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Nanotechnology: a chemist’s constructivist view
Mathematical Modeling, Technology and Bridging to the
Nano-realm in Teaching Undergraduate Chemistry
Dr. Ron Rusay
Diablo Valley College University of California, Berkeley / Lawrence Livermore
National Laboratory
Nanotechnology : Perspectives & Perceptions
• How small is small?• The width of a human hair is ~ 50,000 nanometers
nanometer = 1 billionth of a meter (1/1,000,000,000 m; i.e., 50,000 x 10 -9 meters) • It takes about 200 human hairs lined up side by side to equal 1 cm
….more than 500 per inch.
QuickTime™ and aVideo decompressor
are needed to see this picture.
1/50 of ~ 50,000 nanometers
What is considered too large for the nano realm?Powers of 10 (10 x)
http://www.eamesoffice.com/powers_of_ten/powers_of_ten.htmlhttp://www.powersof10.com/
Earth = 12,760,000 meters wide (12.76 x 10 6), 12.76 million meters
Plant Cell = 0.00001276 meters wide (12.76 x 10 -6) (12.76 millionths of a meter) (12,760 nanometers!)
Nanotechnology: A Brief Chronology
• Feynman’s miniaturization: prescience and seminal views (1959)http://www.zyvex.com/nanotech/feynman.html
• Nanotechnology, (Journal’s first issue: 1990)http://www.iop.org/EJ/journal/0957-4484
• Curl, Kroto, Smalley: Nobel prize (1996); Fullerene, Nano tubes, http://www.nobel.se/chemistry/laureates/1996/
• National, Regional, Local Initiatives eg.– US: http://www.nano.gov/
– UK: http://www.nano.org.uk/
– Molecular Foundry (LBL): http://www.foundry.lbl.gov/ – Nano High School: http://www.lbl.gov/nanohigh/nanoscience_links.html
“Nanotechnology”• Regarded as < 1,000 nanometers ~1/50 the diameter of a
human hair. (Basically anything less than a micron (10-6 m). Chemists typically
think in mental views and images of < 1 nanometer.)
• Can be defined as the science of arranging and re-arranging atoms. (Manufacturing at a molecular level.)
• Two commonly used terms that broadly describe Nanotechnology: – Positional assembly
http://www.zyvex.com/nanotech/CDAarticle.html
– Self replication http://www.zyvex.com/nanotech/selfRep.html
Nano-scale: Models of Atoms & Molecules
• Rutherford (1913-1917)• Atoms, molecules, and nucleii
• 1 nm = 10 Å• An atom vs. a nucleus ~10,000 x larger
~ 0.1 nm
Nucleus =1/10,000of the atom
Anders Jöns Ångström(1814-1874)
1 Å = 10 picometers = 0.1 nanometers = 10-4 microns = 10-8 centimeters
• Resultant Molecular Dipoles > 0• Solubility: Polar molecules that
dissolve or are dissolved in like molecules
Molecular Size, Shape & PropertiesOzone and Water
• The Lotus flower• Water & dirt repellancy
0.1278 nm
http://ep.llnl.gov/msds/orgchem/Chem226/Smell-Stereochem.html
Larger Size Molecules
8.16 Å (0.816 nm)
DNA: Size, Shape & Self Assemblyhttp://www.umass.edu/microbio/chime/beta/pe_alpha/atlas/atlas.htm
Views & Algorithms
10.85 Å10.85 Å
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Several formats are commonly used but all rely on plotting atoms in 3 dimensional space; .pdb is one of the most popular.
Larger Moleculeshttp://info.bio.cmu.edu/courses/03231/ProtStruc/ProtStruc.htm
B-DNA: Size, Shape & Self Assembly
http://molvis.sdsc.edu/pdb/dna_b_form.pdb
46 Å
12 base sequence
(1953-2003)
http://www.rcsb.org/pdb/
PROTEIN DATA BANK
What are PDB files? http://chemistry.Gsu.EDU/glactone/PDB/pdb.htmlThe PDB format (Protein Data Bank), from the Research Collaboratory for Structural Bioinformatics) is a standard file format for the XYZ coordinates of atoms in a molecule.
