Home
Resources
Publications
Chain Length and Temperature Dependence of Alkanedithiol Molecular Conductance Under Ultra High Vacuum

Chain Length and Temperature Dependence of Alkanedithiol Molecular Conductance Under Ultra High Vacuum

Ellis Pires, J Emyr Macdonald, Martin Elliott

Nanoscale. 2013 Oct 7;5(19):9397-403.

PMID: 23959150

Abstract:

We report scanning tunnelling microscope (STM) measurements of the single molecule conductance of α,ω-alkanedithiols for a large range of molecular chain lengths (N = 3-10) and temperatures (180-390 K) under ultra high vacuum. Two STM-based measurement techniques were employed on molecules trapped between tip and substrate: (i) the well established current-distance or I(z) technique and (ii) a new I(V,z) technique in which the current-voltage characteristics are determined as the tip-substrate distance z is varied. Low, medium, and high conductance groups were observed for each molecular length, which were temperature independent over the range examined, consistent with off-resonance tunnelling. For N > 4 the current-voltage characteristics and conductance trend with chain length is well described using a simple rectangular tunnel barrier model with parameters in excellent agreement with previously reported values. However, both 1,3-propanedithiol (N = 3) and 1,4-butanedithiol (N = 4) show an anomalous behaviour which is qualitatively similar to, but much less pronounced than, that reported by Haiss et al. (Phys. Chem. Chem. Phys., 2009, 11, 10831) for measurements performed under air and nitrogen gas.

Chemicals Related in the Paper:

Catalog Number	Product Name	Structure	CAS Number	Price
AP1191088	1,4-Butanedithiol		1191-08-8	Price

As a specialist in analytical chemical Products, Alfa Chemistry offers consumers a wealth of raw materials and a full range of technologies and services.

QUICK LINKS

HEADQUARTERS

Tel:

Fax:

Email: