A Logical Concept of Structure Prediction Derived from Supramolecular Polymers of Alkaline Earth Metal Halides Formed by Hydrogen Bonding and Complexation of the Metal Ion

• Published in: Chemistry : a European journal 2001-05, Vol.7 (10), p.2236-2244
• Main Author: Fromm, Katharina M.
• Format: Article
• Language: English
• Subjects: alkaline earth metals; coordination complexes; hydrogen bonds; structure elucidation; structure prediction
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/1521-3765(20010518)7:10<2236::AID-CHEM2236>3.0.CO;2-S

Several different dimensional polymers derived from alkaline earth metal iodides are obtained as a result of supramolecular noncovalent bonding modes of the metal ion, namely complexation and hydrogen bonding. These polymers consist of complex cations linked to the halide ions by hydrogen bonds of the water ligands coordinated to the metal. They are built up in a logical way, depending on the ratio of complexing ligands to complexing and hydrogen‐bonding ligands so that their dimensionality and, to a certain extent, their structure can be predicted. Four crystal structures of different dimensional polymers of the type [M(H2O)n(L)m]I2 (M = Ca or Ba; n = 1–4; L = polyether, and m = 1 or 2), formed by the combination of metal‐ion complexation and hydrogen bonding, form the basis for development of a general principle with rules for structure prediction (see scheme). The number of complexing water molecules, and therefore the possible number of hydrogen bonds to the anions, defines the dimensionality of the overall structure.