(University of Nottingham)

Programmed by : Richard T Hyde
Subject Specialists : Nick Shaw, Cristina De Matteis, Andy Boyd.
Molecular modelling source code : Oxford Molecular Ltd.

ISBN: 1 84211 019 6
The aim of this courseware package is to teach the assignment of R & S stereochemical designation to chiral molecules. Interactive 3-D molecular models are utilised to allow students to explore the spacial arrangements of atoms.

The courseware is aimed at first year pharmacy/chemistry undergraduates, who tend to focus their learning on facts and formulae. It is hoped that this package can go some way to making them think in terms of the 3-D arrangements of atoms and molecules - which is fundamental to understanding chemistry as a whole.

This courseware has been developed as part of a research project and as such it contains mechanisms for evaluating the effectiveness of the interactive 3-D molecular modelling facilities. These include recording of student scores and mouse movements in the self assessment section. In addition a rating scale is presented when a user exits the program.

[Screenshot]
A Screen from the package

Contents

  1. Molecular Projections
  2. Isomers and Chirality
  3. Assigning Priorities
    • Single Bonds
    • Double and Triple Bonds
  4. Orientating a Molecule
  5. The Final Designation
  6. Self Assessment
    • Part One
    • Part Two
    • Part Three

Molecular projections
Provides an introduction to traditional 2-D wedge, sawhorse, Newman and Fischer projections. Following this, 3-D molecular modelling techniques are introduced and demonstrated. To aid visualisation of 3-D structure, 2-D projections are then shown alongside the equivalent 3-D projection. A student is able to rotate the 3-D model and change the representation to stick, ball and stick or space fill.

Isomers and chirality
This section describes structural isomers with graphical examples. Stereoisomers are introduced and the need for a systematic naming system for enantiomers is highlighted. Finally, the R-S system is mentioned, in preparation for its use in the following sections.

Assigning priorities
This section describes how to assign priorities to the groups surrounding a chiral centre. It is split into two sections, explaining the methods for single and multiple bonds. Animated displays illustrate the procedures for assigning priorities in the different sections.

Orientating a molecule
The orientation of a molecule ready for the final designation is explained and illustrated in this section.

The final designation
An animated display shows how to assign R or S designation to an orientated chiral molecule.

Self assessment
This section is split into three parts, with questions on molecules containing one, two and three chiral centres. To answer a question a student may rotate the molecule by dragging the mouse, change the representation (stick, ball and stick or space fill) and label the atoms, before clicking on their chosen atom. The procedure followed is: detection of the chiral centre, assignment of priorities 1 to 4 to the attached groups and finally assignment of R or S designation. The atoms are labelled as the student clicks on them, with priorities being labelled 1 to 4 to aid the final assignment.

The user has access to several facilities while in the self assessment section to maintain their motivation and aid understanding:

Hints - shows a summary of the assignment of R & S designation.

Score - shows a cumulative score for the current session (displayed automatically when a section is complete).

Info - provides pharmaceutical/chemical information about the displayed molecule.

Periodic table - a simple version gives help with assignment of priorities.


Hardware and Software Requirements

The package is supplied on a CD-ROM Installation Disc and can be installed to a local hard disc or network drive. The minimum requirement is an IBM compatible PC 80386SX computer with 4Mb of RAM and a VGA monitor capable of 16 colours in 640 x 480 resolution. The program is 16-bit and compatible with Windows 3.1 and Windows 95. The software will also run under Windows NT - the PCCAL Co-ordinating Centre can provide support for running PCCAL packages on networked NT workstations.