Synthesis and Characterization of Ca₂(PO₂NH)₄·8H₂O

Abstract

Ca2(PO2NH)4·8H2O was obtained as single‐phase crystalline powder starting from aqueous solution of K4(PO2NH)4·4H2O and Ca(NO3)2·4H2O. A small fiber‐like specimen has been used for single‐crystal X‐ray structure determination. In the structure of Ca2(PO2NH)4·8H2O (Pbcn (no. 60), a = 1700.6(3), b = 1069.3(2), c = 963.2(2) pm, Z = 4) there are (PO2NH)44– ions in saddle conformation which are interconnected by N–H···O hydrogen bonds forming infinite columns running along [001]. These columns are hold together by a complex hydrogen bonding network with crystal water molecules involved. The FTIR spectrum of the title compound has been measured and the relevant bands were assigned. 31P solid‐state NMR investigations yielded three resolved resonances with chemical shift values of –3.1, –4.9 and –7.9 ppm. DTA / TG data are also discussed.

The Long‐Periodic Loop‐Branched Chain Structure of the Oxonitridophosphate La21P40O46N57, Elucidated by a Combination of TEM and Microfocused Synchrotron Radiation

“…Data of several crystallites confirm the atomic ratio La/P of 21:40 (Table S1) obtained in the structure refinement. The infrared spectra show the characteristic fingerprint of oxonitridophosphates at <1500 cm −1 (Figure S3), which corresponds to phosphate framework vibrations. The very weak signal at ca.…”