Lecture 12 - How does understanding the reactivity of acids...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
How does understanding the reactivity of acids and bases relate to understanding reactions? In general: the key to understanding organic reactions is understanding where available electrons are and where they want to go (or with which atoms they want to form bonds) – think of reactions as interactions between electron rich and electron deficient atoms. 1. electron rich atoms – want to share electrons by donating them to the formation of a new bond. NUCLEOPHILE 2. electron poor atoms – want to accept electrons through the formation of a new bond. ELECTROPHILE Identifying nucleophiles and electrophiles Nucleophile a) must have a lone pair of electrons or electrons in a π bond that are less tightly held and therefore available to react b) may or may not be negatively charged c) the more accessible the lone pair is, the better the nucleophile d) in general, when comparing nucleophiles with the same nucleophilic atom : more basic = more nucleophilic recall: the higher pKa of conjugate acid the stronger the base e.g two different oxygen nucleophiles e) when nucleophilic atoms are not the same you must also consider atomic size e.g.
Background image of page 1

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

View Full DocumentRight Arrow Icon
Let’s look at point c) (above) in a little more detail The fluoride anion (F - ) is much smaller than iodide (I - ) and has a much larger charge/size ratio. In solution, the fluoride anion will be solvated to a greater extent than iodide. This solvation blocks it from sharing electrons (or reacting) with an electrophile. We must also consider polarizability or ease with which electrons can be delocalized over
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/13/2011 for the course CHEM 281 taught by Professor Williams during the Spring '11 term at Simon Fraser.

Page1 / 8

Lecture 12 - How does understanding the reactivity of acids...

This preview shows document pages 1 - 3. Sign up to view the full document.

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