A new mixed-valence lead(II) manganese(II/III) phosphate(V): PbMn^II₂Mn^III(PO₄)₃

Abstract

The title compound, lead trimanganese tris(orthophosphate), has been synthesized by hydro­thermal methods. In this structure, only two O atoms are in general positions and all others atoms are in the special positions of the Imma space group. Indeed, the atoms in the Wyckoff positions are namely: Pb1 and P1 on 4e (mm2); Mn1 on 4b (2/m); Mn2 and P2 on 8g (2); O1 on 8h (m); O2 on 8i (m). The crystal structure can be viewed as a three-dimensional network of corner- and edge-sharing PO4 tetra­hedra and MnO6 octa­hedra, building two types of chains running along the b axis. The first is an infinite linear chain, formed by alternating MnIIIO6 octa­hedra and PO4 tetra­hedra which share one vertex. The second chain is built up from two adjacent edge-sharing octa­hedra (MnII 2O10 dimers) whose ends are linked to two PO4 tetra­hedra by a common edge. These chains are linked together by common vertices of polyhedra in such a way as to form porous layers parallel to (001). These sheets are bonded by the first linear chains, leading to the appearance of two types of tunnels, one propagating along the a axis and the other along b. The PbII ions are located within the inter­sections of the tunnels with eight neighbouring O atoms in form of a trigonal prism that is capped by two O atoms on one side. The three-dimensional framework of this structure is compared with similar phosphates such as Ag2Co3(HPO4)(PO4)2 and Ag2Ni3(HPO4)(PO4)2.

Crystal structure of calcium dinickel(II) iron(III) tris(orthophosphate): CaNi2Fe(PO4)3

“…In this context, new phosphates adopting the alluaudite or -CrPO 4 structure type have been synthesized and structurally characterized. For example, the mixed-valence manganese phosphates PbMn II 2 Mn III (PO 4 ) 3 (Alhakmi et al, 2013) and PbMn II 2 Mn III (PO 4 ) 3 (Assani et al, 2013), the magnesium phosphate NaMg 3 (PO 4 )(HPO 4 ) 2 (Ould Saleck et al, 2015) and silver nickel phosphate Ag 2 Ni 3 (HPO 4 )-(PO 4 ) 2 (Assani et al, 2011) were synthesized by hydrothermal methods, while solid-state reactions were applied to synthesize SrNi 2 Fe(PO 4 ) 3 (Ouaatta et al, 2015) and Na 2 Co 2 Fe(PO 4 ) 3 (Bouraima et al, 2015). In a continuation of the latter preparation route, we have investigated pseudo-quaternary systems MO-NiO-Fe 2 O 3 -P 2 O 5 (M represents a divalent cation) and report here on the synthesis and crystal structure of the title compound, CaNi 2 Fe(PO 4 ) 3 .…”

Structural and Spectroscopic Studies of NaCuCr2(PO4)3: A Noncentrosymmetric Phosphate Belonging to the α-CrPO4-Type Compounds

“…They are identified with the general chemical formula □ 3 M 3 (XO 4 ) 3 , where □ is a vacancy that can be filled by monovalent and/or divalent cations, introducing an oxidation state decrease of the transition metal M and XO 4 referring to tetrahedral entity, respectively. They all crystallize with a centrosymmetric Imma space group. − Interestingly, some of them with the following general formula A 2 M 2+ 2 M 3+ (PO 4 ) 3 , where A is an alkali and M are metals able to show an oxidation equal to 2 and/or 3, were recently described as low-temperature polymorphs of the alluaudite-type structure. , …”

Crystal Structure of Baryum Dicobalt Iron (III) Three (Orthophosphate) Belonging to <i>α</i>-CrPO<SUB>4</SUB> Family

“…The crystal structures belonging to α-CrPO 4 family shows a great similarity with of the alluaudite structure, can thus be represented by the In the same concept, our team recently isolated, and then characterize the crystal structures belonging to these different family such as Na 2 Co 2 Fe (PO 4 ) 3 [9], Na 1 , 67 Zn 1 , 67 Fe 1 , 33 (PO 4 ) 3 [10] and Ag 1.655 Co 1.64 Fe 1.36 (PO 4 ) 3 [11] belonging to the alluaudite type structure. Besides, bivalent and trivalent based phosphates, namely SrNi 2 Fe(PO 4 ) 3 [12], SrCo 2 Fe(PO 4 ) 3 [13] and MMn II 2 Mn III (PO 4 ) 3 (M = Pb, Sr, Ba) [14] [15] [16], with rarely observed mixed-valent Mn II…”