Chemistry 506 Dr. Hunter’s Class Chapter 11.1

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

Chemistry 506: Allied Health Chemistry 2

Chapter 11: Alkenes, Alkynes, and Aromatic Compounds

Hydrocarbons with Multiple Bonds

Introduction to General, Organic & Biochemistry, 5th Edition byBettelheim and March: Chapter 11, Pages 353-390

Outline Notes by Dr. Allen D. Hunter, YSU Department ofChemistry, 2000.

Outline

11A SECTION(S) 11.1/2/4 INTRODUCTION AND NOMENCLATURE OF ALKENES ...................................................... 2

11B SECTION(S) 11.3 ππ -BONDS ................................................................................................................................................... 4

11C SECTION(S) 11.5 PHYSICAL PROPERTIES ..................................................................................................................... 5

11D SECTION(S) 11.6 CHEMICAL PROPERTIES: ADDITION REACTIONS................................................................... 6

11E SECTION(S) 11.7 ADDITION POLYMERS ........................................................................................................................ 8

11F SECTION(S) 11.8 ALKYNES ............................................................................................................................................... 13

11G SECTION(S)11.9/10 AROMATIC HYDROCARBONS ................................................................................................... 17

11H SECTION(S)18.2 AMINO ACIDS HAVING SIMPLE AROMATIC SIDE CHAINS .................................................. 22

11I SECTION(S) 11.11 AROMATIC REACTIONS ................................................................................................................. 23

11J SECTION(S) 11.12 FUSED RING AROMATICS .............................................................................................................. 25

11K SECTION(S)11.13 HETEROCYCLICS (NOT COVERED IN DETAIL)....................................................................... 26

Chemistry 506 Dr. Hunter’s Class Chapter 11.2

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

11A Section(s) 11.1/2/4 Introduction and Nomenclature of Alkenes

Ø Ethene = (Ethylene), CH2=CH2

Ø IUPAC Rules

Ø Start numbering from the end that gives the double bond the

lowest number.

Ø Indicate position of double bond(s) by numbers.

Ø Use the ene ending

Ø Indicated number of double bonds by prefixes (ene, diene,

triene, tetraene, etc.)

Ø Examples

Chemistry 506 Dr. Hunter’s Class Chapter 11.3

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

Ø Geometric Isomers

Ø No free rotation (π-bonds)

Ø Experimental observations

Ø cis isomers vs. trans isomers

Ø Examples

Chemistry 506 Dr. Hunter’s Class Chapter 11.4

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

11B Section(s) 11.3 π-Bonds

Ø Bonding: sp2 hybridization for 3 σ-bonds to the three atoms

bonded to each carbon

Ø pz orbital for π-bond

Ø Typical C=C bond distance (i.e., 1.34

Å) shorter than C-C bond distance (i.e., 1.54 Å)

Ø slightly shorter C-H distance than alkanes

Chemistry 506 Dr. Hunter’s Class Chapter 11.5

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

11C Section(s) 11.5 Physical Properties

Ø Almost identical to Alkanes of same MW

Ø Van der Waals forces

Ø Slightly higher Mp and Bp

Ø Smell (turpentine like)

Ø Density

Ø Solubility

Chemistry 506 Dr. Hunter’s Class Chapter 11.6

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

11D Section(s) 11.6 Chemical Properties: Addition Reactions

Ø Addition reaction (generic)

Ø π-bonds weaker than σ-bonds

Ø Hydrogenation: Addition of H2 or D2 (Pt catalyst)

Ø Addition of Cl2 or Br2 (X2)

Chemistry 506 Dr. Hunter’s Class Chapter 11.7

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

Ø Addition of HX ((HF) HCl, HBr (HI))

Ø Halide Influences

Ø Markovnikov Addition

Ø Addition of Water (Hydration)

Ø H+ Catalyst

Ø Markovnikov

Chemistry 506 Dr. Hunter’s Class Chapter 11.8

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

11E Section(s) 11.7 Addition Polymers

Ø Definition of Addition Polymers

Ø No loss of mass

Ø Rapid chain growth

Ø π-bond opening

Ø “Generic” Synthesis Reaction

Ø typical monomers are CH2=CH-R

Ø Role of Catalysts

Ø Speed reaction but aren’t themselves consumed

Ø Highly reactive species

Chemistry 506 Dr. Hunter’s Class Chapter 11.9

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

Ø Reversibility of Reactions

Ø Polymerization under low temperatures/high pressures

Ø i.e., monomer (liquids or gasses) -> polymer (solids)

