OrgoChem I

Spectroscopy

Use spectra as proof to confirm structures

Summary

Treat spectra as proof. Predict the structure first, then verify. Full reference is on the external link.

What you need to know:

This topic covers spectroscopy. Focus on mastering the key concepts in the "Must know checklist" below. Follow the study steps systematically, and use practice problems to reinforce your understanding. The external reference provides comprehensive coverage of all concepts.

Video Tutorial

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IR Infrared Spectroscopy Review - 15 Practice Problems

Click to watch on YouTube →

Must know checklist

0 / 5 complete

IR spectroscopyO-H (3200-3600), N-H (3300-3500), C=O (1650-1750), C=C (1600-1680), C≡C (2100-2260), C≡N (2200-2260); fingerprint region <1500
IR Infrared Spectroscopy Review - 15 Practice Problems→
Proton NMRchemical shift (deshielded = downfield), integration (H count), splitting (n+1 rule, coupling constants), symmetry
How to Read NMR Spectroscopy - Chemical Shift, Integration, Splitting→
Carbon-13 NMRchemical shift ranges (0-220 ppm), number of unique carbons, no splitting (decoupled), DEPT for CH/CH2/CH3 identification
Carbon-13 NMR Spectroscopy Explained→
Degree of unsaturation (DBE)C + 1 - H/2 - X/2 + N/2; DBE = 0 (saturated), 1 (double bond/ring), 2 (triple bond or 2 double bonds), etc.
Degree of Unsaturation - Calculating DBE from Molecular Formula→
Structure determination workflowcalculate DBE, analyze IR for functional groups, analyze NMR for connectivity, propose structure, verify all signals match
Combined Spectroscopy Problems - IR, NMR, Mass Spec→

Common mistakes

Peak hunting without a proposed structure first

Ignoring integration and splitting in 1H NMR

Over trusting one peak instead of matching all major signals