Welcome to the CAChe Molecular Modeling Tutorials

Department of Chemistry

University of Pittsburgh at Johnstown

Home
Getting Started
The Basics of CAChe
The User Interface
Simple Molecules
Inorganic Molecules & Ions
Organic Molecules
The Fragment Library
Viewing & Manipulating
Computing Properties
Optimizing Geometry
Molecular Orbitals
Spectral Properties
Predicting Reactivity
Energy Maps
General Chemistry
Ferrocene

Building Small Molecules - III

Total time: 5 minutes

Task A: Convert Methane, CH4 to ethane CH3CH3

  1. Open the "methane" file you created in the last lesson and change the name by selecting File|Save As . Name the new file "ethane".
  2. Select the Atom icon .

  3. Select the arrow button in the element type box and select carbon.  Make sure the hybridization is sp3 .

  4. Click in the center of the carbon atom in the methane molecule and drag away from the atom .

  5. When you release the mouse key a second carbon atom appears .

  6. Click on the select tool and click in the workspace (not on any atoms or bonds) to select the entire molecule.
  7. To fix the geometry of the ethane molecule, select Beautify|Comprehensive from the menu bar.  The correct number of hydrogen atoms will also be added, as well. 
  8. To save your finished molecule select File|Save and save it as "ethane".

Task B: Convert Ethane CH3CH3 to Butane CH3CH2CH2CH3

  1. Keep the workspace with the ethane molecule open, but change the name by selecting File|Save As . Name the new file "butane".
  2. Select the Atom icon . Make sure that carbon shows in the element type box and select carbon.  Make sure the hybridization is sp3 .

  3. Click in the center of a carbon atom in the ethane molecule and drag to add a third carbon atom. Repeat this step to add a fourth carbon atom.

  4. Click on the select tool and click in the workspace (not on any atoms or bonds) to select the entire molecule.
  5. To fix the geometry of the butane molecule, select Beautify|Comprehensive   from the menu bar. The correct number of hydrogen atoms will also be added, as well.
  6. To save your finished molecule select File|Save and save it as "butane".

This is the last lesson in this module on building simple molecules.

Go on to the next module: building inorganic molecules and ions.