Hydrothermal synthesis of a new lead(II) borate (Pb₄O)Pb₂B₆O₁₄-II

Abstract

A new centrosymmetric modification of the lead borate (Pb4O)Pb2B6O14 has been obtained as a side phase through a facile hydrothermal reaction from Pb(BO2)2·H2O, H2O, and KOH as starting materials. The compound (Pb4O)Pb2B6O14-II crystallizes in the space group P1̅ (no. 2) with the lattice parameters a=695.9(3), b=778.0(3), c=1408.3(3) pm, α=97.35(1)°, β=100.39(1)°, and γ=103.02(1)°. The structure consists of anti-parallel arranged B6O14 chains and isolated oxygen-centered OPb4 tetrahedra. The compound Pb6B12O21(OH)6 constitutes the major phase of the synthesis, as verified through a Rietveld analysis. The characterization of (Pb4O)Pb2B6O14-II is based on a Rietveld analysis, single-crystal X-ray diffraction data, and FT-IR spectroscopy.

Synthesis and Characterization of the First Lead(II) Borosulfate Pb[B2(SO4)4]

“…Taking longer Pb–O distances into account, the distorted Pb1O 8 and Pb2O 8 square prisms are fourfold capped resulting in a 8+4 coordination (see Figure a and b). In case of the eightfold coordination, the Pb–O distances fall in the range between 264.0(5) and 295.4(5) pm (average value: 279.7 pm), which is in good agreement with values found for other oxoanionic lead compounds like borates , . However, the Pb2–O distances are in average about 20 pm longer than found for Pb1O 8 , which might correspond to the differing site occupation.…”

“…values found for other oxoanionic lead compounds like borates. [13,14] However, the Pb2-O distances are in average about 20 pm longer than found for Pb1O 8 , which might correspond to the differing site occupation. Interestingly, neither Pb1 nor Pb2 reveals a sterically demanding lone pair of electrons as often observed for Pb 2+ cations.…”

“…Interestingly, neither Pb1 nor Pb2 reveals a sterically demanding lone pair of electrons as often observed for Pb 2+ cations. [13,14] Possibly, this fact is due to the special stability and large required space of the anionic chains with multiple terminal nucleophilic oxygen atoms. In further experiments we try to elucidate this assumption.…”

Synthesis, Characterization and Optical Properties of Two Metal Borates Containing Two Types of Oxoboron Clusters

“…All the bond lengths and angles are in accordance with the trend observed for other lead borates. As shown in Figure c, B1 and B6 are in BO 3 triangular coordination geometry and B2, B3, B4 and B5 are all bonded with four oxygen atoms, forming BO 4 tetrahedra . The above tetrahedral BO 4 and triangular BO 3 are linked by corner‐sharing to give a B 6 O 15 unit containing two B 3 O 8 rings.…”

“…Pb 6 O(B 6 O 14 ) crystallizes into the triclinic crystal group P ‐1 which contains twenty‐seven crystallographically independent non‐hydrogen atoms including six Pb, six B and fifteen O atoms. Its structure has been reported in great detail by Huppertz and will be briefly described here . The structure features [Pb 6 O 13 ] 14− layers which are further connected by [B 6 O 14 ] 10− chains (Figure d).…”