Ø Depolymerizations (unraveling) at high temperatures

Ø i.e., polymer -> monomer

Ø Molecular Weights and Molecular Weight Distributions

Ø High average Molecular Weights

Ø Distributions rather than discrete weights

Ø Linear Chains vs. Branched Chains

Chemistry 506 Dr. Hunter’s Class Chapter 11.10

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

Ø Examples

Ø Polyethylene, PE, Synthesis

Ø CH2=CH2, R = H

Ø Poly(vinyl chloride), PVC, Synthesis

Ø CH2=CH-Cl, R = Cl

Chemistry 506 Dr. Hunter’s Class Chapter 11.11

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

Ø Polypropylene, PP, Synthesis

Ø CH2=CH-CH3, R = CH3

Ø Polystyrene, PS, Synthesis

Ø CH2=CH-C6H5, R = C6H5

Ø Poly(methyl methacrylate), PMMA, Synthesis

Ø CH2=C(CH3)(CO2CH3)

Chemistry 506 Dr. Hunter’s Class Chapter 11.12

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

Ø Teflon Synthesis

Ø CF2=CF2

Ø Rubber (Polyisoprene) Synthesis

Ø CH2=CH-CH=CH2

Chemistry 506 Dr. Hunter’s Class Chapter 11.13

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

11F Section(s) 11.8 Alkynes

Ø Carbon-Carbon Triple Bonds

Ø sp hybridized

Ø Very Short C≡C Bond distance (i.e., 1.20 Å ), much shorter

than the C=C distance (i.e., 1.34 Å) and the C-C distance

(i.e., 1.20 Å)

Ø Bonding: 1 σ-bond and 2 π-bonds (px and py)

Ø slightly shorter C-H distance than alkanes or even alkanes

Ø Ethyne = Acetylene, H-C≡C-H

Ø Physical Properties

Ø Almost identical to Alkanes/Alkenes of same MW

Ø Van der Waals forces

Ø Slightly higher Mp and Bp

Ø Density

Ø Solubility

Chemistry 506 Dr. Hunter’s Class Chapter 11.14

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

Ø Nomenclature

Ø yne ending

Ø yne > ene in priority of naming

Ø Examples

Chemistry 506 Dr. Hunter’s Class Chapter 11.15

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

Ø Alkyne Reactions

Ø Generic Reaction

Ø Very like Alkenes

Ø Normally Double Addition

Ø Hydrogenation: Addition of H2 or D2 (Pt catalyst)

Ø Addition of X2 (Cl2 or Br2)

Chemistry 506 Dr. Hunter’s Class Chapter 11.16

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

Ø Addition of HX (most commonly HCl and HBr)

Ø Markovnikov Addition

Ø Addition of H2O (H+ catalyst)

Ø Markovnikov Addition

Ø Secondary elimination of water from diol

Ø gives carbonyl group (aldehyde or ketone)

Chemistry 506 Dr. Hunter’s Class Chapter 11.17

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

11G Section(s) 11.9/10 Aromatic Hydrocarbons

Ø Sources

Ø Coal Tar

Ø Coke production

Ø Direct separation

Ø Start of industrial chemistry

Ø Petroleum

Ø multiple processing steps

Ø Uses

Ø Octane enhancers in gasoline

Ø Plastics

Ø Pigments/Dyes

Ø Pharmaceuticals

Ø Aromatic: Properties, Reactivity, C/H Ratios (cf.

Alkane/Alkenes/Alkynes)

Chemistry 506 Dr. Hunter’s Class Chapter 11.18

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

Ø Substitution Reactions not Addition Reactions (i.e., not like

alkenes)

Ø Bonding / Resonance Stabilization

Chemistry 506 Dr. Hunter’s Class Chapter 11.19

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

Ø Nomenclature

Ø IUPAC Names

Ø Halobenzenes (X = F, Cl, Br, I)

Ø Nitrobenzene (Z = NO2)

Ø Alkylbenzenes (phenylalkanes)

Chemistry 506 Dr. Hunter’s Class Chapter 11.20

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

Ø Common Names (IUPAC)

Ø Phenol (Z = OH)

Ø Aniline (Z = NH2)

Ø Toluene (Z = CH3, methylbenzene)

Ø Benzoic Acid (Z = CO2H)

