Angewandte Chemie - International Edition
Angewandte Chemie - International Edition
5 years ago

Intramolecular Hydrogen Bonding Restricts Gd–Aqua-Ligand Dynamics

Intramolecular Hydrogen Bonding Restricts Gd–Aqua-Ligand Dynamics
Hee-Kyung Kim, Andrei V. Astashkin, Oleg G. Poluektov, Jens Niklas, Eszter Boros, Raja Srinivas, Peter Caravan, Arnold M. Raitsimring, Andrew D. Horning, Bruce Tidor
Aqua ligands can undergo rapid internal rotation about the M−O bond. For magnetic resonance contrast agents, this rotation results in diminished relaxivity. Herein, we show that an intramolecular hydrogen bond to the aqua ligand can reduce this internal rotation and increase relaxivity. Molecular modeling was used to design a series of four Gd complexes capable of forming an intramolecular H-bond to the coordinated water ligand, and these complexes had anomalously high relaxivities compared to similar complexes lacking a H-bond acceptor. Molecular dynamics simulations supported the formation of a stable intramolecular H-bond, while alternative hypotheses that could explain the higher relaxivity were systematically ruled out. Intramolecular H-bonding represents a useful strategy to limit internal water rotational motion and increase relaxivity of Gd complexes. Stop the spin: For Gd3+ complexes used in magnetic resonance imaging, rapid rotation of the aqua ligand about the Gd−O bond results in diminished relaxivity. Attenuation of this internal motion is demonstrated to result from the formation of an intramolecular hydrogen bond to the aqua ligand.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/anie.201702274

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.