Research output: Contribution to journal › Article › peer-review
[Pb2F2](SeO4) : a heavier analogue of grandreefite, the first layered fluoride selenate. / Charkin, Dmitri O.; Plokhikh, Igor V.; Zadoya, Anastasiya I.; Kazakov, Sergey M.; Zaloga, Alexander N.; Kozin, Michael S.; Depmeier, Wulf; Siidra, Oleg I.
In: Physics and Chemistry of Minerals, 14.06.2017, p. 1-8.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - [Pb2F2](SeO4)
T2 - a heavier analogue of grandreefite, the first layered fluoride selenate
AU - Charkin, Dmitri O.
AU - Plokhikh, Igor V.
AU - Zadoya, Anastasiya I.
AU - Kazakov, Sergey M.
AU - Zaloga, Alexander N.
AU - Kozin, Michael S.
AU - Depmeier, Wulf
AU - Siidra, Oleg I.
PY - 2017/6/14
Y1 - 2017/6/14
N2 - Co-precipitation of PbF2 and PbSeO4 in weakly acidic media results in the formation of [Pb2F2](SeO4), the selenate analogue of the naturally occurring mineral grandreefite, [Pb2F2](SO4). The new compound is monoclinic, C2/c, a = 14.0784(2) Å, b = 4.6267(1) Å, c = 8.8628(1) Å, β = 108.98(1)°, V = 545.93(1) Å3. Its structure has been refined from powder data to RB = 1.55%. From thermal studies, it is established that the compound is stable in air up to about 300 °C, after which it gradually converts into a single phase with composition [Pb2O](SeO4), space group C2/m, and lattice parameters a = 14.0332(1) Å, b = 5.7532(1) Å, c = 7.2113(1) Å, β = 115.07(1)°, V = 527.37(1) Å3. It is the selenate analogue of lanarkite, [Pb2O](SO4), and phoenicochroite, [Pb2O](CrO4), and its crystal structure was refined to RB = 1.21%. The formation of a single decomposition product upon heating in air suggests that this happens by a thermal hydrolysis mechanism, i.e., Pb2F2SeO4 + H2O (vapor) → Pb2OSeO4 + 2HF↑. This relatively low-temperature process involves complete rearrangement of the crystal structure—from a 2D architecture featuring slabs [Pb2F2]2+ formed by fluorine-centered tetrahedra into a structure characterized by 1D motifs based on [OPb2]2+ chains of oxocentered tetrahedra. The comparative crystal chemistry of the obtained anion-centered structural architectures is discussed.
AB - Co-precipitation of PbF2 and PbSeO4 in weakly acidic media results in the formation of [Pb2F2](SeO4), the selenate analogue of the naturally occurring mineral grandreefite, [Pb2F2](SO4). The new compound is monoclinic, C2/c, a = 14.0784(2) Å, b = 4.6267(1) Å, c = 8.8628(1) Å, β = 108.98(1)°, V = 545.93(1) Å3. Its structure has been refined from powder data to RB = 1.55%. From thermal studies, it is established that the compound is stable in air up to about 300 °C, after which it gradually converts into a single phase with composition [Pb2O](SeO4), space group C2/m, and lattice parameters a = 14.0332(1) Å, b = 5.7532(1) Å, c = 7.2113(1) Å, β = 115.07(1)°, V = 527.37(1) Å3. It is the selenate analogue of lanarkite, [Pb2O](SO4), and phoenicochroite, [Pb2O](CrO4), and its crystal structure was refined to RB = 1.21%. The formation of a single decomposition product upon heating in air suggests that this happens by a thermal hydrolysis mechanism, i.e., Pb2F2SeO4 + H2O (vapor) → Pb2OSeO4 + 2HF↑. This relatively low-temperature process involves complete rearrangement of the crystal structure—from a 2D architecture featuring slabs [Pb2F2]2+ formed by fluorine-centered tetrahedra into a structure characterized by 1D motifs based on [OPb2]2+ chains of oxocentered tetrahedra. The comparative crystal chemistry of the obtained anion-centered structural architectures is discussed.
KW - Anion-centered tetrahedra
KW - Fluoride
KW - Grandreefite
KW - Litharge
KW - Selenate
KW - Thermal decomposition
UR - http://www.scopus.com/inward/record.url?scp=85020747350&partnerID=8YFLogxK
U2 - 10.1007/s00269-017-0903-4
DO - 10.1007/s00269-017-0903-4
M3 - Article
AN - SCOPUS:85020747350
SP - 1
EP - 8
JO - Physics and Chemistry of Minerals
JF - Physics and Chemistry of Minerals
SN - 0342-1791
ER -
ID: 9144315