The self-initiated photografting and photopolymerization (SIPGP) of styrene, methyl methacrylate, and tert-butyl methacrylate on structured self-assembled monolayers (SAMs) of electron beam cross-linked omega-functionalized biphenylthiols SAMs on gold was investigated. Polymer brushes with defined thickness can be prepared on crosslinked benzyl-, phenyl-, hydroxyl-, and amino-functionalized SAMs, whereas non-cross-linked SAM regions desorb from the surface during the SIPGP process. By the preparation of brush gradients on different functionalized SAMs, it was demonstrated that the resulting polymer brush layer thickness is determined by the locally applied electron beam dosage. Defined micro-nanostructured polymer brush patterns can be prepared down to a size of 50 nm. Finally, it was shown that polymer brushes obtained by the SIPGP process have a branched architecture.

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Self-assembled monolayers (SAMs) of omega-substituted biphenylthiolates (omega-MBP) on gold were characterized by spectral ellipsometry, X-ray photoelectron spectroscopy (XPS), infrared reflection absorption spectroscopy (IRRAS), and vibrational sum frequency generation spectroscopy (VSFG). The vibrational studies of the SAMs were supported by an ab initio frequency analysis at HF/6-31G and BP86/6-31G levels, yielding an assignment of all relevant spectral features in the range from 3500 to 1200 cm(-1). We were able to demonstrate that hydroxy-terminated MBP (HMBP) SAMs are basically featureless in the range of the CH stretching vibrations. Accordingly, the adsorption of a SAM of octadecyltrichlorosilane (OTS) on top of this model surface could be studied. A red shift of the C-O stretching vibration from 1281 to 1264 cm(-1) was observed during the chemisorption of OTS, thus allowing for a quantification of the number of OTS molecules involved in surface binding of OTS, which was found to be about 26% on average.

Thiolated phenylethynyl phenothiazines can be regarded as redox-active "alligator clips". They are readily synthesized from ethynyl phenothiazines and show intense blue-green luminescence upon ultraviolet (UV) excitation. Cyclic voltammetry reveals reversible oxidation, also after the chemisorption of in situ liberated thiols on gold electrodes. The chemisorption on Au{111} was studied by ellipsometry, contact angle measurements, X-ray photoelectron spectroscopy, and infrared reflection absorption spectroscopy, and the obtained data support the formation of self-assembled monolayers, depending on the structure of the substrates. These findings classify them as promising candidates for molecular wires switchable by redox manipulation.