che-310 organic chemistry i dr. james lyle; office: nsm d-323 (310) 243-3388 or 243-3376...
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CHE-310
Organic Chemistry I
Dr. James Lyle; office: NSM D-323
(310) 243-3388 or 243-3376
office hours: MWF: 9-10:00am & Tu: 8:00-9:00am
Web page:
http://chemistry.csudh.edu/
texts:
Organic Chemistry, Morrison & Boyd (6th)
Supplement to...,
Morrison & Boyd
(optional)
Supplement...
Model kit
Grading: traditional, no curve!
A=100%-93%, A-=92%-90%,B+=89%-88%,
B=87%-83%,etc.
Daily exams = 100
4 exams @ 100 pts = 400
final exam = 100
homework required
600
Daily exams
No make ups! Drop two lowest scores. Begin at 10:00!
Daily Homework: Required!
(hold until called for)
Cheating: Don’t do it! The penalties are severe.
Turn off all cell phones and pagers!
Organic Chemistry; difficult, challenging! “memorization course” (NOT! well…maybe),
body of knowledge + application of theory!
How to succeed?
1. look over the text before lecture.
2. listen carefully to lectures
3. read the text (take notes)
4. do the homework (twice...?)
5. review
Organic Chemistry - the study of the compounds of carbon, their properties and the changes that they undergo.
Descriptive approach -
nomenclature
syntheses
reactions
mechanisms
...
First: review topics from gen. chem. important to o-chem.
atomic structure
subatomic particles:
mass charge
protons
neutrons
electrons
nucleus: protons & neutrons
electron shells & subshells: electrons
1 amu +1
1 amu 0
~0 amu - 1
atomic number = number of protons in the nucleus of the atom (different for each element); Hydrogen = 1, Helium = 2, Lithium = 3,...
[also the number of electrons in a neutral atom]
Iron = 26 26 protons = +26
26 electrons=-26
net charge= 0
atomic mass = mass of an atom; sum of the weights of the protons & neutrons.
But, not all atoms of a given element are identical.
isotopes - atoms of the same element with different numbers of neutrons.
examples of isotopes
prot. neut. %
H1 1 0 99.985
H2 1 1 0.015
C12 6 6 98.89
C13 6 7 1.11
C14 6 8 ...
Cl35 17 18 75.53
Cl37 17 20 24.47
F19 9 10 100
atomic weight: weighted average mass of the atoms; combining weight...
electrons => energy shells & subshells about the nucleus.
shells = 1, 2, 3, 4, ...
subshells = s, p, d, f
orbitals = region in space where an electron of given energy is likely to be found; no more than two electrons of opposite spin per orbital (Pauli exclusion principle).
order of filling
1s
2s 2p
3s 3p 3d
4s 4p 4d 4f
5s 5p 5d 5f
6s 6p 6d 6f
spectral notation: 1s2,2s2,2p6…
Fluorine (at.# 9) 9p/9e
1s2,2s2,2p5
Chlorine (at.# 17) 17p/17e
1s2,2s2,2p6,3s2,3p5
Bromine (at.# 35) 35p/35e
1s2,2s2,2p6,3s2,3p6,4s2,3d10,4p5
Iodine (at.# 53) 53p/53e
1s2,2s2,2p6,3s2,3p6,4s2,3d10,4p6,5s2,4d10,5p5
valence electrons = electrons in the outermost shell
Fluorine has 7 valence elect.
Chlorine has 7 valence elect.
Bromine has 7 valence elect.
Iodine has 7 valence elect.
