Structure of self-organizing organic films: A near edge x-ray absorption fine structure investigation of thiol layers adsorbed on gold

Abstract

Self-assembled films of thiols on polycrystalline Au substrates have been investigated with near edge x-ray absorption fine structure. From the angular dependence of two different resonances the orientation of the molecular axis of the alkyl chains with respect to the surface normal is determined and compared to results obtained by other techniques. By comparing data for thiol films and LB films of Cd and Ca arachidate it is found that thiol films are considerably better ordered.

Functionalization of silicon step arrays II: Molecular orientation of alkanes and DNA

“…The two primary features are characteristic of alkane monolayers and agree within an experimental error with earlier assignments of transitions from the C 1s core level to the unoccupied ͑C-H͒ and ͑C-C͒ * orbitals for similar chain length alkanethiols. 19 Polarization dependent effects suppress the C-C resonance at normal incidence. An incidence angle of 60°was used so that both features are easily distinguishable.…”

“…[19][20][21] Alkanethiols can be characterized by the energies of transitions from the C 1s core level to the C-C and C-H * orbitals and DNA by the transition from the N 1s to the * orbitals in the nucleotide bases ͑Fig. 1͒.…”

STM Investigations of Thiol Self-Assembled Monolayers

“…[2,11] Methods such as multistep adsorption processes [5,12] or molecular crosslinking [13] were applied for the build-up of three-dimensional nanoparticle arrangements. Despite the success of the LB technique for the assembly of two-dimensional monolayers, it did not lead to satisfactory results for thicker films of pure, undiluted cluster material.…”

Alkylthiol self-assembled monolayers on Au(111) with tailored tail groups for attaching gold nanoparticles

“…This tilting appears since molecules optimize the intermolecular interaction and balance the head group-substrate interaction, thus minimizing the surface energy. Typical alkanethiol molecules within SAMs may have an orientation with an average tilt angle of ~27°-35° with respect to the surface normal [10,16,30]. Such structures are achieved when concentration of 10-1000 mM are used [45].…”