TY - JOUR
T1 - Hydrothermal Synthesis and Structural Characterization of Mixed-Valence Iron Phosphates
T2 - AFe5(PO4)5(OH)·H2O (A = Ca, Sr)
AU - Dvoncova, Edita
AU - Lii, Kwang Hwa
PY - 1993
Y1 - 1993
N2 - Mixed-valence iron phosphates of the stoichiometry AFe5(PO4)5(OH)·H2O (A = Ca, Sr) have been synthesized hydrothermally and structurally characterized by single-crystal X-ray diffraction. Crystal data: CaFe5(PO4)5-(OH)·H2O, triclinic, P1̄, a = 6.404(1) Å, b = 7.866(1) Å, c = 15.694(2) Å, α = 85.00(1)∘, β = 88.79(1)∘, γ = 78.22(1)∘, V= 770.97(18) Å3, Z = 2, R = 0.034 for 2544 unique reflections; SrFe5(PO4)5(OH)·H2O, triclinic, P1̄, a = 6.4303(2) Å, b = 7.8749(8) Å, c = 15.894(2) Å, α = 84.75(1)∘, β = 87.96(1)∘, γ = 78.114(9)∘, V= 784.16(16) Å3, Z = 2, R = 0.0469 for 1854 unique reflections. The two compounds are isostructural. The complex framework consists of dimers of corner-sharing and edge-sharing FeIIIO6 octahedra joined through FeIIO5 trigonal bipyramids by corner- and edge-sharing, and discrete FeIIIO6 octahedra. Phosphate tetrahedra further knit together these Fe-O polyhedra by corner-sharing. Schlegel diagrams are used to help describe the arrangement of the next-nearest neighbors of the coordination polyhedra of Fe. The calcium ions are 7-coordinated and are located at intersections of the tunnels along the [010] and [110] directions. The structures are further defined by thermogravimetric and Mossbauer studies. Mossbauer spectroscopy confirms the presence of one FeII and four FeIII ions.
AB - Mixed-valence iron phosphates of the stoichiometry AFe5(PO4)5(OH)·H2O (A = Ca, Sr) have been synthesized hydrothermally and structurally characterized by single-crystal X-ray diffraction. Crystal data: CaFe5(PO4)5-(OH)·H2O, triclinic, P1̄, a = 6.404(1) Å, b = 7.866(1) Å, c = 15.694(2) Å, α = 85.00(1)∘, β = 88.79(1)∘, γ = 78.22(1)∘, V= 770.97(18) Å3, Z = 2, R = 0.034 for 2544 unique reflections; SrFe5(PO4)5(OH)·H2O, triclinic, P1̄, a = 6.4303(2) Å, b = 7.8749(8) Å, c = 15.894(2) Å, α = 84.75(1)∘, β = 87.96(1)∘, γ = 78.114(9)∘, V= 784.16(16) Å3, Z = 2, R = 0.0469 for 1854 unique reflections. The two compounds are isostructural. The complex framework consists of dimers of corner-sharing and edge-sharing FeIIIO6 octahedra joined through FeIIO5 trigonal bipyramids by corner- and edge-sharing, and discrete FeIIIO6 octahedra. Phosphate tetrahedra further knit together these Fe-O polyhedra by corner-sharing. Schlegel diagrams are used to help describe the arrangement of the next-nearest neighbors of the coordination polyhedra of Fe. The calcium ions are 7-coordinated and are located at intersections of the tunnels along the [010] and [110] directions. The structures are further defined by thermogravimetric and Mossbauer studies. Mossbauer spectroscopy confirms the presence of one FeII and four FeIII ions.
UR - http://www.scopus.com/inward/record.url?scp=0040647583&partnerID=8YFLogxK
U2 - 10.1021/ic00072a034
DO - 10.1021/ic00072a034
M3 - 期刊論文
AN - SCOPUS:0040647583
SN - 0020-1669
VL - 32
SP - 4368
EP - 4372
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 20
ER -