ComputerEnhanced Teaching of Environmental Organic Chemistry

1
Computer-Enhanced Teaching of Environmental
Organic Chemistry

• Angela S. Lindner, Ph.D.
• Environmental Engineering Sciences
• University of Florida

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Goals of This Presentation

• To introduce CAChe software and required hardware
• To present examples for enhancing the study of
  environmental organic chemistry using computer
  software
• To provide initial outcomes of using
  computer-aided chemistry as a teaching tool in
  the environmental engineering classroom

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Structure of This Presentation

• Introduction
• EES 4200, Chemistry of Carbon Compounds
• CAChe software
• Methods
• Overview of CAChe-enhanced concepts
• Examples of how CAChe can be used in lectures
• One-Year Assessment
• Conclusions to Date
• Future Plans for Use of CAChe Software

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The Course Chemistry of Carbon Compounds

• Objective present fundamental organic chemistry
  concepts with an environmental focus to the
  sophomore-level environmental engineer and
  environmental scientist
• Class size 40-60
• Course details 2 required credit hours taken in
  lieu of traditional organic chemistry

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The Predicament

• Time
• Only 2 lecture hours per week
• Class size
• Large number makes use of models difficult
• Motivation level
• The majority of students must be convinced of
  organic chemistrys role in the study of the
  environment!

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Solutions

• Employ a variety of teaching styles
• Coverage is the enemy!
• Use student portfolios
• Use CAChe 4.4 software

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CAChe 4.4 Software

• CAChe Group, Fujitsu, Beaverton, OR
• WEB site
• www.CACheSoftware.com
• Selected features
• 3D visualization of molecules
• Prediction of properties (boiling points, vapor
  pressure, water solubility, etc.)
• Prediction of electron densities and locate
  reactive sites
• Identification of structure of low-energy
  conformations
• Prediction of activities (toxicity, reaction
  rates, etc.)

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Current CAChe Users in Higher Education

• Over 350 universities and colleges in North
  America are listed as CAChe users.
• Approximately 30 of these use CAChe in teaching
  laboratory environments.

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Laboratory Architecture and Cost

• Hardware needs
• IBM 486 or Compatible (Pentium recommended)
• Windows 95 or NT 4.0 Operating System
• 16 MB RAM (24 recommended) and 50 MB hard disk
  space
• Ethernet connection and Group Server for
  Satellite software
• Academic Cost
• CAChe WorkSystem 1995
• CAChe Satellite 900
• CAChe GroupServer(1-4 users) 4500
• (HEP grant provided a 33 discount.)

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Introductory Concepts Lewis Structures, VSEPR
Theory, Molecular Shapes, etc.
Trichloroethylene
Ethanol
Trichloroethylene
Ethanol
MTBE
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Skeletal Isomers C5H12
2-Methylbutane
2,2-Dimethylpropane (Neopentane)
n-Pentane
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Positional Isomers C12H8Cl2
2,5-dichlorobiphenyl (para substitution)
2,3-dichlorobiphenyl (ortho substitution)
2,3-dichlorobiphenyl (ortho substitution)
2,4-dichlorobiphenyl (meta substitution)
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Functional Group Isomers C5H12O
MTBE
Isopentanol
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Computational Capabilities of CAChe
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Bond Lengths (MOPAC with PM3 Parameters)
Ethane
Ethylene
Acetylene
CC 1.34 Angstroms
C-C 1.54 Angstroms
C C 1.21 Angstroms
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Substituent Effects on Selected Properties (MOPAC)
Vinyl Chloride
Ethylene
VC ETH E- density (Cl or H) 6.97 0.92 Heat
of formation (kcal) 9.70 16.60 Ionization
potential 9.83 10.64 Dipole moment 0.90 0.00
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CAChe in Environmental Chemistry
Structure
Forces
Dipole-Dipole Van der Waals Hydrogen Bonding
Properties
TB S Kow VP KH Koc
Mobility in aqueous phase Sorption
potential Bioaccumulation potential Escape to
vapor phase
Behavior
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Which is more likely to migrate to a nearby
drinking water well?
Hexachlorobenzene
Pentachlorophenol
Dipole moment 0.429 1.105 Van der
Waals 8.943 10.505
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Conclusions Benefits of CAChe Use in the
Engineering Classroom

• Better visualization of molecules
• Removal of some memorization work
• Reinforcement of traditional concepts of organic
  chemistry
• Introduction of the environment into organic
  chemistry
• Connection of structure to behavior in
  environment
• Reinforcement of environmental engineering as
  multidisciplinary
• Students prefer this approach to traditional
  organic teaching methods!

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Future CAChe Use at UF

• Laboratory format with problem modules
• Six laptops with CAChe satellite
• Calculations performed on a group server
• Better understanding of mechanisms
  (dehalogenation, nucleophilic substitutions,
  etc.)
• Graduate-level course in bioremediation
• Integrate research into the curriculum
• Quantitative structure-activity relationships
• Visualization of reactions at enzyme active site

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Acknowledgements

• National Science Foundation, SUCCEED Program, UF
• Department of Environmental Engineering Sciences,
  UF
• Mr. Randy Switt, Environmental Engineering
  Sciences, UF
• Ms. Heidi Klein, CAChe Group, Fujitsu