2- NOMENCLATURE, HYBRIDIZATION, IMFA

1. Identify the parent chain prefix

2. Use the parent to determine if the bond type infix

3. Determine the real suffix portion

4. Identify the substituents to prefix, if any

5. Indicate the proper locants on the parent

6. Assemble using the standard format (prefix-parent-suffix)

NOMENCLATURE Recommended approach:

(Arrange from 1-6)

Determine the real suffix portion

Identify the substituents to prefix, if any

Identify the parent chain prefix

Indicate the proper locants on the parent

Assemble using the standard format (prefix-parent-suffix)

Use the parent to determine if the bond type infix

Recommended approach:

1. Identify the parent chain prefix

2. Use the parent to determine if the bond type infix

3. Determine the real suffix portion

4. Identify the substituents to prefix, if any

5. Indicate the proper locants on the parent

6. Assemble using the standard format (prefix-parent-suffix)

Reminders:

1. Use cyclo- for ring systems

2. Use multiplicative prefixes (e.g. di, tri, tetra) when needed

3. Alphabetization (usually for multiple prefixes)

4. Mind rules for locant assignment (often lowest numbers aka first point of difference, sometimes priority groups or alphabetization)

5. Terminal groups have no locants

Recommended approach and reminders (enumerate)

c. cyclo-

[NOMENCLATURE]

Which prefix is used for a ring structure?
a. iso-
b. neo-
c. cyclo-
d. sec-

b. di-

• Use multiplicative prefixes (e.g. di, tri, tetra) when needed

[NOMENCLATURE]

Which prefix indicates two identical substituents?
a. mono-
b. di-
c. tri-
d. tetra-

c. alphabetization

[NOMENCLATURE]

In naming compounds, substituents are generally arranged according to:
a. molecular weight
b. size
c. alphabetization
d. boiling point

d. lowest numbers possible

[NOMENCLATURE]

When assigning numbers to substituents, the preferred rule is:
a. highest numbers possible
b. random numbering
c. alphabetical numbering
d. lowest numbers possible

true

[NOMENCLATURE]

[t/f] Terminal groups have no locants

Uses purely p orbitals = Pi

Uses most orbitals with s character = Sigma

Anything after sigma = Pi

Headways overlap/collision = Sigma

Sideways/lateral overlap/collision = Pi

Stronger = Sigma

First bond = Sigma

Weaker = Pi

[BONDING & HYBRIDIZATION]

Sigma or Pi?

Uses purely p orbitals = ____

Uses most orbitals with s character = ____

Anything after sigma = ____

Headways overlap/collision = ____

Sideways/lateral overlap/collision = ____

Stronger = ____

First bond = ____

Weaker = ____

[BONDING & HYBRIDIZATION]

Example of orbital with s character and headways overlap/collision in formination of sigma bonds.

[BONDING & HYBRIDIZATION]

Example of “anything after sigma bond” in formation of Pi bonds.

[BONDING & HYBRIDIZATION]

Hybridization of Carbon

[BONDING & HYBRIDIZATION]

sp³ or sp² or sp?

3 sigma; 1 pi =____

1s, 3p =____

THREE sp2 orbitals (1 p orbital unhybridized) =____

TWO sp orbitals (2 p orbitals unhybridized) =____

FOUR sp3 orbitals =____

4 sigma =____

180 =____

109.5 =____

1s, 2p =____

120 =____

1s, 1p =____

2 sigma; 2 pi =____

a. sp³

[BONDING & HYBRIDIZATION]

Tetrahedral shape is seen in

a. sp³

b. sp²

c. sp

b. sp²

[BONDING & HYBRIDIZATION]

Trigonal Planar shape is seen in

a. sp³

b. sp²

c. sp

c. sp

[BONDING & HYBRIDIZATION]

Linear shape is seen in

a. sp³

b. sp²

c. sp

1. Type of IMFA – direct relationship

2. Number of carbons – direct relationship

3. Branching of carbons – inverse relationship

FACTORS AFFECTING COMPACTNESS

London dispersion

Dipole-dipole

Hydrogen bond

INTERMOLECULAR FORCES

1. a. London dispersion

2. c. Hydrogen bond

3. b. Dipole-dipole

[INTERMOLECULAR FORCES]

