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Reactivity mapping with electrochemical gradients for monitoring reactivity at surfaces in space and time.

Krabbenborg SO, Nicosia C, Chen P, Huskens J - Nat Commun (2013)

Bottom Line: Because reaction kinetics is different at surfaces compared with solution, frequently, solution-characterization techniques cannot be used.For both systems, the kinetic data were spatially visualized in a two-dimensional reactivity map.In the case of the copper(I)-catalysed azide-alkyne 1,3-dipolar cycloaddition, the reaction order (2) was deduced from it.

View Article: PubMed Central - PubMed

Affiliation: Molecular Nanofabrication Group, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, Enschede 7500 AE, The Netherlands.

ABSTRACT
Studying and controlling reactions at surfaces is of great fundamental and applied interest in, among others, biology, electronics and catalysis. Because reaction kinetics is different at surfaces compared with solution, frequently, solution-characterization techniques cannot be used. Here we report solution gradients, prepared by electrochemical means, for controlling and monitoring reactivity at surfaces in space and time. As a proof of principle, electrochemically derived gradients of a reaction parameter (pH) and of a catalyst (Cu(I)) have been employed to make surface gradients on the micron scale and to study the kinetics of the (surface-confined) imine hydrolysis and the copper(I)-catalysed azide-alkyne 1,3-dipolar cycloaddition, respectively. For both systems, the kinetic data were spatially visualized in a two-dimensional reactivity map. In the case of the copper(I)-catalysed azide-alkyne 1,3-dipolar cycloaddition, the reaction order (2) was deduced from it.

No MeSH data available.


Setup of the system.Schematic overview of the setup, showing the dimensions and overall design of the interdigitated electrode array, with which the electrochemically derived gradients are formed.
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f1: Setup of the system.Schematic overview of the setup, showing the dimensions and overall design of the interdigitated electrode array, with which the electrochemically derived gradients are formed.

Mentions: Figure 1 shows a schematic overview of the setup, showing the dimensions and overall design. As a proof of principle, electrochemically derived gradients of a reaction parameter ((pH) or concentration of a homogeneous catalyst, Cu(I)) were employed to make surface gradients on the micron scale and to study the kinetics of the (surface-confined) imine hydrolysis and the copper(I)-catalysed azide-alkyne 1,3-dipolar cycloaddition (CuAAC; ‘click’ reaction), respectively. The acid-catalysed imine hydrolysis2223 belongs to the area of dynamic covalent chemistry24, combining the reversible and dynamic properties characteristic of supramolecular chemistry with the strength and robustness of covalent bond chemistry. After introduction of the imine bond in surface chemistry25, the imine formation and hydrolysis reactions, owing to their mild reaction conditions, are being used for bioapplications26. The second (CuAAC) reaction is a widely used reaction because of its high yield, orthogonality and chemoselectivity27, which makes it a useful reaction for surface functionalization28.


Reactivity mapping with electrochemical gradients for monitoring reactivity at surfaces in space and time.

Krabbenborg SO, Nicosia C, Chen P, Huskens J - Nat Commun (2013)

Setup of the system.Schematic overview of the setup, showing the dimensions and overall design of the interdigitated electrode array, with which the electrochemically derived gradients are formed.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3644076&req=5

f1: Setup of the system.Schematic overview of the setup, showing the dimensions and overall design of the interdigitated electrode array, with which the electrochemically derived gradients are formed.
Mentions: Figure 1 shows a schematic overview of the setup, showing the dimensions and overall design. As a proof of principle, electrochemically derived gradients of a reaction parameter ((pH) or concentration of a homogeneous catalyst, Cu(I)) were employed to make surface gradients on the micron scale and to study the kinetics of the (surface-confined) imine hydrolysis and the copper(I)-catalysed azide-alkyne 1,3-dipolar cycloaddition (CuAAC; ‘click’ reaction), respectively. The acid-catalysed imine hydrolysis2223 belongs to the area of dynamic covalent chemistry24, combining the reversible and dynamic properties characteristic of supramolecular chemistry with the strength and robustness of covalent bond chemistry. After introduction of the imine bond in surface chemistry25, the imine formation and hydrolysis reactions, owing to their mild reaction conditions, are being used for bioapplications26. The second (CuAAC) reaction is a widely used reaction because of its high yield, orthogonality and chemoselectivity27, which makes it a useful reaction for surface functionalization28.

Bottom Line: Because reaction kinetics is different at surfaces compared with solution, frequently, solution-characterization techniques cannot be used.For both systems, the kinetic data were spatially visualized in a two-dimensional reactivity map.In the case of the copper(I)-catalysed azide-alkyne 1,3-dipolar cycloaddition, the reaction order (2) was deduced from it.

View Article: PubMed Central - PubMed

Affiliation: Molecular Nanofabrication Group, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, Enschede 7500 AE, The Netherlands.

ABSTRACT
Studying and controlling reactions at surfaces is of great fundamental and applied interest in, among others, biology, electronics and catalysis. Because reaction kinetics is different at surfaces compared with solution, frequently, solution-characterization techniques cannot be used. Here we report solution gradients, prepared by electrochemical means, for controlling and monitoring reactivity at surfaces in space and time. As a proof of principle, electrochemically derived gradients of a reaction parameter (pH) and of a catalyst (Cu(I)) have been employed to make surface gradients on the micron scale and to study the kinetics of the (surface-confined) imine hydrolysis and the copper(I)-catalysed azide-alkyne 1,3-dipolar cycloaddition, respectively. For both systems, the kinetic data were spatially visualized in a two-dimensional reactivity map. In the case of the copper(I)-catalysed azide-alkyne 1,3-dipolar cycloaddition, the reaction order (2) was deduced from it.

No MeSH data available.