Formation and NMR Spectroscopy of ω-Thiol Protected α,ω-Alkanedithiol-Coated Gold Nanoparticles and Their Usage in Molecular Charge Transport Junctions

被引：18

作者：

Wallner, Andreas ^{[1
]}

Jafri, S. Hassan M. ^{[2
]}

Blom, Tobias ^{[2
]}

Gogoll, Adolf ^{[1
]}

Leifer, Klaus ^{[2
]}

Baumgartner, Judith ^{[3
]}

Ottosson, Henrik ^{[1
]}

机构：

[1] Uppsala Univ, Dept Biochem & Organ Chem, S-75123 Uppsala, Sweden

[2] Uppsala Univ, Div Elect Microscopy & Nanoengn, Dept Engn Sci, S-75121 Uppsala, Sweden

[3] Graz Univ Technol, Inst Anorgan Chem, A-8010 Graz, Austria

来源：

LANGMUIR | 2011年 / 27卷 / 14期

基金：

瑞典研究理事会;

关键词：

SELF-ASSEMBLED MONOLAYERS; TRIOCTYLPHOSPHINE OXIDE; CLUSTER MOLECULES; CONDUCTANCE; DIFFUSION; EXCHANGE; DYNAMICS; HYDROGEN; NETWORKS; H-1-NMR;

D O I：

10.1021/la2019007

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Gold nanoparticles (AuNPs) coated with stabilizing molecular monolayers are utilized in areas ranging from life sciences to nanoelectronics. Here we present a novel and facile one-pot single phase procedure for the preparation of stable AuNPs with good dispersity, which are coated with alpha,omega-alkanedithiols whose outer omega-thiol is protected by a triphenylmethyl group. Using dielectrophoresis we were able to trap these AuNPs, coated with omega-thiol protecting groups, in a 20 nm gold electrode nanogap. The omega-thiol group was then deprotected under acidic conditions in situ once the AuNPs were correctly positioned in the device. The subsequent deprotection resulted in an increase of conductance by up to 3 orders of Magnitude, indicating that the isolated dithiol-coated AuNPs were fused into a covalently bonded network with AuNP-molecule-AuNP as well as electrode-molecule-AuNP linkages. Furthermore, complete characterization of the AuNP surface-bonded alkanedithiols was achieved using a series of one- and two-dimensional NMR spectroscopy techniques. Our spectra of the molecule-coated AuNPs show well-resolved signals, only slightly broader than for free molecules in solution, which is in contrast to many earlier reported NMR spectral data of molecules attached to AuNPs. Complementary diffusion NMR spectroscopic experiments were performed to prove that the observed alkanedithiols are definitely surface-bonded species and do not exist in free and unattached form.

引用

页码：9057 / 9067

页数：11