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  2. Three-center four-electron bond - Wikipedia

    en.wikipedia.org/.../Three-center_four-electron_bond

    3, X = F, Br, Cl, I) via a molecular orbital (MO) description, building on the concept of the "half-bond" introduced by Rundle in 1947. [ 4 ] [ 5 ] In this model, two of the four electrons occupy an all in-phase bonding MO, while the other two occupy a non-bonding MO, leading to an overall bond order of 0.5 between adjacent atoms (see Molecular ...

  3. Pauling's rules - Wikipedia

    en.wikipedia.org/wiki/Pauling's_rules

    For a given cation, Pauling defined [2] the electrostatic bond strength to each coordinated anion as =, where z is the cation charge and ν is the cation coordination number. A stable ionic structure is arranged to preserve local electroneutrality , so that the sum of the strengths of the electrostatic bonds to an anion equals the charge on ...

  4. Hypervalent molecule - Wikipedia

    en.wikipedia.org/wiki/Hypervalent_molecule

    Relative bond strengths in pentacoordinated silicon compounds. In A, the Si-O bond length is 1.749Å and the Si-I bond length is 3.734Å; in B, the Si-O bond lengthens to 1.800Å and the Si-Br bond shortens to 3.122Å, and in C, the Si-O bond is the longest at 1.954Å and the Si-Cl bond the shortest at 2.307A. [28]

  5. Inductive effect - Wikipedia

    en.wikipedia.org/wiki/Inductive_effect

    In Organic chemistry, the inductive effect in a molecule is a local change in the electron density due to electron-withdrawing or electron-donating groups elsewhere in the molecule, resulting in a permanent dipole in a bond. [1] It is present in a σ (sigma) bond, unlike the electromeric effect which is present in a π (pi) bond.

  6. VSEPR theory - Wikipedia

    en.wikipedia.org/wiki/VSEPR_theory

    A bond of higher bond order also exerts greater repulsion since the pi bond electrons contribute. [10] For example in isobutylene, (H 3 C) 2 C=CH 2, the H 3 CC=C angle (124°) is larger than the H 3 CC−CH 3 angle (111.5°). However, in the carbonate ion, CO 2− 3, all three C−O bonds are equivalent with angles of 120° due to resonance.

  7. Superacid - Wikipedia

    en.wikipedia.org/wiki/Superacid

    At 140 °C (284 °F), FSO 3 H–SbF 5 protonates methane to give the tertiary-butyl carbocation, a reaction that begins with the protonation of methane: [4] CH 4 + H + → CH + 5 CH + 5 → CH + 3 + H 2 CH + 3 + 3 CH 4 → (CH 3) 3 C + + 3H 2. Common uses of superacids include providing an environment to create, maintain, and characterize ...

  8. Sulfur oxoacid - Wikipedia

    en.wikipedia.org/wiki/Sulfur_oxoacid

    3 (ammonium salt prepared in anhydrous methanol at −80 °C [1]) Aqueous solutions decompose. Disulfurous acid or pyrosulfurous acid: H 2 S 2 O 5 +5 (of the sulfur atom bonded to 3 oxygen atoms), +3 (of other sulfur atom) Disulfite commonly known as metabisulfite, S 2 O 2− 5: Not known. Sulfurous acid: H 2 SO 3 +4 Bisulfite, HSO − 3 and ...

  9. Tetrahedral molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Tetrahedral_molecular_geometry

    In a tetrahedral molecular geometry, a central atom is located at the center with four substituents that are located at the corners of a tetrahedron.The bond angles are arccos(− ⁠ 1 / 3 ⁠) = 109.4712206...° ≈ 109.5° when all four substituents are the same, as in methane (CH 4) [1] [2] as well as its heavier analogues.