Symmetry and Type of Peripheral Substituents Tune the Architecture of Gold-Supported Fluoro Phthalocyanine Films

Abstract A solution adsorption process for the facile production of films of C–H bonds free, fluorinated metal–organic phthalocyanines on gold is described. The effects of symmetry, electronic structures, and steric bulkiness, systematically varied within a series of electron-deficient perfluorinated zinc phthalocyanines, FnPcZn (n = 16, 40, 52, 64), have been modeled to account for experimental observations. The models reveal the underlying forces that contribute to Pc adsorptions and the structure of the resulting solid-supported uniform, lyophobic monolayer surfaces. The most energetic adsorption and the highest surface coverage, as revealed by X-ray photoelectron spectroscopy (XPS), adsorption isotherms, and contact angle measurements, occurred for n = 40 and 52 molecules that were arranged “edge-on-head-to-tail”, whereas molecules with n = 16 and 64 favored a “face-down” surface orientation. A structural model of surface coverage is proposed based on variation in interfacial interactions, ascribed to symmetry-imposed variations in molecular dipole moments and steric interactions as main factors that dictate the structure and properties of the constructed monolayers. The reported procedures and modeling might be used to reveal the factors that dictate the structure and properties of other solid-supported monolayers.