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Resolving Intra- and Inter-Molecular Structure with Non-Contact Atomic Force Microscopy.

Jarvis SP - Int J Mol Sci (2015)

Bottom Line: In this review, some of the landmark results related to attaining intramolecular resolution with non-contact atomic force microscopy (NC-AFM) are summarised before focussing on recent reports probing molecular assemblies where apparent intermolecular features have been observed.Several groups have now highlighted the critical role that flexure in the tip-sample junction plays in producing the exceptionally sharp images of both intra- and apparent inter-molecular structure.In the latter case, the features have been identified as imaging artefacts, rather than real intermolecular bonds.

View Article: PubMed Central - PubMed

Affiliation: School of Physics & Astronomy, University of Nottingham, Nottingham NG7 2RD, UK. Samuel.Jarvis@nottingham.ac.uk.

ABSTRACT
A major challenge in molecular investigations at surfaces has been to image individual molecules, and the assemblies they form, with single-bond resolution. Scanning probe microscopy, with its exceptionally high resolution, is ideally suited to this goal. With the introduction of methods exploiting molecularly-terminated tips, where the apex of the probe is, for example, terminated with a single CO, Xe or H2 molecule, scanning probe methods can now achieve higher resolution than ever before. In this review, some of the landmark results related to attaining intramolecular resolution with non-contact atomic force microscopy (NC-AFM) are summarised before focussing on recent reports probing molecular assemblies where apparent intermolecular features have been observed. Several groups have now highlighted the critical role that flexure in the tip-sample junction plays in producing the exceptionally sharp images of both intra- and apparent inter-molecular structure. In the latter case, the features have been identified as imaging artefacts, rather than real intermolecular bonds. This review discusses the potential for NC-AFM to provide exceptional resolution of supramolecular assemblies stabilised via a variety of intermolecular forces and highlights the potential challenges and pitfalls involved in interpreting bonding interactions.

No MeSH data available.


Related in: MedlinePlus

Potential for submolecular imaging of supramolecular systems. (A) STM image of a complex porous hydrogen bonded network comprising a mixed phase of perylene tetra-carboxylic di-imide (PTCDI) and melamine (reprinted by permission from Macmillan Publishers Ltd.: Nature [66], copyright 2003); (B) Nanocavities formed on Cu(100) by 4,1′,4′,1″-terphenyl-1,4″-dicarboxylic acid (TDA) molecules metal-coordinated with Fe atoms imaged in STM (reprinted by permission from Macmillan Publishers Ltd.: Nature Materials [88], copyright 2004); (C) Porous metal-coordinated networks of tunable size formed by NC-Phn-CN molecules coordinated with Co atoms on Ag(111) imaged with STM (reprinted with permission from [89], copyright 2007 by the American Chemical Society); (D) Schematic and STM images of covalently-polymerised molecular assemblies of tetraphenyl porphyrin 2D networks (left) (reprinted by permission from Macmillan Publishers Ltd.: Nature Nanotechnology [90], copyright 2007) and dibromoterfluorene (DBTF) molecular wires (right) (from [91], reprinted with permission from AAAS); (E) CO-mediated NC-AFM (left) and STM (right) images of a covalently-linked oligomer following on-surface cyclisation on Au(111) (reprinted with permission from [92], copyright 2014 by the American Chemical Society); (F) CO-mediated NC-AFM image of a bonded (left) and non-bonded (right) phenazine-gold complex (schematic shows bonded geometry) (reprinted with permission from [93], copyright 2013 by the American Chemical Society).
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ijms-16-19936-f004: Potential for submolecular imaging of supramolecular systems. (A) STM image of a complex porous hydrogen bonded network comprising a mixed phase of perylene tetra-carboxylic di-imide (PTCDI) and melamine (reprinted by permission from Macmillan Publishers Ltd.: Nature [66], copyright 2003); (B) Nanocavities formed on Cu(100) by 4,1′,4′,1″-terphenyl-1,4″-dicarboxylic acid (TDA) molecules metal-coordinated with Fe atoms imaged in STM (reprinted by permission from Macmillan Publishers Ltd.: Nature Materials [88], copyright 2004); (C) Porous metal-coordinated networks of tunable size formed by NC-Phn-CN molecules coordinated with Co atoms on Ag(111) imaged with STM (reprinted with permission from [89], copyright 2007 by the American Chemical Society); (D) Schematic and STM images of covalently-polymerised molecular assemblies of tetraphenyl porphyrin 2D networks (left) (reprinted by permission from Macmillan Publishers Ltd.: Nature Nanotechnology [90], copyright 2007) and dibromoterfluorene (DBTF) molecular wires (right) (from [91], reprinted with permission from AAAS); (E) CO-mediated NC-AFM (left) and STM (right) images of a covalently-linked oligomer following on-surface cyclisation on Au(111) (reprinted with permission from [92], copyright 2014 by the American Chemical Society); (F) CO-mediated NC-AFM image of a bonded (left) and non-bonded (right) phenazine-gold complex (schematic shows bonded geometry) (reprinted with permission from [93], copyright 2013 by the American Chemical Society).