PERIODIC CHART OF THE ELEMENTS I VIII┌────┐ ┌────┐│ H │ │ He ││ 1 │ II III IV V VI VII │ 2 │├────┼────┐ ┌────┬────┬────┬────┬────┼────┤│ Li │ Be │ │ B │ C │ N │ O │ F │ Ne ││ 3 │ 4 │ │ 5 │ 6 │ 7 │ 8 │ 9 │ 10 │├────┼────┤ ├────┼────┼────┼────┼────┼────┤│ Na │ Mg │ │ Al │ Si │ P │ S │ Cl │ Ar ││ 11 │ 12 │ │ 13 │ 14 │ 15 │ 16 │ 17 │ 18 │├────┼────┼────┬────┬────┬────┬────┬────┬────┬────┬────┬────┼────┼────┼────┼────┼────┼────┤│ K │ Ca │ Sc │ Ti │ V │ Cr │ Mn │ Fe │ Co │ Ni │ Cu │ Zn │ Ga │ Ge │ As │ Se │ Br │ Kr ││ 19 │ 20 │ 21 │ 22 │ 23 │ 24 │ 25 │ 26 │ 27 │ 28 │ 29 │ 30 │ 31 │ 32 │ 33 │ 34 │ 35 │ 36 │├────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┤│ Rb │ Sr │ Y │ Zr │ Nb │ Mo │ Tc │ Ru │ Rh │ Pd │ Ag │ Cd │ In │ Sn │ Sb │ Te │ I │ Xe ││ 37 │ 38 │ 39 │ 40 │ 41 │ 42 │ 43 │ 44 │ 45 │ 46 │ 47 │ 48 │ 49 │ 50 │ 51 │ 52 │ 53 │ 54 │├────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┤│ Cs │ Ba │ La │ Hf │ Ta │ W │ Re │ Os │ Ir │ Pt │ Au │ Hg │ Tl │ Pb │ Bi │ Po │ At │ Rn ││ 55 │ 56 │ 57 │ 72 │ 73 │ 74 │ 75 │ 76 │ 77 │ 78 │ 79 │ 80 │ 81 │ 82 │ 83 │ 84 │ 85 │ 86 │├────┼────┼────┼────┼────┼────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┘│ Fr │ Ra │ Ac │ │ │ │ 87 │ 88 │ 89 │104 │105 │ └────┴────┴────┴────┴────┘ ┌────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┐ │ Ce │ Pr │ Nd │ Pm │ Sm │ Eu │ Gd │ Tb │ Dy │ Ho │ Er │ Tm │ Yb │ Lu │ │ 58 │ 59 │ 60 │ 61 │ 62 │ 63 │ 64 │ 65 │ 66 │ 67 │ 68 │ 69 │ 70 │ 71 │ ├────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┤ │ Th │ Pa │ U │ Np │ Pu │ Am │ Cm │ Bk │ Cf │ Es │ Fm │ Md │ No │ Lr │ │ 90 │ 91 │ 92 │ 93 │ 94 │ 95 │ 96 │ 97 │ 98 │ 99 │100 │101 │102 │103 │ └────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┘
periodic chart of the elements
metals & nonmetals
families (groups) of elements
alkali metals (group I)
Li,Na,K,...
alkaline earths (group II)
Be,Mg,Ca,...
halogens (group VII)
F,Cl,Br,I,...
noble gases (group VIII or 0)
He,Ne,Ar,...
group number = valence elec.
Chemical bonding (classical)
chemical bond: force that holds atoms together in compounds.
ionic bond ~ between
metals & non-metals
covalent bond ~ between
non-metals & non-metals
definitions:
ionic bond: a chemical bond formed by the transfer of valence electrons to achieve noble gas electron config-urations, resulting in ions held together by electrostatic attraction.
covalent bond: chemical bond formed by the sharing of valence electrons to achieve noble gas electron configurations.
ionic bond example:
sodium chloride
sodium = Na, atomic # 11
1s2,2s2,2p6,3s1
neon = Ne, atomic # 10
1s2,2s2,2p6
if Na loses 1 elect. then it will have a noble gas elect.
config. like Ne but will be charged, +1 ( 11p/10e ).
=> Na+ sodium ion
chlorine = Cl, atomic # 17
1s2,2s2,2p6,3s2,3p5
argon = Ar, atomic # 18
1s2,2s2,2p6,3s2,3p6
if chlorine can gain an electron it will have a noble gas electron config. like argon but will be charged -1 (17p/18e) Cl-
sodium chloride = NaCl
or Na+Cl-
covalent bonds
Lewis Dot representations
H Be :Cl
Ne C O
H2O = H:O:H
see homework! review your gen chem text!
. .. .