Requirement:

1. Nothing (Universal); No + or - charges

2. Same D-D, but requires partially (+) hydrogen

3. Permanent partial charges (dipoles); EN atoms (X,O,N,S)

Choices:

a. London dispersion

b. Dipole-dipole

c. Hydrogen bond

1. c. Hydrogen bond

2. b. Dipole-dipole

3. a. London dispersion

[INTERMOLECULAR FORCES]

Strength:

1. Strong

2. Moderate

3. Very Weak

Choices:

a. London dispersion

b. Dipole-dipole

c. Hydrogen bond

a. London dispersion

[INTERMOLECULAR FORCES]

aka Van der Waals

a. London dispersion

b. Dipole-dipole

c. Hydrogen bond

1. c. Hydrogen bond

2. a. London dispersion

3. b. Dipole-dipole

[INTERMOLECULAR FORCES]

1. Highly significant in biological systems and biochemistry, such as proteins and DNA

2. Exists in all organic compounds

3. Present in all compounds with electronegative atoms

Choices:

a. London dispersion

b. Dipole-dipole

c. Hydrogen bond

1. b. Dipole-dipole

2. b. Dipole-dipole

3. a. London dispersion

4. c. Hydrogen bond

5. a. London dispersion

6. c. Hydrogen bond

[INTERMOLECULAR FORCES]

Examples:

1. Carbonyl groups

2. Alkyl halides (R-X)

3. Nonpolar substances

4. OH, NH groups

5. Alkanes, alkenes, alkynes

6. O,N,F containing

Choices:

a. London dispersion

b. Dipole-dipole

c. Hydrogen bond

• Number of carbons – direct relationship

• ↑C = ↑BP, ↑MP, ↑Density

[INTERMOLECULAR FORCES]

Arrange increasing BP, MP, Density

C6H14

C8H18

C5H12

C7H16

↑ BP, MP, Density = a>b>c

• ↑Branching = ↓BP, ↓MP, ↓Density

[INTERMOLECULAR FORCES]

Arrange increasing BP, MP, Density

1.Strength of IMF (direct relationship)

2.Number of carbons (inverse relationship)

3.Branching of carbons (direct relationship)

[INTERMOLECULAR FORCES]

Factors affecting polarity (i.e. water-solubility)

HB» DD »» LD

• Strength of IMF (direct relationship)

[INTERMOLECULAR FORCES]

Effect of strength of IMF on water solubility

↑C= ↑Lipophilicity= ↓H2O Solubility

• Number of carbons (inverse relationship)

[INTERMOLECULAR FORCES]

Effect of number of carbons on water solubility

↑Branching= ↑H2O Solubility

• Branching of carbons (direct relationship)

[INTERMOLECULAR FORCES]

Effect of branching of carbons on water solubility

↑C= ↑Lipophilicity= ↓H2O Solubility

[INTERMOLECULAR FORCES]

Water solubility of ethers

[INTERMOLECULAR FORCES]

Branched vs Unbranched effects on compactness (e.g. mp, bp, density) and polarity

[INTERMOLECULAR FORCES]

Carbon count and branching amount have opposite effects on compactness (e.g. mp, bp, density) and polarity (water-solubility)

[INTERMOLECULAR FORCES]

Strength of IMF relationship on physical properties

b. Destabilizing effect

[STRUCTURAL EFFECTS]

Strain generally has what effect on a compound?
a. Stabilizing effect
b. Destabilizing effect

b. Decreased reactivity

[STRUCTURAL EFFECTS]

Increased strain results in:
a. Increased stability
b. Decreased reactivity

b. Unreactive

[STRUCTURAL EFFECTS]

A highly stable compound is generally:
a. Highly reactive
b. Unreactive

c. ↓ Stability = ↑ Reactivity

[STRUCTURAL EFFECTS]