A few lines from a PDB file for a DNA base pair structure AUTHOR GENERATED BY GLACTONESEQRES 1 A 1 GSEQRES 1 B 1 CATOM 1 P G A 1 -6.620 6.196 2.089ATOM 2 OXT G A 1 -6.904 7.627 1.869ATOM 3 O2P G A 1 -7.438 5.244 1.299ATOM 4 O5' G A 1 -5.074 5.900 1.839ATOM 5 C5' G A 1 -4.102 6.424 2.779ATOM 6 C4' G A 1 -2.830 6.792 2.049ATOM 7 O4' G A 1 -2.044 5.576 1.839ATOM 8 C3' G A 1 -2.997 7.378 0.649
The last three columns are the XYZ coordinates of the atoms. PDB format can be applied to any molecule, very small to very large. It includess enormous on-line libraries of molecules.
Even Larger Moleculeshttp://www.umass.edu/microbio/chime/beta/pe_alpha/atlas/atlas.htm
DNA: Size, Shape & Self Assembly
http://www.rcsb.org/pdb/
PROTEIN DATA BANK
Proteins: Size, Shape & Self Assemblyhttp://www.stark.kent.edu/~cearley/PChem/protein/protein.htm
Protein Shape: Forces, Bonds, Self Assembly,Folding
10-40kJ/mol
700-4,000kJ/mol
150-1000kJ/mol
0.05-40kJ/mol
Ion-dipole(Dissolving)40-600kJ/mol
Globular proteins:A larger number of atoms rolled into relative small volumes
RNA polymerase II-transcription factor J. Biol. Chem., Vol. 274, Issue 11, 6813-6816, 1999
The yellow dashed line is ~ 110-Å
Protein sizes are most often referred to by their molecular masses (daltons; 1 amu = 1 dalton),not by their dimensions because of their globular nature.
The Ribosome: RNA Proteins
227 Å
Crystal structure of a part of the ribosome at 5.5 Å Resolution. (1GIX): Contains the 30S Ribosome Subunit, three tRNA, and mRNA molecules
(2001) Noller, Ramakrishnan, Steitz~ 50 proteins + 1,000s nucleotides
Interactions:Large proteins (Enzymes) with small molecules (Substrates)
Models, Theories & InteractionsModels, Theories & InteractionsMolecular Shape & the Sense of SmellMolecular Shape & the Sense of Smell
http://ep.llnl.gov/msds/orgchem/Chem226/smell-links.html
Structure-Odor RelationshipsKaren J. Rossiter, Chem. Rev., 1996, 96, 3201-3240
Three different smell receptors.Three different smell receptors.
Modeling and SmellModeling and SmellFour different molecules fitting the same smell receptor.Four different molecules fitting the same smell receptor.
Shapes & Interactions: Mirror Images & Smell
S-(+)-d-S-(+)-d- R-(-)-l-R-(-)-l-
http://ep.llnl.gov/msds/orgchem/Chem226/Smell-Stereochem.html
S-(+)- carawayS-(+)- caraway R-(-)- spearmintR-(-)- spearmint
Enzyme interaction: neurotransmission
The interaction of a globular protein, The interaction of a globular protein, acetylcholinesterase, with a relatively small acetylcholinesterase, with a relatively small molecule, acetylcholine. molecule, acetylcholine.
Richard Short (Cornell University)
QuickTime™ and aYUV420 codec decompressorare needed to see this picture.
Acetylcholine, Nerves & NeurotransmissionThe Neuron: Shapes and Spaces
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Acetylcholine: OP Pesticides and Nerve gases
Trypsin: Hydrolysis
Acetylcholinesterase works in Acetylcholinesterase works in a similar way to the digestion a similar way to the digestion proteins.proteins.
Another Way to Inhibit EnzymesThe Importance of Shape
Statins:Inhbiting cholesterol biosynthesis
Hemoglobin and Oxygen TransportAn allosteric effect & sickle cell anemiahttp://ep.llnl.gov/msds/Columbia/slide8-3.html
BPG
Oxygen
Heme
NN
NN NN
NN
Fe 2+
HH33CC
HH33CC CHCH33
CHCH33
CHCH22CHCH22COCO22HH
CHCH CHCH22
HH22CC CHCH
HOHO22CCHCCH22CHCH22
• Heme is the coenzyme that binds oxygen in hemoglobin (transport) and myoglobin (storage in muscles)
• Molecule surrounding the iron is a type of porphyrin. • Important in Photodynamic therapy (PDT)• The U.S. would still be a British colony except for porphyria, a medical condition in “blue bloods”.
