1. DRAWING ORGANIC STRUCTURES FUNCTIONAL GROUPS CONSTITUTIONAL ISOMERS Dr. Clower CHEM 2411 Spring 2014 McMurry (8 th ed.) sections 1.12, 3.1, 3.2

2. Draw these structures… C 2 H 6 CH 4 O C 3 H 6 (contains C=C) C 4 H 10 (multiple possible answers)

3. More Lewis structures… CH 5 N CHN HNO 3 Remember… Keep in mind total available valence electrons Try to minimize formal charges Patterns for formal charge

4. Drawing Organic Structures Example: isopropyl alcohol (C 3 H 8 0) Lewis structure Show all bonds, atoms, lone pairs Condensed structure Omit some bonds (C─C, C─H, O─H, N─H) Often omit lone pairs Skeletal structure/line-angle drawing Show bond framework as lines C atoms at intersections of lines (bonds) and end of each line H atoms bonded to C are not shown Heteroatoms (atoms other than C and H) are shown

5. Drawing line-angle structures NameLewis structureCondensed structureLine-angle drawing Acetone Butane 1-Butene Cyclohexane Benzene

6. Interpreting line-angle structures What is the molecular formula for adrenaline? What is the molecular formula for thalidomide?

7. Drawing Organic Structures Draw Lewis and line-angle structures for this condensed structure: (CH 3 ) 3 CCH 2 COCHCH 2

8. Functional Groups Collection of atoms at a site within a molecule with a common bonding pattern Reacts in a typical way, generally independent of the rest of the molecule Four broad classes Hydrocarbons Compounds containing O Compounds containing N Compounds containing S or P

9. 1. Hydrocarbons Alkane: single bonds, sp 3 carbons Cycloalkane: carbons form a ring Alkene: double bond, sp 2 carbons Cycloalkene: double bond in ring Alkyne: triple bond, sp carbons Aromatic (arene): contains a benzene ring Not a hydrocarbon, but related… Alkyl halide: R─X R = any carbon group X = halogen

10. 2. Compounds containing oxygen Alcohol: R─OH Ether: R─O─R ' Carbonyl group: C=O Aldehyde: RCHO Ketone: RCOR '

11. Carboxylic acids and their derivatives Carboxylic Acid: RCOOH Acid Chloride: RCOCl Ester: RCOOR' (RCO 2 R’) Amide: RCONH 2 Acid Anhydride: RCO 2 COR

12. 3. Compounds containing nitrogen Amines: RNH 2, RNHR ', or R 3 N Amides: RCONH 2, RCONHR, RCONR 2 Nitrile: RCN

13. 4. Compounds containing S or P Phosphates (PO 4 2- ) Thiol (R─SH) Sulfides (R─S─R) Sulfoxides (S=O) Thioester (RCOSR)

15. Isomers Isomers have the same molecular formula, but different arrangements of atoms Constitutional isomers differ in their connectivity Stereoisomers differ in the spatial arrangement/orientation of their atoms

16. Constitutional Isomers Molecules with the same molecular formula, but different connectivity Same number and kinds of atoms Differ in which atoms are bonded Example: C 4 H 10 Straight-chain (“normal”) alkane vs. branched-chain alkane

17. Constitutional Isomers

18. Are the following pairs of molecules constitutional isomers, the same molecule, or neither? (a) (b) (c) (d)