Chem 5
Chapter 10
The Periodic Table and Some
Atomic Properties
Part 4
Noble Prize in Chemistry, 2002
Kurt Wüthrich
John B. Fenn
Koichi Tanaka
“The Nobel Prize in Chemistry for 2002 is being shared between scientists in
two important fields: mass spectrometry (MS) and nuclear magnetic
resonance (NMR). The Laureates, John B. Fenn and Koichi Tanaka (for MS)
and Kurt Wüthrich (for NMR), have contributed in different ways to the further
development of these methods to embrace biological macromolecules. This
has meant a revolutionary breakthrough, making chemical biology into the "big
science" of our time. Chemists can now rapidly and reliably identify what
proteins a sample contains. They can also produce three-dimensional images
of protein molecules in solution. Hence scientists can both "see" the proteins
and understand how they function in the cells.”
Mass Spectroscopy for
Macromolecules
Electrospray technique
Time-of-flight mass spectrometer
http://www.nobel.se/chemistry/laureates/2002/chemadv02.pdf
0 42 84 126 168
Liquid columntography elution time (min)
2,500 2,243 1,731 1,475 1,218 962 706 450 1,987 24 33 44 52 62 71
MW
Capillary LC-FTICR 2-D display of peptides from a yeast soluble protein digest
>160,000 isotopic distributions corresponding to >100,000 polypeptides detected
2,500 2,243 1,731 1,475 1,218 962 706 450 1,987 24 33 44 52 62 71 24 33 44 52 62 71
MW
Capillary LC-FTICR 2-D display of peptides from a yeast soluble protein digest
>160,000 isotopic distributions corresponding to >100,000 polypeptides detected
750 1000 1250 1500
Dimension one
Dimension two
2-D display of detected peptide “spots”
Identification of more than two thousand proteins in a bacterium
Identification of more than two thousand proteins in a bacterium
Approach for high throughput microbial
Approach for high throughput microbial
proteomics
proteomics
Time (min)
∆E = hν is sensitively dependent on
the surrounding electrons, i.e
chemical bonds around the proton.
Low resolution
NMR spectrum of
ethanol
Radio frequency
Electrons have spin.
So do protons.
In the presence of a uniform
external magnetic field
Nuclear Magnetic Resonance (NMR) Spectroscopy
Transition at Radio frequency
Nuclear Magnetic Resonance Spectroscopy of Macromolecules
Determine the structures of proteins
Magnetic Resonance Imaging
x
hν = Energy splitting
is position
dependent.
Non-uniform magnetic field
Position x
Freshman Seminar 22j
For Spring 2003
Seeing by Spectroscopy
William Klemperer
The seminar will explore diverse topics and areas of science in which spectroscopy — the observation of energy emitted from a radiant source — plays a leading role. Although there are many practical applications of spectroscopy, the seminar will concentrate on selected topics from chemistry, physics, astronomy, and atmospheric science. Among these are the structure of molecules from the simple measurement of the bond length of a diatomic species to finding out the structure of proteins. The seminar will emphasize spectroscopy as the basis for remote sensing, choosing the grand topic of looking out — astronomical observations and seeing what is in the universe. Participants also will study (Nuclear) Magnetic Resonance Imaging as a model for looking in. This seminar will exploit the great increase in understanding nature that occurred throughout the twentieth century as a result of the invention of quantum mechanics. Participants will cooperate in developing and maintaining a seminar web page.
Although the seminar is directed towards students with an interest in physical science, the required background is not extensive since the seminar will not derive relations but rather state and use them. Participation will involve some use of computational packages.
Freshman Seminar Program Web Pages
Professor William Klemperer
Magnetic property
A paramagnetic atom or ion has unpaired
electrons and the individual magnetic effects
do not cancel out.
A diamagnetic atom or ion has all electrons
paired and the individual magnetic effects
are canceled.
Gd
3+[Xe]4f
7Summary
Closed shell
most stable
Reducing Abilities of Group 1 and Group 2
Comparison of the reducing ability of K and Ca
for water
Demos
)
(
)
(
2
)
(
2
0
2
)
(
2
Li
s
+
H
2
→
Li
+aq
+
OH
−aq
+
H
2g
)
(
)
(
2
)
(
2
0
2
)
(
2
Na
s
+
H
2
→
Na
+aq
+
OH
−aq
+
H
2g
)
(
)
(
2
)
(
2
0
2
)
(
2
K
s
+
H
2
→
K
+aq
+
OH
−aq
+
H
2g
)
(
)
(
2
)
(
0
2
)
(
s
H
2Ca
2aq
OH
aq
H
2g
Ca
+
→
++
−+
Oxidizing Abilities of Halogen Elements
Demo
)
(
2
)
(
)
(
2
)
(
2
2
g
I
aq
I
aq
Cl
aq
Cl
+
−
→
+
−
Cl
2
has higher oxidizing ability than I
2.
)
(
2
)
(
)
(
)
(
2
2
g
Br
aq
Br
aq
Cl
aq
Cl
+
−
→
+
−
Metals tend to lose
electrons to attain noble gas
electron configurations
Nonmetals tend to gain
electrons to attain noble gas
electron configurations.
Na(g)
→ Na
+
(g) + e
-2 2n
Z
R
I
=
H effI
1
=496kJ/mol
[Ne]1s
2[Ne]
Na
+
(g)
→ Na
2+
(g) + e
-
I
2
=4562kJ/mol
[Ne] [He]2s
22p
5I
2>> I
1because n = 3 Æ n = 2
General Trends
and Exceptions
4s
23d
104p
1It is important to
write down the
electron
configurations!
4s
23d
10E
2s
2p>E
2s 22p
12s
22p
3Summary of Chapters 9 &10
• Energy quantization explains three spectroscopic experiments:
– Blackbody radiation
E= h
ν
– Photoelectric effect
h
ν
= h
ν
0+ 1/2mu
2– Hydrogen atom lines
2 2 f i
