Spectrus: Handling NMR spectra with very broad peaks (aggregation or paramagnetism)

Description
Very broad NMR peaks may result from aggregation, paramagnetic centers, or slow molecular tumbling. Such spectra are challenging for assignment and quantitation, but Spectrus can still help extract limited information.

Solution

1. Import and process the spectrum (phase and baseline correction) as usual.
2. Assess overall broadening:
   • Check whether all peaks are broad or only specific regions.
3. Consider possible causes:
   • Aggregation or high molecular weight.
   • Presence of paramagnetic metal ions.
   • Strong hydrogen bonding or exchange processes.
4. In Spectrus:
   • Use zoom and vertical scaling to inspect broad features.
   • Avoid over‑reliance on automatic peak picking; manually note peak maxima or shoulders.
5. For assignments:
   • Use complementary data (MS, IR, UV, elemental analysis) to support structural proposals.
   • Treat NMR primarily as a qualitative check rather than a full assignment tool in these cases.
6. If feasible, adjust acquisition conditions (temperature, concentration, solvent, paramagnetic scavengers) and re‑acquire spectra to reduce broadening.