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| Titel |
New alkali metal diphosphates how materials to preserve the security of the environment: CsNaCu(P2O7), Rb2Cu(P2O7) and CsNaCo(P2O7) synthesis and crystal structure determination |
| VerfasserIn |
Anastasiya Chernyatieva, Alyona Filatova, Dariya Spiridonova, Sergey Krivovichev |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250078038
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| Zusammenfassung |
| In this work we describe preliminary results of the synthesis and of a crystal-chemical study
of synthetic phosphates with transition metals. Due to the increasing requirements for
environmental safety specialists from various industries, we are searching for sustainable
forms of immobilization of hazardous waste during storage. We are also developing a
component-based waste for new materials. In our continued exploratory synthesis of
compounds containing transition-metals, we were able to produce the new diphosphate
phases CsNaCu(P2O7), Rb2Cu(P2O7) and CsNaCo(P2O7).
A crystal chemical study has allowed us to identify new phosphates. Crystals
of CsNaCu(P2O7) (Phase 1) is orthorhombic, crystallizes in space group Pmn21,
with a = 5.147(8), b = 15.126(2), c = 9.717(2) Å, V = 756.20 Å3, R1 = 0.066 and
Rb2Cu(P2O7) (Phase 2) is orthorhombic as well, crystallizes in space group Pmcn, with a =
5.183(8), b = 10.096(1), c = 15.146(3) Å, V = 793.55 Å3, R1 = 0.063, they have been
obtained by high-temperature reaction of RbNO3, CsNO3, Cu(NO3)2, NaOH and
(NH4)4P2O7. Synthetic crystals of the phosphate of copper and rubidium were studied in
detail by us on the structures of Rb2Cu(P2O7) and Rb2Cu3(P2O7)2 - new alkali
metal copper diphosphates (CHERNYATIEVA et al., 2008). Here we report the
synthesis, the structure and the properties of the title compounds and we compare these
phases with the previously discovered K2CuP2O7 (ELMAADI et al., 1995) and
CsNaMnP2O7 (HUANG et al., 1998). These structures crystallize in other space
groups, although their structures are also based on 2-D layers, formed by P2O7
groups combined with polyhedra of the transition metals (CHERNYATIEVA et al.,
2012).
A crystal chemical study has allowed us to identify even new diphosphates
CsNaCu(P2O7) (Phase 3). Crystals of CsNaCoP2O7 is monoclinic, space group P 21/n, with
a = 7,424(2), b = 7,648(1), c = 12,931(3)Å, β = 90,71(2)Ë , V = 734.2(3) Å3 and R1 = 0.060.
The structure is based framework of Co tetrahedra and P2O7 groups. The structure of the
[Co(P2O7)]2-framework in more detail. The phosphate groups and tetrahedra coordinate
cobalt ions form topology. This is a unique 4-coordination topology, where Co and P2O7
groups in the structure are topologically equivalent.
References
CHERNYATIEVA, A. P., KRIVOVICHEV, S. V., SPIRIDONOVA, D. V. (2008):
International conference «Inorganic Materials» Dresden (2008) P3 – 143.
CHERNYATIEVA, A. P, SPIRIDONOVA, D. V., KRIVOVICHEV, S. V. The crystal
structures of two new synthetic compounds CsNaCu(P2O7) and Rb2Cu(P2O7), Acta
Mineralogica-Petrographica (2012) Vol.7, p.25
EL MAADI, A., BOUKHARI, A., HOLT, E.M. (1995) Journal of Alloys Compounds,
223: 13-17.
HUANG, Q., HWU, S. J., MO, X. H. (2001): Angewandte Chemie - International
Edition, 40: 1690-1693. |
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