Drawing Organic Structures Functional Groups

download report

Transcript Drawing Organic Structures Functional Groups

DRAWING ORGANIC STRUCTURES
FUNCTIONAL GROUPS
CONSTITUTIONAL ISOMERS
Dr. Clower
CHEM 2411
Spring 2014
McMurry (8th ed.) sections 1.12, 3.1, 3.2
Draw these structures…
• C2H6
• CH4O
• C3H6 (contains C=C)
• C4H10 (multiple possible answers)
More Lewis structures…
• CH5N
• CHN
• HNO3
• Remember…
• Keep in mind total available valence electrons
• Try to minimize formal charges
• Patterns for formal charge
Drawing Organic Structures
• Example: isopropyl alcohol (C3H80)
• 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
Drawing line-angle structures
Name
Acetone
Butane
1-Butene
Cyclohexane
Benzene
Lewis structure
Condensed structure
Line-angle drawing
Interpreting line-angle structures
• What is the molecular formula for adrenaline?
• What is the molecular formula for thalidomide?
Drawing Organic Structures
• Draw Lewis and line-angle structures for this condensed
structure: (CH3)3CCH2COCHCH2
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
1. Hydrocarbons
• Alkane: single bonds, sp3 carbons
• Cycloalkane: carbons form a ring
• Alkene: double bond, sp2 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
2. Compounds containing oxygen
• Alcohol: R─OH
• Ether: R─O─R'
• Carbonyl group: C=O
O
• Aldehyde: RCHO
CH3CH2
• Ketone: RCOR'
C H
O
CH3
C CH3
Carboxylic acids and their derivatives
• Carboxylic Acid: RCOOH
O
C OH
O
• Acid Chloride: RCOCl
C Cl
O
• Ester: RCOOR' (RCO2R’)
C OCH
3
O
• Amide: RCONH2
• Acid Anhydride: RCO2COR
C NH
2
3. Compounds containing nitrogen
• Amines: RNH2, RNHR', or R3N
• Amides: RCONH2, RCONHR, RCONR2
• Nitrile: RCN
CH3
C N
4. Compounds containing S or P
• Phosphates (PO42-)
• Thiol (R─SH)
• Sulfides (R─S─R)
• Sulfoxides (S=O)
• Thioester (RCOSR)
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
Constitutional Isomers
• Molecules with the same molecular formula, but different
connectivity
• Same number and kinds of atoms
• Differ in which atoms are bonded
• Example: C4H10
• Straight-chain (“normal”) alkane vs. branched-chain alkane
Constitutional Isomers
Constitutional Isomers
• Are the following pairs of molecules constitutional
isomers, the same molecule, or neither?
(a)
(b)
(c)
(d)