Weblink 16.3 The structures of solid AlF₃ and AlCl₃

Aluminium atoms are shown in grey, fluorine in pale green, and chlorine in bright green. In AlF₃ each aluminium is surrounded by six fluorines in a distorted octahedron; these octahedra share corner fluorine atoms.

In AlCl₃ the aluminium atoms are sandwiched between two layers of chlorine atoms. This layered structure is taken as being indicative of greater covalency.

• Click and drag to rotate the structure; hold down shift, then click and drag to zoom.
• Select the size of the atoms with the radio buttons.
• Use the drop-down menu to select which molecule to view.