摘要：

The structure and dynamical behavior of short and long chain alkanethiols, CH3(CH2)7SH and CH3(CH)17SH, and of a hydroxyalkanethiol, HO(CH2)16SH, adsorbed onto gold nanoparticles were studied by variable temperature solid-state 13C NMR spectroscopy. In both the solution and solid state, the resonances of the first three carbons next to the sulfur headgroup disappear upon binding to the gold, indicating a strong interaction with the surface. A 13C-enriched sample, CH3(CH2)12*CH2SH/gold, displays a broad resonance centered at 42 ppm for the carbon next to the sulfur headgroup. Whereas the solid-state 13C shifts of CH3(CH2)7SH/gold are essentially the same as in solution, the methylene carbons of CH3(CH2)17SH and HO(CH2)16SH/gold shift downfield by 4.5 ppm in the solid state, indicating that the chains crystallize into an extended all-trans conformation. The high conformational order, along with reduced methylene proton line widths in the CH3(CH)17SH/gold sample, indicates that the chains are undergoing larg...

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