Hydrocarbons acyclic branched

As noted above, Carlson et al. (1993) initially identified the presence of monocyclic/acyclic branched alkanes in the high molecular weight fractions. More recently Hsieh et al. (2000) noted the presence of alkylaromatic compounds in this fraction along with a wide variety of branched hydrocarbons, alkylcyclohexanes and alkylcyclopentanes. However, the need to document the identities of all the compounds completely cannot be over-emphasized. Physical properties of the branched hydrocarbons, particularly melting points, vary significantly with... 

Alkanes - Acyclic branched or unbranched hydrocarbons having the general formula and therefore consisting entirely... 

Alkenes - Acyclic branched or unbranched hydrocarbons having one carbon-carbon double bond and the general formula Acyclic branched or unbranched hydrocarbons having more than one double bond are alkadienes, alkatrienes, etc. 

Kier and Hall in 2001 considered structure space based on the connectivity indices x (as the y coordinate) and (as the x coordinate) [117]. In Figure 6.9, we show a simplified Kier and Hall plot ( x against x) for 10 hydrocarbons, acyclic and cyclic, having eight atoms and a similar branching pattern. 

Unsaturated branched acyclic hydrocarbons are named as derivatives of the chain that contains the maximum number of double and/or triple bonds. When a choice exists, priority goes in sequence to (1) the chain with the greatest number of carbon atoms and (2) the chain containing the maximum number of double bonds. 

Part A of Table 1.5 shows all the acyclic C4-C6 and some of the Cg hydrocarbons. A general trend is discernible in the data. Branched-chain hydrocarbons are more stable than straight-chain hydrocarbons. For example, A/fj for -octane is —49.82 kcal/mol, whereas the most highly branched isomer possible, 2,2,3,3-tetramethylbutane, is the most stable of the octanes, with of —53.99 kcal/mol. Similar trends are observed in the other series. 

Aliphatic Hydrocarbons. These are acyclic hydrocarbons with an open-chain structure, which can be either straight (i.e., linear) or branched. The former type are called normal (or n-) aliphatic compounds. Unsaturation is manifested in the form of double or triple bonds. 

Given the absence of methyl branches and according to the suggestive positions of the double bonds within the two acyclic C1 hydrocarbons undeca-(l,3E,52)-triene and undeca-(l,3E,5Z,8Z)-tetraene, their origin from fatty acids is highly probable. In the case of higher plants, the... 

Selection of the principal chain in unsaturated branched acyclic hydrocarbons. A principal chain must be chosen upon which to base the name of branched unsaturated acyclic hydrocarbons. The general criteria listed in Table 4.10 are applied. Those that are specifically relevant to polyenes and polyynes are criterion (b), which is the maximum number of double and triple bonds considered together criterion (c), which is the maximum length criteria (d), (f) and (g) criterion (h), which is the maximum number of substituents cited as prefixes and criteria (i) and (j). 

Acyclic Hydrocarbons, A knowledge of the structural features of hydrocarbon skeletons is basic to the understanding of organic chemical nomenclature. The generic name of saturated acyclic hydrocarbons, branched or unbranched, is alkane. The term saturated is applied to hydrocarbons containing no double or triple bonds. 

A saturated branched acyclic hydrocarbon is named by numbering the longest chain from one end to the other, and the positions of the side chains are indicated by the lowest possible numbers. The numbers precede the group, and are separated from them by a hyphen. 

Unsatnrated branched acyclic hydrocarbons aie numbered in the same manner as alkanes. The longest chain is chosen as the parent. If the alkene or alkyne contains two or more chains of equal length, the chain containing tile maximum, number of double bonds is chosen as the parent. 

Rowland, S., and Robson, J.N. (1990) The widespread occurrences of highly branched acyclic C20, C25, and C30 hydrocarbons in recent sediments and biota—a review. Mar. Environ. Res. 30, 191-216. 

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