Question

1. what is the coordination geometry of the Zn and the center O in the center of Zn4O. Use IUPAC naming to describe it.

2.The distance from Zn4O center to Zn4O center=13 $\dot{A}$ but the unit cell =26 $\dot{A}$ . Why is the unit cell double of the distance of the Zn4O center to center distance?

How many Zn4O clusters and terephthalic acid molecules are there in 1 unit cell of MOF-5.

Answer 1

The structure of this unit is as given in the picture. It has a oxide core which is 4 coordinated with Zinc so its name will be

The coordination of Zn is 4 and the coordination of the central oxide is 4 SO the

IUPAC name will be Tetra (tetra alcoholato zinc) mu⁴ oxide

The Zn4O is one cluster and the other Zn4O cluster is another unit in an MOF the two clusters are held together by a space which defines the structure gaps between the active metal centres The length of the unit cell will be the distance between the two units + the ligand framework that has the units together so the cell dimension is double due to the spacer.

There are 8 Zn4O and 8 terephtahlic units in each unit cell