scholarly journals The Role of Acidity in the Synthesis of Novel Uranyl Selenate and Selenite Compounds and their Structures

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 965
Author(s):  
Gabriel L. Murphy ◽  
Philip Kegler ◽  
Eike M. Langer ◽  
Evgeny V. Alekseev

Herein, the novel uranyl selenate and selenite compounds Rb2[(UO2)2(SeO4)3], Rb2[(UO2)3(SeO3)2O2], Rb2[UO2(SeO4)2(H2O)]·2H2O, and (UO2)2(HSeO3)2(H2SeO3)2Se2O5 have been synthesized using either slow evaporation or hydrothermal methods under acidic conditions and their structures were refined using single crystal X-ray diffraction. Rb2[(UO2)2(SeO4)3] synthesized hydrothermally adopts a layered 2D tetragonal structure in space group P42/ncm with a = 9.8312(4) Å, c = 15.4924(9) Å, and V = 1497.38(15) Å, where it consists of UO7 polyhedra coordinated via SeO4 units to create units UO2(SeO4)58− moieties which interlink to create layers in which Rb+ cations reside in the interspace. Rb2[(UO2)3(SeO3)2O2] synthesized hydrothermally adopts a layered 2D triclinic structure in space group P1¯ with a = 7.0116(6) Å, b = 7.0646(6) Å, c = 8.1793(7) Å, α = 103.318(7)°, β = 105.968(7)°, γ = 100.642(7)° and V = 365.48(6) Å3, where it consists of edge sharing UO7, UO8 and SeO3 polyhedra that form [(UO2)3(SeO3)2O2] layers in which Rb+ cations are found in the interlayer space. Rb2[UO2(SeO4)2(H2O)]·2H2O synthesized hydrothermally adopts a chain 1D orthorhombic structure in space group Pmn21 with a = 13.041(3) Å, b = 8.579(2) Å, c = 11.583(2) Å, and V = 1295.9(5) Å3, consisting of UO7 polyhedra that corner share with one H2O and four SeO42− ligands, creating infinite chains. (UO2)2(HSeO3)2(H2SeO3)2Se2O5 synthesized under slow evaporation conditions adopts a 0D orthorhombic structure in space group Cmc21 with a = 28.4752(12) Å, b = 6.3410(3) Å, c = 10.8575(6) Å, and V = 1960.45(16) Å3, consisting of discrete rings of [(UO2)2(HSeO3)2(H2SeO3)2Se2O5]2. (UO2)2(HSeO3)2(H2SeO3)2Se2O5 is apparently only the second example of a uranyl diselenite compound to be reported. A combination of single crystal X-ray diffraction and bond valance sums calculations are used to characterise all samples obtained in this investigation. The structures uncovered in this investigation are discussed together with the broader family of uranyl selenates and selenites, particularly in the context of the role acidity plays during synthesis in coercing specific structure, functional group, and topology formations.

2007 ◽  
Vol 62 (12) ◽  
pp. 1471-1475 ◽  
Author(s):  
Ling Yuan ◽  
Chao Qin ◽  
Xinlong Wang ◽  
Enbo Wang

An unusual cerium-containing decaoxotungstate complex, (NH4)3[Na5(H2O)17Cl]{[Na(H2O)4]2- [CeW10O36]} · 6H2O (1) has been synthesized and characterized by IR, TG, and single crystal X-ray diffraction studies (yellow crystals, orthorhombic, space group Imm2, a = 11.473(2), b = 15.225(3), c = 17.646(7) Å, V = 3082.3(15) °A3, Z = 2, R = 0.046). In this compound, sandwichtype [CeW10O36]9− clusters are linked by binuclear [Na2(H2O)8]2+ units by sharing oxygen atoms into linear chains, which are further extended into a 2D supramolecular network via pentanuclear [Na5(H2O)17Cl]4+ units by strong hydrogen bonding interactions.


1992 ◽  
Vol 47 (12) ◽  
pp. 1711-1716 ◽  
Author(s):  
H. Schmidbaur ◽  
P. Bissinger ◽  
J. Lachmann ◽  
O. Steigelmann

[1,4-Bis(diphenylphosphinyl)butane]digold dichloride 1 and [1,5-bis(diphenylphosphinyl)-pentane]digold dichloride 2 have been prepared from R2SAuCl (R = CH2CH2OH) and the corresponding bidentate phosphines Ph2P(CH2)nPPh2 (n = 4 or 5) in good yields. The structures of the compounds have been determined by single crystal X-ray diffraction (1 · CH2C12: space group P1̅, Z = 2; 2·0.5 CH2Cl2: space group C 2/c, Z = 8). While the monomers [Ph2P(CH2)5PPh2] (AuCl)2 are associated through intermolecular Au···Au contacts (3.323 Å) to form a chain-like structure, the crystal lattice of 1· CH2Cl2 features independent [Ph2P(CH2)4PPh2](AuCl)2 molecules which show no intra- or intermolecular Au···Au interactions. This exceptional behaviour can be rationalized on the basis of efficient packing of solvent molecules and molecules 1 with a particularly favourable conformation, which cannot be altered by weak Au(d10)—Au(d10) interactions.


2018 ◽  
Vol 73 (3-4) ◽  
pp. 265-268
Author(s):  
Xiao-Hong Zhu ◽  
Ding-Yun Jiang ◽  
Tao Hu ◽  
Deng-Hao Li

Abstract The hydrothermal reaction of N3,N5-di(pyridin-4-yl)pyridine-3,5-dicarboxamide (L) with Co(NO3)2·6H2O and ErCl3·6H2O yields a new complex, {[Co(L)2(NO3)1.15(Cl)0.85]·4DMF}n (1). Complex 1 has been characterized by single-crystal and powder X-ray diffraction, IR, and elemental and thermogravimetric analysis. It crystallizes in the orthorhombic space group Fddd and shows a chain structure.


