Topological Index Calculator Manual

          Created by Steven Granz - June 2004

  1. Chemical graphs are mathematical objects that represent chemical compounds.
    In chemical graphs, vertices correspond to atoms and edges represent
    covalent bonds between atoms. Topological indices are a convenient way for
    expressing in a numerical form the chemical structure of chemical structure encoded
    in the chemical graphs.


  2. Create a chemical graph to represent the molecule.

    Example:

    2,4-dimethyl-3-isopropylpentane



  3. Label all vertices from 1 to n; where n = number of carbon atoms.

    Example:

    2,4-dimethyl-3-isopropylpentane

    n = 10

                        Graph 1                                                            Graph 2

             

    Note: It does not matter what order we label the vertices.
    Both of these graphs will produce the same value for the indices.


  4. Create a list of all connections between two vertices.

    Example:

                        Graph 1                                                            Graph 2
                        1   2                                                                  1   2
                        2   3                                                                  2   3
                        3   4                                                                  3   4
                        4   5                                                                  4   5
                        2   6                                                                  4   9
                        4   7                                                                  2   10
                        3   8                                                                  3   6
                        8   9                                                                  6   7
                        8   10                                                                6   8


  5. Open Topological Index Calculator into your favorite web browser.
    www.math-cs.gordon.edu/courses/organic/topo





  6. It is convenient to determine the parent chain or ring of the molecule in order to
    automatically enter some of the connections. If we have the name of the molecule
    the last part of the name is the parent chain or ring.

    Example:

              3,3-dimethylbicyclo[3.3.0]octane – octane is our parent ring.
              2,4-dimethyl-3-isopropylpentane – pentane is our parent chain.

    If we do not have the name of the molecule then we will need to manually enter all the connections.


  7. Select either the parent chain or ring and click on the drop down menu and select the appropriate parent.





  8. Now we need to add the remaining connections into the bonds field.
    The spacing required for a pair is a number, a space, a number and a return.

    Example:

    Graph 1

    Graph 2


  9. Check the indices that we want to compute. Click the Compute button to calculate indices.

    Graph 1


    Graph 2


  10. At any time, click Clear Bonds button to reset parent chain/ring, clear bonds text field and clear index fields.


  11. Click Add Data Line Button to allow entry of the boiling point of the molecule and transfer indices data to the Data Console.





    The data in the data console can now be copied and pasted into a text file and saved as a .csv
    (comma separated value). Most spreadsheets can open this type of file. The data can be
    manipulated inside the spreadsheet for many indices.


  12. At any time click Clear Console button to clear the data console.