Nanoobject microscopy

Self-assembled monolayers of diadamantane-thiol derivatives
Ya.Yu. Lopatina1,2, T.S. Zhuk2, A.A. Fokin2, A.A. Marchenko1

1Department of Physical Electronics, Institute of Physics of NAS of Ukraine, Nauky ave, 46, Kyiv-03039, Ukraine. E-mail: yaroslava.lopatina@gmail.com
2Department of Organic Chemistry, National Technical University of Ukraine “KPI”, Peremohy ave, 37, Kyiv-03056, Ukraine

Self-assembled monolayers of cage molecules are quite promising objects for electronics, patterning, designing and constructing macromolecular complexes [1,2].
Monolayers of 1,1’-diadamantane thiol derivatives (Fig.1,a,b) on Au(111) surface have been investigated using ambient scanning tunneling microscopy (STM). In contrast to highly-ordered monolayers of adamantane-thiol [3], for 1,1’-diadamantane thiols STM-images revealed formation of close-packed molecular islands (Fig.1,c). We associate lack of long-ranged order with additional degrees of freedom due to the C–C bond between adamantane units. Residual surface vacancies allow to incorporate a low-binding ghost adsorbates (defects) thus tailoring the surface properties.

Fig.1. Structure of (a) 1,1’-diadamantane-3-thiol (diAdSH) and (b) 1,1’-diadamantane-3,3’-thiol molecules. (c) STM-image of diAdSH monolayer on Au(111) surface. Scanning area: 21×21 nm2.

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