Aliphatic hydrocarbons structure

Alicyclic Hydrocarbons. These refer to cyclic analogues of aliphatic hydrocarbons and are named accordingly, using the piefix cyclo-." Their properties are similar to their open-chain aliphatic counterparts. Alicyclic hydrocarbons are subdivided into monocyclic (cycloalkanes, cycloalkenes, cycloalkynes, cycloalkadienes, etc.) and polycyclic aliphatic compounds. Monocyclic aliphatic structures having more than 30 carbon atoms in the ring are known, but those containing 5 or 6 carbon atoms are more commonly found in nature [47, p. 28]. 

Irradiation of aliphatic thiols, sulfides, and disulfides with a mercury lamp produces gaseous products identified by the mass spectrograph. Thiols are the least stable to light, with the formation of hydrogen95-129 as the main product. Sulfides and disulfides yield, as the predominant products, saturated hydrocarbons of structures corresponding to the smallest alkyl radical attached to sulfur. Haines et al.95-97 have offered a mechanism to explain the predominant production of hydrogen during photolysis of thiols. 

Product distribution data (Table V) obtained in the hydrocracking of coal, coal oil, anthracene and phenanthrene over a physically mixed NIS-H-zeolon catalyst indicated similarities and differences between the products of coal and coal oil on the one hand and anthracene and phenanthrene on the other hand. There were differences in the conversions which varied in the order coal> anthracene>phenanthrene coal oil. The yield of alkylbenzenes also varied in the order anthracene >phenanthrene>coal oil >coal under the conditions used. The alkylbenzenes and C -C hydrocarbon products from anthracene were similar to the products of phenanthrene. The most predominant component of alkylbenzenes was toluene and xylenes were produced in very small quantities. Methane was the most and butanes the least predominant components of the gaseous product. The products of coal and coal oil were also found to be similar. The most predominant components of alkylbenzenes and gaseous product were benzene and propane respectively. The data also indicated distinct differences between products of coal origin and pure aromatic hydrocarbons. The alkyl-benzene products of coal and coal oil contained more benzene and xylenes and less toluene, ethylbenzene and higher benzenes when compared to the products from anthracene and phenanthrene. The gaseous products of coal and coal oil contained more propane and butanes and less methane and ethane when compared to the products of anthracene and phenanthrene. The differences in the hydrocracked products were obviously due to the differences in the nature of reactants. Coal and coal oil contain hydroaromatic, naphthenic, heterocyclic and aliphatic structures, in addition to polynuclear aromatic structures. Hydrocracking under severe conditions yielded more BTX as shown in Table VI. The yields of BTX obtained from coal, coal oil, anthracene and phenanthrene were respectively 18.5, 25.5, 36.0, and 32.5 percent. Benzene was the most... 

The natiue of the higlier-molecular-weight aliphatic hydrocarbons from the Murchison has been controversial. Kvenvolden et al. [33] detected a wide variety of coeluting isomers dominated by polycyclic aliphatic structures. Oro el al. [41] reported Cg to Cis metliyl and dimetliyl alkanes, alkenes, and cycloalkanes. Studier et al. [42] detected straight-chain alkanes with some isoprenoidal hydrocarbons. It is now widely believed that straight-chain alkanes were the dominant components of the ahphatic fraction in the solar nebula. However, Cronin and Pizzarello [43] analyzed organic materials from the Murchison under less environmental contamination and concluded lliat tire n-alkanes, methyl alkanes, and isoprenoid alkanes reported in the Murchison were terrestrial contaminants. Tliese authors identified Cis to C30 cyclic alkanes as the major indigenous alipliatic components. 

Eriksson, L., Sandstrom, B.E., SjQstrom, M., Tysklind, M. and Wold, S. (1993b). Modelling the Cytotoxicity of Halogenated Aliphatic Hydrocarbons. Quantitative Structure-Activity Relationships for the IC50 to Human HeLa Cells. Quant.Struct.-Act.Relat, 12,124-131. 

Even when it does not contain any RE ions, the Y zeolite is always responsible for a drop in octane number compared to the old amorphous silica-alumina-based catalysts. In order to gain a few points in the octane number, many refiners add to the principal catalyst a small percentage of a ZSM-5-based additive that has pores 0.55 nm in diameter that can only be penetrated by linear aliphatic structures and, to a lesser degree, by monobranched aliphatic structures (Tables 1 and 2). These hydrocarbons, which are those with the lowest octane number, are mainly cracked to olefin-rich LPG, obviously at the expense of a few percentage points in gasoline yield. 

The first exothermic peak was considered to be the result of thermal combustion of polysaccharides, decarboxylation of acidic groups, and dehydration of hydroxylate aliphatic structures the second exothermic peak was attributed to the combustion of aromatic structures and cleavage of C-C bonds. The high-temperature peak in the L sample was assumed to be related to high-temperature combustion accompanied by a polycondensation. In addition, the presence of long-chain hydrocarbons and N compounds can contribute to thermal reactions over 450°C. 

Mixed hydrocarbon residues (MHRs) are obtained by reevaluation of some unsaturated fractions with a wide compositional spectrum (aliphatic or aromatic) [135-137]. Introduction of aliphatic structures along with the aromatic ones in HRs generally has a favorable effect on the products obtained [138-140]. 

Contact angles were measured on plasma polymers deposited from numerous hydrocarbon monomers of different structure containing triple bond, olefinic double bonds, aromatic and aliphatic structures. The results of contact angle measurements and evaluated surface energy properties for these polymers are summarized in Table II, column A. The data for plasma polymers from acetylene, ethylene, and hexane indicate that monomer unsaturation does not change substantially the dispersion component but increases the polar component to a considerable extent as in the case of acetylene. This, undoubtedly, is due to the high concentration of radicals in PP-AC and resulting rapid formation of carbonyls and... 

The relationship between structure and properties of polyethylene is largely in accord with the principles enunciated in Chapters 4, 5 and 6. The polymer is essentially a long chain aliphatic hydrocarbon of the type... 

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