The preparation of a novel self-assembling monolayer film containing an aromatic ring substituted with a sulfonyl group is described. The quality of the monolayer film is evaluated by spectroscopic methods, including FTIR and XPS, and by physical methods, including ellipsometry and contact angle measurements. A comparison with an analogous aromatic ester-containing monolayer film is presented. The results indicate that a donor-acceptor substituted phenyl ring containing the sulfonyl group can be incorporated into selfassembled monolayers. The ester-containing material formed monolayers with anomalously low contact angles for nonpolar liquids such as hexadecane, indicating greater disorder in the monolayer structure. © 1990, American Chemical Society. All rights reserved.