Take a molecule apart.Put a spectrum back together.
Working tools for organic chemists. One takes a target apart, bond by bond, until everything left is something you can buy. The other works a structure back out of its spectrum.
Real molecules, in their real shapes. Tap one, or pick it up and throw it.
Disconnection
A canvas for working backwards. Hover a bond to see what cutting it would give you, click to commit, and keep going until everything left is something you can buy.
- Look-ahead
- Before you choose, the two best ways to make a bond appear as ghosts beside it.
- Reactions
- 72, from amide coupling to Diels–Alder
- Targets
- 18 worked examples, paracetamol to propranolol
- Leaves
- Marked with a rough price and, where it applies, where the compound occurs in nature.
- Route
- A shopping list and the forward synthesis, written out as you go.
NMR
A structure solver. Type in a peak table and it reads the clues the way you were taught to, then ranks candidate structures against their predicted spectra.
- Input
- A ¹H peak table. A formula, ¹³C shifts and IR bands if you have them.
- First
- Degrees of unsaturation, then fragments: an ethyl on oxygen, a para-disubstituted ring.
- Then
- Candidates ranked by how well their predicted spectrum fits, peak by peak.
- Shows
- Observed against predicted as a mirror plot, with every peak linked to its atoms.
- Unknowns
- 12 worked problems with literature shifts
The bank
A disconnection is finished when everything left can simply be bought. The bank is the list the canvas checks against: 249 building blocks, each with a rough price, and 44 of them with where they turn up in nature.
Table 1. Eight of the 249 entries, cheapest first.
| Compound | Formula | Mr | Price | Occurs in | |
|---|---|---|---|---|---|
| ethanol | commodity | ||||
| benzaldehyde | commodity | ||||
| salicylic acid | commodity | ||||
| 4-aminophenol | cheap | ||||
| 4-aminobenzoic acid | cheap | ||||
| vanillin | cheap | ||||
| phenylboronic acid | cheap | ||||
| 4-isobutylacetophenone | moderate |
How it works
Today these are rule-based engines you can see inside: 72 named reactions, shift tables and the bank. There is no language model in the loop yet.
- Real cheminformatics, in the browser
- The chemistry runs on RDKit, compiled to WebAssembly and loaded into the page. Structures are parsed, matched and drawn on your own machine. Nothing you type leaves it.
- Rules you can check
- Every reaction is a template written in reaction SMARTS. Every shift comes from textbook additivity tables. Any answer can be checked by hand, and when one is wrong you can see which rule made it.
- Where the AI comes in
- Not yet, and on purpose. The plan is to put models on top of engines like these: the model proposes a disconnection, or a structure for a spectrum, and the engine checks it. The engines are the ground truth, so they come first.
Not built yet
- Drawing or pasting your own structure
- Disconnections proposed by a model and checked by the template engine
- Open-ended structure elucidation, beyond the built-in library
- 2D NMR: COSY and HSQC
- Stereochemistry
This is a prototype. Stereochemistry is ignored throughout. Price tiers are rules of thumb, not quotes. Predicted shifts are good to about ±0.3 ppm for ¹H and ±5 ppm for ¹³C. None of it is a substitute for the literature, or for a risk assessment.
Quantum theory
Not a tool, a course. NMR works because a proton’s spin has two states; this starts further back, with what a quantum state is in the first place, and builds up from experiments you run on the page.
- Lessons
- 13, in three parts
- Each has
- An experiment to run, a prediction to make first, and questions at the end.
- Starts from
- School physics: waves, sines and cosines.
- Ends with
- State vectors, observables and density matrices.
- Follows
- Asher Peres, Quantum Theory: Concepts and Methods, chapters 1 to 3.