Mentions: There are a wide variety of intermolecular interactions available to stabilise 2D supramolecular networks. Even, for the moment, remaining within the confines of hydrogen bonding interactions, many complex structures can be formed exploiting a variety of molecules and hydrogen bond donors and acceptors. In the pioneering paper by Theobald et al. [66], for instance, a mixed phase of PTCDI and melamine was found to produce large porous networks of well-defined size, capable of templating the subsequent growth of C60 fullerenes, as shown in Figure 4A. In this case, the molecules arranged in a well-defined manner, maximising the number of hydrogen bonds in a way that can be easily understood. In addition, a recent AFM investigation has shown that such structures are stable across a range of insulating materials, even under ambient conditions [67]. In other systems with more complex arrangements [68,69,70] and varying molecular species [71,72,73,74], however, the location and number of hydrogen bonds formed is not always trivial to answer, often requiring simulation input. The prospect of a technique capable of single bond resolution is therefore extremely attractive, provided, of course, that the necessary care is taken in the image analysis so as not to mistakenly assign artificial interconnecting features as real bonds.


Resolving Intra- and Inter-Molecular Structure with Non-Contact Atomic Force Microscopy.

Jarvis SP - Int J Mol Sci (2015)

Potential for submolecular imaging of supramolecular systems. (A) STM image of a complex porous hydrogen bonded network comprising a mixed phase of perylene tetra-carboxylic di-imide (PTCDI) and melamine (reprinted by permission from Macmillan Publishers Ltd.: Nature [66], copyright 2003); (B) Nanocavities formed on Cu(100) by 4,1′,4′,1″-terphenyl-1,4″-dicarboxylic acid (TDA) molecules metal-coordinated with Fe atoms imaged in STM (reprinted by permission from Macmillan Publishers Ltd.: Nature Materials [88], copyright 2004); (C) Porous metal-coordinated networks of tunable size formed by NC-Phn-CN molecules coordinated with Co atoms on Ag(111) imaged with STM (reprinted with permission from [89], copyright 2007 by the American Chemical Society); (D) Schematic and STM images of covalently-polymerised molecular assemblies of tetraphenyl porphyrin 2D networks (left) (reprinted by permission from Macmillan Publishers Ltd.: Nature Nanotechnology [90], copyright 2007) and dibromoterfluorene (DBTF) molecular wires (right) (from [91], reprinted with permission from AAAS); (E) CO-mediated NC-AFM (left) and STM (right) images of a covalently-linked oligomer following on-surface cyclisation on Au(111) (reprinted with permission from [92], copyright 2014 by the American Chemical Society); (F) CO-mediated NC-AFM image of a bonded (left) and non-bonded (right) phenazine-gold complex (schematic shows bonded geometry) (reprinted with permission from [93], copyright 2013 by the American Chemical Society).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4581333&req=5

