Preservation of Chirality and Polarity between Chiral and Polar Building Units in the Solid State

The new lamellar phases [Zn­(2,2′-bpy)2(H2O)2]­(ZrF6)·3H2O (I) and [Ni­(2,2′-bpy)3]­(MoO2F4)·5H2O (II) (bpy
= bipyridine),
which are built from a chiral cation and respectively an inherently
nonpolar and a polar anion, provide two contrasting structures with
respect to chirality and polarity in the solid state. Each nonpolar
layer of I contains enantiomers of both handednesses;
conversely, each layer of II contains only a Δ
or Λ enantiomer and polar anions oriented along the b or −b axes. A comparison with
previously reported structures reveals which combinations and interactions
between chiral and polar basic building units can preserve elements
of polarity and chirality in the solid state.