Thiolate Chemistry: A Powerful and Versatile Synthetic Tool for Immobilization/Functionalization of Oligothiophenes on a Gold Surface

Abstract

The synthesis and characterization of a series of quaterthiophenes (4Ts) with thiolate groups protected with 2-cyanoethyl (CNE), 2-trimethylsilylethyl (TMSE), and acetyl (Ac) groups are described. Sequential cleavage of these different protecting groups allows for the preparation of 4Ts derivatized with ferrocene and/or alkanethiol chains. The electrochemical behavior of these compounds has been analyzed in solution by cyclic voltammetry (CV). A ferrocene-derivatized dithiol 4T 14 and a dithiol 4T 15 with two TMSE-protected thiolate groups have been immobilized on a gold surface as monolayers that have been characterized by CV, ellipsometry, contact-angle measurement, and X-ray photoelectron spectroscopy (XPS). The results show that molecules 14 and 15 are doubly grafted with a horizontal orientation of the conjugated system relative to the surface. Furthermore, application of the deprotection/alkylation sequence of the remaining protected thiolate groups on a monolayer of 15 allows for efficient post-functionalization.

Electrochemically Durable Thiophene Alkanethiol Self-Assembled Monolayers

“…Because the S 2p peak shows spin−orbit splitting consisting of a high-intensity S 2p 3/2 peak at lower energy and a low-intensity S 2p 1/2 peak at higher energy with an intensity ratio of 2:1, four peaks suggest that XPS detected two components corresponding to two kinds of sulfur atoms. 17,18,25,31,32 The peak pair at 162.1 and 163.3 eV is consistent with that observed in C 12 H 25 SH SAMs (162.2 and 163.4 eV). 31 Therefore, this peak pair was assigned to the thiol chemisorbed on the gold surface.…”

“…Tran et al prepared thiophene SAMs in which quaterthiophene was doubly grafted on the surface. 25 They introduced the ferrocene unit to the surface-attached quaterthiophene. In their CV analysis, the ferrocene unit showed intensive redox peaks, and the redox peak of the thiophene unit was broad and unclear.…”

Neuromorphic Time‐Dependent Pattern Classification with Organic Electrochemical Transistor Arrays

“…Monomer Synthesis: The monomer TEDOT has been synthesized by deprotection/functionalization of the appropriately protected thiolate groups according to the already published method, [26] and will be described elsewhere. The identity and purity of TEDOT were confirmed by 1 H and 13 C NMR spectrometry and HR mass spectrometry giving satisfactory results: Yellowish oil.…”

A DFT-Elucidated Comparison of the Solution-Phase and SAM Electrochemical Properties of Short-Chain Mercaptoalkylferrocenes: Synthetic and Spectroscopic Aspects, and the Structure of Fc–CH2CH2–S–S–CH2CH2–Fc

“…IR spectra (cm –1 ) were recorded on a Bruker Tensor 27 spectrometer with a PIKE MIRacle ATR-attachment. Compounds 6 , 7 , 8 , 9 , 11 , 12 , 13 , 14 , 15 , 17 , and 18 were synthesized according to the literature procedures.…”