ijms-16-19936-f004: Potential for submolecular imaging of supramolecular systems. (A) STM image of a complex porous hydrogen bonded network comprising a mixed phase of perylene tetra-carboxylic di-imide (PTCDI) and melamine (reprinted by permission from Macmillan Publishers Ltd.: Nature [66], copyright 2003); (B) Nanocavities formed on Cu(100) by 4,1′,4′,1″-terphenyl-1,4″-dicarboxylic acid (TDA) molecules metal-coordinated with Fe atoms imaged in STM (reprinted by permission from Macmillan Publishers Ltd.: Nature Materials [88], copyright 2004); (C) Porous metal-coordinated networks of tunable size formed by NC-Phn-CN molecules coordinated with Co atoms on Ag(111) imaged with STM (reprinted with permission from [89], copyright 2007 by the American Chemical Society); (D) Schematic and STM images of covalently-polymerised molecular assemblies of tetraphenyl porphyrin 2D networks (left) (reprinted by permission from Macmillan Publishers Ltd.: Nature Nanotechnology [90], copyright 2007) and dibromoterfluorene (DBTF) molecular wires (right) (from [91], reprinted with permission from AAAS); (E) CO-mediated NC-AFM (left) and STM (right) images of a covalently-linked oligomer following on-surface cyclisation on Au(111) (reprinted with permission from [92], copyright 2014 by the American Chemical Society); (F) CO-mediated NC-AFM image of a bonded (left) and non-bonded (right) phenazine-gold complex (schematic shows bonded geometry) (reprinted with permission from [93], copyright 2013 by the American Chemical Society).
Mentions: There are a wide variety of intermolecular interactions available to stabilise 2D supramolecular networks. Even, for the moment, remaining within the confines of hydrogen bonding interactions, many complex structures can be formed exploiting a variety of molecules and hydrogen bond donors and acceptors. In the pioneering paper by Theobald et al. [66], for instance, a mixed phase of PTCDI and melamine was found to produce large porous networks of well-defined size, capable of templating the subsequent growth of C60 fullerenes, as shown in Figure 4A. In this case, the molecules arranged in a well-defined manner, maximising the number of hydrogen bonds in a way that can be easily understood. In addition, a recent AFM investigation has shown that such structures are stable across a range of insulating materials, even under ambient conditions [67]. In other systems with more complex arrangements [68,69,70] and varying molecular species [71,72,73,74], however, the location and number of hydrogen bonds formed is not always trivial to answer, often requiring simulation input. The prospect of a technique capable of single bond resolution is therefore extremely attractive, provided, of course, that the necessary care is taken in the image analysis so as not to mistakenly assign artificial interconnecting features as real bonds.

Bottom Line: In this review, some of the landmark results related to attaining intramolecular resolution with non-contact atomic force microscopy (NC-AFM) are summarised before focussing on recent reports probing molecular assemblies where apparent intermolecular features have been observed.Several groups have now highlighted the critical role that flexure in the tip-sample junction plays in producing the exceptionally sharp images of both intra- and apparent inter-molecular structure.In the latter case, the features have been identified as imaging artefacts, rather than real intermolecular bonds.

View Article: PubMed Central - PubMed

Affiliation: School of Physics & Astronomy, University of Nottingham, Nottingham NG7 2RD, UK. Samuel.Jarvis@nottingham.ac.uk.

ABSTRACT
A major challenge in molecular investigations at surfaces has been to image individual molecules, and the assemblies they form, with single-bond resolution. Scanning probe microscopy, with its exceptionally high resolution, is ideally suited to this goal. With the introduction of methods exploiting molecularly-terminated tips, where the apex of the probe is, for example, terminated with a single CO, Xe or H2 molecule, scanning probe methods can now achieve higher resolution than ever before. In this review, some of the landmark results related to attaining intramolecular resolution with non-contact atomic force microscopy (NC-AFM) are summarised before focussing on recent reports probing molecular assemblies where apparent intermolecular features have been observed. Several groups have now highlighted the critical role that flexure in the tip-sample junction plays in producing the exceptionally sharp images of both intra- and apparent inter-molecular structure. In the latter case, the features have been identified as imaging artefacts, rather than real intermolecular bonds. This review discusses the potential for NC-AFM to provide exceptional resolution of supramolecular assemblies stabilised via a variety of intermolecular forces and highlights the potential challenges and pitfalls involved in interpreting bonding interactions.

No MeSH data available.


Related in: MedlinePlus