CHEM 140A Chapter 3: Chapter 3 - Reactions of Alkanes
11 Sep 2016
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Document Summary
Chapter 3 - reactions of alkanes page 95 - page 130. Radical reactions includes several types of transformations. Synthesis of an alkyne through an alkenyl halide intermediate. Strength of alkane bonds: radicals page 96 - page 99. Bond dissociation energy (dho) - the energy required to break a chemical bond through homolytic cleavage, or the energy released in forming that bond. Homolytic cleavage - dissociation in which the two bonding electrons are split between the resulting radicals in contrast to heterolytic cleavage. Separation of bonding electrons shown by barbed arrows. Radical - a fragment of a molecule possessing an unpaired electron as a result of homolytic cleavage. Radicals and free atoms are very reactive, usually can"t be isolated, present in low concentration as intermediates. Heterolytic cleavage - dissociation in which the bonding electron pair is donated to one atom only in contrast to homolytic cleavage. Homolytic cleavage observed in nonpolar solvents, gas phase.
