Chapter 19 The Chemistry of Radicals

Chapter 19 The Chemistry of Radicals - Chapter 19 The...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 19 The Chemistry of Radicals 19.1~19.2 Radicals The mechanism of organic reactions can be divided into 2 types: a. ionic reactions b. free radical reactions A free radical is a species with an unpaired electron.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
19.3 Stability of radicals The energy required to break a covalent bond homolytically is called bond dissociation energy . i. To calculate H o (enthalpy, C ) H o = 104 + 58 - 83.5 – 103 = -24.5 kcal/mol H CH 3 + Cl Cl CH 3 Cl + H Cl +104 +58 -83.5 -103 ( kcal/mol) endothermic exothermic
Background image of page 2
Another example: H o = +32.5 kcal/mol ii . To estimate the relative stability of free radicals e.g. C C H H +98 +91 (kcal/mol) +94 C C C C C-C-C-H C C-C-Cl + H-Cl +78.5 C C C C +103 -91 -58 (kcal/mol) + Cl-Cl H C C
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
19.4 The structure of carbon free radicals PhCH 2 >CH 2 =CHCH 2 > C > C > C >CH 3 . . . . . . 3 2 1 The relative stability of carbon free radicals: C . R R ' R'' sp 2 e.g. (R) (S ) C H CH 3 H 5 C 2 Br C Br CH 3 H C 2 H 5 CH 3 CH 2 CH 2 CH 3 + Br 2 HBr h ν C C 2 H 5 CH 3 H . Br 2 Br 2 from the right from the left ROOR
Background image of page 4
19.5 Generation of radicals The most useful starting compounds for
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 20

Chapter 19 The Chemistry of Radicals - Chapter 19 The...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online