Electrochemically directed self-assembly of alkylthiosulfates enables the selective formation of monolayers on gold surfaces. These monolayers are identical to those formed from the corresponding alkanethiols. However, the mechanistic details of monolayer formation under electrochemical conditions as well as the role of other variables and residual water in the solvent have not been extensively studied. A systematic investigation shows that self-assembly is not a result of an outer-sphere one-electron oxidation of alkylthiosulfate. Voltammetry and electrochemical quartz crystal microbalance techniques reveal that self-assembly involving alkylthiosulfates as well as alkanethiols under oxidative conditions proceed through direct reaction with gold oxide and in some cases is accompanied by corrosion. X-ray photoelectron spectroscopy indicates that monolayers can undergo rapid exchange with molecules in solution under electrochemically directed self-assembly conditions.

Summary: The complexation of saccharides with poly(anilineboronic acid) as a function of pH has been studied with simultaneous measurements of open‐circuit potential and mass change. This study provides an insight into this reaction as well as the relationship between complexation and open‐circuit potential and the optimum pH for complexation of D‐fructose and D‐glucose. The optimum pH values for poly(anilineboronic acid)‐D‐fructose and ‐D‐glucose complexation are near the pKa values of the complex reported in homogeneous solution. At physiological pH (7.4), the apparent binding constant of D‐fructose and D‐glucose with poly(anilineboronic acid) is 19.2 and 0.2 M−1, respectively. In contrast, at pH 9.0, the apparent binding constant of D‐glucose with poly(anilineboronic acid) is 12 M−1, double than that of D‐fructose. The decrease in complexation in the polymer films at pH values above the pKa of the complexes is in contrast to the behavior in homogeneous solutions. This trend is observed for both D‐fructose and D‐glucose using open‐circuit potential, mass change and polarization modulated infrared reflection absorption spectroscopic measurements. Also, the complexation is limited in the polymer film, i.e., ≤23% boron is involved. These results suggest that steric and/or electrostatic interactions may play an important role in complexation within polymer films.