Chemical and electronic properties of polycyclic aromatic. Aromatic compounds are cyclic structures in which each ring atom is a participant in alatex\pilatex bond, resulting in delocalized latex\pilatex electron density on both sides of the ring. Pdf on sep 17, 2011, sergio manzetti and others published chemical and electronic properties of polycyclic aromatic hydrocarbons. Today, an aromatic compound is any compound that contains a benzene ring or has certain benzenelike properties but not necessarily a strong aroma. The influence of the carbon sorbent surface structure and electron affinity of the molecule on the adsorption of poly and heterocyclic aromatic hydrocarbons is evaluated. Saturated hydrocarbons contain carboncarbon and carbonhydrogen single bonds. Carbon has a valence of four and thus requires four electrons or bonds to complete its octet in the neutral state. Properties of aromatic compounds introduction to chemistry. The aromatic hydrocarbons contain at least one unsaturated ring system with the general structure c 6 r 6, where r is any functional group see fig. Molecular elucidating of an unusual growth mechanism for. Pahs are abundant in the universe, and have recently been found to. Due to this connected network of latex\pilatex bonds, the rings are planar, unlike the boat or table structures typical of cycloalkanes. Ultradur, pbt is a plastic polymer that contains an aromatic functional group. Aromatic hydrocarbons are defined by having 6membered ring structures with alternating double bonds fig 8.
Polycyclic aromatic hydrocarbons pahs are ubiquitous, ranging from combustion chemistry to catalysis chemistry. If different carbon atoms are joined together to form open chain of carbon atoms with single bonds, they are termed as alkanes as you have already studied in unit 12. They are also produced by the thermal decomposition of organic matter. The parent hydrocarbon of this class of compounds is benzene c 6 h 6, which exhibits the resonance, or delocalization of electrons, typical of unsaturated cyclic structures.
Main idea some hydrocarbons have the same molecular formula but have different molecular structures. Polycyclic aromatic hydrocarbons are hydrocarbonsorganic compounds containing only carbon and hydrogenthat are composed of multiple aromatic rings. Aromatic hydrocarbon an overview sciencedirect topics. Aromatic hydrocarbons contain the 6membered benzene ring structure a that is characterized by alternating double bonds. The simplest such chemicals are naphthalene, having two aromatic rings, and the threering compounds anthracene and phenanthrene. Chemicalabstractservicecasregistrynumbers,chemicalformulas,molecular weights, and lengthtobreadth ratios lb andshape descriptors of pahs listedin order of. Chemicalabstractservicecasregistrynumbers,chemicalformulas, molecular weights, and lengthtobreadth ratios lb andshape descriptors of pahs listedin order of increasing molecular weight. Pahs are uncharged, nonpolar molecules found in coal and in tar deposits. Chemfacts the primary source of hydrocarbons is petroleum. Introduction hydrocarbons are organic compounds consisting of cc and ch bonds. Historically, benzenelike substances were called aromatic hydrocarbons because they had distinctive aromas.