1. Interdisciplinarity: Chemistry ↔ Biology Dr. Fida Mohammad, GIKI- Topi Learning from: ►How chemists think ►What they do & How they do it Attitude until 1828 Organic compounds made by plants or animals cannot be made by man

2. Birth of Molecules Dalton’s theory 1808 ► Two or more than two atoms sticking together form molecules & that during chemical reactions atoms remain intact OH + HCl → H 2 O + Cl ☺ Maxwell: Nature, Sept 1873, 13 page article ” Molecule ”

3. Birth of Organic Chemistry: Woehler synthesis- 1828 ► He produced urea outside kidney ► He discovered Isomerism-I HCN vs HNC Isomerism ( connectivity )

4. Van’t Hoff considers third dimension removing isomer paradox (1874 ) Two Isomers No Isomer Cl

5. Van’t Hoff & Le Bel: Tetrahedral carbon atom also explains optical activity Chirality enters chemistry

6. Carbon atom insists on 109º angle Chair or Boat form ? Can molecules bend, twist curl, fold coil, turn Puckered rings Conformations Molecular angle is adjusted to relieve strain Zigzag Molecules

7. Precise measurements of angles and bond lengths What if the angle in water changes to 109º ?

8. Distribution of atoms in molecules - I

9. Distribution of charge in molecules - II: Dipole forces Dispersion forces ►Be careful with charge distribution in CO ►Don’t underestimate dispersion forces

10. Dispersion forces depend on shape also CH 3 -CH 2 -CH 2 -CH 2 -CH 3 CH 3 -C-CH 3 CH 3 CH 3 -C- CH 3 CH 3

11. Kevlar ( Hydrogen bonding ) Fiber Axis

12. Twisting, folding, coiling molecule

13. Great debate on Macromolecules: formation, size, flexibility, molar mass

14. : : Ultra-high-molecular-weight-polyethylene ( UHMWPE ) Bullet proof Jackets Dispersion forces

15. Alternative structure for macromolecules

16. The restless Molecules Translation Rotation Vibration

17. Distance between base pairs = 340pm Rotation from base to base = 36º No. of bases per turn = 10 Length of DNA from one chromosome = 5 cm Molar mass= 1000 tons Unraveling the code of life

19. Understanding genetic make-up and Health Forecasting

20. Definition of chemistry: transformation of matter but how ?. Cyclobutane Ethylene

21. Femto-second chemistry ( Intermediates, transition states etc )

22. Exothermic reaction: where does the energy go ? F + D 2 → DF ( v ) + H + ∆H (147 kJ/mol ) V Rel. Amount 0 1 2 2 44 3 100 4 49 Studied for star war