Selective Binding, Self-Assembly and Nanopatterning of the Creutz-Taube Ion on Surfaces

International Journal of Molecular Sciences

Yuliang Wang¹  Marya Lieberman¹  Qingling Hang² 

[1] Department of Chemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA; E-Mail:;Department of Electric Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA; E-Mails:

关键词: Creutz-Taube ions;    Surface;    Hydrophilic;    Hydrophobic;    XPS;    AFM;    Self-assembled Monolayers;    E-beam lithography;    PMMA;    Nanopatterning;   

DOI  :  10.3390/ijms10020533

来源: mdpi

【 摘 要 】

The surface attachment properties of the Creutz-Taube ion, i.e., [(NH₃)₅Ru(pyrazine)Ru(NH₃)₅]⁵⁺, on both hydrophilic and hydrophobic types of surfaces were investigated using X-ray photoelectron spectroscopy (XPS). The results indicated that the Creutz-Taube ions only bound to hydrophilic surfaces, such as SiO₂ and –OH terminated organic SAMs on gold substrates. No attachment of the ions on hydrophobic surfaces such as –CH₃ terminated organic SAMs and poly(methylmethacrylate) (PMMA) thin films covered gold or SiO₂ substrates was observed. Further ellipsometric, atomic force microscopy (AFM) and time-dependent XPS studies suggested that the attached cations could form an inorganic analog of the self-assembled monolayer on SiO₂ substrate with a “lying-down” orientation. The strong electrostatic interaction between the highly charged cations and the anionic SiO₂ surface was believed to account for these observations. Based on its selective binding property, patterning of wide (∼200 nm) and narrow (∼35 nm) lines of the Creutz-Taube ions on SiO₂ surface were demonstrated through PMMA electron resist masks written by electron beam lithography (EBL).

【 授权许可】

CC BY   
© 2009 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.