• ChemTube3D home
• Interactive Features

  • Explanation of features
  • Discussion forum
• Image Gallery
• C=O nucleophilic addition
  • Borohydride reduction
  • Cyanide addition
  • Hemiacetal formation
  • Grignard and organolithium addition
• C=O nucleophilic substitution
  • Ester hydrolysis/formation - acid catalysis
  • Amide formation from acid chloride
• C=O addition - loss of carbonyl oxygen
  • Acetal formation
  • Cyclic acetal formation
  • Enamine formation
  • Wittig reaction
  • Imine formation
• Conjugate addition
  • How conjugation changes the reactivity of carbonyl groups
  • Enolisation
  • Direct conjugate addition with enols
  • Conjugate addition of enolates
  • Robinson annelation
  • Dimedone synthesis
• Cycloadditions
  • Ozonolysis
• Electrophilic addition to alkenes
  • Stereospecific addition
  • Epoxidation peracid
  • Unsymmetrical alkenes HBr
  • Regioselective addition
  • Diene bromination
• Diels-Alder reactions
  • Endo v Exo
  • Diels Alder: orbital explanation for the endo rule
  • Regioselectivity in Diels-Alder
  • Dienophile stereochemistry
  • Diene stereochemistry
    • E,E diene
    • E,Z diene
    • Z,Z diene
• Nucleophilic substitution
  • Simple S_N2 reaction
  • S_N1 and S_N2
  • Carbocation structure and stability
• Elimination
  • E2 bimolecular examples
    • E2 to form diene
    • E2 Stereoselective for E
    • E2 Stereospecific Acyclic
    • E2 Cyclohexyl Diast A
    • E2 Cyclohexyl Diast B
  • E1 unimolecular
  • E1cb unimolecular conjugate base
• Electrophilic aromatic substition
  • Nitration of benzene
  • Friedel-Crafts alkylation
  • Friedel-Crafts acylation
  • Sulfonation of benzene
• Enols and Enolates as nucleophiles
  • Cyclopentanone Aldol - acid cat.
  • Intramolecular aldol reactions
  • Knoevenagel condensation
  • Lithium enolates
  • Mannich reaction
  • Enolate acylation - Claisen condensation
• Pericyclic reactions
  • Cycloadditions
    • Diels Alder: orbital explanation for the endo rule
    • Regioselectivity in Diels-Alder
    • Ozonolysis 1,3-dipolar
    • Nitrone 1,3-dipolar
  • Sigmatropic rearrangements
    • [3,3]-Claisen rearrangement acyclic
    • [3,3]-Ireland-Claisen
    • [2.3]-shift sulfoxide
    • [1,5]-H shift cyclopentadiene
    • [3,3]-Fischer Indole
  • Electrocyclic reactions
    • Stereospecificity
    • Conrotatory - cyclobutene
    • Disrotatory - hexatriene
• Atomic and Molecular Orbitals
  • Atomic Orbitals
  • Simple Molecular Orbitals
    • Hydrogen
    • Fluorine
    • Methane
    • Ethylene (Ethene)
    • Acetylene(Ethyne)
    • Allene
    • Formaldehyde(Methanal)
    • Benzene
  • Butadiene Molecular Orbitals
  • Benzene Molecular Orbitals
  • Aromaticity of cyclic polyenes
• Molecular vibrations-IR
  • Water
  • Hydrogen Cyanide
  • Carbon Dioxide
  • Ammonia
  • Boron Trifluoride
  • Methane
  • Ethylene(Ethene)
  • Phophorus Pentafluoride
  • Iron Pentacarbonyl
  • Benzene
• Dipoles and Electrostatic surfaces
  • Small Polar Molecules
  • Unsaturated Molecules
  • Lone Pair Conjugation
  • Hydration of Carbonyl Compounds
• UV - conjugation
  • Butadiene v Ethylene
  • Linear Polyenes
  • Coming soon
• Coming soon - new
• Feedback to Nick Greeves

Bonding orbitals in Acetylene (Ethyne)

Use the buttons to display the Hydrogen 1s and Carbon sp orbitals that make up the sigma framework and the remaining p orbitals which form the two pi-bonds.

Observe that the two pi orbitals are perpendicular.

Explore bonding orbitals in other small molecules

Hydrogen | Fluorine | Methane | Ethylene | Acetylene | Allene | Formaldehyde | Benzene