orthonym.rules.ring_chalcogen_oxide

Note

Internal API. Names and behaviour may change between releases.

Ring-chalcogen oxide namer /, Wave-2 completion).

A NEUTRAL ring sulfur/selenium/tellurium bearing 1-2 exocyclic terminal =O is named additively on the intact ring parent — the S-oxide sibling of the established pyridine 1-oxide N-oxide path:

O=S1c2ccccc2-c2ccccc21 -> dibenzo[b,d]thiophene 5-oxide
O=S1(=O)c2ccccc2-c2ccccc21 -> dibenzo[b,d]thiophene 5,5-dioxide
O=S1CCCC1 -> thiolane 1-oxide

SCOPE (fail-closed, accuracy-first): a single oxidised ring chalcogen; every non-ring heavy atom of the molecule is one of its oxide oxygens (bare ring system otherwise — substituted variants cascade onward); the de-oxidised base ring must resolve BOTH a name and an authoritative IUPAC locant for the chalcogen. Anything else returns None — never a wrong name.

Graph/atom classifier (no SMARTS broadening); pure — no mol mutation.

orthonym.rules.ring_chalcogen_oxide.name_ring_chalcogen_oxide(mol)

Return the additive ring-chalcogen oxide name, else None.