Re: If ferrocene have rotating Cp rings, why 1,2 subst. ferrocene is chiral?

This is "off the top of my head," but I've done some reading in metallocenes.

If only one ring is substituted, of course the 1,2-disubstituted ferrocene 
will be chiral. The molecule contains no mirror plane! The ring may be planar, 
but the whole molecule certainly is not!

If both rings are substituted identically, I would expect the molecule to be 
chiral as long as the rings are not mirror images of each other (that is, a 
mirror plane passing through the metal atom). If one ring reflects the other,
the molecule will be *meso*.

                                           Dan Berger