284474-40-4Relevant articles and documents
The preparation of three new partially deuterated hexadecanethiols for applications in surface chemistry
Sheepwash, Erin E.,Rowntree, Paul A.,Schwan, Adrian L.
experimental part, p. 391 - 398 (2009/04/07)
The synthesis of three partially deuterated hexadecanethiols has been achieved. Thiols CH3(CH2)7(CD2) 8SH, CD3(CD2)7(CH2) 8SH and CD3(CH2)15SH were targeted, as these compounds, after formation of self-assembled monolayers on Au(1 1 1) or Au nanoparticles, can provide mechanistic information pertaining to reactive atom migrations within the assembly. The syntheses of each of these compounds called upon Grignard coupling chemistry, which was activated by Li 2CuCl4. Applicable deuterium containing fragments were either commercially obtained or constructed from by way of an inexpensive and efficient ring opening, protection and dimerization of THF-d8. Sulfur incorporation was by thiolacetate substitution or addition reactions. The protocols presented possess general applicability in a number of syntheses requiring block-deuterated fattyalkyl sections. Copyright
Inter- and intramolecular temperature-dependent vibrational perturbations of alkanethiol self-assembled monolayers
Garand, Eì?tienne,Picard, Jean-Francì§ois,Rowntree, Paul
, p. 8182 - 8189 (2007/10/03)
The infrared spectra of octanethiol, dodecanethiol, and hexadecanethiol (C8, C12, and C16, respectively) monolayers adsorbed on Au(111) textured surfaces have been explored in the 25-300 K regime. The C-H stretching modes typically shift by several wavenumbers to lower frequencies and the intensities increase by as much as 75% as the temperature is decreased, providing evidence of, among other effects, the coupling of these stretching modes with lower energy vibrational modes. In contrast, for all temperatures below 300 K, the positions of the C-H bands of fully hydrogenated C16, shift by several wavenumbers to higher frequencies as the hydrogenated adsorbates are increasingly diluted in a matrix of fully deuterated C16, showing that all bands are subject to intermolecular couplings. The analysis of the behavior of the C-H stretching bands suggests that the temperature dependence of the vibrational frequencies associated with the methylene stretching modes is principally due to intermolecular couplings, whereas the temperature dependence of the vibrations associated with the methyl terminations is largely due to intramolecular couplings. It is suggested that the highly constrained geometry of the isotopically diluted monolayer may provide an environment that is less sensitive to intramolecular couplings with low-frequency modes than that of urea-clathrate-isolated species.
