Details

Autor(en) / Beteiligte

• Aboudzadeh, M. Ali
• Dolz, Mikel
• Monnier, Xavier
• González de San Román, Estibaliz
• Cangialosi, Daniele
• Grzelczak, Marek
• Barroso-Bujans, Fabienne

Titel

Synthesis of macrocyclic poly(ethylene oxide)s containing a protected thiol group: a strategy for decorating gold surfaces with ring polymers

Ist Teil von

• Polymer chemistry, 2019-12, Vol.1 (47), p.6495-654

Ort / Verlag

Cambridge: Royal Society of Chemistry

Erscheinungsjahr

2019

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• We introduce an approach to synthesize macrocyclic poly(ethylene oxide)s containing a pendant protected thiol group (pSH-CPEO), which is demonstrated to be able to attach to gold surfaces without prior deprotection. Our strategy is based on a bimolecular approach by which a di-alkyne molecule derived from thiol-protected 3-mercapto-1,2-propanediol and a series of PEO bis(azides) of M n = 2, 6, and 11 kg mol −1 are coupled via copper-catalyzed azide-alkyne cycloaddition. The cyclization reaction was verified by size exclusion chromatography and matrix-assisted laser desorption ionization time of flight mass spectrometry. In addition, we used fast scanning calorimetry to evaluate the glass transition temperature ( T g ) of the synthesized pSH-CPEOs. Thanks to the extremely rapid cooling power of this technique, PEO crystallization can be circumvented and, therefore, its fully amorphous state can be investigated. The results confirmed higher T g values for macrocycles compared to their chemically equivalent linear precursors. This result highlights the importance of the chain end in affecting the T g of polymers. Finally, to demonstrate the ability of pSH-CPEO to covalently attach to gold surfaces, pSH-CPEO samples were allowed to react with gold-coated glass slides and the surface properties were compared with those of the samples obtained by the reaction of linear α-thiol, ω-methoxy PEO (with and without protection of the thiol group) and gold-coated glass slides. X-ray photoelectron spectroscopy data confirmed the formation of Au-S linkages as well as the removal of the thiol protector group through the quantitative analysis of the chemical composition at the surface. The contact angle data of pSH-CPEO/gold exhibited increased hydrophilicity compared to bare gold and topological effects at the interface. A reaction mechanism between the 2,4-dinitrobenzene-protected thiol group and the gold surface is also proposed. Macrocyclic poly(ethylene oxide)s containing a protected thiol group are able to attach to gold substrates without thiol deprotection enabling surface modification.