Adsorbed .omega.-hydroxy thiol monolayers on gold electrodes: evidence for electron tunneling to redox species in solution

Abstract

In the l80-exchanged reaction, the 02 atoms in the internal SiOH groups or in the nonintact Si-O-Si groups in the nest type defect sites attained the equilibrium state at ca. 15 h. Moreover, the bands at 3505 cm"1 2were observed less in the IR spectra for the HZSM-5 having fewer defect sites. From these results, it is suggested that the broad band at 3505 cm"1 can be identified with the SiOH groups of the hydroxyl nests.If aluminum atoms are inserted into hydroxyl nests in the HZSM-5 by alumination with A1C13, the band at 3505 cm"1 will disappear. The IR spectrum for aluminated HZSM-5 prepared from the parent HZSM-5 (sample 9 in Table I) is depicted in Figure 8E. The aluminated HZSM-5 exhibited a new band at 3610 cm"1 attributed to the framework Si(OH)Al groups,23 while the band at 3505 cm"' disappeared. These results indicate that (23) Jacobs, P.

Structural, Electrochemical, and Photophysical Properties of a Molecular Shuttle Attached to an Acid-Terminated Self-Assembled Monolayer

“…On the other hand, the value for k 0 at the clean gold surface is 0.031 cm s -1 , 58 whence, according to the relationship for tunneling an electronic tunneling factor ) 0.93/CH 2 was obtained. This is in very good agreement with reported values of for alkanethiols 50,51,59 and confirms the highly blocking nature of the 11-MUA monolayer. Furthermore, the low value of C dl ( Table 2) is also typical of electrodes covered by a well-formed SAM of long-chain thiols.…”

Zwitterionic self-assembly of l -methionine nanogratings on the Ag(111) surface

“…By using this methodology, regular low-dimensional systems such as supramolecular clusters, chains, or nanoporous arrays can be fabricated (2-6). A wide variety of molecular species as well as substrate materials proved to be useful (7), exploiting noncovalent directional interactions including dipole-dipole coupling (2, 3), hydrogen bridges (4,5,(8)(9)(10)(11), and metal-ligand interactions (6,(12)(13)(14)(15). With the exception of multiple H-bonded networks or coordination networks incorporating metal centers, it remains challenging to realize robust systems, and there is a need to develop protocols exploiting stronger intermolecular bonds to realize purely organic low-dimensional architectures.…”

Bifunctional Tri(ethylene glycol) Alkanethiol Monolayer Modified Gold Electrode for On-Chip Electrochemical Immunoassay of pg Level Leptin

“…The electron transfer behavior on the SAMs modified gold electrode has already been reported. 16,17 The peak shifts and current decrease in PAP could be influenced by two main factors: namely, the thickness or the rigidity of the monolayer. TEGCnSH with a longer alkylchain can form much thicker and more rigid SAMs.…”