Abstract
Crystals of the title compounds were grown under hydrothermal
conditions. The crystal structures were determined by single crystal
data.
NaFe[BP2O7(OH)(3)] (monoclinic, C 2/c, a = 1042.0(2), b = 821.5(1), c =
9217(1) pm, beta = 116.60(1)degrees, Z=4): The crystal structure
contains isolated anions [BP2O7(OH)(3)](4-), which correspond to
trinuclear units PO1/2O3-BO2/2(OH)(2)-PO1/2O2(OH) of corner sharing
tetrahedra. Fe3+ is coordinated octahedrally by oxygen, Na+ is 8-fold
coordinated by oxygen forming cubes.
K2Fe2[B2P4O16(OH)(2)] (triclinic, P (1) over bar, a = 516.7(1), b =
808.9(1), c = 834.0(1) pm, alpha = 87.06(1), beta = 80.21(1), gamma =
86.59(1)degrees, Z = 1): The crystal structure contains isolated anions
[B2P4O16(OH)(2)](8-). Four-membered rings of tetrahedra with two
additional terminal phosphate groups are formed by condensation of two
trinuclear units PO1/2O3-BO3/2(OH)-PO2/2O2. Fe3+ is in an octahedral and
K+ in an irregularly 10-fold coordination by oxygen.