Redox‐induced configuration conversion for thioacetamide dimer can function as a molecular switch

Abstract

The electronic switching properties of thioacetamide dimer (TAD) were investigated using the nonequilibrium Green's function method combined with density functional theory for design of a novel molecular switch. The H-bonded TAD can be converted upon hole-trapping to a three-electron (3e)-bonded configuration with a S [symbol: see text] S linkage which could provide a more favorable channel for charge transfer than the before. The redox-induced configuration conversion between the H-bonded and the 3e-bonded TADs could govern the charge migration through the molecular junction with a considerable difference in conduction currents. The calculated I-V characteristic curves of two configurations exhibit a switching behavior with an On-Off ratio in a range of about 4.3-7.6 within the applied voltages. Clearly, this hypothetical scheme provides a potential way to explore the novel conformation-dependent molecular switch.

Gate-Modulated Conductance of Extended Conjugation in Atomically Arrayed Molecular Assemblies

“…Accordingly, it seems probable that transmission in a decylcarbazole (6) structure could be modulated substantially by gate voltage without incurring any form of gate leakage for biases in the range of −1 to 4 V. It is thus suggested that proper isolation of the π-stack by an adequate alkyl chain dielectric imparts the possibility for σ−π molecular structures to operate as true transistor devices. It should be noted that these observations concern systems modeled at 0 K. Deviations from the reported behavior at higher temperatures may arise due to phonon scattering.…”

“…Device structures with π-stacked wires of length n = 6 are displayed in Figure 1. A complete device layout, illustrating the left and right electrode regions and central scattering region for ethylcarbazole (6), is depicted in Figure 2.…”

“…4 Variations in β can be informative with respect to tunneling pathways. From this body of knowledge has come the rise in theoretical and experimental single molecule equivalents of standard logic devices such as diodes, 5 switches, 6 and transistors, 7 as well as new quantum mechanical capabilities such as negative differential resistors 8 and spin filters. 9 Out of these examples, the transistor stands as the most critical for logic execution.…”

“…Figure 6. Transistor device structures for σ−π molecular devices composed of (a) ethylcarbazole(6) or (b) decylcarbazole(6). A theoretical metallic gate is positioned directly below the Si(100)2 × 1 slab in each device.…”

DFT Studies on the Terminal Dependent Reversible Switching of Selenoxo Peptides Induced by Cationization

“…The conformational flexibility in structures of bio−entities including nucleic acids, carbohydrates, peptides, and their mimetics, make them a versatile tool in the area of molecular switches, which can be controlled by external stimuli like pH, optical, electrical, and electrochemical pulses. Many experimental and theoretical methods have been devoted to realise molecular switches among biomolecules and their synthetic analogues Molecular switching triggered using redox phenomenon is advantageous over others of its kind for being reversible for many cycles.…”