Deep-Dive Guides · Organic Spectroscopy & Structure Determination
Spectroscopy for Organic Structure Determination — the complete deep dive
Four spectroscopic methods, used together, take an unknown to a structure. Mass spectrometry gives the molecular mass, formula, and skeleton clues from fragmentation. IR is a functional-group detector. UV-Vis reports conjugation. NMR (¹H and ¹³C) is the connectivity engine.
Free extract — the opening section of the guide, in full.
0. The four-technique workflow
Each method answers a different question; the power is in combining them, always anchored to the molecular formula's degree of unsaturation (DBE) (see the Characterization guide).
| Technique | Physics probed | What it tells you |
|---|---|---|
| MS | mass/charge of ions | molecular mass, formula (HRMS), heteroatoms (isotopes), skeleton (fragments) |
| IR | bond-vibration energies | functional groups present/absent |
| UV-Vis | π→π*, n→π* electronic transitions | extent of conjugation, chromophores |
| ¹H / ¹³C NMR | nuclear spin in a field | number & type of H/C environments, connectivity, stereochem |
Read the rest of this guide
The remaining 11 sections — Mass spectrometry, Infrared spectroscopy, UV-Visible spectroscopy, ¹H NMR and more — are part of ChemVidya Full Access, along with the other guides, the books, the study notes and 6,000+ practice questions with worked solutions.