Uranyl interactions: The title compound is the first example of an actinide that contains three different actinyl-ion coordination geometries, namely, octahedral, pentagonal bipyramidal, and hexagonal bipyramidal. Strong cation–cation interactions between uranyl ions lead to pentamers with a rather unusual configuration (see picture; U dark gray, O light gray).

The crystal structures of minerals and inorganic compounds with OPb 4 oxocentered tetrahedra are reviewed. It is shown that the tetrahedral units may link by sharing common Pb atoms to form structural various shape dimensionality. These determine basic topology influence their stability properties. high strength te trahedral involves interplay between basicity additional O 2– anions stereochemical activity 6 s 2 lone electron pairs on 2+ cations. chemistry polycations based upon tetrahedra,...

Abstract Kreiterite, CsLi2Fe+3(Si4O10)F2, a new cesium trioctahedral mica was discovered in the Darai-Pioz alkaline massif (Tajikistan). It is named after Russian geologist, Prof. Vladimir Mikhailovich Kreiter (1897–1966). Kreiterite occurs as lamellar grains or flakes up to 0.2 mm across, irregular shape and usually slightly deformed, quartz-pectolite aggregates within so-called “quartz lumps”, rocks consisting mainly of granular quartz. The mineral colorless transparent with vitreous...

Abstract Thermal expansion of the mineral soddyite, (UO 2 ) SiO 4 (H O) , and structurally related synthetic compound Na F ( NAUSIF has been studied by means high-temperature single-crystal powder X-ray diffraction. The is orthorhombic, Fddd while tetragonal, I 1 / amd . framework structures both compounds are comprised either neutral [(UO (SiO )(H ] or negatively charged )F 2- chains similar topology. In structure cross at angle 72°, in 90°. Upon increasing temperature, acute inter-chain...

The crystal chemistry of syngenite K2Ca(SO4)2·H2O and its lattice dynamics under low high temperatures pressure were studied. research facilities used include in situ temperature variable single-crystal (SCXRD) powder X-ray diffraction (PXRD), PXRD (HP), thermal analysis (DSC TGA), Raman spectroscopy. For the first time, a detailed study range negative down to −180 °C was performed. It indicates absence phase transitions from 240 °C. largest expansion structure is observed along α11, which...

Abstract A new uranyl silicate [(K,Na) 4 Cl 2 ][(UO ) 6 (Si O 7 F ] ( 1 was obtained from melt in evacuated silica tubes. The crystal structure of is orthorhombic, Pnma , a = 36.8677(7), b 7.7946(2), c 19.1931(4) Å, V 5,515.5(2) Å 3 . It represents microporous framework comprised Ur 5 and pentagonal bipyramids Si disilicate groups. contains two types channels with the size 8.14 × 8.66 6.38 4.42 ; smaller ones host potassium cations while larger contain more complex alkali-chloride species.

Abstract Hydrated iron sulfate minerals receive considerable attention from the standpoint of environmental science, and also due to extensive studies mineralogy Mars. In this paper, we report on thermal evolution coquimbite AlFe3+3(SO4)6(H2O)12·6H2O by single-crystal X-ray diffraction (SCXRD) in range −173 77 °C. Powder (PXRD) was performed temperature −180 740 °C low vacuum 600 Pa. Magnetic properties for are reported −271 7 It observed that is stable between +145 We a gradual transition...

The crystal structure of Pb21[Si7O22]2[Si4O13] has been solved on crystals grown by crystallization from melt. compound is hexagonal, P63/m, a = 9.9244(5), c 34.2357(16) Å, V 795.28(6) Å3, R1 0.042 for 3361 unique observed reflections. contains five symmetrically independent Si sites tetrahedrally coordinated O atoms. Si1O4, Si3O4, and Si4O4 tetrahedra share corners to form branched heptameric [Si7O22]16- units, whereas the Si2O4 Si5O4 tetrameric [Si4O13]10- anions. six Pb with PbOn...

White lead or basic carbonate, 2PbCO 3 ·Pb(OH) 2 , the synthetic analogue of hydrocerussite Pb (OH) (CO ) has been known since antiquity as most frequently used white paint. A number different minerals and materials compositionally structurally related to have described within last two decades. Herein, a review is given general structural principles, chemical variations IR spectra rapidly growing family hydrocerussite-related materials. Only structures containing hydroxo- and/or...

