Phosphate hydrogénophosphate hydrate de manganèse

Abstract

1829Representative results of the energy minimization are given in Table 3. As observed, the calculated equilibrium configuration is in good agreement with the experimental structure. Considering the molecular parameters the optimized structure remains very similar to the experimental one, as shown in Table 3: the shifts of the positoinal and orientational molecular parameters are lower than 0.02 A and 2.5 °, respectively, and the torsion angle of the intramolecular relaxed rotation is reproduced within 0.3 ° . The agreement is improved when the electrostatic interaction is considered, in spite of the method used in estimating the residual charges. The expansion of the cell volume (1.4%) is also reduced (0.15%) when the electrostatic term is included in the calculations. SHORT-FORMAT PAPERSContributions intended for publication under this heading should follow the format given in the Checklist for Authors [Acta Cryst. (1985

Single-crystal neutron diffraction and Mössbauer spectroscopic study of hureaulite, (Mn,Fe)5(PO4)2 (HPO4)2 (H2O)4

“…Menchetti & Sabelli (1973) provided a partially anisotropic refinement, listing also the potential coordinates of the H sites (in five independent sites), which were fixed but not refined. The structure models of hureaulite of Moore & Araki (1973) and Manchetti & Sabelli (1973) are mutually consistent and agree with the experimental findings of Gerault et al (1987) on the synthetic Mn 5 (HPO 4 ) 2 (PO 4 ) 2 (H 2 O) 4 . Keller (1971) reported for hureaulite three possible crystal-chemical…”

Nanocrystalline serrabrancaite (MnPO4·H2O) prepared by a simple precipitation route at low temperature

“…These previously reported methods were time consuming with high temperature and had been found to evolve toxic gases such as NO 2 and CO 2 . So far, only the structure, physical and chemical properties of manganese phosphate hydrate (MnPO 4 ·xH 2 O, x = 1.0-1.7 mol) have been reported [13][14][15][16][17][18].…”

“…Manganese phosphate monohydrate was synthesized either by hydrothermal method or high-temperature method and also found in nature [13][14][15][16][17][18][19][20][21][22]. It was first synthesized by Christensen [23] from manganese(III) nitrate and phosphoric acid and also from the oxidation of manganese(II) nitrate by nitric acid in the presence of phosphoric acid.…”

The solid solution Co4.32Mn2.68(HPO4)4(PO4)2

“…2H 2 O and Co(H 2 PO 4 ) 2 . 2H 2 O (Boudjada & Durif, 1979;Effenberger, 1992), Mn 5 (HPO 4 ) 2 (PO 4 ) 2 (H 2 O) 4 and Co 5 (HPO 4 ) 2 (PO 4 ) 2 (H 2 O) 4 (Han et al, 2006;Menchetti & Sabelli, 1973;Gerault et al, 1987), and Mn 7 (HPO 4 ) 4 (PO 4 ) 2 and Co 7 (HPO 4 ) 4 (PO 4 ) 2 Lightfoot & Cheetham, 1988). Hydrothermal and solvothermal methods have been used to synthesize numerous novel transition metal phosphates with three-dimensional framework structures such as Fe (Zhou et al, 2002),…”

“…The hydrothermal preparation of transition metal phosphates has been described for M = Fe (Zhou et al, 2002), Co (Lightfoot & Cheetham, 1988) and Mn (Riou et al, 1987). For isotypic phosphates with M = Co or Mn, see: M 5 (OH) 5 (PO 4 ) 2 (Ruszala et al, 1977), M(H 2 PO 4 ) 2 Á2H 2 O (Boudjada & Durif, 1979;Effenberger, 1992), M 5 (HPO 4 ) 2 (PO 4 ) 2 (H 2 O) 4 (Han et al, 2006;Menchetti & Sabelli, 1973;Gerault et al, 1987) and M 7 (HPO 4 ) 4 (PO 4 ) 2 (Riou et al, 1987;Lightfoot et al, 1988). The solid solution series Mn 5Àx Co x (HPO 4 ) 2 (PO 4 ) 2 (H 2 O) 4 (x = 1.25, 2, 2.5 and 3) was characterized by Larrea et al (2007).…”