cg050312j_si_001.cif (436.78 kB)
[M(H2O)2(15-crown-5)](NO3)2: A System Rich in Polymorphic and Modulated Phases†
dataset
posted on 2005-11-02, 00:00 authored by Xiang Hao, Maxime A. Siegler, Sean Parkin, Carolyn Pratt BrockThe series of structurally related compounds [M(H2O)2(15-crown-5)](NO3)2, M = Cu, Mg, Zn, and Co
(four phases) has been extended to include three new phases for M = Mn and two new phases for M = Fe. Two new
structure types have been discovered, so nine phases of two basic types (two- or three-dimensional H-bonding pattern)
are now known. For the 2-D H-bonded (or layered) structure type, four variants having different modulation patterns
have been observed. All phases have more than one crystallographically independent formula unit (Z‘ > 1) The
cation conformations of all the independent units in all the structures are essentially identical. Reversible phase
transitions during which crystallinity is preserved link the two layered structures of the Mn compound and of the
Fe compound. A reason for the existence of so many related phases has been identified.