title: Stability of single- and few-molecule junctions of conjugated diamines.
abstract: We study the stability of molecular junctions based on an oligo(phenylenethynylene) (OPE) diamine using a scanning tunneling microscope at room temperature. In our analysis, we were able to differentiate between junctions most probably formed by either one or several molecules. Varying the stretching rate of the junctions between 0.1 and 100 nm/s, we observe practically no variation of the length over which both kinds of junction can be stretched before rupture. This is in contrast with previously reported results for similar compounds. Our results suggest that, over the studied speed range, the junction breakage is caused purely by the growth of the gap between the gold electrodes and the elastic limit of the amine-gold bond. On the other hand, without stretching, junctions would survive for periods of time longer than our maximum measurement time (at least 10 s for multiple-molecule junctions) and can be considered, hence, very stable.
authors.affiliation: Instituto Madrileño de Estudios Avanzados en Nanociencia, Ciudad Universitaria de Cantoblanco, E-28049 Madrid, Spain. teresa.gonzalez@imdea.org
authors.forename: M Teresa
authors.initials: MT
authors.lastname: González
authors.forename: Adrián
authors.initials: A
authors.lastname: Díaz
authors.forename: Edmund
authors.initials: E
authors.lastname: Leary
authors.forename: Raúl
authors.initials: R
authors.lastname: García
authors.forename: M Ángeles
authors.initials: MÁ
authors.lastname: Herranz
authors.forename: Gabino
authors.initials: G
authors.lastname: Rubio-Bollinger
authors.forename: Nazario
authors.initials: N
authors.lastname: Martín
authors.forename: Nicolás
authors.initials: N
authors.lastname: Agraït
mesh_terms: D000480:Alkynes / Q000737:chemistry; D003959:Diamines / Q000737:chemistry*; D004566:Electrodes; D004987:Ethers / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D016252:Microscopy, Scanning Tunneling; D015394:Molecular Structure; D013696:Temperature
chemical_list: D000480:Alkynes; D003959:Diamines; D004987:Ethers; C436384:phenyleneethynylene; D006046:Gold