title: Crystal to crystal transformations and polymorphism in anionic hydrogen bonding networks stabilized by crown ether metal complexes.
abstract: 15-crown[5] or 18-crown[6] complexes of alkali, transition metal and ammonium cations together with polyprotic inorganic and organic anions have been used to construct crystalline molecular salts based on hydrogen bonded anionic networks. This new class of organic-inorganic complexes displays a variety of crystal-to-crystal transformations, mainly associated to the loss/uptake of water molecules and/or to the ionic reorganization accompanying phase transitions on varying the temperature. The dehydration and phase transition processes have been investigated by DSC, TGA and variable temperature X-ray powder diffraction. Most of the complexes described herein have been prepared by solid state mixing of the solid reactants.
authors.affiliation: Department of Chemistry G. Ciamician, Alma Mater Studiorum University of Bologna, Via Selmi 2, 40126, Bologna, Italy. dario.braga@unibo.it
authors.forename: Dario
authors.initials: D
authors.lastname: Braga
authors.forename: Simone
authors.initials: S
authors.lastname: D'Agostino
authors.forename: Fabrizia
authors.initials: F
authors.lastname: Grepioni
authors.forename: Massimo
authors.initials: M
authors.lastname: Gandolfi
authors.forename: Katia
authors.initials: K
authors.lastname: Rubini