. ...
. .
..
..
..
..
..
..
.. .. .. ..CO2 :O::C::O: :O=C=O:
N2 :N:::N: :NN:
HCN H:C:::N: H-CN:
.. ..H2CO H:C::O: H-C=O: .. | H H
Hybrid atomic orbitals:
sp = linear; 180o
sp2 = trigonal; 120o
sp3 = tetrahedral; 109.5o
B ABB
B
AB B
B
B A B
VSEPR (valence shell electron pair repulsion)
prediction of hybridization
number of ligands (X)
plus
number of unshared pair of valence electrons (E)
equals
number of orbitals needed
what type of hybrid orbitals are needed
eg. H2O => H:O:H or H—O—H
2 ligands + 2 lone pair = 4 orbitals
AX2E2
sp3 tetrahedral, 109.5o
water is a bent molecule with bond angles of 105o
..
..
H
OH
..
..
VSEPR
AX2 sp 180o linear
AX3 sp2 120o trigonal
AX2E sp2 ~120o or “bent”
AX4 sp3 109.5o tetrahedral
AX3E sp3 ~109.5o or “pyramidal
AX2E2 sp3 ~109.5o or “bent”
We can use the VSEPR method to predict the shape and bond angles for simple covalent molecules.
SHAPE is important!
review gen chem text!
Do the homework!!!!!
PERIODIC CHART OF THE ELEMENTS I VIII┌────┐ ┌────┐│ H │ │ He ││ 1 │ II III IV V VI VII │ 2 │├────┼────┐ ┌────┬────┬────┬────┬────┼────┤│ Li │ Be │ │ B │ C │ N │ O │ F │ Ne ││ 3 │ 4 │ │ 5 │ 6 │ 7 │ 8 │ 9 │ 10 │├────┼────┤ ├────┼────┼────┼────┼────┼────┤│ Na │ Mg │ │ Al │ Si │ P │ S │ Cl │ Ar ││ 11 │ 12 │ │ 13 │ 14 │ 15 │ 16 │ 17 │ 18 │├────┼────┼────┬────┬────┬────┬────┬────┬────┬────┬────┬────┼────┼────┼────┼────┼────┼────┤│ K │ Ca │ Sc │ Ti │ V │ Cr │ Mn │ Fe │ Co │ Ni │ Cu │ Zn │ Ga │ Ge │ As │ Se │ Br │ Kr ││ 19 │ 20 │ 21 │ 22 │ 23 │ 24 │ 25 │ 26 │ 27 │ 28 │ 29 │ 30 │ 31 │ 32 │ 33 │ 34 │ 35 │ 36 │├────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┤│ Rb │ Sr │ Y │ Zr │ Nb │ Mo │ Tc │ Ru │ Rh │ Pd │ Ag │ Cd │ In │ Sn │ Sb │ Te │ I │ Xe ││ 37 │ 38 │ 39 │ 40 │ 41 │ 42 │ 43 │ 44 │ 45 │ 46 │ 47 │ 48 │ 49 │ 50 │ 51 │ 52 │ 53 │ 54 │├────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┤│ Cs │ Ba │ La │ Hf │ Ta │ W │ Re │ Os │ Ir │ Pt │ Au │ Hg │ Tl │ Pb │ Bi │ Po │ At │ Rn ││ 55 │ 56 │ 57 │ 72 │ 73 │ 74 │ 75 │ 76 │ 77 │ 78 │ 79 │ 80 │ 81 │ 82 │ 83 │ 84 │ 85 │ 86 │├────┼────┼────┼────┼────┼────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┘│ Fr │ Ra │ Ac │ │ │ │ 87 │ 88 │ 89 │104 │105 │ └────┴────┴────┴────┴────┘ ┌────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┐ │ Ce │ Pr │ Nd │ Pm │ Sm │ Eu │ Gd │ Tb │ Dy │ Ho │ Er │ Tm │ Yb │ Lu │ │ 58 │ 59 │ 60 │ 61 │ 62 │ 63 │ 64 │ 65 │ 66 │ 67 │ 68 │ 69 │ 70 │ 71 │ ├────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┤ │ Th │ Pa │ U │ Np │ Pu │ Am │ Cm │ Bk │ Cf │ Es │ Fm │ Md │ No │ Lr │ │ 90 │ 91 │ 92 │ 93 │ 94 │ 95 │ 96 │ 97 │ 98 │ 99 │100 │101 │102 │103 │ └────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┘
Polarity
Covalent bonds are polar when the two atoms sharing electrons have different electronegativities.
eg. H—Cl δ+ δ-
a charge separation or a dipole gives a polar bond.
