Self-Assembled Monolayers of Disulfide-Functionalized Diacetylenes on Gold Films and Nanoparticles

Abstract

This paper reports on the fabrication of self-assembled monolayers containing disulfide-functionalized diacetylenes. To this purpose, two diacetylene derivatives were synthesized: the novel 14-(9H-9-carbazolyl)tetradeca-10,12-diyn-1-yl disulfide (CDS9) and the henicosa-10,12-diyn-1-yl disulfide (DS9). Both monomers were employed to prepare two-dimensional self-assembled monolayers (2D-SAMs) by chemisorption on gold-sputtered platforms and three-dimensional self-assembled monolayers (3D-SAMs) on gold nanoclusters by direct synthesis in organic solvent. The chemisorbed diacetylenes were then converted to the polymeric form by exposure to UV radiation, and their morphological and spectroscopic properties investigated by several techniques. From SERS data it was inferred that both monomers show the same behavior, in that the highly conjugated blue phase was observed in the 3D-SAMs, while only the less extended red conformation was found in the corresponding 2D-SAMs.

Photopolymerization in water of diacetylenes chemisorbed onto noble metal nanoparticles: a spectroscopic study

“…The signal at 702 cm −1 is attributable to the CCC in-plane bending mode. [31,32] By increasing the irradiation time, the 2092 and 1460 cm −1 components disappear in favour of the 2120 and 1512 cm −1 signals of the red form. The time evolution of the Raman spectra behaves in the whole similarly to that of the electronic spectra.…”

Spectroscopical investigation on colloidal suspensions of diacetylene-capped gold nanoparticles

“…FT-IR spectra obtained from the polymerized nanohybrids after deposition onto KBr pellets confirmed the insight that only the lessconjugated red conformation is present in nanoparticles of diameter below 2 nm. 3 ) -a Mode assignment nomenclature: n a = asymmetric stretching, n s = symmetric stretching, d a = asymmetric bending, d s = symmetric bending, d = bending. The peak positions are reported with an error of AE1 cm À1 .…”

“…The synthesis conditions were properly manipulated in order to obtain nanoparticles of different core size [3].…”

“…In previous papers, we have reported the synthesis of diacetylene-capped gold nanoparticles performed for the first time directly in organic solvents, and their deposition onto functionalized glass substrates [3]. Two diacetylene disulfides, the DS9 (henicosa-10,12-diyn-1-yl) and the CDS9 (14-(9H-9-carbazolyl)tetradeca-10,12-diyn-1-yl) monomers, ad hoc synthesized [2], were used.…”

Nanostructured Metal-Dielectric Interfaces for Photonic Applications

“…In general, the morphology of the metal surface is a key factor both for the achievement of polymerization and for the predominance of one or another polymeric form. This effect was studied in detail by chemisorption of thiol-functionalized diacetylene molecules either on planar metal surfaces having different roughness [3] and on gold nanoparticles [4]. In the second case, it was found that the particle diameter drives the polymerization process and the blue form prevails in the case of larger metal cores.…”