σ–σ Stacked supramolecular junctions

Characterization and Application of Supramolecular Junctions

“…For supramolecular junctions based on the metal electrodes, commonly Au, the maintenance time is generally limited to the hundred-millisecond level at room temperature due to thermal perturbations, vibrational disturbances and especially the rearrangement of metal atoms on the electrode surface. [13] Compared with metal electrodes, graphene-based electrode materials have natural advantages, like atomically stiff with honeycomb lattice, high stability, π-delocalized framework et al [4a, 18a] Different from the above dynamic construc-tion techniques, Prins et al fabricated the few-layer graphene nanogap with 1-2 nm separation through feedbackcontrolled electroburning, and bridged the nanogap using an anthracene terminated curcuminoid molecule through π-π stacking interaction (top in Figure 3c). [18a] This leads to a kind of specific supramolecular junction with the noncovalent molecule-electrode interfaces.…”

“…Beyond the conductance difference, the reported formation probability of H-bonded junction is relatively low (3 % � 15 %), [10b,c] in comparison to single-molecule [8a, 65] and other supramolecular junctions. [13,31] This low formation probability may arise from the following reasons. First, hydrogen bonds are directional, a feature that is favorable for the construction of structurally well-defined dimers but could have a detrimental effect on the in situ formation of molecular junctions during stretching.…”

“…[6] The development of the mechanically controllable break junction (MCBJ) technique allows the investigation of intermolecular charge transport at the single-molecule scale, and a pioneering experimental investigation of the supramolecular assemblies is the aromatic π-π stacking system reported by Calame's group in 2008, which accessed the electrical signals of the π-stacked oligo-phenylene ethynylene (OPE). [7] Since that, the advances in single-molecule electrical characterization techniques, such as stretching distance [8] and flicker noise analysis, [9] drive the further investigation of different non-covalent interactions, including intermolecular charge transport through numerous non-covalent interactions, including hydrogen bonding, [10] host-guest interaction [11] and charge transfer interactions, [12] and recent σ-σ stacking, [13] and offers new insight beyond the conductance such as the quantum effects [14] and dynamic monitoring. [15] On the other hand, studies of supramolecular electronics have been seeking new functions of supramolecular electronic devices, which leads to emerging applications such as sensors, [10a, 16] diodes [17] and field-effect transistors.…”

“…(e) Three proposed configurations of the 1-adamantanethiol junctions. Reproduced from Ref [13]. with permission.…”

Controlling Charge Transport in Molecular Wires through Transannular π–π Interaction

“…It is well-known that both electronic and geometric changes could result in a considerable effect on electric conductance of symmetric single-molecule wire, and the molecule rectification effect of asymmetric single-molecule wire could be rendered by dipole [ 5 , 6 , 7 ]. Although there are some publications concerning both experimental measurements [ 8 , 9 , 10 ] and theoretical calculations [ 11 , 12 , 13 , 14 , 15 ] on charge-transport properties, regulating the transport of the charge in a controllable manner (e.g., de/protonation, photon absorption, isomerization, oxidation/reduction) with single molecules is still a challenging subject [ 16 , 17 , 18 , 19 , 20 ].…”