orthonym.validation.spelling.checks_one_carbon_parent

Note

Internal API. Names and behaviour may change between releases.

Spelling check of the locant ‘1’ on a one-carbon amine parent; registered with orthonym.validation.pin_spelling.register()).

(the Blue Book, under “ Omission of locants”): “Locants are omitted when no

isomer can be generated by moving suffixes and/or prefixes (if any) from their position to another or by interchanging them between two different positions.” The parent ‘methanamine’ has two positions, the carbon and the nitrogen of the suffix, so the locant ‘1’ of a group on the carbon is cited exactly when a group can be moved between them:

• the nitrogen holds a hydrogen, so a group of the carbon could stand on it: ‘1-hydrazinylmethanamine (PIN)’ (:38535), ‘1-chloromethanaminium’;

• the carbon holds a hydrogen and a group of the nitrogen that keeps the parent (a ring atom or a heteroatom; an acyclic carbon would lengthen the chain) could stand on it: ‘N,1-bis(4-chlorophenyl) methanimine (PIN)’ (:26524), ‘(1E)-1-[…]-N-[…]methanimine (PIN)’ (:50452);

• otherwise no isomer exists and the locant is omitted: ‘cyano-N,N-dimethylmethanamine N-oxide (PIN)’

  “aci-Nitro compounds”,:36580), ‘(Z)-N-hydroxy(4-chlorophenyl)(phenyl)methanimine (PIN)’

  (:47666).

A protonated tertiary amine holds a hydrogen the neutral amine does not, so ‘1-methoxy-N,N-dimethyl- methanaminium’ cites the locant where ‘methoxy-N,N-dimethylmethanamine’ omits it. The check reads the structure and the name text only, and decides only when the name and the structure agree on one parent; it abstains otherwise.

orthonym.validation.spelling.checks_one_carbon_parent.one_carbon_amine_locant_check(mol, name)

The locant ‘1’ of a group on the carbon of ‘methanamine’, ‘methanaminium’, ‘methanimine’ or ‘methaniminium’ is cited exactly when requires it (see the module text).