Alkenes - Reactions and Catalysts

hydrogenation

• Adding hydrogen to form an alkane

• Raney Nickel at 180

halogenation

• CCl4 - inert solvent

halogenation in aq conditions

• OH- takes place of 1 X

Hydrohalogenation

• with HX in CCl4

Hydrohalogenation in aq conditions

• OH will take place of X

Markovnikov’s Rule

• The Electrophile (H+) will go onto the least substituted carbon

Hydration

• conc H2SO4 then h20 Reflux

Ozonolysis

• -78, CCl4, then Zn and Acetic Acid CH3COOH

Oxidation

• Cold, Dilute, Alkaline, KMnO4

Addition Polymerization

• RO-OR

• UV/HEAT

  • Ziegler- Natta

Catalytic VS Thermal Polymerization

• Catalytic

  • regulates degree of branching

  • Ziegler - Natta Catalyst

  • 20-50C and 5-25 atm

• Thermal

  • RO-OR

  • 1000-2000ATM and 200C

HDPE

High Density Polyethene

• linear branching

• good strength

• utensils and bottles

LDPE

• low density polyethene

  • weaker branching leads to more flexibility

  • plastic bags

Ziegler-Natta

• Al(C₂H₅)₃) and TiCl₄

Mechanism for Addition Polymerization

Dehydrohalogenation

• presence of B-hydrogen on haloalkane

• Heat and Alcoholic KOH

Dehydration

• conc h2SO4 at 180

• Beta Hydrogen