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  2. Triphenylcarbethoxymethylenephosphorane - Wikipedia

    en.wikipedia.org/wiki/Triphenylcarbethoxym...

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  3. Wittig reagents - Wikipedia

    en.wikipedia.org/wiki/Wittig_reagents

    Wittig reagents are usually described as a combination of two resonance structures: Ph 3 P + CR 2 − ↔ Ph 3 P=CR 2. The former is called the ylide form and the latter is called the phosphorane form, which is the more familiar representation. Crystallographic characterization of methylenetriphenylphosphorane shows that the phosphorus atom is ...

  4. Methylenetriphenylphosphorane - Wikipedia

    en.wikipedia.org/wiki/Methylenetriphenylphosphorane

    2 Structure. 3 Uses. 4 Related reagents. ... The compound is usually described as a combination of two resonance structures: ... triphenylphosphorane;

  5. Carbomethoxymethylenetriphenylphosphorane - Wikipedia

    en.wikipedia.org/wiki/Carbomethoxymethylenetri...

    This article about an organic compound is a stub. You can help Wikipedia by expanding it.

  6. Resonance (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Resonance_(chemistry)

    Contributing structures of the carbonate ion. In chemistry, resonance, also called mesomerism, is a way of describing bonding in certain molecules or polyatomic ions by the combination of several contributing structures (or forms, [1] also variously known as resonance structures or canonical structures) into a resonance hybrid (or hybrid structure) in valence bond theory.

  7. Clar's rule - Wikipedia

    en.wikipedia.org/wiki/Clar's_rule

    Clar's rule states that for a benzenoid polycyclic aromatic hydrocarbon (i.e. one with only hexagonal rings), the resonance structure with the largest number of disjoint aromatic π-sextets is the most important to characterize its chemical and physical properties. Such a resonance structure is called a Clar structure. In other words, a ...

  8. Mesomeric effect - Wikipedia

    en.wikipedia.org/wiki/Mesomeric_effect

    In chemistry, the mesomeric effect (or resonance effect) is a property of substituents or functional groups in a chemical compound.It is defined as the polarity produced in the molecule by the interaction of two pi bonds or between a pi bond and lone pair of electrons present on an adjacent atom. [1]

  9. Three-center four-electron bond - Wikipedia

    en.wikipedia.org/wiki/Three-center_four-electron...

    This bonding scheme is succinctly summarized by the following two resonance structures: I—I···I − ↔ I − ···I—I (where "—" represents a single bond and "···" represents a "dummy bond" with formal bond order 0 whose purpose is only to indicate connectivity), which when averaged reproduces the I—I bond order of 0.5 obtained ...