Little exchange at the liquid/solid interface: defect-mediated equilibration of physisorbed porphyrin monolayers

Coenen, Michiel J. J.; Cremers, Melissa; Boer, Duncan den; Bruele, Fieke J. van den; Khoury, Tony; Sintic, Maxine; Crossley, Maxwell J.; Enckevort, W.J.P. van; Hendriksen, Bas L. M.; Elemans, Johannes A. A. W.; Speller, S.

doi:10.1039/c1cc12569a

Cited by 25 publications

(50 citation statements)

References 26 publications

(5 reference statements)

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“…54 They observed the behavior of monolayers of copper 5,10,15,20tetraundecylporphyrin ((TUP)Cu, Fig. 54 They observed the behavior of monolayers of copper 5,10,15,20tetraundecylporphyrin ((TUP)Cu, Fig.…”

Section: Strong Kinetic Controlmentioning

confidence: 96%

Kinetic and thermodynamic processes of organic species at the solution–solid interface: the view through an STM

2015

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A focused review is presented on the evolution of our understanding of the kinetic and thermodynamic factors that play a critical role in the formation of well ordered organic adlayers at the solution-solid interface. While the current state of knowledge is in the very early stages, it is now clear that assumptions of kinetic or thermodynamic control are dangerous and require careful confirmation. Equilibrium processes at the solution-solid interface are being described by evolving thermodynamic models that utilize concepts from the thermodynamics of micelles. A surface adsorption version of the Born-Haber cycle is helping to extract the thermodynamic functions of state associated with equilibrium structures, but only a very few systems have been so analyzed. The kinetics of surface phase transformation, especially for polymorphic phases is in an early qualitative stage. Adsorption and desorption kinetics are just starting to be measured. The study of kinetics and thermodynamics for organic self-assembly at the solution-solid interface is experiencing very exciting and rapid growth.

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Section: Strong Kinetic Controlmentioning

confidence: 96%

Kinetic and thermodynamic processes of organic species at the solution–solid interface: the view through an STM

2015

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“…Different 2D polymorphs of Cu−C 11 P have been produced by varying the porphyrin concentration in the supernatant solution, with higher-coverage polymorphs forming at higher solution concentrations (51,52). Increasing the porphyrin concentration once a SAM has formed brings about dynamic changes to the SAM only around defects, however, indicating that the SAMs are kinetically trapped, and this trapping takes only seconds to manifest after first application of the solution to the substrate.…”

mentioning

confidence: 99%

A priori calculations of the free energy of formation from solution of polymorphic self-assembled monolayers

Reimers

Panduwinata

Visser

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

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110

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Modern quantum chemical electronic structure methods typically applied to localized chemical bonding are developed to predict atomic structures and free energies for meso-tetraalkylporphyrin self-assembled monolayer (SAM) polymorph formation from organic solution on highly ordered pyrolytic graphite surfaces. Large polymorphdependent dispersion-induced substrate−molecule interactions (e.g., −100 kcal mol −1 to −150 kcal mol −1 for tetratrisdecylporphyrin) are found to drive SAM formation, opposed nearly completely by large polymorph-dependent dispersion-induced solvent interactions (70-110 kcal mol −1 ) and entropy effects (25-40 kcal mol −1 at 298 K) favoring dissolution. Dielectric continuum models of the solvent are used, facilitating consideration of many possible SAM polymorphs, along with quantum mechanical/molecular mechanical and dispersion-corrected density functional theory calculations. These predict and interpret newly measured and existing high-resolution scanning tunnelling microscopy images of SAM structure, rationalizing polymorph formation conditions. A wide range of molecular condensed matter properties at room temperature now appear suitable for prediction and analysis using electronic structure calculations.self-assembled monolayers | density functional theory | dispersion | free energy | polymorphism A priori calculations of the free energies of chemical reactions using density functional theory (DFT) and/or ab initio methods are now well established for gas-phase processes (1, 2), gas surface reactions (3), and, using continuum self-consistent reaction field (SCRF) methods, for condensed phase processes also (4). Over the last few years, a major advance in computational methods has occurred, however, allowing for rapid and accurate evaluation of intermolecular dispersion interactions. This makes feasible similar SCRF calculations for physisorption, macromolecule structuring, and other self-assembly processes in condensed phases. We present the first application of this type, to our knowledge, considering the free energy of formation of various polymorphs of tetraalkylporphyrin self-assembled monolayers (SAMs) at solid/liquid interfaces on highly ordered pyrolytic graphite (HOPG) surfaces. Calculated structures and free energies are used to interpret new and existing high-resolution scanning tunneling microscopy (STM) images, focusing on the critical roles played by the dispersion interaction in driving SAM formation and by entropy and dispersion-based desolvation effects that oppose it.Calculating a priori free energies for SAM formation from solution is a significant challenge. Accurate representations of the substrate−molecule energies, the intermolecular energies, the solvent interaction energies, and the effects of solvent structure are required, a set of tasks that, with a few exceptions (see e.g., refs. 5 and 6), has remained prohibitive a priori. Alternatively, model calculations have been useful for identifying key qualitative features (7-11), whereas some full molecular dynamics si...

