Fig. 2: Identifying charges confined in deprotonated phthalocyanines.
a, e, i Constant current dI/dV maps (I = 30 pA, V = 400 mV, 12.5 × 10.8 nm2, modulation voltage δVmod = 50 mV) recorded on (a) H2Pc, (e) HPc−, and (i) Pc2−. Images (a), (e), and (i) were acquired on a 2ML-NaCl island where the interface state scattering is stronger than on 3ML for a better visualization of the scattering. The conclusions regarding the charged character of the different species on 2 or 3ML NaCl remain however the same (see Supplementary Fig. 8). The insets show topographic STM images (3.7 × 3.7 nm2) recorded simultaneously that reveal dark areas around HPc− and Pc2−, characteristic of charged molecules on NaCl35. b, f, j dI/dV spectra recorded on (b) H2Pc, (f) HPc−, and (j) Pc2− on 3ML of NaCl. c, g, k DFT calculations of the electronic structure of the frontier orbitals of (c) H2Pc, (g) HPc−, and (k) Pc2− together with their iso-surface representations and their electronic occupation. d, h, l calculated images of the electrostatic field for (d) H2Pc, (h) HPc−, and (l) Pc2−. The potential is displayed 0.21 nm above the plane of the molecule. The NaCl layer is not included in the calculation. Source data are provided as a Source Data file.