.. ..O2 :O=O: has a non-polar bond
Representation of dipoles using vectors
a) magnitude = length
b) direction = positive negative
A molecule will be non-polar if the vector sum of the bond dipoles is zero; eg. they cancel one another.
A molecule with be polar if the vector sum of the bond dipoles is non-zero.
Determining polarity of covalent molecules:
1. Lewis dot structure
2. VSEPR hybridization shape of the molecule
3. dipoles for polar bonds
4. vector sum of the bond dipoles
5. vector sum = 0 non-polar molecule
6. vector sum 0 polar molecule
CO2 :O=C=O: sp linear
vector sum = 0
non-polar molecule
H2O ..
H—O—H AX2E2 sp3 tetrahedral (bent) ..
H OH
vector sum 0
polar molecule!
H
CO H
H
H
CH3OH
Both C & O are sp3
hybridized.
The bond dipole vectors do not cancel each other and the molecule is polar.
NB: must know shape to determine polarity!
Intermolecular forces. Attractions between molecules.
ionic attractions Na+Cl-
(very strong) Cl-Na+
dipole-dipole attractions H—Br Br—H
hydrogen bonding ( H attached to N,O,F )
H—O----H—O | | H H
van der Waals (London forces) Br—Br(weak) Br—Br
intermolecular attractions strongest
ionic attractions
dipole-dipole / hydrogen bonding
van der Waals
weakest
ionic bonds => ionic attractions
polar covalent => dipole-dipole attractions
non-polar covalent => van der Waals
Cl2
CO2
H2O
CH4
KBr
non-polar covalent => van der Waals
non-polar covalent => van der Waals
polar covalent => dipole-dipole &
Hydrogen bonding
non-polar covalent => van der Waals
ionic bonding => ionic attractions
bonding => shape => polarity => physical properties
physical properties:
melting point
boiling point
solubility
The stronger the intermolecular forces the higher the mp/bp. Ionic substances have significantly higher mp/bp than do covalent substances. [note: mp/bp also increase with increasing size.]
Prediction of mp/bp (relatively high or low?):
Mg(OH)2
CH3OH
CH2O
CH3CH3
ionic => ionic attractions
polar => dipole-dipole + H-bond
polar => dipole-dipole
non-polar => van der Waals
mp bp
350oC --
-94oC 65oC
-920C -21oC
-183oC –89oC
Solubility
“like dissolves like”
~ water soluble? must be ionic or highly polar + H-bond
(hydrophilic)
~ water insoluble? must be non-polar or weakly polar
(hydrophobic)
Most organic compounds are water insoluble!
Acids/Bases
historic:
acids – from L. acidus = “sour”
sour taste
react with metals H2
react with bases water + salts
change litmus red
react with limestone CO2
examples: HCl, H2SO4, HNO3, HClO4
historic:
bases - bitter taste
soapy feel
react with acids water + salts
change litmus blue
examples: NaOH, Al(OH)3, K2CO3, NaHCO3
Lowry-Brønsted Acid - a substance that donates a proton (H+) in a chemical reaction.
Lowry-Brønsted Base – a substance that accepts a proton (H+) in a chemical reaction.
CH3MgBr + NH3 CH4 + Mg(NH2)Br
NaOH + H2SO4 H2O + NaHSO4
base acid acid base
base acid acid base
Lewis Acid – a substance that accepts an electron pair in a chemical reaction to form a covalent bond.
Lewis Base – a substance that donates an electron pair in a chemical reaction to form a covalent bond.
