orthonym.rules.pyrrole_type

Note

Internal API. Names and behaviour may change between releases.

The pyrrole-type atom of a monocyclic mancude parent.

orthonym.rules.pyrrole_type.is_pyrrole_type(atom)

True for a ring nitrogen or phosphorus that holds three single bonds, whatever the third bond carries: the N-H, or the N-substituent of 1,2-dimethyl-4,5-dihydro-1H-imidazole. It is the atom the mancude parent carries its indicated hydrogen on, the Blue Book, “imidazole (1H-isomer shown; the PIN is 1H-imidazole)”; ‘2-hydrazinyl-4,5-dihydro-1H-imidazole (PIN)’,:19389). Taking only the N-H left a molecule with no N-H to the order of its atoms, which put the hydrogen on the =N- and sent one drawing of the ring to the Hantzsch-Widman name (‘1,2-dimethyl-4,5-dihydro-1H-1,3-diazole’) and another to imidazole.