Chemical nomenclature — IUPAC systematic naming conventions and the associated formal-language / combinatorial machinery that makes the system unambiguous. Foundations: (1) Substitutive nomenclature (IUPAC Blue Book 2013) — identify the…
chemical-nomenclature
IUPAC substitutive nomenclature: parent-chain + locants + suffix-priority
Substitutive IUPAC nomenclature (Blue Book, Favre & Powell 2013) is the canonical algorithmic procedure for naming organic compounds. Step…
CIP (Cahn-Ingold-Prelog) priority: R/S from S₄-permutation parity
Cahn-Ingold-Prelog stereodescriptors (Cahn, Ingold, Prelog 1956 / 1966). For a tetrahedral stereocenter with four distinct substituents,…
Oxidation-state assignment: EN-based bond partition; Σ OS = molecular charge
Oxidation-state assignment rules (IUPAC recommendations 2016, Karen et al.). For each atom A in the Lewis structure: (i) list its valence…
Locant-min: heptane C-3,C-4 substituents ⇒ (3,4) < (4,5) lex-min
Sympy-exact witness of the IUPAC lowest-locant rule on a heptane (n = 7) parent chain bearing two substituents at positions 3 and 4. …
CIP parity: cyclic σ=(0 1 2) sgn=+1 (S); transposition sgn=−1 (R)
Sympy-exact witness of the CIP priority-permutation parity identity using sympy.combinatorics. Permutation. The 3-cycle (0 1 2) acting on…
OS balance: KMnO₄ ⇒ Mn = +7; Cr₂O₇²⁻ ⇒ Cr = +6; Σ OS = q_mol
Sympy-exact witness of the oxidation-state conservation identity on two textbook anchors. KMnO₄ (potassium permanganate, neutral): K at…