- + BF3 + :NH3 F3B:NH3
Lewis Lowry-Brønsted
Rule: acid/base reactions must run “down hill.”
stronger acid/base weaker acid/base
H2SO4 + H2O HSO4- + H3O+
stronger stronger weaker weakeracid base base acid
H2O + NH3 NH4+ + OH-
weaker weaker stronger stronger acid base acid base
(note direction of reactions)
Within a period of the periodic chart, acid strength increases with increasing electronegativity:
CH4 < NH3 < H2O < HF
Within a family of elements, acid strength increases with increasing size:
HF < HCl < HBr < HI
PERIODIC CHART OF THE ELEMENTS I VIII┌────┐ ┌────┐│ H │ │ He ││ 1 │ II III IV V VI VII │ 2 │├────┼────┐ ┌────┬────┬────┬────┬────┼────┤│ Li │ Be │ │ B │ C │ N │ O │ F │ Ne ││ 3 │ 4 │ │ 5 │ 6 │ 7 │ 8 │ 9 │ 10 │├────┼────┤ ├────┼────┼────┼────┼────┼────┤│ Na │ Mg │ │ Al │ Si │ P │ S │ Cl │ Ar ││ 11 │ 12 │ │ 13 │ 14 │ 15 │ 16 │ 17 │ 18 │├────┼────┼────┬────┬────┬────┬────┬────┬────┬────┬────┬────┼────┼────┼────┼────┼────┼────┤│ K │ Ca │ Sc │ Ti │ V │ Cr │ Mn │ Fe │ Co │ Ni │ Cu │ Zn │ Ga │ Ge │ As │ Se │ Br │ Kr ││ 19 │ 20 │ 21 │ 22 │ 23 │ 24 │ 25 │ 26 │ 27 │ 28 │ 29 │ 30 │ 31 │ 32 │ 33 │ 34 │ 35 │ 36 │├────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┤│ Rb │ Sr │ Y │ Zr │ Nb │ Mo │ Tc │ Ru │ Rh │ Pd │ Ag │ Cd │ In │ Sn │ Sb │ Te │ I │ Xe ││ 37 │ 38 │ 39 │ 40 │ 41 │ 42 │ 43 │ 44 │ 45 │ 46 │ 47 │ 48 │ 49 │ 50 │ 51 │ 52 │ 53 │ 54 │├────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┤│ Cs │ Ba │ La │ Hf │ Ta │ W │ Re │ Os │ Ir │ Pt │ Au │ Hg │ Tl │ Pb │ Bi │ Po │ At │ Rn ││ 55 │ 56 │ 57 │ 72 │ 73 │ 74 │ 75 │ 76 │ 77 │ 78 │ 79 │ 80 │ 81 │ 82 │ 83 │ 84 │ 85 │ 86 │├────┼────┼────┼────┼────┼────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┘│ Fr │ Ra │ Ac │ │ │ │ 87 │ 88 │ 89 │104 │105 │ └────┴────┴────┴────┴────┘ ┌────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┐ │ Ce │ Pr │ Nd │ Pm │ Sm │ Eu │ Gd │ Tb │ Dy │ Ho │ Er │ Tm │ Yb │ Lu │ │ 58 │ 59 │ 60 │ 61 │ 62 │ 63 │ 64 │ 65 │ 66 │ 67 │ 68 │ 69 │ 70 │ 71 │ ├────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┤ │ Th │ Pa │ U │ Np │ Pu │ Am │ Cm │ Bk │ Cf │ Es │ Fm │ Md │ No │ Lr │ │ 90 │ 91 │ 92 │ 93 │ 94 │ 95 │ 96 │ 97 │ 98 │ 99 │100 │101 │102 │103 │ └────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┘
Which is the stronger acid?
H2O or H2S?
What is the order of base strength?
F- Cl- Br- I-
oxygen & sulfur are in the same family and sulfur is bigger: H2S > H2O
in the halogen family base strength decreases with increasing size:
F- > Cl- > Br- > I-
Will H2O react with NaSH as shown below?
H2O + NaSH NaOH + H2S
Will the following reaction proceed as shown?
HI + NaCl HCl + NaI
WA SA
no, H2O < H2S
SA WA
yes, HI > HCl