Figure 1
AFM images of LLM-105 nanosheets and the computed model of the molecular packing structure on HOPG surfaces.
(a) Configuration of a single LLM-105 molecule, The atoms are labeled with numbers and letters in the blanks for convenience in description of the intermolecular hydrogen bonds. (b) Topographical image of a LLM-105 nanosheet in contact mode, measured with a gold coated tip under atmosphere and room temperature. The images were recorded at tip load of 0.1 nN,The sheet presents a rectangular shape and a lateral dimension more than 1.0 um × 1.0 um. (c) Line profile along the blue line in a, shows a profile of the nanosheet. It reveals that the sheet has a completely flat plane surface and the thickness averages about 0.8 nm. (d) High-magnification current image of LLM-105 nanosheet with size of 20 nm×20 nm under the conductive AFM mode with load of 0.2 nN, bias of 0.2 V and scanning rate of 0.5 Hz. The inset of d shows a high resolution current image with size of about 5 nm×5 nm. The bright patches are relative high current and the dark patches are relative low current. The bright spots are arranged regularly. The black arrows and blue arc are used to label the distances in corresponding directions and included angle of two directions, respectively. (e) Top view of the computed 2D structure model of the nanosheet. The black circles mark the regions of adjacent two tilted nitro groups with torsion angle of about 154°. The black arrows and numbers note the directions and distances between circles, respectively. (f) Side view of the computed 2D structure model of the nanosheet. (g) Magnification image of computed model outlined in e with a black parallelogram. The torsion angles of N(1)-C(6)-N(7)-O(8) focus on two values, one if 154°, the other is 167°. In a,e,f,g, C, N, O and H atoms are indicated in gray, blue, red and white balls, respectively.
