enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Hückel's rule - Wikipedia

    en.wikipedia.org/wiki/Hückel's_rule

    For benzene the lowest π orbital is non-degenerate and can hold 2 electrons, and the next 2 π orbitals form a degenerate pair which can hold 4 electrons. The 6 π electrons in benzene therefore form a stable closed shell in a regular hexagonal molecule. [13] [8] However for cyclobutadiene or cyclooctatrene with regular geometries, the highest ...

  3. Simple aromatic ring - Wikipedia

    en.wikipedia.org/wiki/Simple_aromatic_ring

    Every atom in the ring must have an occupied p orbital, which overlaps with p orbitals on either side (completely conjugated). Molecule must be planar. It must contain an odd number of pairs of pi electrons; must satisfy Hückel's rule: (4n+2) pi electrons, where n is an integer starting at zero.

  4. Aromatic compound - Wikipedia

    en.wikipedia.org/wiki/Aromatic_compound

    Heteroarenes are aromatic compounds, where at least one methine or vinylene (-C= or -CH=CH-) group is replaced by a heteroatom: oxygen, nitrogen, or sulfur. [3] Examples of non-benzene compounds with aromatic properties are furan, a heterocyclic compound with a five-membered ring that includes a single oxygen atom, and pyridine, a heterocyclic compound with a six-membered ring containing one ...

  5. List of chemistry mnemonics - Wikipedia

    en.wikipedia.org/wiki/List_of_chemistry_mnemonics

    It is accomplished by loss of one or more electrons. The atom whose oxidation number decreases gains (receives) one or more electrons and is said to be reduced. This relation can be remembered by the following mnemonics. Leo says Ger! or Leo the lion, Ger! can be used to represent Loss of electron is oxidation; Gain of electron is reduction ...

  6. Benzene - Wikipedia

    en.wikipedia.org/wiki/Benzene

    Benzene is an organic chemical compound with the molecular formula C 6 H 6. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, benzene is classed as a hydrocarbon.

  7. Thermal rearrangement of aromatic hydrocarbons - Wikipedia

    en.wikipedia.org/wiki/Thermal_rearrangement_of...

    Both mechanisms are shown as follows for the ring contraction of biphenylene: The first involves a 1,2-hydrogen shift to a carbene followed by a 1,2-carbon shift on the same C-C bond but in opposite directions. The second differs from the first only by the order of the 1,2-shifts, with the 1,2-carbon shift preceding the 1,2-hydrogen shift.

  8. Cation–π interaction - Wikipedia

    en.wikipedia.org/wiki/Cation–π_interaction

    Benzene, the model π system, has no permanent dipole moment, as the contributions of the weakly polar carbon–hydrogen bonds cancel due to molecular symmetry.However, the electron-rich π system above and below the benzene ring hosts a partial negative charge.

  9. Cyclic compound - Wikipedia

    en.wikipedia.org/wiki/Cyclic_compound

    The model for benzene consists of two resonance forms, which corresponds to the double and single bonds superimposing to produce six one-and-a-half bonds. Benzene is a more stable molecule than would be expected without accounting for charge delocalization. [citation needed]