Preparation, Crystal Structure and Vibrational Spectra of Ca2P2O6·2H2O and [Ca(H2O)3(H2P2O6)]·0.5(C12H24O6)·H2O

The calcium salts Ca2P2O6·2H2O (1) and [Ca(H2O)3(H2P2O6)]·0.5(C12H24O6)·H2O (2) were prepared and structurally characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the orthorhombic space group Pbca and compound 2 in the monoclinic space group P21/n. The crystal structure of compound 1 consists of chains of edge-sharing [CaO7] polyhedra linked by hypodiphosphate(IV) anions to form a three-dimensional network. The crystal structure of compound 2 consists of alternated layers of crown ether and water molecules and respective ionic units. Within the layers of ionic units the Ca2+ cations are octahedrally coordinated by three monodentate dihydrogenhypodiphosphate(IV) anions and three water molecules. The IR/Raman spectra of the title compounds were recorded and interpreted, especially with respect to the [P2O6]4– and [H2P2O6]2– groups. The phase purity of 2 was verified by powder diffraction measurements.

[1]  M. Haase,et al.  Crystal structure of catena-poly[[tetraaquamagnesium]-μ-(dihydrogen hypodiphosphato)-κ2 O:O′] , 2015, Acta crystallographica. Section E, Crystallographic communications.

[2]  V. Petříček,et al.  Crystallographic Computing System JANA2006: General features , 2014 .

[3]  Peng Wu,et al.  Preparation, Crystal Structure, Vibrational Spectra, and Thermal Behavior of Rb2H2P2O6·2H2O , 2014 .

[4]  V. Kinzhybalo,et al.  Electron density distribution in tetralithium hypodiphosphate hexahydrate, Li4P2O6·6H2O. , 2013, Acta crystallographica Section B, Structural science, crystal engineering and materials.

[5]  T. Lis,et al.  Potassium salts of hypodiphosphoric acid. , 2012, Acta crystallographica. Section C, Crystal structure communications.

[6]  Peng Wu,et al.  New Quaternary Alkali‐Metal Hypodiphosphate Hydrates: Preparation, Crystal Structure, Vibrational Spectrum, and Thermal Behavior of K4P2O6·8H2O and Na2K2P2O6·8H2O in Comparison to Na4P2O6·10H2O , 2012 .

[7]  H. Eckert,et al.  New hypodiphosphates of the alkali metals: Synthesis, crystal structure and vibrational spectra of the hypodiphosphates(IV) M2[(H2P2O6)(H4P2O6)] (M=Rb and Cs) , 2012 .

[8]  P. Szklarz,et al.  Discovery of Ferroelectric Properties in Diammonium Hypodiphosphate (NH4)2H2P2O6 (ADhP) , 2011 .

[9]  J. Levalois-Grützmacher,et al.  Tetrakis(trimethysilyl)hypophosphate P2O2(OTMS)4: Synthesis, reactivity and application as flame retardant , 2007 .

[10]  B. Twamley,et al.  Room temperature synthesis and solid-state structure of Ni2P2O6·12H2O , 2005 .

[11]  M. Jansen,et al.  Darstellung und Kristallstruktur von Cobalt(II)‐Hexaoxodiphosphat(P ? P)(4−)‐dodecahydrat, Co2P2O6 · 12 H2O , 1995 .

[12]  Y. Marcus,et al.  The entropies of polyatomic gaseous ions , 1984 .

[13]  J. Stejskal,et al.  The infrared spectra and conformations of H2P2O62− anion , 1972 .

[14]  R. Collin,et al.  The crystal structure of disodium dihydrogen hypophosphate hexahydrate (Na2H2P2O6.6H2O) and disodium dihydrogen pyrophosphate hexahydrate (Na2H2P2O7.6H2O) , 1971 .

[15]  H. Beck,et al.  Quantitative Fällung von vierwertigem Uran mit Natriumhypophosphat aus stark saurer Lösung , 1967 .

[16]  W. Palmer.  217. The preparation and methods of determination of hypophosphate , 1961 .

[17]  W. Palmer.  304. The vibrational spectra and structures of dithionate, hypophosphate, and related ions , 1961 .

[18]  M. Baudler.  Untersuchungen über Phosphorverbindungen. IV. RAMAN‐Spektrum und Konstitution der Unterphosphorsäure , 1955 .