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  2. Pi bond - Wikipedia

    en.wikipedia.org/wiki/Pi_bond

    A typical triple bond, for example in acetylene (HC≡CH), consists of one sigma bond and two pi bonds in two mutually perpendicular planes containing the bond axis. Two pi bonds are the maximum that can exist between a given pair of atoms. Quadruple bonds are extremely rare and can be formed only between transition metal atoms, and consist of ...

  3. Ball-and-stick model - Wikipedia

    en.wikipedia.org/wiki/Ball-and-stick_model

    Double and triple bonds are usually represented by two or three curved rods, respectively, or alternately by correctly positioned sticks for the sigma and pi bonds. In a good model, the angles between the rods should be the same as the angles between the bonds , and the distances between the centers of the spheres should be proportional to the ...

  4. Covalent bond - Wikipedia

    en.wikipedia.org/wiki/Covalent_bond

    Pi (π) bonds are weaker and are due to lateral overlap between p (or d) orbitals. A double bond between two given atoms consists of one σ and one π bond, and a triple bond is one σ and two π bonds. [8] Covalent bonds are also affected by the electronegativity of the connected atoms which determines the chemical polarity of the bond. Two ...

  5. Pi backbonding - Wikipedia

    en.wikipedia.org/wiki/Pi_backbonding

    Oxidation of R 3 P–M complexes results in longer M–P bonds and shorter P–C bonds, consistent with π-backbonding. [13] In early work, phosphine ligands were thought to utilize 3d orbitals to form M–P pi-bonding, but it is now accepted that d-orbitals on phosphorus are not involved in bonding as they are too high in energy. [14] [15]

  6. Sigma-pi and equivalent-orbital models - Wikipedia

    en.wikipedia.org/wiki/Sigma-pi_and_equivalent...

    Linus Pauling proposed that the double bond in ethylene results from two equivalent tetrahedral orbitals from each atom, [5] which later came to be called banana bonds or tau bonds. [6] Erich Hückel proposed a representation of the double bond as a combination of a sigma bond plus a pi bond.

  7. Electronic properties of graphene - Wikipedia

    en.wikipedia.org/wiki/Electronic_properties_of...

    Sigma and pi bonds in graphene. Sigma bonds result from an overlap of sp 2 hybrid orbitals, whereas pi bonds emerge from tunneling between the protruding p z orbitals. For clarity, only one p z orbital is shown with its three nearest neighbors.

  8. How To Report On Jail Deaths - The Huffington Post

    data.huffingtonpost.com/2016/jail-deaths/howto

    1. Identify jails and police lockups in your community. There may be one county jail in your area but multiple police lockups. Contact the local sheriff and police departments to determine how many facilities hold new detainees, even if it's only for 24 to 72 hours.

  9. Valence bond theory - Wikipedia

    en.wikipedia.org/wiki/Valence_bond_theory

    Pi bonds occur when two orbitals overlap when they are parallel. [9] For example, a bond between two s-orbital electrons is a sigma bond, because two spheres are always coaxial. In terms of bond order, single bonds have one sigma bond, double bonds consist of one sigma bond and one pi bond, and triple bonds contain one sigma bond and two pi bonds.