1. Presented by Leticia Bonita Prince Newcastle University 4 th Year MChem Student

2. Aims of Today Increase your understanding of reaction mechanisms and the bromination of alkenes Increase your spatial skills and awareness using software designed by the CCDC

3. What are Spatial Skills? The ability to mentally manipulate 2-dimensional and 3- dimensional figures. Important in chemistry, biology, medicine, mathematics, physics and everyday life.

4. Curly Arrows In a chemical reaction NEW BONDS ARE MADE and BONDS ARE BROKEN. A reaction mechanism illustrates how this happens. Curly Arrows are used to highlight the MOVEMENT OF ELECTRONS. A FULL ARROW REPRESENTS 2 ELECTRONS A HALF ARROW REPRESENTS 1 ELECTRON H + + Cl - 2Cl. Heterolytic Fission Homolytic Fission

5. Direction of Movement NUCLEOPHILEELECTROPHILE

6. Nucleophiles Electron Pair DONORS Lewis Bases - CN, - OH, Cl -

7. Electrophiles Electron Pair ACCEPTOR Lewis Acids H +, CH 3 +, NO 2 +

8. Electrophilic Addition to Ethene (Bromination) Ethene has a π bond which has high electron density – NUCLEOPHILE Bromine molecule will have a δ + from Van der Waals’ - ELECTROPHILE

9. Mechanism

10. The REAL Mechanism

11. Proof Bromonium Ions Exist

12. The WebCSD Type in http://webcsd.ccdc.cam.ac.uk/teaching_database_demo.php http://webcsd.ccdc.cam.ac.uk/teaching_database_demo.php Answer the questions by typing the refcodes into the “find entry” box

13. THANK YOU! ENJOY THE REST OF YOUR DAY!