Differing HOMO and LUMO Mediated Conduction in a Porphyrin Nanorod

Friesen, Benjamin A.; Wiggins, Bryan; McHale, Jeanne L.; Mazur, Ursula; Hipps, K. W.

doi:10.1021/ja103078q

Cited by 65 publications

(65 citation statements)

References 15 publications

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“…The image clearly shows that the molecules are organized in a square lattice, with a spacing of (1.48 ± 0.04) nm, which is not compatible with the hexagonal symmetry of the substrate: this suggests that the molecule‐molecule interactions are stronger than those between each porphyrin and the graphite surface. These findings are in agreement both with recent theoretical calculations and with experimental observation of H 2 TPP aggregates on metallic substrates and in different environments . The square lattice is almost parallel to the exfoliation direction, suggesting that such an alignment could be influenced by the presence of surface steps created in the HOPG surface during exfoliation (see Figure ).…”

Section: Resultssupporting

confidence: 92%

Stable Alignment of Tautomers at Room Temperature in Porphyrin 2D Layers

Bussetti

Campione

Riva

et al. 2013

Adv Funct Materials

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A major challenge in molecular electronics is to develop logic devices based on a truly intramolecular switching mechanism. Recently, a new type of molecular device has been proposed where the switching characteristic is mediated by the bistability in the position of the two hydrogen atoms which can occupy different, energetically equivalent positions (tautomerization) in the inner cavity of porphyrins and naphthalocyanines. Up to now, such a reaction has only been exploited at low temperatures and induced or detected through atomic scale manipulation. In addition, the unpredictability of the tautomer orientation currently excludes molecular interconnection to functional electronic circuits. Here, full evidence is provided that, following a newly proposed growth strategy, 2D layers of metal-free tetraphenylporphyrins (H2TPP) show frozen tautomerization even at room temperature on macroscopic domains, with the H atoms aligned along a direction settled a priori. This behavior is ascribed to the buckling of the molecule, anchored to the substrate, which removes the degeneracy between the two tautomer alignments. On this basis, a new way to exploit uniaxially oriented H2TPP tautomers in a first elementary logic device is proposed

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Section: Resultssupporting

confidence: 92%

Stable Alignment of Tautomers at Room Temperature in Porphyrin 2D Layers

Bussetti

Campione

Riva

et al. 2013

Adv Funct Materials

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“…Porphyrin nanostructures may demonstrate some degree of conductivity [19,20,[22][23][24][25][26][27][49][50][51] due to intermolecular transfer or delocalization of the excitation energy in their nanostructures, which generates photoconductance. Most studies so far have dealt with the Jaggregate nanorods self-assembled from metal-free porphyrins [23][24][25][26][27][28] as it was discussed in the introduction section. Frenkel exciton transport was also extensively studied and discussed in the tubular J-aggregates of the H4TPPS 2self-assembly [30,52,53].…”

Section: Photoconductivitymentioning

confidence: 99%

“…Porphyrin nanostructures, polymers, and arrays demonstrate some degree of conductivity and their conductivities have been investigated [19][20][21][22][23][24][25][26][27][28]. Ability of porphyrin molecules to absorb certain wavelengths in the visible wavelength spectrum promotes intermolecular transfer or delocalization of the excitation energy in their nanostructures, which generates photoconductivity [6,7,25,29].…”

Section: Introductionmentioning

confidence: 99%

Self-assembly and photoconductivity of binary porphyrin nanostructures of meso -tetrakis(4-sulfonatophenyl)porphine and Co(III) meso -tetra(4-pyridyl)porphine chloride

Koposova

Ermolenko

Offenhäusser

et al. 2018

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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“…By embracing the supramolecular approach, 1-3 that relies on spontaneous association of suitably designed small molecules into one-, two-and three-dimensional superstructures, this spatial control may be attained via self-assembly of suitably designed molecular building blocks. 25 STM was used to explore the self-assembly of porphyrins under ultra-high vacuum (UHV) on graphite 26 and metallic substrates [27][28][29] , and under ambient conditions on graphite supports. [4][5][6][7][8][9][10][11][12][13][14][15][16] Self-assembly at interfaces enables the controlled positioning of functional units with sub-nanometer precision over areas of micrometers and thereby allows the fine-tuning of numerous properties of the resulting nanostructures [17][18][19][20][21] for technological applications, in particular in optics, catalysis, electronics and sensing.…”

Section: Introductionmentioning

confidence: 99%

Molecular design driving tetraporphyrin self-assembly on graphite: a joint STM, electrochemical and computational study

et al. 2016

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Tuning the intermolecular interactions among suitably designed molecules forming highly ordered self-assembled monolayers is a viable approach to control their organization at the supramolecular level. Such a tuning is particularly important when applied to sophisticated molecules combining functional units which possess specific electronic properties, such as electron/energy transfer, in order to develop multifunctional systems. Here we have synthesized two tetraferrocene-porphyrin derivatives that by design can selectively self-assemble at the graphite/liquid interface into either face-on or edge-on monolayer-thick architectures. The former supramolecular arrangement consists of two-dimensional planar networks based on hydrogen bonding among adjacent molecules whereas the latter relies on columnar assembly generated through intermolecular van der Waals interactions. Scanning Tunneling Microscopy (STM) at the solid-liquid interface has been corroborated by cyclic voltammetry measurements and assessed by theoretical calculations to gain multiscale insight into the arrangement of the molecule with respect to the basal plane of the surface. The STM analysis allowed the visualization of these assemblies with a sub-nanometer resolution, and cyclic voltammetry measurements provided direct evidence of the interactions of porphyrin and ferrocene with the graphite surface and offered also insight into the dynamics within the face-on and edge-on assemblies. The experimental findings were supported by theoretical calculations to shed light on the electronic and other physical properties of both assemblies. The capability to engineer the functional nanopatterns through self-assembly of porphyrins containing ferrocene units is a key step toward the bottom-up construction of multifunctional molecular nanostructures and nanodevices.

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Differing HOMO and LUMO Mediated Conduction in a Porphyrin Nanorod

Cited by 65 publications

References 15 publications

Stable Alignment of Tautomers at Room Temperature in Porphyrin 2D Layers

Stable Alignment of Tautomers at Room Temperature in Porphyrin 2D Layers

Self-assembly and photoconductivity of binary porphyrin nanostructures of meso -tetrakis(4-sulfonatophenyl)porphine and Co(III) meso -tetra(4-pyridyl)porphine chloride

Molecular design driving tetraporphyrin self-assembly on graphite: a joint STM, electrochemical and computational study

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