Boats and Molecules

<H5>Trans</H5> <IMG ALIGN=MIDDLE SRC="Trans.gif"> <P>In the trans isomer all six lithium atoms (red spheres) are equivalent to each other. Similarly, the six methyl groups (grey spheres) are equivalent to each other. The six methyl groups are located over six of the eight faces of the distorted lithium octahedron leaving two empty faces. In this isomer the two unoccuppied faces are opposite, trans, to each other. However, the methyl groups are not located over the centers of the faces of the distorted lithium octahedron but have moved towards that edge of the face which is shared with one of the empty faces. This moves the negatively charged methyl groups away from each other, thereby reducing methyl:methyl electrostatic repulsion. Focusing on the six methyls groups it can be seen that they have formed a distorted octahedorn around the lithium atoms which themselves form a distorted octahederon.