Dark-green platy crystals of the new compound Pb31O22Br10Cl8 (1) have been obtained by rapid quenching a lead oxide halide melt. The structure 1 (triclinic, P1̄, = 12.1192(7) Å, b 16.2489(10) c 18.3007(11) α 93.104(2)°, β 95.809(2)°, γ 111.252(1)°, V 3325.4(3) Å3, Z 2) can be viewed as incorporation [PbX6]4- units (X Br, Cl) into defect PbO matrix. latter represents two-dimensional [O22Pb30]16+ cationic layer OPb4 tetrahedra that derived from [OPb] tetrahedral observed in tetragonal PbO....

Abstract The crystal structures of the mendipite series Pb 3 O 2 Cl —Pb Br have been solved by direct methods. are based upon [O ] 2+ double chains edge-sharing OPb 4 tetrahedra. There three symmetrically independent cations. number nonequivalent halogen sites is two (X1, X2). Short Pb—O bonds located on one side cations and weak Pb-X other coordination sphere. evident strong distortion polyhedra due to stereoactivity 6 s lone electron pairs Pb1-X2 Pb2-X2 most sensitive X site occupancy,...

Prewittite, ideally KPb1.5Cu6Zn(SeO3)2O2Cl10, was found in the fumarole field of second cinder cone North Breach Great fissure Tolbachik eruption (1975-1976, Kamchatka peninsula, Russia). It occurs as separate olive-green tabular crystals up to 0.2 mm maximum dimension. has vitreous luster and brownish-green streak. Prewittite is orthorhombic, space group Pnnm, a = 9.132(2), b 19.415(4), c 13.213(3) Å, V 2342.6(9) Å3, Z 4, Dcalc 3.89 g/cm3, Dmeas 3.90(2) g/cm3. The eight strongest lines...

Abstract Two novel isopropylamine‐templated uranyl chromates, [(CH 3 ) 2 CHNH ] [(UO (CrO 4 O(OH) ( 1 and (H O)] were prepared by hydrothermal method at 100 °C. The compounds characterized electron microprobe analysis X‐ray diffraction crystal structure [ : trigonal, P 31 m , a = 9.646(4), c 8.469(4) Å, V 682.4(5) Å ; monoclinic, / 11.309(3), b 11.465(3), 17.055(5) β 99.150(6)°, 2183.2(11) ]. of is based upon trimers bipyramids interlinked CrO tetrahedra to form 3– layers, whereas, in the UO...

ABSTRACT The new mineral saranchinaite, ideally Na 2 Cu(SO 4 ) , was found in sublimates of the Saranchinaitovaya fumarole, Naboko Scoria Cone, Tolbachik volcano, Kamchatka, Russia. Its discovery and study has enabled characterization thermal decomposition kröhnkite provided an insight into high-temperature behaviour other kröhnkite-type materials. Saranchinaite is monoclinic, P 1 a = 9.0109(5), b 15.6355(8), c 10.1507(5) Å, β 107.079(2)°, V 1367.06(12) Å 3 Z 8 R 0.03. unique that two its...

Six different dichromate-based uranyl compounds were obtained. Their structures belong to four principally but related structure types with dimensionality of basic structural units. The units in Cs2(UO2)(Cr2O7)(NO3)2 (1) and (C6H11N2)2(UO2)(Cr2O7)2(H2O) (2) are unique, these the first “pure” uranyl-dichromates known date. Rb2(UO2)(CrO4)(Cr2O7) (3), (C2NH8)2(UO2)(CrO4)(Cr2O7) (4), (C2NH8)2(UO2)(CrO4)2(Cr2O7)(H2O)2 (5), (C3NH10)2(UO2)(CrO4)2(Cr2O7)(H2O)2 (6) novel representatives a rather...

Single crystals and polycrystalline samples of a synthetic analogue saranchinaite, Na2Cu(SO4)2, have been prepared by two different methods. The structural analysis revealed unusual heptahedral CuO7 coordination [4 + 1 2] Cu2+ cations in its crystal structure. title compound crystallizes the noncentrosymmetric space group P21 exhibits averaged nonlinear coefficient ⟨d⟩ = 1.4[d14(SiO2)] ≈ 0.5 pm/V. Electrochemical tests showed limited electrochemical performance low mobility Na ions magnetic...

A new spin-1/2 frustrated antiferromagnet, Cu9O2(VO4)4Cl2, was synthesized via chemical vapor transport method that emulates mineral formation in volcanic fumaroles. Cu9O2(VO4)4Cl2 is the first copper oxychloride vanadate obtained ternary CuO-V2O5-CuCl2 anhydrous system. Copper ions constitute a three-dimensional complex framework with topological structure novel for synthetic compounds but similar to fumarolic yaroshevskite. All of oxygen atoms except O7 site are strongly bonded VO4...