Studies on the structure and properties of a self-assembled phenylazonaphthalene monolayer

The structure and functionality are two important aspects in the study of f unctionalized self-assembled monolayers (SAMs). A novel thiol-terminated ph enylazonaphthalene derivative, namely 1-mercapto-6-[1-(4-phenylazonaphthoxy )] hexane (shortly as MPH), was used to fabricate SAM on thin, optically tr ansparent gold films, which were deposited either on quartz for spectral me asurement or on mica for atomic force microscopy (AFM) observation. W-visib le spectroscopy, grazing-incidence Fourier transform infrared spectroscopy and AFM demonstrated that the SAM was densely packed and well oriented. Whe reas the photochemical hans-to-cis isomerization of phenylazonaphthalene in the SAM could be induced by UV Light irradiation with maximum trans-cis co nversion efficiency of approximately 42%, which was estimated from the UV-v isible absorption spectra. rn addition, the electrochemical study on the SA M indicates that the electron transfer rate was 2.56 x 10(-5) s(-1) and 64% of MPH were electrochemical electroactive. (C) 2000 Elsevier Science S.A. All rights reserved.