Effects Of Multiple Anchor Anchoring Points And Aromaticity On The Electron Transport Properties Of Molecular Wires

1.As the silicon-based semiconductor device micro-fabrication technology is about to reach its limit,molecular electronics has attracted wide attention due to its" bottom-up”construction of electronic devices based on single molecules.The molecular wire serves as a bridge between the molecular device and the outside,and plays a role in transmitting energy and information.How to measure and control the electron transport behavior of the molecular wire has become a basic problem faced by molecular electronics.The core is the electronic transmission performance of a single molecular wire.For monitoring,metal-molecule-metal heterojunctions(ie,single-molecule junctions)are usually constructed to measure the conductance of single-molecule junctions.It has been found that the conductance of single-molecule junctions is usually affected by factors such as molecular configuration and self-property,anchor groups,electrode materials,and environment.In addition,the position and number of anchoring groups also affect the electron transport performance of molecular junctions.The thiol and pyridyl groups are more anchorage groups because they have a higher probability of forming a stable molecular junction with the gold electrode and a simpler configuration.In this paper,a series of oligomeric aromatic organic molecular wires with fluorenyl and pyridyl as anchor groups were designed and synthesized.The STM-BJ cracking technique was used to study the aromaticity of the bridged molecules and the position and number of anchor groups.The effect of the line's electronic transmission operation.The phenylacetylene and pyridine acetylene organic molecular wires with pyridyl and thioacetyl(SAc)as anchor groups were designed and synthesized,and their 1H NMR,13C NMR,MS and UV-Vis spectra were studied.The STM-BJ technique was used to construct the molecular junction and the single-molecule conductance data of the target molecule was measured.The study found that:(1)increased the number of thioacetyl(SAc)molecule conjugation enhancement,thioacetyl(SAc)anchor group located in the para position of the benzene ring,the conjugation of the molecule is better than The position and number of anchoring groups all have an effect on the conjugation of the molecule;(2)The anchor group has a greater conductance compared to the meta-position of the phenylethynyl group,and the multi-anchor anchoring point There are multiple electron transport channels in the molecule,resulting in two sets of data:high conductance and low conductance.The number of anchor groups will affect the electron transport of the molecule,and it is not simply the result of superposition.2.A series of oligophenylenevinylene(OPE)organic molecular wires with thiol(BT)as anchor group were designed and synthesized.The target molecules were characterized by 1H NMR,13C NMR,MS and UV-Vis spectra.And use STM-BJ technology to build molecular junctions to obtain the single molecule junction conductance data of the target molecule.The results showed that:(1)The atomic number,species and number of heteroatoms in the molecule may affect the conjugation of the molecule;(2)There is no obvious difference between the aromaticity of the target molecule and its single-molecule conductivity value.Correlation,but this result may also be because of the combined effect of other properties of the molecule(such as the electronegativity of the molecule).