Synthese und Kristallstruktur der ersten zinkhaltigen Pyroborate Ni1,5Zn0,5(B2O5) und Co1,5Zn0,5(B2O5) / Synthesis and Crystal Structure of the First Zinc Containing Pyroborates Ni1,5Zn0,5(B2O5) and Co1,5Zn0,5(B2O5)
The first zinc containing pyroborates Ni1,5Zn0,5(B2O5) (A ) and Co1,5Zn0,5(B2O5) (B) were prepared by using a B2O3 flux technique. Single crystals were investigated by X-ray diffraction and showed triclinic symmetry, space group Ci1-P1̅. The structures are isotypic to Co2(B2O5) with the lattice parameters (A ) a = 331.28(6), b = 613.87(11), c = 922.2(2), α = 104.067(11) °, β = 90.672(13) °, γ = 92.413(12) ° and (B) a = 315.89(2), b = 612.84(6), c = 927.72(6), α = 104.103(7) °, β = 91.020(6) °, γ = 92.540(7) °, Z = 2. All metal point positions show an octahedral oxygen coordination and a partly statistical distribution of Zn2+ and Ni2+ or Co2+, respectively. Isolated nearly planar B2O5 units connect ribbons consisting of edge sharing metal octahedra.