Crystal chemistry of struvite analogs of the type MgMPO4.6H2O (M+ = potassium(1+), rubidium(1+), cesium (1+), thallium(1+), ammonium(1+)

Banks, E.; Chianelli, R. R.; Korenstein, Rafi

doi:10.1021/ic50149a041

Cited by 125 publications

(46 citation statements)

References 2 publications

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“…Struvite analogues of the type MgMPO4.6H20 (M = K, Rb, Cs, T1, NH 4) have been reported by Banks, Chianelli & Korenstein (1975). Although these compounds appear to be isomorphous, there are substantial differences in their structures.…”

Section: Ld-ha (°)mentioning

confidence: 99%

“…Mg(NH4)PO4.6H20 and MgKPO4.6H20 are orthorhombic (isomorphous) and contain a direct contact between phosphate O and the K+/NH~ " ion. With the increasing size of the monovalent ion, higher-symmetry forms are preferred; for example, MgCsPO4.6H20 exists in a hexagonal and a cubic form (Banks et al, 1975).…”

Section: Ld-ha (°)mentioning

confidence: 99%

“…(b) Mathew & Schroeder (1979). (c) Banks et al (1975 Mathew et al (1982). (e) Dickens analogue, the cubic form of MgCsAsO 4.…”

Section: Ld-ha (°)mentioning

confidence: 99%

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The structure of sodium strontium phosphate nonahydrate

Takagi¹,

Mathew²,

Brown³

1982

Acta Crystallogr Sect B

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STRUCTURE OF LITHIUM SODIUM YTTRIUM SILICATE Na2LiYSi6Ol5 many types of metasilicate rings, e.g. Si309, Si4012, Si6018, Si12036.One peculiarity of the Sechser-Doppelkette unit is that, unlike other metasilicate units, it does persist essentially unchanged in a wide variety of structures containing ions of different charges in octahedral sites, e.g. M 2+, M 3+ and M 4+, as well as different numbers of charge-balancing cations. Thus, in the series NaELiM3+Si6015, stable phase formation occurs for octahedral ions as small as Fe 3+ (0.66 A) and as large as Sm 3+ (0.96 A). The present structure determination was undertaken because Y (0.90 A) is amongst the largest trivalent ions which can be substituted in melt-grown crystals.In the compounds Na2MgESi6015, NaELiFeSi60~5, NaLiZrSi6015 and Na2LiYSi6015 the following features are observed. In the unit cells of these compounds the c axis, which is parallel to the direction of propagation of the silicate double chains and is thus a rough measure of the degree to which the chains are folded, lies in the relatively narrow range 10.072-10.375 A. Also, the Si-O-Si angles are similar in all four. Thus the silicate chain constitutes a stable and relatively inflexiblc building unit. Again, in all cases there is marked distortion of the bond angles at the tetrahedral site. We conclude, therefore, that this distortion enables the structure to accommodate a wide range of cations on the octahedral sites without necessitating changes to the Sechser-Doppelkette unit. AbstractThe crystal structure of SrNaPO4.9H20 has been determined by single-crystal X-ray diffraction. The crystals are cubic, a = 10.544 (2) A, space group P2~3, with Z = 4, Pm = 2.11, Pc = 2.083 g cm -3. The structure was refined by full-matrix least-squares techniques to R = 0.025 and R w = 0.026 for the 323 reflections used in the refinement. All cations and anions are completely surrounded by water molecules. All nine water molecules are coordinated to the same Sr 2+ ion, forming a tricapped trigonal prism. The Na + ion is coordinated to six water molecules, forming a distorted octahedron. Extensive edge-sharing of Sr(H20) 9 and Na(H20)6 polyhedra exists. The environment of the PO]-ion consists of 15 water molecules all of which are probably hydrogen bonded to PO 4 oxygens. However, there is considerable disordering of the phosphate O atoms, somewhat similar to those of SO 4 groups in alums.

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Section: Ld-ha (°)mentioning

confidence: 99%

Section: Ld-ha (°)mentioning

confidence: 99%

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The structure of sodium strontium phosphate nonahydrate

Takagi¹,

Mathew²,

Brown³

1982

Acta Crystallogr Sect B

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“…Struvites are also known as infection crystals, because they are form due to urinary tract infections with ureolithic microorganisms in humans and animals [16]- [18]. A series of orthorhombic struvite analogues crystals (MM' with M = Mg, Zn, Cd and M' = K, Ti, NH 4 , Rb) were reported due to their biomedical importance [19] [20]. One of the analogous compounds of struvite is potassium magnesium phosphate hexahydrate (KMg-PO 4 •6H 2 O), known as struvite-k crystal [21]- [23], which has been approved (CNMMN-IMA2003) as a new inorganic phosphate mineral [24].…”

Section: Introductionmentioning

confidence: 99%

“…Zhang et al [22] observed the dehydration characteristics of synthesized struvite-k at N 2 atmosphere. Banks et al [19] have grown the struvite-k crystals by gel diffusion technique and observed the needle shape crystals; however Chauhan et al [21] have grown these crystals in silica gel by single diffusion gel techniques and observed different morphologies with changing growth parameters. Till today, the growth of struvite-k crystals in agar gel by single and double diffusion techniques have not been reported.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Struvite-k Crystals by Agar Gel

Suryawanshi¹,

Chaudhari²

2014

JCPT

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The phosphate mineral struvite is basically formed in urinary tracks and kidney. One of the analogous compounds of struvite is potassium magnesium phosphate hexahydrate (KMgPO 4 •6H 2 O), known as struvite-k crystal and found in animal urinary calculi. In the present investigation, struvite-k crystals were grown by single diffusion and double diffusion techniques in agar gelmedium. The grown crystals were analyzed by optical microscopy, scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray analysis (EDXA) and thermogravimetric analysis (TGA). Optical microscopy and SEM exhibited the different morphologies. The FTIR spectra revealed the presence of water molecules, stretching and bending vibrations of phosphate (PO4) ions. However the powder XRD results from the crystalline nature. Elemental composition in the crystal was obtained by EDXA, while 36.89% weight loss of water molecules is observed in TGA study.

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