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Chemistry 3719 - Organic Chemistry I
Professor : Dr. Peter NorrisOffice : 6014 Ward BeecherTelephone : (330) 941-1553Email : [email protected] :
http://www.as.ysu.edu/~pnorris/public_html
www.chemfinder.com
Lecture needs:
• Carey
• Molecular models
• Adobe Acrobat Reader
• Web access
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Molecular Models – www.darlingmodels.com
May be used on exams, will be used in lectureYSUYSU
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Lab needs:
• Pavia, Lampman, Krizand Engel
• Goggles
• Lab coat
• Bound notebook
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Chemistry 3719 and 3720 (and labs)
Lectures
• Structure and nomenclature of compounds and groups
• Physical properties and analysis of materials
• Reactivity and transformations with reagents
• Importance of organic compounds in other subjects
Labs
• Glassware and equipment used to prepare organics
• Instrumentation used to analyze compounds
• Keeping a good notebook of lab preparations
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Chemistry 3719R and 3720R (Recitation)
Objectives
• Practice the problems sets, old exams
• Practice the problems from the book
• Ask ?? of a professional chemist (other than lecture Prof)
• To encourage students to keep up with material (quizzes)
When: 12-12.50 or 1-1.50 on Mondays
(1 Semester hour, Separate grade to 3719/3719L)
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Chemistry 3719 Personnel
Dr. Peter Norris3719 lecture
Dr. John Jackson3719 recitation
Calvin Austin3719 lab
Lucas Beagle3719 lab
Lemuel Carlisle3719 lab
Brian Dobosh3719 lab
Mike Evans3719 lab
Ashley Malich3719 lab
Kevin White3719 lab
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Some does and don'ts for 3719 and 3720
Does• Prepare for lecture and lab; read ahead
• Ask questions at any time; lecture, recitation, office hours
• Use all of your resources; email, website, tutors
• If you struggled in General Chemistry, seek help soon
Don'ts• Don’t get behind, blow off class, ignore the available help• Don’t wait until October to say “dude, I thought I knew the stuff.”
• Don’t complain when you get 20/100 if you ignore the above
Get help : [email protected]
Peter Norris B.Sc., Ph.D.
Born : 1965, Liverpool, England
B.Sc. Chemistry : 1986, Salford University, England
Ph.D. Organic Chemistry: 1992, The Ohio State University
Post-doctoral : 1993-96, American University, Wash’n DC
Assistant Professor : 1996-2000 YSU Chemistry
Associate Professor : 2000-2004 YSU Chemistry
Full Professor : 2004 – present YSU Chemistry
40 publications, graduated 23 Masters degree students since 1998
~ $1,000,000 in grant money since 1999
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"Cu(I)-Catalyzed formation of D-mannofuranosyl 1,4-disubstituted 1,2,3-triazole carbohybrids," P.L. Miner, T.R. Wagner, and P. Norris, Heterocycles 2005, 65, 1035-1049.
>40 total, most with YSU undergrad or MS students as coauthors
"Crystal structure of 1-(2,3:5,6-di-O-isopropylidene-beta-D-mannofuranosyl)-1H-[1,2,3]triazol-4,5-dicarboxylic acid diethyl ester," H. Seibel, P.L. Miner, P. Norris, and T.R. Wagner, J. Chem. Cryst., 2006.
"Application of Bis(diphenylphosphino)ethane in Staudinger-type N-Glycosyl Amide Synthesis," D. P. Temelkoff, C. R. Smith, D. A. Kibler, S. McKee, S. Duncan, M. Zeller, M. Hunsen, and P. Norris, Carbohydrate Research, 2006, 341, 1645-1656.
"N-Glycoside neoglycotrimers from 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl azide," D. P. Temelkoff, M. Zeller, and P. Norris, Carbohydrate Research 2006, 341, 1081-1090.
Research and Publication
"Crystal and molecular structure of 6,7-dideoxy-1,2;3,4;9,10-tris-O-(1-methylethylidene)-D-erythro-alpha-D-galacto-undecopyranosid-8-ulose," T. D. Weaver, M. Zeller, and P. Norris, J. Chem. Cryst., 2006.
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What is Organic Chemistry?
The study of the compounds that contain carbon and the reactions of those materials (millions known)
Why a whole year of Organic?
Carbon can bond in multiple ways to form a huge number of different molecules, and these compounds form the basis of many different disciplines, e.g.:
Biology (DNA, proteins, carbohydrates)
Medicine and Pharmacy (Aspirin, Taxol, AZT)
Chemical Engineering (oil, plastics, fine chemicals)
Forensics (Biological materials, chemical tests)
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From Organic Chemistry to Biology, Medicine, Pharmacy, etc.From Organic Chemistry to Biology, Medicine, Pharmacy, etc.
