= Solution
\b[An individual bipyramid is <chiral>.] Matching helicities at the two <iron> centres give the homochiral $\Delta\Delta$ and $\Lambda\Lambda$ <enantiomers>, with the three spanning connections winding in opposite senses in the two structures. The idealized molecular framework has a threefold axis but no mirror plane, inversion centre or improper rotation that converts it into itself. Achiral synthesis can give a <racemic mixture> of these <chiral> cages; racemic bulk composition does not make each cage achiral. The corresponding experimentally characterized methyl-substituted Fe–Pd bipyramid contains both homochiral <enantiomers> in its crystal.<Dynamic Complex-to-Complex Transformations of Heterobimetallic Systems Influence the Cage Structure or Spin State of Iron(II) Ions by Matthias Hardy and others>[Figure 1 and discussion of the bipyramidal crystal structure]{ref}
Back to article page
