Publication Date:
2020-02-25
Description:
Two novel K/Mn phosphate hydrates, namely, dipotassium trimanganese dipyrophosphate dihydrate, K2Mn3(H2O)2[P2O7]2, (I), and potassium manganese dialuminium triphosphate dihydrate, KMn(H2O)2[Al2(PO4)3], (II), were obtained in the form of single crystals during a single hydrothermal synthesis experiment. Their crystal structures were studied by X-ray diffraction. Both new compounds are members of the morphotropic series of phosphates with the following formulae: A 2 M 3(H2O)2[P2O7]2, where A = K, NH4, Rb or Na and M = Mn, Fe, Co or Ni, and AM 2+(H2O)2[M 3+ 2(PO4)3], where A = Cs, Rb, K, NH4 or (H3O); M 2+ = Mn, Fe, Co or Ni; and M 3+ = Al, Ga or Fe. A detailed crystal chemical analysis revealed correlations between the unit-cell parameters of the members of the series, their structural features and the sizes of the cations. It has been shown that a mixed type anionic framework is formed in (II) by aluminophosphate [(AlO2)2(PO4)2]∞ layers, with a cationic topology similar to the Si/Al-topology of the crystal structures of feldspars. A study of the magnetic susceptibility of (II) demonstrates a paramagnetic behaviour of the compound.
Electronic ISSN:
2053-2296
Topics:
Chemistry and Pharmacology
,
Geosciences
,
Physics
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