▎ 摘　　要

NOVELTY - Pyridinium based supramolecular compound (A), which are (I) or (II) new. USE - (A) are useful in preparing supramolecular-graphene heterojunction molecule composition for single molecule field effect transistor (claimed). ADVANTAGE - The single molecule field effect transistor can be constructed to realize the switching function. DETAILED DESCRIPTION - Pyridinium based supramolecular compound (A), which are of formulae (I) or (II) new. x1, x2 = 0 or positive integer, preferably 0-3; R1 = absent, ethene-1,2-diyl or 3a,6a-dihydrothiazolo(5,4-d)thiazole-2,5-diyl; and R2 = H, halo, hydroxy, amino, cyano, nitro, carboxy, 1-6C alkyl, 1-6C alkoxy, halogenated 1-6C alkyl, halogenated 1-6C alkoxy, hydroxy 1-6C alkyl, hydroxy 1-6C alkoxy or 1-6C alkylamino. INDEPENDENT CLAIMS are also included for: (1) Pyridinium based supramolecular compound based single-molecule field-effect transistor, comprising a graphene array point electrode, a grid electrode, an ionic liquid, and a supramolecular-graphene heterojunction molecule composition, where the gate is located on both sides of the graphene array dot electrode, and has no conductive contact with the graphene array dot electrode, the heterojunction molecule composition is connected to the graphene array dot electrode through an amide bond, the ionic liquid covers the graphene array point electrode and the grid and fills the channel between the graphene array point electrode and the grid, the gate is specifically a platinum gate electrode, and the heterojunction molecule composition is obtained by self-assembly of at least one of (A); and (2) preparing single-molecule field-effect transistor, comprising (i) preparing graphene array electrodes, (ii) introducing a grid near the graphene array electrode but at a non-conductive contact position, and (iii) constructing graphene nano-gap point electrodes, (iv) obtaining (A) through self-assembly of host and guest molecules in a solvent, (v) contacting (A) with the system obtained in step (iii), i.e. the point electrodes of the graphene array are connected by amide bonds to obtain heterojunction molecule composition, and (vi) adding an ionic liquid into the graphene array dot electrode and grid, thus ionic liquid covers the graphene array dot electrode and grid and fills the channel between the graphene array dot electrode and grid.