Single-molecule conductance of a chemically modified, π-extended tetrathiafulvalene and its charge-transfer complex with F₄TCNQ

• Raúl García,
• M. Ángeles Herranz,
• Edmund Leary,
• M. Teresa González,
• Gabino Rubio Bollinger,
• Marius Bürkle,
• Linda A. Zotti,
• Yoshihiro Asai,
• Fabian Pauly,
• Juan Carlos Cuevas,
• Nicolás Agraït and
• Nazario Martín

Beilstein J. Org. Chem. 2015, 11, 1068–1078, doi:10.3762/bjoc.11.120

• theoretical calculations. To the best of our knowledge, these are the first reported single-molecule conductance measurements on a molecular charge-transfer species. Keywords: break junction measurements; charge-transfer complex; DFT-based transport; molecular electronics; tetrathiafulvalene; Introduction

• similar to the oxidation peak found for pristine exTTF (Epa = 244 mV, ΔE = 350 mV) (Figure 2). Break junction measurements Neutral molecule We first tried to form neutral-molecule molecular junctions. Simply, compound 5 can be seen as an analogue of an oligo(phenylene ethynylene), specifically an OPE3

• methanol (see Supporting Information File 1, Figure S2). Specifically, we observe three peaks at 689 nm, 764 nm and 867 nm, which can be assigned to the radical anion F4TCNQ species [30]. For the break junction measurements, it was necessary to avoid having an excess of the acceptor because F4TCNQ forms