▎ 摘　　要

NOVELTY - A diamine compound (I) with quantum interference effect, is new. USE - New diamine compound with quantum interference effect, used in preparation of single-molecule field effect transistor (claimed). ADVANTAGE - The compound (I) with quantum interference effect can be stably connected to the gap of the two-dimensional monolayer graphene with nano-gap array through amide covalent bond to form molecular heterojunction. The formation of van der Waals heterostructure can realize precise control and preparation of the single-molecule field effect transistor device, so that the single-molecule field effect transistor has strong gate electric field regulation ability, and excellent stability and integration. DETAILED DESCRIPTION - A diamine compound with quantum interference effect, of formula: H2N-R2-R1-R2-NH2(I), is new. R1=group selected from groups of formulae (II)-(VII); R2=(CH2)mor group of formula (VIII); m=1-6; R,Rx,Ry=CH3(CH2)n; and n=0-5. INDEPENDENT CLAIMS are included for: (1) a single-molecule field effect transistor, which includes the compound (I); and (2) preparation of the single molecule field effect transistor, which involves: (a) preparing a graphene gate electrode layer (1) on the substrate; (b) preparing a bismuth selenium oxide (Bi2SeO5) dielectric layer (2) on the upper surface of the graphene gate electrode layer; (c) preparing a graphene electrode layer on the upper surface of the bismuth selenium oxide dielectric layer; (d) constructing a nano-gap with the graphene electrode layer to obtain a graphene point electrode, where the graphene point electrode includes a graphene source electrode (3) and a graphene drain electrode (4); (e) connecting the graphene point electrode and a molecular heterojunction (5) through an amide bond, where the molecular heterojunction is composed of the compound (I) with quantum interference effect; and (f) covering upper surface of the graphene point electrode and the molecular heterojunction with a hexagonal boron nitride (h-BN) protective layer (6). DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of the single-molecule field effect transistor. 1Graphene gate electrode layer 2Bismuth selenium oxide dielectric layer 3Graphene source electrode 4Graphene drain electrode 5Molecular heterojunction 6Hexagonal boron nitride protective layer