Myoglobin
N-terminusN-terminus
C-terminusC-terminus Heme
myosin-actin: muscle
Some Examples of Structural Proteins http://info.bio.cmu.edu/courses/03231/ProtStruc/ProtStruc.htm
collagen: connective tissue
Michael Ferenczi
Mechanical proteinsPathogens & Cell Invasion
http://ep.llnl.gov/msds/Staph-infection/infection.html
Streptococcus pyogenes96,000 x
Vincent A. Fischetti Ph.D., Rockefeller University
Human’s total ~ 100 x 10 6 immunoproteins
AntibodiesProlific Immunoproteins
Immunoglobin
Human Genome ~30,000 proteins
Combinatorial syntheses from libraries of 250, 10, and 6 possible contributors
Gecko & it’s toe, setae, spatulae6000x Magnification
http://micro.magnet.fsu.edu/primer/java/electronmicroscopy/magnify1/index.html
Geim, Nature Materials (2003) Glue-free Adhesive100 x 10 6 hairs/cm2
Full et. al., Nature (2000)5,000 setae / mm2
600x frictional force; 10-7 Newtons per seta
The “Lotus Effect” Biomimicry
http://www.bfi.org/Trimtab/spring01/biomimicry.htm
• Lotus petals have micrometer-scale roughness, resulting in water contact angles up to 170°
• See the Left image in the illustration on the right.
Wax
The “Lotus Effect” Biomimicry
http://www.sciencemag.org/cgi/content/full/299/5611/1377/DC1
• Isotactic polypropylene (i-PP) melted between two glass slides and subsequent crystallization provided a smooth surface. Atomic force microscopy tests indicated that the surface had root mean square (rms) roughness of 10 nm.
• A) The water drop on the resulting surface had a contact angle of 104° ± 2
• B) the water drop on a superhydrophobic i-PP coating surface has a contact angle of 160°.
Science, 299, (2003), pp. 1377-1380, H. Yldrm Erbil, A. Levent Demirel, Yonca Avc, Olcay Mert
ColloidsHydro- philes & phobes
Hydrophilic and Hydrophobic
Colloids
Colloids
Bridging to the Nano realmMolecular Modeling: Visualizations & Predictions
Modeling Methods:• Numerical Methods
• Integral Method
• Ab Initio Methods
• Semi-Empirical MO-SCF Methods
• Approximate MO Methods
Web MOhttp://c4.cabrillo.cc.ca.us/projects/webmo/index.html
login: dvc1 password:chem
• Web MO Project: undergraduate molecular modeling college consortium
• Web-based, free, instructional service• Uses MOPAC 7 & GAMESS 2000, others
to be added• Modeling tools, activities and lessons are
under construction
Web MOhttp://c4.cabrillo.cc.ca.us/projects/webmo/index.html
login: dvc1 password:chem
• Output:– Dipole moment– Bond Orders– Partial Charges– Vibrational Modes– Molecular Orbitals– Ultraviolet-Visible-Infrared Graphics– NMR Chemical Shifts
0.143 nm
Web MO Visual Output
Color coded electron density distribution: blue-lowest, red highest, green balanced
• 1) S-(+)- caraway1) S-(+)- caraway R-(-)- spearmint R-(-)- spearmint
• 2) Ambrox-Ambergris
http://ep.llnl.gov/msds/orgchem/Chem226/Mol-Modl-II.html#ambergris
Examples of Planned Web MO Projects
• 3) d- and l- tartaric acid
Examples of Planned Web MO Projects
Modeling & Energy Calculations of Acetylene Lawrence Berkeley Laboratory (LBL)
Example of a Web MO Project
C
C
H
H
C
C
H
H
Calculated image (Philippe Sautet)
orbital
pz
TIP
H
O+
Imaging: acetylene on Pd(111) at 28 K
Molecular Image Tip cruising altitude ~700 pmΔz = 20 pm
Surface atomic profile
Tip cruising altitude ~500 pm
Δz = 2 pm
1 cm(± 1 μm)
The STM image is a map of the pi-orbital of distorted acetylene
Why don’t we see the Pd atoms?Because the tip needs to be very close to image the Pd atoms and would knock the molecule away
If the tip was made as big as an airplane, it would be flying at 1 cm from the surface and waving up an down by 1 micrometer
M. Salmeron (LBL)
Excitation of frustrated rotational modes in acetylene molecules on Pd(111) at T = 30 K
