Introduction Cycloalkanes, also known as cycloparaffins, are saturated hydrocarbons in which the carbon atoms are joined together in a ring or cyclic structure. Since they are “saturated,” every carbon atom is connected by single bonds (sigma bonds) and carries the maximum possible number of hydrogen atoms. The general formula for a cycloalkane is CnH2n (where … Read more
Introduction Baeyer’s Strain Theory assumed that bonds are straight lines between nuclei. Coulson and Moffitt (1947) corrected this by applying quantum mechanics, proving that in small rings like cyclopropane, bonds are actually curved. The Concept of Bent (Banana) Bonds In a normal alkane, carbon uses sp3 hybrid orbitals to form bonds. For maximum strength, these … Read more
Introduction: Sachse-Mohr’s Theory was proposed by Hermann Sachse in 1890 and later refined by Ernst Mohr in 1918. It can be summarized in one sentence: “Rings don’t have to be flat.” While previous theories (like Baeyer’s) assumed that carbon rings were almost flat, Sachse and Mohr realized that larger rings “pucker” or fold into 3D … Read more
Introduction Understanding the specific types of strain is crucial for fully grasping cycloalkane stability. The total Ring Strain is the sum of three main components: Ring Strain = Angle Strain + Torsional Strain + Steric Strain Angle Strain (EA) Torsional Strain (ET) Steric Strain (ES) Summary of Strains in Small Rings The total strain energy … Read more
Baeyer Strain Theory explains why some rings of carbon atoms (cycloalkanes) are very stable while others are “unhappy” and want to break open. The stability of cycloalkanes is explained by the concept of ring strain. It is the total strain energy stored in a cyclic molecule due to its geometry. The main contributions to ring … Read more
Naphthalene (C₁₀H₈)Bicyclic Aromatic (Fused Benzene Rings) Important Derivatives: Naphthalene sulfonates, α-Naphthol, β-Naphthol, Naphthoquinones Anthracene (C₁₄H₁₀) Linearly Fused Tricyclic Aromatic Important Derivatives: Anthraquinone, Hydroxyanthraquinones (e.g., Emodin, Chrysophanol), Danthron, Senna glycosides Phenanthrene (C₁₄H₁₀) Angularly Fused Tricyclic Aromatic Important Derivatives: Morphine, Codeine, Thebaine, Hydromorphone, Oxycodone (all phenanthrene alkaloids) Diphenylmethane ( C₁₃H₁₂ ) Non-Fused Aromatic (Two Benzene rings linked … Read more
Introduction Naphthalene is a simple organic compound made of two benzene rings fused together, looking a bit like a double hexagon. In its physical form, it appears as shiny, white crystals or flakes. Naphthalene is famous for sublimation. This means it turns directly from a solid crystal into a gas without ever melting into a … Read more