Numerous compounds containing central cubane structures, formally derived from the cubi...

Numerous compounds containing central cubane structures, formally derived from the cubic organic molecule cubane, C₈H₈ , have been prepared. The core structure typically have four metals at opposite corners of a distorted cube, with nonmetals such as O and S at the other corners, as shown (E = nonmetal).

In addition to cubanes in which all metals and nonmetals are identical, they have been prepared with more than one metal and/or more nonmetal in the central 8-atom core; attached groups on the outside may also vary.

a. How many isomers are possible if the core has the following formulas:

1. Mo₃WO₃S?

2. Mo₃WO₂S₂?

3. CrMo₂WO2SSe?

b. Assign the point groups for each isomer identified in part a.

c. Is it possible for the central 8-atom core of a cubane structure to be chiral? Explain.