title: AgPO2F2 and Ag9(PO2F2)14: the first Ag(i) and Ag(i)/Ag(ii) difluorophosphates with complex crystal structures.
abstract: The reaction of AgF2 with P2O3F4 yields a mixed valence Ag(I)/Ag(II) difluorophosphate salt with AgAg(PO2F2)14 stoichiometry - the first Ag(ii)-PO2F2 system known. This highly moisture sensitive brown solid is thermally stable up to 120 °C, which points at further feasible extension of the chemistry of Ag(ii)-PO2F2 systems. The crystal structure shows a very complex bonding pattern, comprising of polymeric Ag(PO2F2)14(4-) anions and two types of Ag(I) cations. One particular Ag(II) site present in the crystal structure of Ag9(PO2F2)14 is the first known example of square pyramidal penta-coordinated Ag(ii) in an oxo-ligand environment. Ag(i)PO2F2 - the product of the thermal decomposition of Ag9(PO2F2)14 - has also been characterized by thermal analysis, IR spectroscopy and X-ray powder diffraction. It has a complicated crystal structure as well, which consists of infinite 1D [Ag(I)O4/2] chains which are linked to more complex 3D structures via OPO bridges. The PO2F2(-) anions bind to cations in both compounds as bidentate oxo-ligands. The terminal F atoms tend to point inside the van der Waals cavities in the crystal structure of both compounds. All important structural details of both title compounds were corroborated by DFT calculations.
authors.affiliation: Laboratory of Technology of Novel Functional Materials, Center of New Technologies, University of Warsaw, ul. S. Banacha 2c, 02-097, Warsaw, Poland. malin@cent.uw.edu.pl dominik.kurzydlowski@gmail.com w.grochala@cent.uw.edu.pl.
authors.forename: Przemysław J
authors.initials: PJ
authors.lastname: Malinowski
authors.affiliation: Laboratory of Technology of Novel Functional Materials, Center of New Technologies, University of Warsaw, ul. S. Banacha 2c, 02-097, Warsaw, Poland. malin@cent.uw.edu.pl dominik.kurzydlowski@gmail.com w.grochala@cent.uw.edu.pl and Faculty of Mathematics and Natural Sciences, Cardinal Stefan Wyszynski University in Warsaw, ul. Wóycickiego 1/3, 01-938, Warsaw, Poland.
authors.forename: Dominik
authors.initials: D
authors.lastname: Kurzydłowski
authors.affiliation: Laboratory of Technology of Novel Functional Materials, Center of New Technologies, University of Warsaw, ul. S. Banacha 2c, 02-097, Warsaw, Poland. malin@cent.uw.edu.pl dominik.kurzydlowski@gmail.com w.grochala@cent.uw.edu.pl.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Grochala