3 years ago

Electrostatic Constraints Assessed by 1H MAS NMR Illuminate Differences in Crystalline Polymorphs

Electrostatic Constraints Assessed by 1H MAS NMR Illuminate Differences in Crystalline Polymorphs
Jayasubba Reddy Yarava, Manoj Kumar Pandey, Yusuke Nishiyama, Kamal H. Mroue, Kortney M. Kersten, Ayyalusamy Ramamoorthy, Joshua T. Damron, Adam J. Matzger
Atomically resolved crystal structures not only suffer from the inherent uncertainty in accurately locating H atoms but also are incapable of fully revealing the underlying forces enabling the formation of final structures. Therefore, the development and application of novel techniques to illuminate intermolecular forces in crystalline solids are highly relevant to understand the role of hydrogen atoms in structure adoption. Novel developments in 1H NMR MAS methodology can now achieve robust measurements of 1H chemical shift anisotropy (CSA) tensors which are highly sensitive to electrostatics. Herein, we use 1H CSA tensors, measured by MAS experiments and characterized using DFT calculations, to reveal the structure-driving factors between the two polymorphic forms of acetaminophen (aka Tylenol or paracetamol) including differences in hydrogen bonding and the role of aromatic interactions. We demonstrate how the 1H CSAs can provide additional insights into the static picture provided by diffraction to elucidate rigid molecules.

Publisher URL: http://dx.doi.org/10.1021/acs.jpclett.7b01650

DOI: 10.1021/acs.jpclett.7b01650

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.