Abstract
We have examined the geometric and electronic structures of iron phthalocyanine assemblies on a Cu(111) surface at different sub- to mono-layer coverages and the changes induced by thermal annealing at temperatures between 250 and 320 °C by scanning tunneling microscopy, x-ray photoelectron spectroscopy, and x-ray absorption spectroscopy. The symmetry breaking observed in scanning tunneling microscopy images is found to be coverage dependent and to persist upon annealing. Further, we find that annealing to temperatures between 300 and 320 °C leads to both desorption of iron phthalocyanine molecules from the surface and their agglomeration. We see clear evidence of temperature-induced homocoupling reactions of the iron phthalocyanine molecules following dehydrogenation of their isoindole rings, similar to what has been observed for related tetrapyrroles on transition metal surfaces. Finally, spectroscopy indicates a modified substrate-adsorbate interaction upon annealing with a shortened bond distance. This finding could potentially explain a changed reactivity of Cu-supported iron phthalocyanine in comparison to that of the pristine compound.
Highlights
Metal phthalocyanines (MPcs) have considerable potential for the use in new functional nanoscale materials due to the possibility of accurate characterization and manipulation of their chemical state
We have examined the geometric and electronic structures of iron phthalocyanine assemblies on a Cu(111) surface at different sub- to mono-layer coverages and the changes induced by thermal annealing at temperatures between 250 and 320 ◦C by scanning tunneling microscopy, x-ray photoelectron spectroscopy, and x-ray absorption spectroscopy
Surface-driven modification of the molecular properties plays an important role, and recent research into phthalocyanine compounds includes the control of the Kondo effect,10 switching of magnetic anisotropy,11 and uneven charge transfer leading to distortion and symmetry reduction
Summary
Metal phthalocyanines (MPcs) have considerable potential for the use in new functional nanoscale materials due to the possibility of accurate characterization and manipulation of their chemical state. MPcs exhibit excellent chemical and thermal stabilities, uncomplicated synthesis, and tunable physical properties, and, today they are widely employed as building blocks for molecular switches and for molecular and quantum computing devices, e.g., for data storage.. MPcs exhibit excellent chemical and thermal stabilities, uncomplicated synthesis, and tunable physical properties, and, today they are widely employed as building blocks for molecular switches and for molecular and quantum computing devices, e.g., for data storage.5 These interesting properties of MPcs have spurred significant interest in the adsorption of metal phthalocyanines on single crystal surfaces of materials such as copper, silver, and aluminium.. Surface-driven modification of the molecular properties plays an important role, and recent research into phthalocyanine compounds includes the control of the Kondo effect, switching of magnetic anisotropy, and uneven charge transfer leading to distortion and symmetry reduction.. Nona)Present address: Institut für Chemie, Karl-Franzens-Universität Graz, 8010 Graz, Austria
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
