Assembly, characterization, and electrochemical properties of immobilized metal bipyridyl complexes on silicon(111) surfaces

作者：Lattimer Judith R C; Blakemore James D; Sattler Wesley; Gul Sheraz; Chatterjee Ruchira; Yachandra Vittal K; Yano Junko; Brunschwig Bruce S^*; Lewis Nathan S; Gray Harry B

来源：Dalton Transactions, 2014, 43(40): 15004-15012.

DOI：10.1039/c4dt01149j

Silicon(111) surfaces have been functionalized with mixed monolayers consisting of submonolayer coverages of immobilized 4-vinyl-2,2'-bipyridyl (1, vbpy) moieties, with the remaining atop sites of the silicon surface passivated by methyl groups. As the immobilized bipyridyl ligands bind transition metal ions, metal complexes can be assembled on the silicon surface. X-ray photoelectron spectroscopy (XPS) demonstrates that bipyridyl complexes of [Cp*Rh], [Cp*Ir], and [Ru(acac)(2)] were formed on the surface (Cp* is pentamethylcyclopentadienyl, acac is acetylacetonate). For the surface prepared with Ir, X-ray absorption spectroscopy at the Ir L-III edge showed an edge energy as well as post-edge features that were essentially identical with those observed on a powder sample of [Cp*Ir(bpy)Cl]Cl (bpy is 2,2'-bipyridyl). Charge carrier lifetime measurements confirmed that the silicon surfaces retain their highly favorable photoelectronic properties upon assembly of the metal complexes. Electrochemical data for surfaces prepared on highly doped, n-type Si(111)electrodes showed that the assembled molecular complexes were redox active. However the stability of the molecular complexes on the surfaces was limited to several cycles of voltammetry.

• 出版日期2014-10-28