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“…This means that the relative abundance of the polymorphs on the surface is completely governed by kinetics. We found that transformation of domains from one polymorph to another can only occur at specific defect sites in the physisorbed layer 33. Domains lacking these defects were found to be unable to adapt to a changing composition of the supernatant for timescales of at least hours to days.…”

Section: Introductionmentioning

confidence: 89%

“…Self‐assembled molecular networks of (TUP)Cu on HOPG are, in many cases, not in thermodynamic equilibrium with the supernatant solution 33. We observed that adsorption of the molecules at the interface, upon application of the solution to the surface, is a fast process (on the order of seconds), whereas their desorption is extremely slow.…”

Section: Introductionmentioning

confidence: 91%

“…The surface areas of the unit cells of these polymorphs are 3.72±0.26, 2.54±0.12, and 2.07±0.16 nm 2 for B, M, and S, respectively. We studied the self‐assembly of (TUP)Cu in this and our previous studies32, 33 because this molecule lacks variation in metal‐centered redox states, which eliminates the possibilities of side effects that might influence structural behavior. However, the surface polymorph behavior was found to be independent of the nature of the central metal in the porphyrin core, as the zinc, nickel, cobalt, and free‐base analogues of (TUP)Cu also self‐assemble into the same polymorphs, with the same unit cell parameters (within experimental error).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Nanostructuring of Self‐Assembled Porphyrin Networks at a Solid/Liquid Interface: Local Manipulation under Global Control

Coenen¹,

Khoury²,

Crossley³

et al. 2014

ChemPhysChem

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Molecules of (5,10,15,20-tetraundecylporphyrinato)-copper(II) [(TUP)Cu] can self-assemble into four different polymorphs at the interface between highly oriented pyrolytic graphite and 1-octanoic acid. Scanning tunneling microscopy (STM) reveals that it is possible to combine the global control over monolayer structure, provided by the composition and concentration of the supernatant solution, with local control, from nanomanipulation by the STM tip. In the initially formed monolayer, with a polymorph composition governed by the concentration of (TUP)Cu in the supernatant solution, the exchange of molecules physisorbed at the solid/liquid interface with those in the liquid is very limited. By using a nanoshaving procedure at the tip, defects are created in the monolayer, and these serve as local manipulation sites to create domains of higher or lower molecular density, and to incorporate a second molecular species, (TUP)Co into the monolayer of (TUP)Cu.

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Little exchange at the liquid/solid interface: defect-mediated equilibration of physisorbed porphyrin monolayers

Cited by 25 publications

References 26 publications

Kinetic and thermodynamic processes of organic species at the solution–solid interface: the view through an STM

Kinetic and thermodynamic processes of organic species at the solution–solid interface: the view through an STM

A priori calculations of the free energy of formation from solution of polymorphic self-assembled monolayers

Nanostructuring of Self‐Assembled Porphyrin Networks at a Solid/Liquid Interface: Local Manipulation under Global Control

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