Anhydrous Anaerobic Conditions Straight Chain Alkyl Derivatives Preparation And Electrical Properties Of The Tunnel Junction

Electron transfer across molecules has become the focus of molecular electronics, and it depends strongly on the electrode material, atmosphere, the functional molecular structure and its spatial scale. Studying on the mechanism of electron transfer across organic molecules by the capillary method is one of the most important methods for constructing the molecular devices. In this work, gallium was used as the electrode material. A number of capillary tunnel junctions with"gallium-functional molecular monolayer-gallium"structure were constructed by molecule self-assembled technology in the vacuum box in which oxygen and water were removed. The electrical behavior of the functional organic molecular tunnel junction was widely without oxygen and water. By testing the electronic characteristics of the molecular tunnel junctions at room temperature, the electron behavior under different conditions was compared, and the relationship between electron transfer and molecular structure was explored. The HOMO-LUMO gaps (HLG) of the molecules were also calculated based on the frontier orbital theory.In the experiments, functional molecules such as CnH_2n+1X (n=10,12,14,16,18; X=OH, NH₂),C₁₂H₂₅Cl,C₁₂H₂₅Br and C₁₂H₂₄O₂ were explored by the self-designed equipment. Typical nonlinear electrical behavior of the metal-molecule-metal junctions that were made in the vacuum was also found from the current-voltage curve, the electron transports more easily than that in the air. While the molecules with the same terminal group, the chainlength of the molecules affected the energy gaps of the tunnel junctions. While the molecules with the same backbone, the high electro-negativity of the terminal group made the harder electron transfer in the molecular tunnel junctions.In addition, functional molecules such as C₆H₄Cl₂, C₈H₈Cl₂, C₆H₄Br₂ and C₈H₈Br₂ were also explored. The results indicated that the participation of the methylene at both ends of benzene made the easier electron transfer in the molecular tunnel junctions. The theoretical calculated HLG values bahaved the same trend with the energy gaps obtained from the experiments.