Symmetry Properties of Molecules

In this exercise, symmetry operations can be examined for [Cu(NH3)4H2O]SO4.
This is perhaps the first coordination compound known, having been recorded in 1597 by Libau, but it is still often described as square planar.

In the simplest view we consider only the central Cu(II) ion and its nearest neighbours the 4N and the O to give a C4v point group.

Click on the molecule then drag with the left-mouse button down to view from different angles. In addition, before starting the exercise scroll down the page to look at other views of this compound for comparison.
To start: FIRST set the view down the "Z" axis. Identify one of the N atoms (on/off)
Highlight the C4 axis by rotating by: 90°, 1C4 +90 = 180°, 2C4 +90 = 270°, 3C4 +90 = 360°, 4C4
180° (equiv. to 2C4) 360° (in 4 steps)
Reset to initial alignment

After viewing this rotation, try to identify all the symmetry elements for the point group C4v.
These include E 2C4 C2 2σv 2σ'v

Use the buttons below the display to re-start any operation.

In the next view the H atoms are shown as well as the sulfate anion.

This view shows 2 molecules and now it is possible to detect the presence of H bonding between the coordinated water molecules and the oxygens of the sulfate ion.

The final view shows the lattice structure containing numerous Cu(II) sites. Note the angles between the CuN4 planes. The crystal structure was solved in 1969 and showed a space group of Pnam.

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Copyright © 2004 by Robert John Lancashire, all rights reserved.

Created and maintained by Prof. Robert J. Lancashire,
The Department of Chemistry, University of the West Indies,
Mona Campus, Kingston 7, Jamaica.
Created January 2004. Links checked and/or last modified 1st February, 2004.