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N-acetylneuraminic acid
Tamiflu - Giliad/Roche
Relenza - GSK
From Scientific American – www.sciam.com
CO2EtO
NH3.HPO4AcHN
O CO2H
H2N NH
AcHN
OHOH
OH
O CO2H
AcHN
OHOH
OH
OH
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VancomycinYSUYSU
Staphylococcus Staphylococcus aureusaureus –– Norris/FaganNorris/Fagan
Gram-positive, cluster-forming coccus, causes food poisoning, endocarditis, osteomyelitis, septiceamia, infections on implants
Organic Chemistry – Materials and Uses
Organic Chemistry
chemicalsynthesis
NewCompounds
NewMedicines
medicinal
chemistry
materials
chemistry
NewMaterials
Pharmacy,Medicine
Nanotech,Engineering
Biochemistryand
Chemical Biology
Proteomics,Genetics
~1800 – Organic Chemistry : the chemistry of natural products based on carbon
2006 – Organic Chemistry : “molecular engineering”
Chemistry 3719Chemistry 3719--37203720
H
CH
HH
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Timeline1807 Berzelius introduces the term “Organic Chemistry” to describe
the study of compounds isolated from nature
1828 Wöhler makes urea, the first natural organic compound to be
synthesized in the laboratory
1890 Fischer studies the chemistry of proteins, carbohydrates and
the nucleic acids - Biochemistry
1950 Woodward and Eschenmoser complete the first total synthesis
of Vitamin B12. NMR begins to be useful.
1990 Kishi, Nicolau, Smith, Schreiber, etc. complete total syntheses
of compounds such as Brevetoxin B, Taxol, etc.
2000 Chemical Biology, Molecular Engineering
OHcatalytic H+
+OH
O
O
O
OH
OH
OH
OH
HO HO OH
OH
HO O
O
HHH+
transfer
OH
O
O
OH
H2O
OH
O
(- H2O)
(- H2O)
(- H+)
Teaching Philosophy: Organic Chemistry as a Language
H2N
O
NH2
UREA - 1828
Natural Products Chemistry
Ley, Veitch, Beckmann, Burke, Boyer and Maslen. ACIEE, August 2007
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Carey Chapter 1 - Chemical Bonding
“Structure determines properties”
• Atomic and electronic structure of atoms
• Ionic and covalent bonding
• Electronegativity and polar covalent bonds
• Structures of organic compounds - representations
• Resonance within molecules
• Shapes of molecules
• Molecular orbitals and orbital hybridization
Periodic Table of the Elements
1.1 Atoms, electrons, and orbitals
Probability distribution for an electronFigure 1.1
9
Boundary surfaces of a 1s and 2s orbitalFigure 1.2
Boundary surfaces of the 2p orbitalsFigure 1.3
Electronic Configurations of Atoms
10
Electronic Structure of Atoms
Atom Atomic No. Electronic Structure
H 1 1s1
He 2 1s2
Li 3 1s2 2s1
Be 4 1s2 2s2
B 5 1s2 2s2 2px1
C 6 1s2 2s2 2px1 2py1
N 7 1s2 2s2 2px1 2py1 2pz1
O 8 1s2 2s2 2px2 2py1 2pz1
1.1 General Concepts
• Orbitals higher in energy further they are from nucleus.
• Designated by principal quantum number (1, 2, 3, etc.).
• Degenerate orbitals (same energy) fill up singly before they double up (Aufbau).
• Maximum of two electrons per orbital, each having opposite spin (Pauli exclusion principle).
• Impossible to know both the speed and location of an electron at the same time (Heisenberg uncertainty).
1
1.3 Covalent Bonding - Electrons Shared
1.2-1.3 Bonding
Atoms trying to attain the stable configuration of a noble (inert) gas - often referred to as the octet rule
1.2 Ionic Bonding - Electrons Transferred
type of bond that is formed is dictated by the
relative electronegativities of the elements involved
Electronegativity
the attraction of an atom for electrons
1.2 Ionic bonding
Electrons Transferred
Big differences in E.N. values
Metals reacting with non-metals
2
Important Electronegativity Values
H
2.1
Li Be B C N O F
1.0 2.0 2.5 3.0 3.5 4.0
Cl
3.0
Br
2.8
I
2.5
1.3 Covalent Bonding - Similar electronegativities
H . + H . H : H Hydrogen atoms Hydrogen molecule
C + 4 H CH
H
H
H
Lewis dot representations of molecules
B.D.E
+104 kcal/mol
B.D.E
+104 kcal/mol
B.D.E. = bond dissociation energy
1.3 Lewis Dot Structures of Molecules
3
1.4 Double bonds and triple bonds
H C C HH : C : : : C : H
C : : CH H
H HC C
H
H
H
H
Double bonds - alkenes
Triple bonds - alkynes
1.5 Polar covalent bonds and electronegativity
H2 HF H2O
CH4 CH3ClBased on electronegativity
LiLiHHδδ−− δδ++
FF::........HH
δ+δ+ δ−δ−
1.6 Structural Formula - Shorthand in Organic Chemistry
CH3CH2CH2CH3
H H
HH H
H HH
HH
CH3CH2CH2CH2OH OH
H ClH
HH
HH H
HHH
H Cl
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1.6 Constitutional Isomers
HCHH
O C HH
HH C C O H
H
H
H
H
Same molecular formula, completely different chemical and physical properties
1.7 Formal Charge
Formal charge = group number
- number of bonds
- number of unshared electrons
O NO
OH
OO
O
1.8 Resonance Structures - Electron Delocalization
OO
O OO
O
CH3C
O
O
CH3C
O
O
Table 1.6 – formal rules for resonance
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1.9 Shapes of Molecules
Shapes of molecules are predicted using VSEPR theory
1.9 Shape of a molecule in terms of its atoms
Figure 1.9
Table 1.7 – VSEPR and molecular geometry
6
Trigonal planar geometry of bonds to carbon in H2C=O
Linear geometry of carbon dioxide
1.10 Molecular dipole moments
Figure 1.7
• Curved arrows are used to track the flow of electrons in chemical reactions.
