Question

If a compound has no chirality centers can the compound be chiral?

Answer 1

Yes, a compound can be chiral even though it has no chirality centres.

Explanation:

Such compounds usually have a "screw-like" structure, similar to right-handed and left-handed screws, because of restricted rotation.

If you draw the mirror images of dimethylallene, dichlorospiroheptane, and trans-cyclooctene, you will find that the mirror images are nonsuperimposable.

Each compound has its enantiomer.

In dibromobiphenyl, the rings cannot rotate about the single bond, because the `"Br"` atoms on each ring are too big to slide past the ortho atoms on the other ring.

The rings are at an angle to each other, and the mirror images are again nonsuperimposable.