Chain unsaturated hydrocarbons

It is convenient to divide the petrochemical industry into two general sectors (/) olefins and (2) aromatics and their respective derivatives. Olefins ate straight- or branched-chain unsaturated hydrocarbons, the most important being ethylene (qv), [74-85-1] propjiene (qv) [115-07-17, and butadiene (qv) [106-99-0J. Aromatics are cycHc unsaturated hydrocarbons, the most important being benzene (qv) [71-43-2] toluene (qv) [108-88-3] p- s.y en.e [106-42-3] and (9-xylene [95-47-5] (see Xylenes and ethylbenzene) There are two other large-volume petrochemicals that do not fall easily into either of these two categories ammonia (qv) [7664-41-7] and methanol (qv) [67-56-1]. These two products ate derived primarily from methane [74-82-8] (natural gas) (see Hydrocarbons, c -c ). [Pg.171]

Some proteins can be posttranslationally modified by the addition of prenyl groups. Prenyl groups are long-chain, unsaturated hydrocarbons that are intermediates in isoprenoid synthesis. The farnesyl group has 15 carbons, and the geranylgeranyl has 20 carbons. They are attached to a cysteine residue near the end of the protein as a thiol ether (Protein-S-R). Other proteins can have a long-chain fatty acid (C14=myristoyl, C16=palmitoyl) attached to the amino terminus as an amide. These fatty acid modifications can increase the association of proteins with the membrane. [Pg.39]

Table 3.2 (continued) C-H BDEs in Chain Unsaturated Hydrocarbons... [Pg.26]

Oils are long-chain, unsaturated hydrocarbon esters and are liquids at room temperature. How can you explain the fact that many oils have higher viscosity and surface tension than H2O, but smaller dipole moments ... [Pg.467]

These strategies have been applied experimentally and/or practically. Those of major lepiclopteran pests have been identified (12, 13) and most of these may be classified as aldehydes, acetates, or alcohols derived from long-chain unsaturated hydrocarbons. The amounts used, usually several grams/hectare, are ordinarily so small as to have little potential to cause adverse environmental effects and the molecules are generally of low mammalian toxicity since they mimic the natural compounds and are rapidly degraded in the environment. [Pg.484]

Isoprene is a branched-chain, unsaturated hydrocarbon of five C atoms. This same carbon skeleton... [Pg.235]

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