Extended Data Fig. 9: On-surface synthesis of FePor-3ZGNR.
From: Zigzag graphene nanoribbons with periodic porphyrin edge extensions
(a) On-surface synthetic route to FePor-3ZGNR using FePorCl-DBA precursors. While there is a Cl atom attached to the Fe center of the as-synthesized FePor-DBA precursor, degassing of the compound under UHV conditions detaches Cl before actual precursor sublimation. (b) Overview STM image of the sample after annealing to 570 K for 15 min. FePor-3ZGNR is fully planarized. (c) High-resolution STM images of FePor-3ZGNRs of different lengths, specified by the number NFePor of precursor units. (d) dI/dV spectra taken from dimer (NFePor = 2) to hexamer (NFePor = 6), at locations indicated by the colored dots in (c). The arrows indicate the position of detected resonances. As judged from dI/dV maps taken at corresponding energies (see Supplementary Fig. 17), resonances 1, 2, 5 and 6 exhibit the typical LDOS features of the VB-1, VB, CB and CB + 1, respectively, of the Por-3ZGNR backbone, as also observed for the ZnPor-3ZGNR. Resonance 3 and 4 are specific to the FePor-3ZGNR, that is they are not observed in ZnPor-3ZGNR. Scanning parameters: (b) U = −1.5 V, I = 100 pA. (c) U = −1.5 V, I = 300 pA.
