Research output: Contribution to journal › Article › peer-review
Synthesis, crystal structures and properties of the new compounds K7-xAg1+x(XO4)4 (X = Mo, W). / Spiridonova, Tatyana S.; Solodovnikov, Sergey F.; Savina, Aleksandra A. et al.
In: Acta Crystallographica Section C: Structural Chemistry, Vol. 73, No. 12, 01.12.2017, p. 1071-1077.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Synthesis, crystal structures and properties of the new compounds K7-xAg1+x(XO4)4 (X = Mo, W)
AU - Spiridonova, Tatyana S.
AU - Solodovnikov, Sergey F.
AU - Savina, Aleksandra A.
AU - Solodovnikova, Zoya A.
AU - Stefanovich, Sergey Yu
AU - Lazoryak, Bogdan I.
AU - Korolkov, Iliya V.
AU - Khaikina, Elena G.
PY - 2017/12/1
Y1 - 2017/12/1
N2 - Two new isostructural compounds, namely heptapotassium silver tetrakis(tetraoxomolybdate), K7-xAg1+x(MoO4)4 (0 ≤ x ≤ 0.4), and heptapotassium silver tetrakis(tetraoxotungstate), K7-xAg1+x(WO4)4 (0 ≤ x ≤ 0.4), have been synthesized and found to crystallize in the polar space group P63mc (Z = 2) with the unit-cell dimensions a = 12.4188(2) and c = 7.4338(2)Å for K6.68Ag1.32(MoO4)4 (single-crystal data), and a = 12.4912(5) and c = 7.4526(3)Å for K7Ag(WO4)4 (Rietveld analysis data). Both structures represent a new structure type, with characteristic [K1(XO4)6] 'pinwheels' of K1O6 octahedra and six XO4 tetrahedra (X = Mo, W) connected by common opposite faces into columns along the c axes. The octahedral columns are linked to each other through Ag1O4 tetrahedra along with the K2 and K3/Ag2 polyhedra, forming the polar rods (...Ag1O4-X1O4-empty octahedron-Ag1O4...). Ag1 is located almost at the centre of the largest face of its coordination tetrahedron and seems to have some mobility. The new structure type is related to the Ba6Nd2Al4O15 and CaBaSiO4 types, and to other structures of the α-K2SO4-glaserite family. The differential scanning calorimetry (DSC) and second harmonic generation (SHG) results show that both compounds undergo first-order phase transformations to high-temperature centrosymmetric phases.K7-xAg1+x(XO4)4 (0 ≤ x ≤ 0.4; X = Mo, W) represent a new structure type related to the α-K2SO4-glaserite family. Open AgO4 tetrahedra have a polar disposition along the c axes. The compounds undergo first-order acentric-to-centrosymmetric polymorphous transitions.
AB - Two new isostructural compounds, namely heptapotassium silver tetrakis(tetraoxomolybdate), K7-xAg1+x(MoO4)4 (0 ≤ x ≤ 0.4), and heptapotassium silver tetrakis(tetraoxotungstate), K7-xAg1+x(WO4)4 (0 ≤ x ≤ 0.4), have been synthesized and found to crystallize in the polar space group P63mc (Z = 2) with the unit-cell dimensions a = 12.4188(2) and c = 7.4338(2)Å for K6.68Ag1.32(MoO4)4 (single-crystal data), and a = 12.4912(5) and c = 7.4526(3)Å for K7Ag(WO4)4 (Rietveld analysis data). Both structures represent a new structure type, with characteristic [K1(XO4)6] 'pinwheels' of K1O6 octahedra and six XO4 tetrahedra (X = Mo, W) connected by common opposite faces into columns along the c axes. The octahedral columns are linked to each other through Ag1O4 tetrahedra along with the K2 and K3/Ag2 polyhedra, forming the polar rods (...Ag1O4-X1O4-empty octahedron-Ag1O4...). Ag1 is located almost at the centre of the largest face of its coordination tetrahedron and seems to have some mobility. The new structure type is related to the Ba6Nd2Al4O15 and CaBaSiO4 types, and to other structures of the α-K2SO4-glaserite family. The differential scanning calorimetry (DSC) and second harmonic generation (SHG) results show that both compounds undergo first-order phase transformations to high-temperature centrosymmetric phases.K7-xAg1+x(XO4)4 (0 ≤ x ≤ 0.4; X = Mo, W) represent a new structure type related to the α-K2SO4-glaserite family. Open AgO4 tetrahedra have a polar disposition along the c axes. The compounds undergo first-order acentric-to-centrosymmetric polymorphous transitions.
KW - crystal chemistry
KW - crystal structure
KW - double molybdate
KW - double tungstate
KW - nonstoichiometry
KW - phase transitions
KW - potassium
KW - powder diffraction
KW - second harmonic generation
KW - silver
KW - RBLIMOO4
KW - NATRIYA I KALIYA
KW - PHASE-TRANSITIONS
KW - IONIC-CONDUCTIVITY
KW - DOUBLE MOLYBDATE
KW - TUNGSTATES
KW - CHEMISTRY
KW - SYSTEMS
KW - POTASSIUM
KW - LITHIUM
UR - http://www.scopus.com/inward/record.url?scp=85037158625&partnerID=8YFLogxK
U2 - 10.1107/S2053229617015674
DO - 10.1107/S2053229617015674
M3 - Article
C2 - 29206117
AN - SCOPUS:85037158625
VL - 73
SP - 1071
EP - 1077
JO - Acta Crystallographica Section C: Structural Chemistry
JF - Acta Crystallographica Section C: Structural Chemistry
SN - 2053-2296
IS - 12
ER -
ID: 9647309