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    Wikipedia
    https://en.wikipedia.org › wiki › Polycyclic_aromatic_hydrocarbon

    Polycyclic aromatic hydrocarbon - Wikipedia

    • A Polycyclic aromatic hydrocarbon (PAH) is a class of organic compounds that is composed of multiple aromatic rings. Most are produced by the incomplete combustion of organic matter— by engine exhaust fumes, tobacco, incinerators, in roasted meats and cereals, or when biomass burns at lower temperatures as in forest fires. The simplest representative is naphthal… 展开

    Nomenclature and structure

    The terms polyaromatic hydrocarbon, or polynuclear aromatic hydrocarbon (abbreviated as PNA) are also used for this concept.
    By definition, polycyclic aromatic hydrocarbons ha… 展开

    Bonding and aromaticity

    The aromaticity varies for PAHs. According to Clar's rule, the resonance structure of a PAH that has the largest number of disjoint aromatic pi sextets—i.e. benzene-like moieties—is the most important for the characterization … 展开

    Properties

    PAHs are nonpolar and lipophilic. Larger PAHs are generally insoluble in water, although some smaller PAHs are soluble. The larger members are also poorly soluble in organic solvents and in lipids. The larger members, e.g. p… 展开

    Why are polycyclic aromatic hydrocarbons recalcitrant?
    Polycyclic aromatic hydrocarbons (PAHs) are widespread across the globe mainly due to long-term anthropogenic sources of pollution. The inherent properties of PAHs such as heterocyclic aromatic ring structures, hydrophobicity, and thermostability have made them recalcitrant and highly persistent in the environment.
    pmc.ncbi.nlm.nih.gov
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