1. Organic Nomenclature

2. C Expected Lewis Structure of Carbon: Problems: 4 valence electrons
Allows 2 orbitals for covalent bonding
Can’t fill octet rule C

3. ORBITAL HYBRIDIZATION
- s and p orbitals combine to form an even distribution of electrons around the nucleus
Redraw Lewis Dot Structure
allows for the formation of 4 covalent bonds

4. IMPORTANCE:
Allows carbon to form complex structures
- many being biological compounds
Organic Chemistry: study of compounds containing Carbon (except CO2 and CO)

5. Types of Formulas
1. Chemical - Empirical: Reduced Form - Molecular: Non-Reduced Form 2. Structural - shows the location and bond types of each atom 3. Compact Structural - shows the groupings of atoms around the carbons

6. Example
Butane: Molecular: C4H10 Empirical: C2H5 Structural: Compact Structural: CH3CH2CH2CH3 or CH3(CH2)2CH3

7. Ethane
Molecular Formula: C2H6
Empirical Formula: CH3

8. Ethane
Molecular Formula: C2H6
Empirical Formula: CH3
Lewis Dot Diagram:

9. Ethane
Molecular Formula: C2H6
Empirical Formula: CH3
Lewis Dot Diagram:
Structural Formula:
Compact Structural Formula: CH3CH3

10. Ethene
Molecular Formula: C2H4
Empirical Formula: CH2

11. Ethene
Molecular Formula: C2H4
Empirical Formula: CH2
Lewis Dot Diagram:

12. Ethene
Molecular Formula: C2H4
Empirical Formula: CH2
Lewis Dot Diagram:
Structural Formula:
Compact Structural Formula: CH2CH2

13. Ethyne
Formula: C2H2
Empirical Formula: CH

14. Ethyne
Formula: C2H2
Empirical Formula: CH
Lewis Dot Diagram:

15. Ethyne
Formula: C2H2
Empirical Formula: CH
Lewis Dot Diagram:
Structural Formula:
Compact Structural Formula: CHCH

16. Importance Structure and Function:
differences in structure, even slight, change the properties
- absorption site, metabolism, and effects
differences must be indicated in the names = Nomenclature

17. NOMENCLATURE: process of naming
1st step: # of carbons determines the base or root name
# of Carbons
Root Name 1
Meth 11
Undec 2
Eth 12
Dodec 3
Prop (“rope”) 13
Tridec 4
But (“cute”) 14
Tetradec 5
Pent 15
Pentadec 6
Hex 20
Icos 7
Hept 21
Henicos 8
Oct 22
Docos 9
Non (“known”) 30
Triacont 10
Dec 40
Tetracont

18. 2nd step: identify types of bonds
Saturated - all carbons are single bonded to one another and contain all possible hydrogens (full of H)
Unsaturated - two or more carbons are double or triple bonded to one another - decreases the # of hydrogens

19. Saturated – all single bonds
- ending is “ane”
Unsaturated: at least one double or triple bond
- double bond “ene”
- triple bond “yne”

20. Examples:

21. Examples:
Butane

22. Condensed Formula

25. Pentene

26. Simplified Structural Form4 2 1 5 3
Double Bond

28. Propyne

29. Propyne

30. SAME???? NO – bond is in a different position
HOWEVER:
Formula: C4H8 Formula: C4H8
SAME???? NO – bond is in a different position
- ISOMER: same chemical formula, but different STRUCTURE

31. SAME???? NO – bond is in a different position
HOWEVER:
2 – Butene 1-Butene
Formula: C4H8 Formula: C4H8
SAME???? NO – bond is in a different position
- ISOMER: same chemical formula, but different STRUCTURE

32. Types of Isomers
1. Positional Isomers: - differ by position of double or triple bonds 2. Geometric Isomers: - differ by the orientation around a double bond 3. Structural Isomers: - differ due to side chains

33. Positional Isomers CΞC-C-C-C C-C-C-C=C-C
difference in location of double or triple bond
Name based on position of the different bond (double or triple):
RULE: - number the carbon chain so the bond has the smallest “address”
- list the number in front of the root name with the appropriate ending - separate the number from the root name with a dash
EXAMPLES:
CΞC-C-C-C C-C-C-C=C-C
3-hexene 3-octyne
What should 3-pentene be called?

