596108-07-5Relevant academic research and scientific papers
Hydrogen sulfide-induced desorption/reorganization of self-assembled monolayers of alkanethiol and its derivatives
Tao, Yu-Tai,Pandian, Kannaiyan,Lee, Wen-Chung
, p. 7072 - 7079 (2000)
Self-assembled monolayers of alkanethiolate on gold were shown to desorb or be replaced from the gold surface by exposure to H2S vapor. Under the same conditions, the desorption occurred faster with shorter chain length thiols than with longer ones. The thiolate moiety desorbed mainly in the form of a free thiol, which underwent various structural reorganizations depending on the chain length as well as the terminal functional group it carries. For nonpolar, methyl-terminated thiols, the assembly either randomized to give a disordered liquid state (for chain length C16) or maintained a well-ordered but physisorbed monolayer state (for chain length ≥C18). With polar terminal groups such as hydroxyl, ester, acid, arnide and, cyano groups, the desorbed molecules reorganized into discrete clusters of the corresponding thiol compound. The results demonstrate the important role of the terminal functional group at the film - Air interface in determining the ultimate structure of a molecular assembly.
Self-assembled monolayers of nitrile-functionalized alkanethiols on gold and silver substrates
Frey,Shaporenko,Zharnikov,Harder,Allara
, p. 7716 - 7725 (2007/10/03)
Self-assembled monolayers (SAMs) formed from nitrile-functionalized alkanethiols (AT), NC(CH2)16SH (NC-Cl6), on (111) gold and silver substrates were characterized by X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure spectroscopy, and contact angle measurements. The average chain tilt angles in NC-C16/Ag and NC-C16/Au were estimated to be 29.5° ± 5° and 42.5° ± 5° from the surface normal, respectively, while the data suggest lower ordering for NC-C16/Au. The -C≡N bonds were found to be predominantly oriented in the surface plane with a tilt angle of 65° ± 7° for both NC-C16/Au and NC-C16/ Ag. Comparison with previous data on CH3-terminated SAMs reveals that substitution of weakly interacting CH3 groups by the CN entities results in an increase in the average tilt angles of the alkyl chains by ～7.5° and ～17.5° in AT/Au and AT/Ag, respectively. A strong electrostatic interaction between the polar nitrile groups is assumed to underlie the structural behavior by controlling a balance between the headgroupsubstrate and interchain interactions. The near-parallel orientation of the nitrile groups to the surface in both of these SAMs can be explained on the basis of minimization of the unfavorable CN - CN dipole - dipole interactions.
