Aromatic Unsaturated Hydrocarbons

Albert [53] developed a GC method for determining the types of hydrocarbons (aromatics, unsaturated, n-alkanes and isoalkanes) in mixtures of Cs-Cn hydrocarbons. The method is based on the use of a selective liquid stationary phase, N,N-bis(2-cyanethyl) formamide, from which aromatic hydrocarbons are eluted after the other compoimds, molecular sieves, which retain n-alkanes selectively, and an absorber containing mercury perchlorate, in which unsaturated compounds are absorbed. 

Benzene, toluene, anthracene, phenanthrene, biphenyl. Aromatic hydrocarbons with unsaturated side-chains. Styrene, stilbene. 

Aromatic hydrocarbons with unsaturated side-chains. 

Considerable attention has been directed in determining the products from reactions of aliphatic hydrocarbons, aromatic compounds, and unsaturated compounds including biogenic terpenes that exhibit appreciable volatility. These studies have been conducted both in simulation chambers and using natural sunlight in the presence of NO. 

C2H2 —> unsaturated hydrocarbons —> aromatics — polynuclear aromatics —> carbon (2.91)... 

In contrast to saturated hydrocarbons, the unsaturated hydrocarbons react with atomic fluorine by two pathways, i.e. (atomic fluorine addition at >C=C< double bond and hydrogen substitution by fluorine atoms. The reaction of fluorine with aromatic hydrocarbons proceeds with the formation of F-derivatives and hydrogen atoms break off ... 

Refineries employ a wide spectrum of contact solvent processes, which are dependent upon the differential solubilities of the desirable and undesirable feedstock components. The principal steps are countercurrent extraction, separation of solvent and product by heating and fractionation, and solvent recovery. Naphthenics, aromatics, unsaturated hydrocarbons, and sulfur and other inorganics are separated, with the solvent extract yielding high-purity products. Many... 

In order to extend the applicability of the same simple methods to olefinic, polyenic, and aromatic unsaturated hydrocarbons, additional parameters are required those for the bonds involving sp carbons. One must thus consider... 

Aromatics Unsaturated hydrocarbons such as benzene, toluene, xylene, and related compounds. Aromatic compounds share electrons equally among carbon atoms. 

Aromatic hydrocarbons are unsaturated cyclic compounds that are resistant to addition reactions. The aromatic hydrocarbons derive their name from the distinctive odors they exhibited when discovered. Benzene is the most important aromatic compound. Because many other aromatic compounds are derived from benzene, it can be considered the parent of other aromatic compounds. Benzene molecular formula is... 

Antipyretic substance that reduces fever Aromatic Hydrocarbon an unsaturated cyclic hydrocarbon that does not readily undergo additional reaction, benzene and related compounds... 

C2H2 -> high unsaturated hydrocarbons -> aromatics, polynuclear aromatics > carbon... 

Chlorinated Hydrocarbons Other Chlorinated Compounds. The substitution of chlorine atom for hydrogen in a compd greatly increases the anesthetic action of the derivative. In addn, the chlorine deriv is less specific than the parent hydrocarbon in its action, and may affect other tissues along with those of the central nervous system of this body. The chlorine deriv is generally quite toxic and may cause liver, heart Sc kidney damage. As a rule, unsaturated chlorine derivs are highly narcotic but less toxic than saturated derivs. Sax(Ref 4) has discussed in detail the toxicities Sc hazards of a number of chlorinated compds, including Chlorinated Diphenyls Chlorinated Hydrocarbons, Aromatic Aliphatic Chlorinated Naphthalenes Chlorinated Phenols Chlorinated Triphenyls others. 

Although aromatic hydrocarbons are unsaturated, they have very different chemical properties to alkenes and allies. For example, benzene doesn t undergo an addition reaction with bromine despite having a double bond. 

Aromatic compounds are unsaturated cyclic molecules that possess additional stability as a result of the arrangement of 7i-electrons associated with the unsaturation of the ring system. This book will concentrate on the chemistry of benzene (4) and its derivatives and related polynuclear hydrocarbons. Aromatic compounds are also known as arenes they can becarbocydic, indicating that the ring skeleton contains only carbon atoms, or heterocyclic, with at least one atom other than carbon in the ring. These heteroatoms are typically N, O or S. Heterocyclic compounds, which can be aromatic or alicyclic, are covered in another book in this series. 

Aromatic hydrocarbons with unsaturated side chains undergo the reactions characteristic of aromatic rings and of the carbon-carbon double or triple bond. (Their analysis by spectroscopic methods is discussed in Secs. 13.15-13.16.)... 

The silanes are very easily oxidized, Si2Hg, for exampie, being spontaneously inflammable in air. In marked contrast to carbon, silicon appears to form no simple unsaturated hydrides corresponding to the olefines, acetylenes, and aromatic hydrocarbons. Solid unsaturated hydrides such as (SiH2) , of unknown constitution, have been described, though in a study of the higher silanes no solid products were found at any stage. Structurally the silanes are presumably similar to the saturated hydrocarbons. Many substituted monosilanes have been prepared, for example ... 

The nature of crude oils depends on their source. Initial separation into components is carried out by atmospheric and vacuum distillation. Heavy ends are particular boiling point cuts, which can include atmospheric gas oil (250-350°C), atmospheric residues (350°C+) vacuum gas oil (350-5S0°C) and vacuum residues (5S0°C+). The descriptions are based on boiling points and, within a particular distillation cut, various chemical species can be identified. These include saturated and unsaturated hydrocarbons, aromatic and polyaromatic hydrocarbons and inorganic atoms such as V, Ni, and S, which are associated with large organic molecules [5]. As a result of this complexity, the composition of the boiling cuts is often described in terms of their content of oils, resins and asphaltenes [6,7,8], the relative amounts of which vary depending on the cut and the source of the crude [6] Of these species, asphaltenes are particularly important in the present context since they are known to be associated with heavy coke formation [7,8]. 

Aromatic hydrocarbons (arenes) unsaturated compounds hexagonal ring structure single and multiple fused rings... 

C2H2 high unsaturated hydrocarbons aromatics polynuclear aromatics carbon... 

---