NMR confirms molecular switches retain function in 2D-array

May 13, 2020

Prague, 15 May 2020 - Researchers led by Jiri Kaleta of IOCB Prague have synthesized regular 2D assemblies of isotopically labelled molecular switches and measured the properties of their isomerization, revealing that formation of such an assembly doesn't hamper the photochemical switching properties of the embedded molecules. The isotopic labels came into use when measuring the switching properties using an analytic technique dependent on the labels. The team published the results in the Journal of the American Chemical Society.

Self-organization of individual molecular machines, such as motors, rotors, and switches, into regular and well-defined two- (2D) or three-dimensional (3D) arrays is a promising path towards a new generation of smart materials. Two-dimensional assemblies seem to be particularly interesting because of their possible application in fields such as optics (OLEDs) and nanoelectronics (memory devices, frequency filters, etc.).

In collaboration with researchers from the Faculty of Science, Charles University in Prague and the University of Colorado, the IOCB Prague team obtained these assemblies with a method previously tested on other molecular machines in accordance with their ongoing research in the 2D arrays of such supramolecular systems. The researchers mounted the molecular switch moieties (substituted azobenzenes) onto rod-like molecules and distributed them on the porous nanocrystals of a tris(o-phenylenedioxy)cyctlotriphosphazene (TPP) matrix. The regularly distributed straight pores enforced the regular spread and parallel orientation of these structures.

The researchers labelled the switches 15N, which allowed them to use solid-state 15N NMR spectroscopy to detect the cis/trans isomerization. A suite of other analytical techniques confirmed the regular structure of the assemblies. Comparison of thermal steps in solution and supramolecular surface inclusions revealed that switching of individual molecules is not compromised by the close proximity of neighbors.

Binding the molecular switches to the surface of a solid material produces several key advantages. Unlike in bulk crystals, the switch segments of the molecules have enough space to change their configuration. And unlike in a solution, the molecules are part of a solid periodical system, giving more control of their position, which may lead to the potential use of such materials in applications where their specific position plays a role, e.g. memory devices.
The original paper: Santos Hurtado, C.; Bastien, G.; Masat, M.; Stocek, J. R.; Dracinsky, M.; Roncevic, I.; Cisarova, I.; Rogers, C. T.; Kaleta, J., Regular Two-Dimensional Arrays of Surface-Mounted Molecular Switches: Switching Monitored by UV-vis and NMR Spectroscopy. Journal of the American Chemical Society 2020. DOI: 10.1021/jacs.0c01753

Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences (IOCB Prague)

Related Molecules Articles from Brightsurf:

Finally, a way to see molecules 'wobble'
Researchers at the University of Rochester and the Fresnel Institute in France have found a way to visualize those molecules in even greater detail, showing their position and orientation in 3D, and even how they wobble and oscillate.

Water molecules are gold for nanocatalysis
Nanocatalysts made of gold nanoparticles dispersed on metal oxides are very promising for the industrial, selective oxidation of compounds, including alcohols, into valuable chemicals.

Water molecules dance in three
An international team of scientists has been able to shed new light on the properties of water at the molecular level.

How molecules self-assemble into superstructures
Most technical functional units are built bit by bit according to a well-designed construction plan.

Breaking down stubborn molecules
Seawater is more than just saltwater. The ocean is a veritable soup of chemicals.

Shaping the rings of molecules
Canadian chemists discover a natural process to control the shape of 'macrocycles,' molecules of large rings of atoms, for use in pharmaceuticals and electronics.

The mysterious movement of water molecules
Water is all around us and essential for life. Nevertheless, research into its behaviour at the atomic level -- above all how it interacts with surfaces -- is thin on the ground.

Spectroscopy: A fine sense for molecules
Scientists at the Laboratory for Attosecond Physics have developed a unique laser technology for the analysis of the molecular composition of biological samples.

Looking at the good vibes of molecules
Label-free dynamic detection of biomolecules is a major challenge in live-cell microscopy.

Colliding molecules and antiparticles
A study by Marcos Barp and Felipe Arretche from Brazil published in EPJ D shows a model of the interaction between positrons and simple molecules that is in good agreement with experimental results.

Read More: Molecules News and Molecules Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.