orthonym.rules.n_branch

Note

Internal API. Names and behaviour may change between releases.

The branch an amine nitrogen carries on a chain carbon, whole.

“Selection of the principal chain or senior ring system in secondary and tertiary amines”

(the Blue Book): “When a choice for parent hydride is possible between a ring and a chain, the ring is preferred.” An amine whose nitrogen is bonded to a ring and to a chain is named on the ring, the chain a prefix of the nitrogen (‘N-[1-(phenylsulfanyl)butan-2-yl]aniline (PIN)’): the chain is a substituent whatever it holds, so it is named whole by the substituent namer, rings it carries included (their own seniority is no competition for the parent: the amine is not on them). The producers of the ring parents first read a branch that is a plain alkyl; this is the other case.

The group is perceived with ONE bearing carbon of its nitrogen (seniority._normalize_pcg_match: the most heavy neighbours, then the lowest atom index), chosen before any parent is. reanchor_bridging_amine moves that carbon into the parent the selection chose, so the producers of that parent find the group on it whatever the order of the input (‘CC(C)NC1CCCCC1’ and ‘C1CCCCC1NC(C)C’ are one molecule).

orthonym.rules.n_branch.holds_amine_or_senior_group(mol, atoms)

True when atoms (the branch on a nitrogen) holds an amine or a group of a class senior to it.

(the Blue Book): “The senior parent structure has the maximum number of

substituents corresponding to the principal characteristic group (suffix)… in accord with the seniority of classes “, (:26375): in a complex polyamine the parent is chosen by . A branch that holds one more amine (‘N-(2-aminoethyl)aniline’) makes the chain the parent (‘N1-phenylethane-1,2-diamine’); one that holds a senior class (‘2-anilinoethan-1-ol’, ‘2-anilinoethane-1-peroxol’) makes that class the principal group. The nitrogen is then no suffix of the ring parent, and no ‘N-substituted aniline’ is built from it.

orthonym.rules.n_branch.amine_promotion(mol, branch_atoms, branch_name)

The payload with which a nitrogen on a ring promotes to the amine suffix of that ring (‘N-<branch>aniline’): empty when the branch holds an amine or a group senior to it (holds_amine_or_senior_group()).

orthonym.rules.n_branch.reanchor_bridging_amine(mol, principal_group, principal_group_atoms, parent_atoms)

principal_group_atoms with the bearing carbon of a secondary or tertiary amine moved into parent_atoms, when the nitrogen is bonded to a carbon of the parent, the Blue Book, the nitrogen belongs to every parent it is bonded to). A match whose carbon is in the parent already, and any other group, stay as they are.

orthonym.rules.n_branch.is_saturated_chain_carbon(atom)

True for a carbon outside every ring whose bonds are all single: the carbon of an alkyl chain, not the carbon of an acyl, imidoyl or aryl group (an amide nitrogen is another class).

orthonym.rules.n_branch.acyclic_branch_on_nitrogen(mol, carbon, blocked)

(atoms, 0) of the branch that starts at carbon, a saturated chain carbon bonded to the nitrogen, without the blocked atoms (the parent ring and the nitrogen); (None, 0) when carbon is no saturated chain carbon, the branch is bonded to a blocked atom other than the nitrogen’s own bond, or it holds an amine or a group senior to it (holds_amine_or_senior_group). The zero is the count of carbons of a plain alkyl, which this branch is not: a caller that names it by the carbon count then finds no name and declines.