Tip
e-
((( ) ( )))
M. Salmeron (LBL)
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0.1
1
10
100
-300-250-200-150-100-500Tip Bias (mV)
Log
(Hop
s/s) 253 pA
-37mV
0
8
16
24
32
0 50 100 150 200 250 300 350 400 450current (pA)
rota
tion
s p
er
secon
d
1.72 seconds
V = 20 mV
0
50
100
150
200 1
2,3
Pd
Pd
Pd1
23
Pd
Pd
Pd
2
Measuring the excitation rate
Tip fixed at position 1:
Curr
ent
(pA
)
((( ) ( )))
x
Center of molecule
M. Salmeron (LBL)
Excitation of translations of C2H2 molecules:
R = 150 M R = 94 M R = 0.55 G
Rotation by electron excitation:
R = 10.5 M
Translation by direct contact (orbital overlap):
z ~ +0.8 Åz ~ -0.2 Å
z ~ - 1 Å
Tip
z
((( ) ( )))
Trajectories of molecule pushed by the tipM. Salmeron (LBL)
http://www.foundry.lbl.gov/
• Inorganic Nanostructures (A.P. Alivisatos)
• Nanofabrication (J. Bokor)
• Organic Polymer/Biopolymer Synthesis (J.M.J. Frechet)
• Biological Nanostructures (C.R. Bertozzi)
• Imaging and Manipulation (M.B. Salmeron)
• Theory of Nanostructured Materials (S.G. Louie)
Invited speakers:
• Pat Dehmer, Office of Basic Energy Sciences
• Paul Alivisatos, Director, Molecular Foundry
• Grant Willson, University of Texas at Austin
• Roberto Car, Princeton University
• Vicki Colvin, Rice University
• Mike Roukes, California Institute of Technology
• Mike Garner, Intel (invited)
___________________________
• Capabilities of the Foundry facilities and affiliated laboratories
• Types of projects that could be pursued in the facilities and affiliated laboratories
• Procedures for writing and review of proposals
• Logistics of working at the Foundry• A special session exploring the application of single molecule characterization and
manipulation techniques•Sessions dedicated to issues related for the call for proposals for research in the two-year
ramp-up period while the Foundry building is under construction.
Crystals for the ClassroomBridging the realms of the macro and atomic/nano scale
http://crystals.llnl.gov
• A modular collection of teaching-learning tools for undergraduate chemistry courses that can be adapted to teach various Science, Technology, Engineering and mathematics (STEM) topics and concepts
• Chemistry lessons are embedded in the story of NIF ( The National Ignition Facility) http://crystals.llnl.gov/nif-kdp-frameset.html
• Learning activities were developed relative to the context of the research and science behind NIF.
Crystals for the ClassroomBridging the realms of the macro and atomic/nano scale
http://crystals.llnl.gov
• Web based, distributed freely • Activities provide a diverse collection that support a wide variety of
learning and teaching styles: http://ep.llnl.gov/msds/Chem120/learning.html
Crystals for the ClassroomBridging the realms of the macro and atomic/nano scale
http://crystals.llnl.gov
Instructor - StudentActivities, Exercises & Resources
http://crystals.llnl.gov• Seeing - Hearing - Doing
• Powerpoint Presentations
• Visualizations: Time lapsed Growth
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• Seeing - Hearing - Doing
• Powerpoint Presentations
• Visualizations: Time lapsed Growth
• Simulations: Fusion - Fission
Instructor - StudentActivities, Exercises & Resources
http://crystals.llnl.gov
• Seeing - Hearing - Doing• Powerpoint Presentations• Visualizations: Time lapsed Growth• Simulations: Fusion - Fission• President Truman’s Announcement• Numerical and Graphical Problems• Student Worksheets• Glossary• Debate on Nuclear Energy• Writing Exercises• Interpreting Research Data• Experimentation
Instructor - StudentActivities, Exercises & Resources
http://crystals.llnl.gov
Acknowledgements
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