An electrically actuated molecular toggle switch

Abstract

Molecular electronics is considered a promising approach for future nanoelectronic devices. In order that molecular junctions can be used as electrical switches or even memory devices, they need to be actuated between two distinct conductance states in a controlled and reproducible manner by external stimuli. Here we present a tripodal platform with a cantilever arm and a nitrile group at its end that is lifted from the surface. The formation of a coordinative bond between the nitrile nitrogen and the gold tip of a scanning tunnelling microscope can be controlled by both electrical and mechanical means, and leads to a hysteretic switching of the conductance of the junction by more than two orders of magnitude. This toggle switch can be actuated with high reproducibility so that the forces involved in the mechanical deformation of the molecular cantilever can be determined precisely with scanning tunnelling microscopy.

Electrical and SERS detection of disulfide-mediated dimerization in single-molecule benzene-1,4-dithiol junctions

“…During the past decade, charge transport in molecular electronics has been explored through various types of single-molecule junctions. 1 – 10 Among these molecules, benzene-1,4-dithiol ( BDT ) has widely attracted interest as it has been a well studied model junction over the past few decades. 1 , 11 – 13 Interestingly, the reported single-molecule conductances for BDT are split into two groups: a high conductance feature at around 10 –1 to 10 –2 G 0 , 3 , 14 , 15 and a low conductance feature at around 10 –3 to 10 –4 G 0 , 1 , 16 – 18 where G 0 is the conductance quantum.…”

Molekulares Kästchenpapier

“…Damit solche selbstorganisierten geordneten Strukturen als beschreibbare Schablonen genutzt werden können, muss ein geeigneter modifizierbarer Marker eingebaut werden, der gezielt von außen angesteuert werden kann. Während die Selbstorganisation von Molekülen bereits genutzt wurde, um die Reaktionspartner für anschließende zwischenmolekulare Reaktionen zu organisieren, sind für einen Marker ausschließlich durch die Spitze des RTMs ausgelöste lokale Prozesse geeignet, beispielsweise in Einzelmolekülschaltern oder auch Einzelmolekülreaktionen …”

Multidentate Anchors for Surface Functionalization

“…Tripodal anchors with three binding sites are one type of most employed molecules with multiple contact sites. Among them, the C 3 ‐symmetric platform tetraphenylmethane, tetraphenylsilane and related structures, 1,3,5,7‐tetrasubstitted adamantane, and 9,9′‐spirobifluorene have received considerable interest. Figure shows the representative molecules 1 – 4 of these four kinds of platforms with thiol groups as the contact sites .…”