Chemistry 506 Dr. Hunter’s Class Chapter 11.21

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

Ø Multiply Substituted Arenes

Ø Numbering Ring Positions

Ø Ortho, Meta, Para, Ipso

Ø As Side Chains (phenyl groups)

Chemistry 506 Dr. Hunter’s Class Chapter 11.22

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

11H Section(s) 18.2 Amino Acids having Simple Aromatic Side

Chains

Ø Generic AA = H2N-CHR-CO2H

Ø Phenyl Alanine (non-polar)

Ø R = CH2C6H5

Ø PKU

Chemistry 506 Dr. Hunter’s Class Chapter 11.23

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

11I Section(s) 11.11 Aromatic Reactions

Ø Substitution Reactions

Ø Require catalyst

Ø "Generic"

Ø Z+ Electrophiles

Ø Nitration (Z = NO2, HNO3/H2SO4, TNT)

Chemistry 506 Dr. Hunter’s Class Chapter 11.24

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

Ø Sulfonation (Z = SO3H, H2SO4/SO3)

Ø Halogenation (X = Cl or Br, Cl2/Fe or Br2/Fe)

Chemistry 506 Dr. Hunter’s Class Chapter 11.25

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

11J Section(s) 11.12 Fused Ring Aromatics

Ø Polycyclic Aromatic Hydrocarbons, PAHs

Ø Toxicity

Ø Naphthalene (C10H8)

Ø Anthracene (C14H10)

Ø Phenanthrene (C14H10)

Chemistry 506 Dr. Hunter’s Class Chapter 11.26

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

11K Section(s) 11.13 Heterocyclics (Not covered in detail)

Ø Replace C-H by Heteroatom Groups such as: N, O, S, etc.

Ø Important in Biomolecules

Ø Pyridine (C5H5N)

Problems: All up to 11.50

Chemistry 506 Dr. Hunter’s Class Chapter 11.27

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

Index of Topics and Vocabulary

1

1.20 Å................................................................................ 13

1.34 Å............................................................................ 4, 13

1.54 Å 4

A

Acetylene .......................................................................... 13Addition ............................................................................ 15Addition of HX................................................................... 7Addition of Water ............................................................... 7Addition Polymers.............................................................. 8Addition reaction................................................................. 6Addition Reactions............................................................ 18aldehyde ............................................................................ 16alkanes ................................................................................. 4alkenes ............................................................................... 18Alkenes.............................................................................. 15Alkylbenzenes................................................................... 19Alkyne Reactions.............................................................. 15Alkynes ............................................................................. 13Amino Acids having Simple Aromatic Side Chains......... 22Aniline............................................................................... 20Anthracene ........................................................................ 25Arenes ............................................................................... 21Aromatic............................................................................ 17Aromatic Hydrocarbons.................................................... 17Aromatic Reactions........................................................... 23

B

Benzoic Acid..................................................................... 20Biomolecules ..................................................................... 26Bonding................................................................... 4, 13, 18Bp ................................................................................. 5, 13Br2 ................................................................................. 6, 15Br2/Fe................................................................................ 24Branched Chains ................................................................. 9

C

C≡C Bond distance ........................................................... 13C/H Ratios......................................................................... 17C=C bond distance.............................................................. 4C=C distance..................................................................... 13C10H8 ................................................................................. 25C14H10................................................................................ 25C5H5N ............................................................................... 26Carbon-Carbon Triple Bonds............................................ 13carbonyl group .................................................................. 16catalyst .............................................................................. 23Catalysts.............................................................................. 8C-C distance...................................................................... 13CF2=CF2............................................................................ 12C-H distance.................................................................. 4, 13CH2=C(CH3)(CO2CH3)..................................................... 11CH2=CH2 ...................................................................... 2, 10

CH2=CH-C6H5 .................................................................. 11CH2=CH-CH=CH2............................................................ 12CH2=CH-CH3 ................................................................... 11CH2=CH-Cl....................................................................... 10CH2=CH-R.......................................................................... 8chain growth........................................................................ 8Chemical Properties: Addition Reactions.......................... 6cis isomers........................................................................... 3Cl2 ................................................................................. 6, 15Cl2/Fe................................................................................. 24Coal Tar............................................................................. 17Coke .................................................................................. 17Common Names ................................................................ 20

D

D2 ................................................................................. 6, 15Density .......................................................................... 5, 13Depolymerizations.............................................................. 9diene .................................................................................... 2diol..................................................................................... 16Double Addition................................................................ 15Dyes .................................................................................. 17

