orthonym.data.fused_interior_pins

Note

Internal API. Names and behaviour may change between releases.

Fused parents the Blue Book prints with an interior-atom locant.

Numbering of interior carbon atoms (the Blue Book), (:12658): “Interior

atoms are numbered by identifying the minimum number of bonds linking them to a peripheral atom. The locant for the interior atom is that of the peripheral atom with a superscript number corresponding to the number of bonds between the two atoms.” The interior atom of phenalene is ‘3a^1’, not ‘9b’.

LIMITATIONS OF FUSION NOMENCLATURE: THREE COMPONENTS ORTHO- AND PERI-FUSED TOGETHER (:14456), (:14470): “If the corresponding hydrocarbon fused ring system can be named by fusion

principles or has a retained name, then heteroatoms are identified by skeletal replacement (‘a’) nomenclature using the appropriate ‘a’ prefixes (see. The numbering of the fused hydrocarbon system is not altered by the ‘a’ prefixes.” Its example: ‘1,3a^1,4,9-tetraazaphenalene (PIN)’ (:14491).

The names are in their own table: OPSIN 2.9.0 has no grammar for the superscript locant, so a name from this table is checked through its twin spelling with the old locant (validation.twin_spellings, rule interior_phenalene), and a shared entry of FUSED_HETEROCYCLE_DATA would reach every reader of that table at every tier. Only the default tier reads this table (rules.fused_interior).

Each entry is the parent hydride as a SMILES whose atoms are written in the order of locants: atom i carries locant i of the tuple (peripheral locants as in 1H-phenalene, the interior atom last).

orthonym.data.fused_interior_pins.INTERIOR_PIN_PARENTS: Dict[str, Dict] = {'N1=CC=C2N=CC=C3C=CC=C1N23': {'bluebook': 'P-51.4.2.4 :23474, :23486', 'locants': (1, 2, 3, '3a', 4, 5, 6, '6a', 7, 8, 9, '9a', '3a^1'), 'name': '1,3a^1,4-triazaphenalene'}, 'N1=CC=C2N=CC=C3C=CN=C1N23': {'bluebook': 'P-25.5.1.1 :14470, :14491', 'locants': (1, 2, 3, '3a', 4, 5, 6, '6a', 7, 8, 9, '9a', '3a^1'), 'name': '1,3a^1,4,9-tetraazaphenalene'}}

skeleton SMILES (atom order = numbering) -> the printed parent