history of benzene
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History of Benzene1824 - 1825 Isolated from burnt whale oil by Michael Faraday1834 Eilhardt Mitscherlich finds benzene has formula of C6H6
1861 Loschmidt proposes structure for benzoic acid and aniline
History of Benzene1824 - 1825 Isolated from burnt whale oil by Michael Faraday1834 Eilhardt Mitscherlich finds benzene has formula of C6H6
1861 Loschmidt proposes structure for benzoic acid and aniline
O
OH
N
H
H
History of Benzene1865 Kekule has a dream1865 Kekule invokes sausage diagramsBulletin de la Société Chimique de France, 3, 98 (1865)
10–4
History of Benzene1865 Kekule has a dream1865 Kekule invokes sausage diagramsBulletin de la Société Chimique de France, 3, 98 (1865)
1866 Kekule introduces ring model for benzene
Alternate Benzene Structures
Dewar 18671972
proposedsynthesized
Landenburg Prismane
18691973
Claus18671967
Fig. 15-2, p. 521
Hückel’s Rules for aromaticity
p. 521
H
H
H
H
H
H
Benzene electron distribution map
Fig. 15-12, p. 532
Hückel’s Rules for aromaticity
Aromaticity vs. antiaromaticity
p. 523
p. 524
Hückel’s Rules for aromaticity
Aromaticity vs. antiaromaticity
Why 4n + 2 for aromatic and 4n for antiaromatic?Frost’s cycle
Fig. 15-3, p. 522
Benzene Molecular Orbitals
Cyclopentadienyl ions
Fig. 15-11, p. 531
H H H
Fig. 15-5, p. 526
Fig. 15-7, p. 527
Fig. 15-9a, p. 529
Fig. 15-9b, p. 529
17%
27%
57% A. Aromatic
B. Antiaromatic
C. Neither
5. 14-annulene
NN
OCH3CH3O
Pyridyl DHA Targets
NN
OCH3CH3O
N
N
OCH3CH3O
NN
OCH3CH3O1+2 1+2 1+0, 1+2 none 1+0 1+0
N
N
CH3O OCH3
N
N
CH3O OCH3
N
N
CH3O OCH3
N
N
CH3O OCH3
2+1 1+1 2+0, 2+1 none none 1+0, 1+1 2+0 1+0
Fig. 15-14, p. 535
p. 535
p. 540
p. 535
TIPSTIPS
Br Br
19 11
Aromatic Biomolecules
1.Amino acids2.Nucleic acids
Fig. 15-8, p. 528
Fig. 15-9, p. 529
p. 533
p. 529
p. 533
p. 530
p. 540
p. 541
p. 337
p. 338
Table 9-2, p. 337
Summary
-H (unsubstituted)
-R or -Ar, ortho- and para- -R or -Ar, meta-
-NH2 or -OH, meta-
-NH2 or -OH, ortho- and para-
-Cl or -Br, ortho- and para-
-Cl or -Br, meta-
-NO2 or -CO2H, meta-
-NO2 or -CO2H, ortho- and para-
Deactivators
Activators
Reactants
[CarbocationIntermediate]
Reaction Progress
Energy
Fig. 9-16, p. 338
p. 340
p. 345
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