E

Electrophiles...................................................................... 23ene ................................................................................. 2, 14ene ending............................................................................ 2Ethene.................................................................................. 2Ethylene .............................................................................. 2Ethyne............................................................................... 13

F

free rotation......................................................................... 3Fused Ring Aromatics ....................................................... 25

G

gasoline.............................................................................. 17Geometric Isomers .............................................................. 3

H

H+ catalyst......................................................................... 16H+ Catalyst.......................................................................... 7H2 ................................................................................. 6, 15H2O ................................................................................... 16H2SO4/SO3......................................................................... 24Halide Influences................................................................. 7Halobenzenes .................................................................... 19Halogenation ..................................................................... 24HBr................................................................................ 7, 16H-C≡C-H .......................................................................... 13HCl................................................................................ 7, 16Heteroatom Groups........................................................... 26Heterocyclics..................................................................... 26HF ....................................................................................... 7HI ....................................................................................... 7HNO3/H2SO4..................................................................... 23HX................................................................................. 7, 16

Chemistry 506 Dr. Hunter’s Class Chapter 11.28

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University

Hydration ............................................................................ 7Hydrogenation............................................................... 6, 15

I

industrial chemistry .......................................................... 17Ipso ................................................................................... 21IUPAC Names .................................................................. 19IUPAC Rules ...................................................................... 2

K

ketone................................................................................ 16

L

Linear Chains ...................................................................... 9

M

Markovnikov....................................................................... 7Markovnikov Addition ................................................. 7, 16Meta .................................................................................. 21methylbenzene .................................................................. 20Molecular Weight Distributions ......................................... 9Molecular Weights.............................................................. 9monomer.............................................................................. 9monomers............................................................................ 8Mp................................................................................. 5, 13

N

Naphthalene....................................................................... 25Nitration............................................................................ 23Nitrobenzene..................................................................... 19Nomenclature .............................................................. 14, 19

O

Octane ............................................................................... 17Ortho................................................................................. 21

P

PAH .................................................................................. 25Para.................................................................................... 21PE ..................................................................................... 10Petroleum .......................................................................... 17Pharmaceuticals................................................................. 17Phenanthrene..................................................................... 25Phenol................................................................................ 20Phenyl Alanine.................................................................. 22phenyl groups.................................................................... 21phenylalkanes .................................................................... 19Physical Properties........................................................ 5, 13Pigments............................................................................ 17PKU .................................................................................. 22Plastics .............................................................................. 17PMMA.............................................................................. 11Poly(methyl methacrylate)................................................ 11Poly(vinyl chloride)........................................................... 10Polycyclic Aromatic Hydrocarbons.................................. 25Polyethylene...................................................................... 10Polyisoprene...................................................................... 12Polymerization.................................................................... 9Polymers ............................................................................. 8Polypropylene ................................................................... 10Polystyrene........................................................................ 11PP ..................................................................................... 10

Problems............................................................................ 26Properties .......................................................................... 17PS ..................................................................................... 11Pt catalyst...................................................................... 6, 15PVC ................................................................................... 10px ..................................................................................... 13py ..................................................................................... 13Pyridine............................................................................. 26pz ....................................................................................... 4

R

Resonance Stabilization .................................................... 18Reversibility of Reactions................................................... 9Ring Positions ................................................................... 21Rubber............................................................................... 12

S

Secondary elimination of water ........................................ 16Smell.................................................................................... 5Solubility....................................................................... 5, 13sp hybridized..................................................................... 13sp2 hybridization ................................................................. 4Substitution Reactions ................................................ 18, 23Sulfonation ........................................................................ 24

T

Teflon................................................................................ 12tetraene................................................................................ 2TNT................................................................................... 23Toluene.............................................................................. 20trans isomers ....................................................................... 3triene.................................................................................... 2

V

Van der Waals forces .................................................... 5, 13

X

X2 ................................................................................. 6, 15

Y

yne ending......................................................................... 14

Z

Z+ ..................................................................................... 23

C-CC-C

C-C bond distance ............................................................... 4

ππ

π-bond ................................................................................. 4π-bond opening.................................................................... 8π-bonds.......................................................................... 3, 13π-Bonds............................................................................... 4π-bonds weaker than σ-bonds............................................. 6

σσ

σ-bond ............................................................................... 13σ-bonds................................................................................ 4

Chemistry 506 Dr. Hunter’s Class Chapter 11.29

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University