How would a benzene ring be attached to Rh3(CO)9 to create a 3 fold axis of symmetry?
I make each Rh bonding to three (CO)3 groups have 16 electrons, so the remaining 2 electrons needed must be the attachment of another Rhodium to form a triangular arrangement and the benzene ring.
I can only see it as one bond per Rhodium to the benzene ring, but then the bonding in benzene ring would be uneven
Rhodium is 3d8