Which relationship is correct?
a. ↑ Stability = ↑ Reactivity
b. ↑ Strain = ↑ Stability
c. ↓ Stability = ↑ Reactivity
d. ↓ Reactivity = ↓ Stability

a. Ring strain

[STRUCTURAL EFFECTS]

aka angle strain

a. Ring strain

b. Steric effect/ hindrance

c. Torsional Strain

a. Ring strain

[STRUCTURAL EFFECTS]

Twisting of angles away from the expected due to ring closures due to deviation from the ideal bond angle

a. Ring strain

b. Steric effect/ hindrance

c. Torsional Strain

b. Steric effect/ hindrance

[STRUCTURAL EFFECTS]

Competition for space due to bulky groups, pushing bonds away from expected angles

a. Ring strain

b. Steric effect/ hindrance

c. Torsional Strain

c. Torsional Strain

[STRUCTURAL EFFECTS]

Steric strain in rotatable bonds due to small dihedral angles between them

a. Ring strain

b. Steric effect/ hindrance

c. Torsional Strain

c. Torsional Strain

[STRUCTURAL EFFECTS]

Occurs due to eclipsing of bonds → ring flipping

a. Ring strain

b. Steric effect/ hindrance

c. Torsional Strain

a. 109.5

<109.5 = strain

[STRUCTURAL EFFECTS]

ideal angle to avoid strain

a. 109.5

b. 120

c. 180

a. Ring strain

[STRUCTURAL EFFECTS]

Instability observed in cyclopropane

a. Ring strain

b. Steric effect/ hindrance

c. Torsional Strain

c. chair

[STRUCTURAL EFFECTS]

Most stable configuration of cyclohexane

a. butterfly

b. boat

c. chair

d. enveloped

b. Steric effect/ hindrance

[STRUCTURAL EFFECTS]

Instability observed in:

a. Ring strain

b. Steric effect/ hindrance

c. Torsional Strain

INDUCTIVE EFFECTS

[STRUCTURAL EFFECTS]

____ effect is the push (EDG: Alkyl groups) or pull (EWG: EN atoms) of electrons

[STRUCTURAL EFFECTS]

Effects of EWG and EDG on stability

[STRUCTURAL EFFECTS]

Arrange based on stability

[STRUCTURAL EFFECTS]

Effects on stability: Increase or Decrease?

Resonance =____

Ring strain =____

Electron donating groups (EDG) =____

Steric and torsional strains =____

Electron withdrawing groups (EWG) =____

b. Resonance

[STRUCTURAL EFFECTS]

Electron delocalization is also known as:
a. Induction
b. Resonance
c. Hybridization
d. Strain

c. Pi or lone pair electrons

[STRUCTURAL EFFECTS]

Resonance involves the movement of:
a. Sigma electrons
b. Neutrons
c. Pi or lone pair electrons
d. Protons

b. sp²-hybridized atom

[STRUCTURAL EFFECTS]

For resonance to occur, the electrons must be adjacent to a(n):
a. sp³ carbon
b. sp²-hybridized atom
c. alkane carbon
d. tetrahedral carbon

b. Resonance

[STRUCTURAL EFFECTS]

What can be seen in Benzene ring?

a. Induction
b. Resonance
c. Hybridization
d. Strain

1. Being cyclic

2. Being Planar

3. Flat Configuration

4. Follows Huckel’s rule

CRITERIA FOR AROMATICITY

aromatic

[CRITERIA FOR AROMATICITY]

Identify if aromatic or anti aromatic

aromatic

[CRITERIA FOR AROMATICITY]

Identify if aromatic or anti aromatic

aromatic

[CRITERIA FOR AROMATICITY]

Identify if aromatic or anti aromatic

[CRITERIA FOR AROMATICITY]

Identify if aromatic or anti aromatic

antiaromatic

• not conjugated

[CRITERIA FOR AROMATICITY]

Identify if aromatic or anti aromatic

Neither. This is aliphatic

[CRITERIA FOR AROMATICITY]

Identify if aromatic or anti aromatic