Introduction to the Theory of Benzenoid Hydrocarbons

1 Benzenoid Hydrocarbons
1.1 Acquaintance
1.2 Nomenclature
1.3 Occurrence
1.4 Applications
1.5 Benzenoid Hydrocarbons as Pollutants

2 Benzenoid Systems
- Interlude

3 Anatomy
3.1 Symmetry
3.2 Vertices, Edges, and Related Concepts
3.3 Coloring of Vertices
3.4 Peaks and Valleys
3.5 1-Factors and Kekulé Structures
3.6 The Dualist Graph
3.7 More about Symmetry

4 Enumeration
4.1 General Principles
4.2 Symmetry
4.3 First and Second Classification
4.4 Catacondensed Benzenoid Systems
4.5 Pericondensed Benzenoid Systems
4.6 Classification According to the Number of Internal Vertices or the Number of External Vertices, and Enumeration of Chemical Isomers
4.7 Classification According to Color Excess
4.8 More about Symmetry
4.9 All-Benzenoid Systems

5 Kekulé Structures
5.1 Methods for Kekulé Structure Enumeration
5.1.1 Method of Fragmentation
5.1.2 Recurrence Relations
5.1.3 The Numeral-in-Hexagon Algorithm
5.1.4 Combinatorial Formulas
5.1.5 The Dewar-Longuet-Higgins Formula
5.1.6 The John-Sachs Formula
5.2 The Case of K = 0
5.3 Resonance Theory
5.4 Kekulé Structures and the Thermodynamic Stability of Benzenoid Hydrocarbons
5.5 Kekulé Structures and Bond Lengths
5.6 Kekulé Structures and Other Physico-Chemical Properties of Benzenoid Hydrocarbons

6 Conjugated Circuits
6.1 Alternating Cycles
6.2 The Conjugated Circuit Model
6.3 The Basic Theorem
6.4 Connection with Herndon's Resonance Theory
6.5 Algorithms and Theorems

7 Aromatic Sextets
7.1 The History of the Aromatic Sextet
7.2 Clar's Aromatic Sextet Theory
7.2.1 Clar Structural Formulas
7.2.2 Some Chemical Implications of Clar Structural Formulas
7.2.3 All-Benzenoid Systems
7.2.4 Clar Structures and Kekulé Structures
7.3 Generalized Clar Structures
7.3.1 The Super-Ring
7.4 The Sextet Polynomial
7.5 Concepts Related to the Sextet Polynomial
7.5.1 Aihara's Resonance Energy
7.5.2 The Clar Graph
7.5.3 Calculation of the Independence Polynomial
7.5.4 The Gutman