34. More than one double/triple bond:
RULE: The carbon chain is numbered unidirectionally so that each bond has the lowest possible combination of addresses
list each address number separated by commas
add a prefix before the bond suffix to indicate the number of double or triple bonds
EXAMPLES:
C-C=C-C=C-C-C C-CΞC-CΞC-CΞC-C
1,3,5-heptatriene 2,5-octadiyne

35. Mix of double and triple bonds
RULE: Number to give smallest addresses – if no difference “ene” has priority. Name in this order:
Double bond address # – carbon chain root name“ene” – triple bond address # - “yne”
If there are multiple double/triple, follow those rules as well

36. Examples
C-C=C-CΞC C=C-C=C-CΞC-C-C C-C=C-CΞC-CΞC-C-C-C C-C=C-CΞC-C 4-hexene-1-yne

37. Geometric Isomers
Difference based on the orientation around a double bond
Two possibilities can result due to rotational restriction by the double bond
If the groups are on the same side of the double bond = cis
If the groups are on the opposite side of the double bond = trans

38. Geometric Isomers
Difference based on the orientation around a double bond
Two possibilities can result due to rotational restriction by the double bond
If the groups are on the same side of the double bond = cis
If the groups are on the opposite side of the double bond = trans
cis - 2-butene trans - 2- butene

39. Structural Isomer: different assembly of carbons – side chains
RULE: Name parent chain and side chains based on position
Process:
1. Name parent chain
- count longest chain = parent chain = base
- chain must include double or triple bonds
- if more than one double/triple bond, number them so both bonds have the
lowest possible number
- if double and triple bonds, triple bonds have priority so it should have the lowest number
2. Name Side Chain(s)
- count carbons in side chain and name appropriately
- # of carbons in side chain = name of side chain
- add ”yl” suffix

40. Examples

41. More than One Side chain:
each side chain gets its own number (even if on the same carbon of parent chain)
if more than one of the same type of side branch add pre-fix to the side chain’s root name
“di” = two of the same side chain
“tri” = three of the same side chain
“tetra” = four of the same side chain
list the side chains and their numbers before the name of the parent chain – separate numbers with commas
Different types of side chains are listed in alphabetical order of the root of the side chain (butyl before ethyl before methyl before pentyl…) , but not by the “di, tri, tetra prefix”,

42. Examples

43. Branched Side Chains

44. Naming Halogenated Compounds
Halogens:
- column next to the Noble Gases
– F, Cl, Br, I
- acts as a side chain (same numbering rules), but instead of “yl” as the ending, add an “o”
F - fluoro
Cl - chloro
Br - bromo
I - iodo

45. Examples

46. Naming Ring Structures
Ring structures are represented by geometric shapes where each angle represents a carbon
Add a “cyclo” in front of the name and use the root for the number of angles and the proper ending (ane or ene – no yne)

47. Rules for side chains and double bonds
1. Double bonds have priority. The bonds must be numbered with the smallest address but the numbering determines the direction around the ring. 4 3 2 1 6 5 1 6 5 4 3 2 6 1 2 3 4 5

48. Rules for side chains and double bonds
Double bonds have priority. The bonds must be numbered with the smallest address but the numbering determines the direction around the ring. 4 3 2 1 6 5 1 6 5 4 3 2 6 1 2 3 4 5

49. 4 3 2 1 6 5 1 2 3 4 5 6

50. 4 3 2 1 6 5 1 2 3 4 5 6
1,3-cyclohexadiene

51. Rule for Ring Structures with Side Chains
2) if no double bonds, number the side chains so they have the lowest address
3) same naming as before

52. Examples

53. What if the side chain is bigger than the ring structure?
If the number of carbons in the ring is greater than the number of carbons on the largest side chain, then the parent name is based on the ring structure.
If the number of carbons on the straight chain is larger than the number of carbons in the ring structure, the parent name is based on the straight chain and the ring structure is treated as a side chain
- Rule: add a “yl” to the ring structure name
2-cyclopropylhexane vs. propylcyclohexane

54. A special case: Benzene
1,3,5-cyclohexatriene

55. Benzene Resonance

57. Naming Benzene Compounds
Rules:
Benzene is the base name.
Number side chains and/or halogens to give them the smallest address.
If it’s a di-substituted (2 side chains), the following roots can be used:
1,2 = ortho or o
1,3 = meta or m
1,4 = para or p

62. Examples

63. Benzene Derivatives

64. Benzene as a Side Chain
Use the word “Phenyl”