Understanding the Interaction of the Porphyrin Macrocycle to Reactive Metal Substrates: Structure, Bonding, and Adatom Capture
Journal article, 2011
We investigate the absorption and conformation of free-base porphines on Cu(110) using STM, reflection absorption infrared spectroscopy, and periodic DFT calculations in order to understand how the central polypyrrole macrocycle, common to all porphyrins, interacts with a reactive metal surface. We find that,the-macrocycle forms a chemisorption bond with the surface,, arising from electron donation into down-shifted, and nearly degenerate unoccupied porphine orbitals accompanied with electron back-donation from molecular pi-orbitals. Our calculations show that van der Waals interactions give rise to an overall Increase in the adsorption energy but only minor changes in the adsorption geometry and electronic structure. In addition, we observe copper adatoms being weakly attracted to adsorbed porphines at specific molecular sites. These results provide important insights into porphyrin-surface interactions that ultimately, will govern the design of robust surface mounted molecular devices based on this important class of molecules.
tetrapyridyl
cu(110)
Cu(110) surface
ptcda
scanning
chemistry
stm
functional calculations
molecular adsorption
molecules
van der Waals interactions
reflection absorption infrared spectra
adsorption
density
free-base porphine
surface
ag(110)
tunneling microscopy
au(111)
Author
M. S. Dyer
University of Liverpool
A. Robin
University of Liverpool
S. Haq
University of Liverpool
R. Raval
University of Liverpool
Mats Persson
Chalmers, Applied Physics, Materials and Surface Theory
J. Klimes
University College London (UCL)
ACS Nano
1936-0851 (ISSN) 1936-086X (eISSN)
Vol. 5 3 1831-1838Subject Categories
Chemical Sciences
DOI
10.1021/nn102610k