2012 ◽  
Vol 67 (6) ◽  
pp. 594-604 ◽  
Author(s):  
Frank Tappe ◽  
Falko M. Schappacher ◽  
Thorsten Langer ◽  
Inga Schellenberg ◽  
Rainer Pöttgen

Several samples of solid solutions RE16Rh11-xZx (RE = La, Ce, Pr, Nd, Sm; Z = Ga, Zn, Cd,In, Sn, Sb, Pb, Bi) were synthesized by high-frequency melting of the elements in sealed tantalum ampoules. The samples were characterized by powder X-ray diffraction, and the structures of eight compounds were refined on the basis of single-crystal X-ray diffractometer data. The compounds crystallize with a centrosymmetric variant (space group P4⁄mbm) of the Ca16Sb11 type (P4̄ 21m). The relation between both structure types is discussed on the basis of a group-subgroup scheme. Only for La16Rh8Sn3 we observed full rhodium-tin ordering. The striking structural motif is a chain of face-sharing square prisms (filled with tin) and anti-prisms (filled with rhodium). The La16Rh8Sn3 structure is closely related to the structure types W5Si3, Ca16Sb11, Y3Rh2, Sm26Co11Ga6, Pu31Pt20, and Yb36Sn23 and is the centrosymmetric n = 2 member of Parthé’s A5n+6B3n+5 series. 119Sn Mössbauer spectra resolved the two crystallographically independent tin sites of La16Rh8Sn3, while a Pr16Rh9Sb2 sample shows only a singlet in its 121Sb Mössbauer spectrum.


Author(s):  
Süheyla Özbey ◽  
F. B. Kaynak ◽  
M. Toğrul ◽  
N. Demirel ◽  
H. Hoşgören

AbstractA new type of inclusion complex, S(–)-1 phenyl ethyl ammonium percholorate complex of R-(–)-2-ethyl - N - benzyl - 4, 7, 10, 13 - tetraoxa -1- azacyclopentadecane, has been prepared and studied by NMR, IR and single crystal X-ray diffraction techniques. The compound crystallizes in space group


2020 ◽  
Vol 75 (8) ◽  
pp. 765-768
Author(s):  
Bohdana Belan ◽  
Dorota Kowalska ◽  
Mariya Dzevenko ◽  
Mykola Manyako ◽  
Roman Gladyshevskii

AbstractThe crystal structure of the phase Ce5AgxGe4−x (x = 0.1−1.08) has been determined using single-crystal X-ray diffraction data for Ce5Ag0.1Ge3.9. This phase is isotypic with Sm5Ge4: space group Pnma (No. 62), Pearson code oP36, Z = 4, a = 7.9632(2), b = 15.2693(5), c = 8.0803(2) Å; R1 = 0.0261, wR2 = 0.0460, 1428 F2 values and 48 variables. The two crystallographic positions 8d and 4c show Ge/Ag mixing, leading to a slight increase in the lattice parameters as compared to those of the pure binary compound Ce5Ge4.


2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Yogesh Kumar ◽  
Rabia Sultana ◽  
Prince Sharma ◽  
V. P. S. Awana

AbstractWe report the magneto-conductivity analysis of Bi2Se3 single crystal at different temperatures in a magnetic field range of ± 14 T. The single crystals are grown by the self-flux method and characterized through X-ray diffraction, Scanning Electron Microscopy, and Raman Spectroscopy. The single crystals show magnetoresistance (MR%) of around 380% at a magnetic field of 14 T and a temperature of 5 K. The Hikami–Larkin–Nagaoka (HLN) equation has been used to fit the magneto-conductivity (MC) data. However, the HLN fitted curve deviates at higher magnetic fields above 1 T, suggesting that the role of surface-driven conductivity suppresses with an increasing magnetic field. This article proposes a speculative model comprising of surface-driven HLN and added quantum diffusive and bulk carriers-driven classical terms. The model successfully explains the MC of the Bi2Se3 single crystal at various temperatures (5–200 K) and applied magnetic fields (up to 14 T).


2008 ◽  
Vol 72 (4) ◽  
pp. 987-990 ◽  
Author(s):  
L. Secco ◽  
F. Nestola ◽  
A. Dal Negro

AbstractThree natural crystals of the wulfenite (PbMoO4)—stolzite (PbWO4) series were investigated by single-crystal X-ray diffraction. The results indicate that the symmetry is I41/a from nearly pure wulfenite to intermediate compositions, in contrast to previous work which claimed a symmetry change to 74 symmetry (acentric) for intermediate compositions compared with I41/a (centric space group) for the end-members. The results reported here show that the reflections violating I41/a symmetry observed in this work and in a previous study are related primarily to λ/2 effects, even if Renninger effects are not excluded. Consequently, we find that the I41/a symmetry is retained throughout the wulfenite— stolzite.


2017 ◽  
Vol 72 (12) ◽  
pp. 983-988 ◽  
Author(s):  
Martin K. Schmitt ◽  
Hubert Huppertz

Abstractβ-Y(BO2)3 was synthesized in a Walker-type multianvil module at 5.9 GPa/1000°C. The crystal structure has been elucidated through single-crystal X-ray diffraction. β-Y(BO2)3 crystallizes in the orthorhombic space group Pnma (no. 62) with the lattice parameters a=15.886(2), b=7.3860(6), and c=12.2119(9) Å. Its crystal structure will be discussed in the context of the isotypic lanthanide borates β-Ln(BO2)3 (Ln=Nd, Sm, Gd–Lu).


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