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Title: Observation of electron orbital signatures of single atoms within metal-phthalocyanines using atomic force microscopy

Journal Article · · Nature Communications

Resolving the electronic structure of a single atom within a molecule is of fundamental importance for understanding and predicting chemical and physical properties of functional molecules such as molecular catalysts. However, the observation of the orbital signature of an individual atom is challenging. We report here the direct identification of two adjacent transition-metal atoms, Fe and Co, within phthalocyanine molecules using high-resolution noncontact atomic force microscopy (HR-AFM). HR-AFM imaging reveals that the Co atom is brighter and presents four distinct lobes on the horizontal plane whereas the Fe atom displays a “square” morphology. Pico-force spectroscopy measurements show a larger repulsion force of about 5 pN on the tip exerted by Co in comparison to Fe. Our combined experimental and theoretical results demonstrate that both the distinguishable features in AFM images and the variation in the measured forces arise from Co’s higher electron orbital occupation above the molecular plane. The ability to directly observe orbital signatures using HR-AFM should provide a promising approach to characterizing the electronic structure of an individual atom in a molecular species and to understand mechanisms of certain chemical reactions.

Research Organization:
Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
Sponsoring Organization:
USDOE; National Science Foundation (NSF); Welch Foundation
Grant/Contract Number:
AC02-09CH11466; DMR-2011750; F-2094
OSTI ID:
1996982
Journal Information:
Nature Communications, Vol. 14, Issue 1; ISSN 2041-1723
Publisher:
Nature Publishing GroupCopyright Statement
Country of Publication:
United States
Language:
English

References (37)

Surface chemistry of porphyrins and phthalocyanines journal November 2015
Identification of adsorbed molecules via STM tip manipulation: CO, H 2 O, and O 2 on TiO 2 anatase (101) journal January 2014
Chemical Identification of Single Atoms in Heterogeneous III–IV Chains on Si(100) Surface by Means of nc-AFM and DFT Calculations journal July 2012
The Chemical Structure of a Molecule Resolved by Atomic Force Microscopy journal August 2009
Orbital-Resolved Imaging of the Adsorbed State of Pyridine on GaP(110) Identifies Sites Susceptible to Nucleophilic Attack journal December 2015
Remark on “algorithm 778: L-BFGS-B: Fortran subroutines for large-scale bound constrained optimization” journal November 2011
Discovering rare-earth-free magnetic materials through the development of a database journal November 2020
Accurate formulas for interaction force and energy in frequency modulation force spectroscopy journal March 2004
Imaging the wave functions of adsorbed molecules journal December 2013
Atomic Fingerprinting of Heteroatoms Using Noncontact Atomic Force Microscopy journal October 2021
H2Pc and pentacene on Cu(110)-(2×1)O: A combined STM and nc-AFM study journal June 2020
Electronic and magnetic properties of molecule-metal interfaces: Transition-metal phthalocyanines adsorbed on Ag(100) journal April 2012
Chemical identification of individual surface atoms by atomic force microscopy journal March 2007
Hydrogen Atoms under Magnification: Direct Observation of the Nodal Structure of Stark States journal May 2013
Nanostructured transition-metal phthalocyanine complexes for catalytic oxygen reduction reaction journal February 2022
Inhomogeneous Electron Gas journal November 1964
Finite-difference-pseudopotential method: Electronic structure calculations without a basis journal February 1994
Visualization of the Molecular Jahn-Teller Effect in an Insulating K4C60 Monolayer journal October 2005
Combined orbital tomography study of multi-configurational molecular adsorbate systems journal November 2019
PARSEC – the pseudopotential algorithm for real-space electronic structure calculations: recent advances and novel applications to nano-structures journal April 2006
Breaking a dative bond with mechanical forces journal September 2021
Atomically precise graphene nanoribbon heterojunctions from a single molecular precursor journal September 2017
Real-space imaging of molecular structure and chemical bonding by single-molecule inelastic tunneling probe journal May 2014
Discrimination of Bond Order in Organic Molecules Using Noncontact Atomic Force Microscopy journal July 2019
Subatomic resolution force microscopy reveals internal structure and adsorption sites of small iron clusters journal March 2015
Guide for Atomic Force Microscopy Image Analysis To Discriminate Heteroatoms in Aromatic Molecules journal April 2019
Reaction Mechanisms of Well-Defined Metal-N 4 Sites in Electrocatalytic CO 2 Reduction journal November 2018
Chemical bond formation showing a transition from physisorption to chemisorption journal September 2019
Chemical and steric effects in simulating noncontact atomic force microscopy images of organic molecules on a Cu (111) substrate journal May 2020
Electronegativity determination of individual surface atoms by atomic force microscopy journal April 2017
Scalable implementation of polynomial filtering for density functional theory calculation in PARSEC journal September 2020
Real-Space Identification of Intermolecular Bonding with Atomic Force Microscopy journal September 2013
High harmonic interferometry of multi-electron dynamics in molecules journal July 2009
Bond-Order Discrimination by Atomic Force Microscopy journal September 2012
Direct quantitative measurement of the C═O⋅⋅⋅H–C bond by atomic force microscopy journal May 2017
High-Resolution Molecular Orbital Imaging Using a p -Wave STM Tip journal August 2011
Self-Consistent Equations Including Exchange and Correlation Effects journal November 1965