• Consider the reaction shown below which shows the dissociation of AB:
1.11 Curved Arrows – Extremely Important
A B A+ + B-
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Many reactions involve both bond breaking and bond formation. More than one arrow may be required.
Curved Arrows to Describe a Reaction
H O + C
H
H
H
Br C
H
O
H
HH + Br-
1.12 Acids and Bases - Definitions
ArrheniusAn acid ionizes in water to give protons. A base ionizes in water to give hydroxide ions.
Brønsted-LowryAn acid is a proton donor. A base is a proton acceptor.
LewisAn acid is an electron pair acceptor. A base is an electron pair donor.
H AB .. B H A–..
+
1.13 A Brønsted-Lowry Acid-Base Reaction
A proton is transferred from the acid to the base.
+ +
base acid conjugate acid
conjugate base
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hydroniumhydronium ion (Hion (H33OO++))
HH BrBrOO
HH
HH
.... ....
HH
HH
.... OO HH BrBr––.... ....
....
............
....++
Proton Transfer from HBr to Water
basebase acidacid conjugate conjugate conjugateconjugateacid acid basebase
++ ++
[H3O+][Br–]
[HBr]Ka =
H BrO
H
H
.. ..
H
H
.. O H Br–.. ..
..
......
.. ++ +
pKa = – log10 Ka
Equilibrium Constant for Proton Transfer
H O H + H Br H O H + BrH?
Acids and Bases: Arrow Pushing
H O H + H Br H O H + BrH
H O H + H Br H O H + BrH
[H3O+][Br–]
[HBr]Ka = ~ 106 for HBr, pKa = - 5.8
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Need to know by next class:pKa = -log10Ka
STRONG ACID = LOW pKa WEAK ACID = HIGH pKa
HI, HCl, HNO3, H3PO4 pKa -10 to -5 Super strong acids
H3O+ pKa – 1.7
RCO2H pKa ~ 5 acids
PhOH pKa ~ 10 get
H2O, ROH pKa ~ 16 weaker
RCCH (alkynes) pKa ~ 26
RNH2 pKa ~ 36 Extremely weak acid
RCH3 pKa ~ 60 Not acidic at all
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1.14 What happened to pKb?
• A separate “basicity constant” Kb is not necessary.
• Because of the conjugate relationships in the Brønsted-Lowry approach, we can examine acid-base reactions by relying exclusively on pKa values.
CH
HH
H CH
HH
pKa ~60
Essentially not acidic
Corresponding base
Extremely strong
1.15 How Structure Affects Acid/Base Strength
Bond Strength
• Acidity of HX increases (HI>HBr>HCl>HF) down the periodic table as H-X bond strength decreases and conjugate base (X:- anion) size increases (basic strength of anion decreases).
strongest H—X bond weakest H—X bond
ElectronegativityAcidity increases across periodic table as the atom attached to H gets more electronegative (HF>H2O>H2N>CH4).
least electronegative most electronegative
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Inductive EffectsElectronegative groups/atoms remote from the acidic H can effect the pKa of the acid.
pKa = 16 pKa = 11.3
CH3CH2O H CF3CH2O H
• O – H bond in CF3CH2OH is more polarized
• CF3CH2O- is stabilized by EW fluorine atoms
Resonance Stabilization in AnionDelocalization of charge in anion (resonance) makes the anion more stable and thus the conjugate acid more acidic
e.g. (CH3CO2H > CH3CH2OH).
CH3C
O
O
CH3C
O
O
CH3C
OH
O
CH3 CH2 OH CH3 CH2 O
pKa ~16
pKa ~5
1.16 Acid-base reactions - equilibria
H Cl NaOH NaCl + H2O+
H3C
O
OHNaOH
H3C
O
ONaH2O+ +
H2OCH3ONaNaOHCH3OH + +
The equilibrium will lie to the side of the
weaker conjugate base
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1.17 Lewis acids and Lewis bases
FF33BB ++ OOCHCH22CHCH33
CHCH22CHCH33
•••• ••••–– ++
FF33BB OOCHCH22CHCH33
CHCH22CHCH33
••••
Lewis acidLewis acid Lewis baseLewis base
Product is a stable substance. It is a liquid with a boiling point of 126°C. Of the two reactants, BF3 is a gas and CH3CH2OCH2CH3 has a boiling point of 34°C.