization of the RuII over RuIII oxidation state due to a relative stronger π-back-bonding interaction with the empty low-lying dπ orbitals of the sulfur atom. Computational data reinforce the experimental results showing that the 2-pySS Lewis base centers are located on the sulfur atoms. Ligands containing only sulfur atoms as coordination sites (2,2′-dithiodipyridine N-oxide (2-pySSNO), 1,4-dithiane (1,4-dt), and 2,6-dithiaspiro[3.3]heptane (asp)) were also coordinated to the [Ru(CN)5]3− metal center to undoubtedly correlate the electrochemical results with the ligand coordination atom. Among the synthesized compounds, the [Ru(CN)5(1,4-dt)]3− and [Ru(CN)5(asp)]3− complexes showed to be able to form self-assembled monolayers (SAMs) on gold. These SAMs, which were characterized by SERS (surface-enhanced Raman scattering) spectroscopy, successfully assessed the heterogeneous electron transfer reaction of the cytochrome c metalloprotein in physiological medium. [Copyright &y& Elsevier]
- Published
- 2007
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