Question

please write down the answer properly.

2. Numerous compounds containing central cubane structures, formally derived from the cubic organic molecule cubane C8Hs, have been prepared. The core structures 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. E- M ME ME (a) How many isomers are possible if the core has the following formulas: (9p) (1) Mo3 WO3S (2) Mo3 WO2S2 (3) CrMoZWO2SSe (b) Is it possible for the central 8-atom core of a cubane structure to be chiral? Explain. (11p)

Answer 1

Part (a).

(1) 4 isomers

Explanation: 2 different metals (Mo, W) * 2 different nonmetals (O, S) = 4 isomers

(2) 4 isomers

Explanation: 2 different metals (Mo, W) * 2 different nonmetals (O, S) = 4 isomers

(3) 9 isomers

Explanation: 3 different metals (Cr, Mo, W) * 3 different nonmetals (O, S, Se) = 9 isomers

Part (b).

Yes, it is possible for the central 8-atom core of a cubane structure to be chiral.

Explanation: Some atoms are out-plane and some are in-plane. As a result, the central 8-atom core will be chiral.