News News

Back

Researchers from the Schools of Chemistry and Pharmacy reveal a novel NMR technique to study internal dynamics in small organic molecules

The “inner life” of a small organic or organometallic molecule in solution can be highly “dynamic”. The spatial arrangements of the constituent atoms can change along time interconverting among different conformations of the molecule, mostly due to rotation around single covalent bonds. These processes are collectively known as intramolecular chemical exchange, and are common and important phenomena in organic molecules, that can affect important properties like reactivity. It is highly desirable to characterize the internal kinetics of chemical exchange processes in organic or organometallic molecules, in order to correlate their internal dynamics with their ability to provide a given functionality (reactivity, catalysis, etc…).  New research published in Chemical Communications proposes a novel use of an NMR methodology, well known in the field of protein screening and drug discovery, to the study of these internal chemical exchange processes.

Researchers from the Schools Pharmacy and Chemistry have been able to demonstrate that STD NMR spectroscopy, a technique originally devised to study the interactions of small molecules with protein receptors to form stable protein-ligand complexes, can be efficiently applied to characterize the kinetics of the intramolecular dynamics of small organic and organometallic complexes. The new technique is called Spin Saturation Transfer Difference NMR spectroscopy (SSTD NMR).

Dr. Jesús Angulo (PHA), and Dr. M. Paz Muñoz-Herranz (CHE), lead authors of the investigation said: “The studies of internal rotations in organic molecules by NMR date back to the early seventies, but those techniques were developed in an scenario of old NMR instruments. With the more powerful magnets and pulsed NMR techniques currently available we realized that the experiments could be made much easier to carry out.”

This is a good example of the formidable synergies existing among the different expertise available at the Faculty of Science at UEA. “We wanted to apply old NMR techniques to a particular problem in the Muñoz Organic Chemistry lab related to the kinetics of internal rotations, and ended up with the Angulo lab realizing that the same techniques that they apply to study interactions between ligand and proteins could be readily applied to this kind of problems, additionally making easier the measurements”, said Dr. Angulo and Dr. Muñoz-Herranz.

Read the publication here.

Diagram of Initial Growth Rates SSTD NMR

 

Dr Jesus Angulo photo
Dr. Jesús Angulo

Dr. M. Paz Muñoz-Herranz image
Dr. M. Paz Muñoz-Herranz