▎ 摘　　要

NOVELTY - An azulene derivative (I), is new. USE - New azulene derivative used in preparation of single-molecule heterojunction or single-molecule field effect transistors (all claimed). ADVANTAGE - The azulene derivative can construct single-molecule transistor switching devices, when compared with existing optically controllable switches, electrically controllable single-molecule field effect transistors lay the foundation for true integration and application. DETAILED DESCRIPTION - An azulene derivative of formula (I), is new. X = C, N, Si or CO; R1-R4 = C, N, Si or CO; Y' = none or group chosen from groups of formulae (a)-(c); Z1, Z2 = group chosen from groups of formulae (d)-(g);and a' = NH2, NHCH2CH2NH2, HN-Ac, CN, SH, SMe, Sac or Py. (i) when R1-R4 are H, control the number of hydrogen atoms in the preferred range of 1-10; (ii) when R1-R4 are fluoro, control the number of fluorine atoms in the preferred range of 1-10; and (iii) when R1-R4 are alkyl, control the ratio of carbon atoms to hydrogen atoms as n:2n-1 (where n is 1-10); (iv) when R1-R4 are fluorinated alkyl, control the number of carbon atoms in the preferred range of 1-10 and control the number of fluorine atoms in the preferred range of 1-3; and (v) when R1-R4 are fluorinated alkoxy, control the number of carbon atoms in the preferred range of 1-10, control the number of fluorine atoms in the preferred range of 1-3 and control the number of oxygen atoms within the preferred range of 1-3. INDEPENDENT CLAIMS are included for the following: (1) usage of the azulene compound to prepare single-molecule heterojunction or single-molecule field effect transistors, which involves (1) constructing graphene devices comprising source electrode, a drain electrode and a conductive channel containing graphene, (2) exposing with electron beam photoresist on graphene, using oxygen plasma etching, obtaining nano-gap between the source and drain electrodes. The nano-gap is perpendicular to the source and drain electrodes. (3) preparing monomolecular device by introducing the compound (I) through amide bond between the nano-gaps, and (4) evaluating the electrical properties of its switches through different gate voltages. The nano-gap is perpendicular to the source and drain electrodes; (2) single molecule field effect transistor, which comprises graphene array point electrode, molecular heterojunction electrode and ionic liquid. Grid is located on both sides of the graphene array dot electrode, there is no conductive contact with the graphene array point electrode. The molecular heterojunction and the graphene array dot electrode are connected with amide bonds in different countries. The ionic liquid covers the graphene array dot electrode and the grid and fills the channel between the graphene array dot electrode and the grid. The single-molecule heterojunction is obtained by self-assembly of one or more of compound (I); and (3) preparation of the single molecule field effect transistor, which involves (1) preparing graphene array electrodes, (2) introducing the grid near the graphene array electrode but not in the shop contact position, (3) constructing graphene nano-gap point electrodes, (4) contacting the compound (I) or nuclear weapons with the system obtained in step (3) for self-assembly, connecting the dot electrodes of the graphene array by amide bonds to obtain a molecular heterojunction, (5) adding ionic liquid to the point electrode and grid of the graphene array, making the ionic liquid cover the graphene array dot electrode and the grid, and filling the channel between the graphene array dot electrode and the grid.