Site- and Configuration-Selective Anchoring of Iron–Phthalocyanine on the Step Edges of Au(111) Surface

Abstract

Adsorption behavior of iron–phthalocyanine (FePc) at low submonolayer coverage on a reconstructed Au(111) single crystalline surface was investigated by a combination of low temperature scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. A site- and orientation-selective adsorption was found at different temperatures and molecular coverages by means of STM. Further DFT calculations demonstrate that the energy difference between different adsorption configurations leads to the selectivity, and thus the formation of one-dimensional molecular chains on the monatomic step edges in the fcc surface reconstruction domains. The exact adsorption site and configuration of the FePc molecule as well as the simulated STM images are obtained on the basis of DFT calculations, which is in good agreement with experimental observations.

Binding configuration, electronic structure, and magnetic properties of metal phthalocyanines on a Au(111) surface studied withab initiocalculations

“…At low coverage, molecules and atoms prefer to adsorb on the FCC packing region. [53][54][55] We found that top-angle was the most stable configuration, which is in agreement with previous experimental observations and calculations in ref. 10,28,29 .…”

Copper phthalocyanine thin films on Cu(111): Sub-monolayer to multi-layer

“…2b by an arrow. A similar geometry has been reported for sub-ML coverages of FePc molecules on the Au(111) surface [26]. In the case of FePc on Au(111) the conformation of the step-edge adsorbed molecules with two lobes on each terrace is observed with near uniformity, but a very small number of molecules are also detected with one lobe on each terrace.…”

Surface chemistry of porphyrins and phthalocyanines

“…The adsorption of FePc has been studied mainly on Au(1 1 1) [271][272][273][274][275], Ag(1 1 1) [202,[276][277][278], Ag(1 1 0) [279][280][281][282][283], Au(1 1 0)-(1 Â 2) [257] and Cu(1 1 1) [284]. On the reconstructed Au(1 1 1) surface, FePc was found to form ordered, commensurate monolayers with a square 15 Â 15 Å 2 unit cell [271,273,274,285].…”

“…[285]. At very low submonolayer coverage (0.01 ML), preferential adsorption occurred at the step edges in the fcc stacking regions [272,273]. Similar to CoPc/Au(7 8 8) [259] or CuPc and ZnPc on Cu(1 1 0) [237], the FePc molecules were also found to adsorb on step edges by bridging two adjacent terraces of the Au(1 1 1) surface, with two benzene lobes of the molecules on the lower and two on the upper terrace at a temperature of 5 K. At 77 K, a different configuration with only one lobe at the upper terrace was observed.…”

“…Similar to CoPc/Au(7 8 8) [259] or CuPc and ZnPc on Cu(1 1 0) [237], the FePc molecules were also found to adsorb on step edges by bridging two adjacent terraces of the Au(1 1 1) surface, with two benzene lobes of the molecules on the lower and two on the upper terrace at a temperature of 5 K. At 77 K, a different configuration with only one lobe at the upper terrace was observed. The next sites occupied with increasing coverage were the step edges in the hcp stacking regions [272]. After adsorption at the steps was complete, adsorption continued at the terraces; however, the molecules at the step edges did not act as nucleation sites for further growth [272].…”