NMR assignment exercises

Interpreting NMR spectra is a skill that every chemist needs, but it requires practice and experience. A recent paper describes a new interactive website that offers many NMR assignment exercises based on experimental one- and two-dimensional spectra. Working through this website allows a user to practice and improve their NMR assignment skills. In addition, there are several other websites available that provide NMR spectra, along with MS and IR data, for users to try their hand at. This post lists some of the currently available resources.

NMR Challenge is a Czech website described in a recent paper. It provides over 160 problems in a modern interactive interface where users draw a proposed structure. Submitting the structure provides the user with an immediate assessment of its appropriateness. Basic problems use only 1D ¹H, ¹³C and ¹⁹F NMR data. Advanced problems introduce 2D spectra, such as ¹H,¹³C-HSQC and ¹H,¹³C-HMBC, and in some cases COSY and ¹H,¹⁵N-HMBC.

NMR Tips is a German website available in German and English. The 75 problems are presented as PDF slideshows with multiple steps shown for solving the problems. Exercises are broken up into introductory 1D spectra, coupling constants, 2D spectra, and non-categorized.

WebSpectra is one of the oldest NMR assignment problem websites. It was developed at UCLA and provides 74 problems based on 1D ¹H and ¹³C spectra. Some problems include ¹³C DEPT or COSY spectra, and some include IR data. Expansions of the peaks in the NMR spectra allow the user to examine the splitting patterns. Spectra and the correct structure are provided as separate links.

Organic Structure Elucidation Workbook offers 64 problems using 1D ¹H and ¹³C NMR spectra as well as IR and mass spectrometry data. The user can toggle between the various spectra. Answers are not provided but can be requested by emailing the authors at the University of Notre Dame.

References
NMR-Challenge.com: An Interactive Website with Exercises in Solving Structures from NMR Spectra
Ondřej Socha, Zuzana Osifová, and Martin Dračínský
J. Chem. Educ. 2023, 100, 2, 962–968

Acknowledgments
This post was suggested by Jim La Clair