ISSN:
1572-8854
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Physics
Notes:
Abstract Monoclinic (N2H6)3Zr2F13·F crystallizes in space group P21-C 2 2 (No. 4) with unit cell dimensionsa=5.670(1),b=10.984(2),c=10.601(2) Å,β=93.88(1)°,V=658.7(4) Å3 andZ=2. Two different types of N2H6 2+ ions are present. One is involved in strong H-bonds to F− ions in infinite chains running along the a axis (the shortest N-F distance is 2.437(5) Å), and the other links the structure through weaker bi- and trifurcated H-bonds to fluorine ligands of the Zr2F13 5− ions. The N-N bond lengths range from 1.430(5) to 1.446(5) Å with apparently no meaningful correlation to the type of N2H2 2+ ions. The Zr2F13 5− ions have very nearly C2 point symmetry and are formed by joining two distorted bicapped trigonal prisms of ZrF8-units through a common face. Distances of Zr-F terminal bonds range from 2.015(2) to 2.112(2) Å and of bridging bonds from 2.133(2) to 2.212(2) Å. (N2H6)3Hf2F13·F is isomorphous. The vibrational spectra of the two compounds are nearly identical, with the exception of a strong infrared band, which is assigned to a stretching mode with the moving central atom within the anion. The anion part of the spectrum is simple, showing broad unresolved bands. The cation part shows two types of N2H6 – ions. H-Bonding is strongly present in the spectra, but no simple correlations with the H-bond strength is evident.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01181669
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