We analyze the formation and evolution statistics of single molecule junctions bonded to gold electrodes using amine, methyl sulfide and dimethyl phosphine link groups by measuring conductance as a function of junction elongation. For each link, maximum elongation and formation probability increase with molecular length, strongly suggesting that processes other than just metal-molecule bond breakage play a key role in junction evolution under stress. Density functional theory calculations of adiabatic trajectories show sequences of atomic-scale changes in junction structure, including shifts in attachment point, that account for the long conductance plateau lengths observed.
@article{arxiv.0901.1134,
title = {Formation and Evolution of Single Molecule Junctions},
author = {M. Kamenetska and M. Koentopp and A. C. Whalley and Y. S. Park and M. L. Steigerwald and C. Nuckolls and M. S. Hybertsen and L. Venkataraman},
journal= {arXiv preprint arXiv:0901.1134},
year = {2009}
}