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  2. Nitrobenzene - Wikipedia

    en.wikipedia.org/wiki/Nitrobenzene

    Nitrobenzene is an aromatic nitro compound and the simplest of the nitrobenzenes, with the chemical formula C 6 H 5 NO 2. It is a water-insoluble pale yellow oil with an almond -like odor. It freezes to give greenish-yellow crystals.

  3. 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 ]

  4. Electrophilic aromatic directing groups - Wikipedia

    en.wikipedia.org/wiki/Electrophilic_aromatic...

    On the other hand, the nitrobenzene resonance structures have positive charges around the ring system: The nitro group can withdraw electron density through resonance. Attack occurs at the meta position, since the (partial) formal positive charges at the ortho and para positions indicate electron deficiency at these positions.

  5. 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.

  6. 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 ...

  7. Nucleophilic aromatic substitution - Wikipedia

    en.wikipedia.org/wiki/Nucleophilic_aromatic...

    A 2019 review argues that such 'concerted S N Ar' reactions are more prevalent than previously assumed. [3] Aryl halides cannot undergo the classic 'backside' S N 2 reaction. The carbon-halogen bond is in the plane of the ring because the carbon atom has a trigonal planar geometry. Backside attack is blocked and this reaction is therefore not ...

  8. Béchamp reduction - Wikipedia

    en.wikipedia.org/wiki/Béchamp_reduction

    The reaction was first used by Antoine Béchamp to reduce nitronaphthalene and nitrobenzene to naphthylamine and aniline, respectively. [3] The Béchamp reduction is broadly applicable to aromatic nitro compounds. [4] [5] Aliphatic nitro compounds are however more difficult to reduce, often remaining as the hydroxylamine. Tertiary aliphatic ...

  9. Nitrosobenzene - Wikipedia

    en.wikipedia.org/wiki/Nitrosobenzene

    Nitrosobenzene was first prepared by Adolf von Baeyer by the reaction of diphenylmercury and nitrosyl bromide: [4] (C 6 H 5) 2 Hg + BrNO → C 6 H 5 NO + C 6 H 5 HgBr. A modern synthesis entails reduction of nitrobenzene to phenylhydroxylamine (C 6 H 5 NHOH) which is then oxidized by sodium dichromate (Na 2 Cr 2 O 7).