orthonym.rules.thioimides#

Note

Internal API. Names and behaviour may change between releases.

Thioimide namer, BB 33172).

A thioimide is the di-thioacyl analogue of an imide: two C(=S) groups bonded to a common nitrogen, R-C(=S)-NH-C(=S)-R'. The Blue Book PIN names one thioacyl group as the parent alkanethioamide suffix and cites the other as an N-(alkanethioyl) acyl substituent prefix (BB verbatim example):

CC(=S)NC(C)=S -> N-(ethanethioyl)ethanethioamide (PIN)

This mirrors the shipped O-imide behaviour, which the decomposition engine produces (CCC(=O)NC=O -> N-propanoylformamide): the LESS-senior (shorter) thioacyl chain becomes the parent thioamide and the MORE-senior (longer) chain becomes the N-(alkanethioyl) substituent prefix. The decomposition engine never reaches the thio case because its amide-bond SMARTS requires C(=O), so the C(=S)-N bond is not recognised as a cleavable amide bond; this dedicated graph classifier fills exactly that gap.

SCOPE (fail-closed, accuracy-first): emit ONLY when

  • exactly two thiocarbonyl carbons C(=S) share one nitrogen (the thioimide N);

  • that nitrogen carries nothing else but the two thioacyl carbons plus H (i.e. an N-H thioimide — N-substituted thioimides are NOT built here);

  • each thioacyl carbon’s remaining branch is a PLAIN, saturated, acyclic, all-carbon alkyl group (no rings, no heteroatoms, no unsaturation, no charges/radicals/isotopes) — the alkanethioyl retained acyl form only covers unbranched alkanethioyl chains here.

Anything else returns None and the dispatch cascade continues; never a wrong name.

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

orthonym.rules.thioimides.name_thioimide(mol)#

Return the N-(alkanethioyl)alkanethioamide PIN for an acyclic N-H thioimide, else None (fail-closed cascade continuation).