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  2. List of esters - Wikipedia

    en.wikipedia.org/wiki/List_of_esters

    An ester of carboxylic acid.R stands for any group (organic or inorganic) and R′ stands for organyl group.. In chemistry, an ester is a compound derived from an acid (organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group (−OH) of that acid is replaced by an organyl group (−R).

  3. 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 ...

  4. Hückel's rule - Wikipedia

    en.wikipedia.org/wiki/Hückel's_rule

    In 2011, Jordi Poater and Miquel Solà expanded the rule to open-shell spherical compounds, finding they were aromatic when they had 2n 2 + 2n + 1 π-electrons, with spin S = (n + 1/2) - corresponding to a half-filled last energy level with the same spin. For instance C 60 1– is also observed to be aromatic with a spin of 11/2. [16]

  5. 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 ...

  6. Aliphatic compound - Wikipedia

    en.wikipedia.org/wiki/Aliphatic_compound

    Acyclic aliphatic/non-aromatic compound Cyclic aliphatic/non-aromatic compound (cyclobutane)In organic chemistry, hydrocarbons (compounds composed solely of carbon and hydrogen) are divided into two classes: aromatic compounds and aliphatic compounds (/ ˌ æ l ɪ ˈ f æ t ɪ k /; G. aleiphar, fat, oil).

  7. Aroma compound - Wikipedia

    en.wikipedia.org/wiki/Aroma_compound

    Fragrance bottles. An aroma compound, also known as an odorant, aroma, fragrance or flavoring, is a chemical compound that has a smell or odor.For an individual chemical or class of chemical compounds to impart a smell or fragrance, it must be sufficiently volatile for transmission via the air to the olfactory system in the upper part of the nose.

  8. Simple aromatic ring - Wikipedia

    en.wikipedia.org/wiki/Simple_aromatic_ring

    Many simple aromatic rings have trivial names. They are usually found as substructures of more complex molecules ("substituted aromatics"). Typical simple aromatic compounds are benzene, indole, and pyridine. [1] [2] Simple aromatic rings can be heterocyclic if they contain non-carbon ring atoms, for example, oxygen, nitrogen, or sulfur.

  9. Ester - Wikipedia

    en.wikipedia.org/wiki/Ester

    An ester of a carboxylic acid.R stands for any group (typically hydrogen or organyl) and R ′ stands for any organyl group.. In chemistry, an ester is a compound derived from an acid (organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group (−OH) of that acid is replaced by an organyl group (R ′). [1]