Stereochemistry of Tl I in inorganic oxysalts

International audienc

KCu(SeO 4 )Cl(H 2 O) 2 , a first copper chloride selenate

International audienceAbstract A first copper chloride selenate was obtained upon attempted preparation of a selenate analog of chlorothionite. The new compound is monoclinic, P 2 1 / c , a = 7.1833(5) Å, b = 11.7784(8) Å, c = 8.2419(6) Å, β = 91.083(2)°, V = 697.20(8) Å 3 , R 1 = 0.033. KCu(SeO 4 )Cl(H 2 O) 2 has no structural analogs and adds to the small family of transition metal selenate halides. The CuO 3 (H 2 O) 2 Cl strongly distorted octahedra share common O–O edges thus forming dimeric units with a Cu–Cu distance of 3.49 Å. Dimeric units and SeO 4 tetrahedra in KCu(SeO 4 )Cl(H 2 O) 2 share common O atoms to produce unique [Cu(SeO 4 )Cl(H 2 O) 2 ] − chains. We discuss further perspectives of the selenate halide family and expected differences in crystal chemistry of sulfate and selenate halides

Porous layered and open-framework mixed-valence copper tellurites

International audienc

Copper hydroselenite nitrates ( A + NO 3 ) n [Cu(HSeO 3 ) 2 ] ( A =Rb + , Cs + and Tl + , n =1, 2) related to Ruddlesden – Popper phases

International audienceAbstract Three new layered copper hydrogen selenite nitrates, ( A NO 3 )[Cu(HSeO 3 ) 2 ] ( A = Cs, and Tl), and (RbNO 3 ) 2 [Cu(HSeO 3 ) 2 ] have been prepared via isothermal evaporation of concentrated nitric acid solutions. The Tl and Cs compounds adopt a motif related to previously known (NH 4 Cl)[Cu(HSeO 3 ) 2 ]; the structure of the Rb compound represents a new structure type. The structures of ( A NO 3 )[Cu(HSeO 3 ) 2 ] ( A = Cs, Tl), (RbNO 3 ) 2 [Cu(HSeO 3 ) 2 ], and (NH 4 NO 3 ) 3 [Cu(HSeO 3 ) 2 ] form a unique homological series distantly related to Ruddlesden – Popper series of layered perovskites

Layered calcium hydrogen selenite chlorides Ca(HSeO 3 )Cl and Ca(HSeO 3 )Cl(H 2 O), the first halides obtained in СaCl 2 –H 2 SeO 3 –H 2 O system

International audienceAbstract Synthesis, crystal structures and IR spectra of the first representatives of calcium hydrogen selenite halides are reported. Colourless prismatic crystals of calcium hydrogen selenite chloride Ca(HSeO 3 )Cl and corresponding hydrated analogue Ca(HSeO 3 )Cl(H 2 O) were produced upon evaporation of aqueous solutions. Ca(HSeO 3 )Cl is monoclinic, P 2 1 / c , a = 7.0031(11) Å, b = 7.7336(12) Å, c = 8.5024(13) Å, β = 109.889(3)°, V = 433.02(12) Å 3 , R 1 = 0.039. Ca(HSeO 3 )Cl(H 2 O) is orthorhombic, Pbca , a = 6.222(4) Å, b = 10.413(7) Å, c = 16.875(10) Å, V = 1093.3 (12) Å 3 , R 1 = 0.041. Ca(HSeO 3 )Cl and Ca(HSeO 3 )Cl(H 2 O) represent new structure types. In both structures, Ca 2+ cations adopt mixed-ligand environments formed by oxygen atoms of hydrogen selenite anions (and water molecules for Ca(HSeO 3 )Cl(H 2 O)) and chloride ions. Both structures are layered. The crystal structure of Ca(HSeO 3 )Cl(H 2 O) demonstrates a rare phenomenon of hydrogen-bonded assembly of water and chloride in the interlayer space

Litharge-derived compounds structurally based on layers of Cl− and Br−-centered tetrahedra: Synthesis and structures of the new representatives of MX(ReO4) family (M=Ba, Pb; X=Cl, Br)

International audienc

Influence of the alkali cation size on the Cu 2+ coordination environments in ( AX )[Cu(HSeO 3 ) 2 ] ( A =Na, K, NH 4 , Rb, Cs; X =Cl, Br) layered copper hydrogen selenite halides

International audienceAbstract Using solution evaporation techniques, we succeeded in preparation of new members essentially extending the layered copper hydrogen selenite family, ( AX )[Cu(HSeO 3 ) 2 ] with A = Na, K, Rb, Cs, and NH 4 , and X = Cl and Br. Bromides and chlorides are isostructural in the family of described new compounds crystallizing in three different structure types. (Na X )[Cu(HSeO 3 ) 2 ] and (K X )[Cu(HSeO 3 ) 2 ] ( X = Cl, Br) are monoclinic, whereas ( AX )[Cu(HSeO 3 ) 2 ] ( A = NH 4 , Rb, Cs; X = Cl, Br) are orthorhombic. Upon the enlargement of the A + ionic radii inserted in the interlayer between the neighboring [Cu(HSeO 3 ) 2 ] slabs, the effective distance is increasing and results in essential elongation of the apical Cu- X ( X = Cl, Br) distances. Three different types of CuO 4 X n ( n = 0–2) polyhedra are formed. The observed trend is an interesting example of the chemical tuning of the Cu 2+ coordination environments

Molecular inorganic polymers: synthesis and crystal structures of KCl72H 2 SeO 3 and CsCl7H 2 SeO 3

International audienceAbstract KCl72H 2 SeO 3 and CsCl7H 2 SeO 3 have been synthesized using solution evaporation methods from aqueous solution. Both compounds are monoclinic ( P 2/ n and P 2 1 / c ) and demonstrate new structure types. One symmetrically unique SeO(OH) 2 molecule is present in each structure. SeO(OH) 2 molecules via strong hydrogen bonds form chains in KCl72H 2 SeO 3 and layers in ?sCl7H 2 SeO 3 . The structures of KCl72H 2 SeO 3 and CsCl7H 2 SeO 3 can be described as consisting of ionic KCl chains and CsCl layers incorporated into the covalent- and hydrogen-bonded H 2 SeO 3 matrix. To the best of our knowledge, the cases when selenious acid acts as a contributor to the molecular building blocks of salt-inclusion structures are not known to date

Li2(Se2O5)(H2O)1.5·CuCl2: a salt-inclusion diselenite structurally based on tetranuclear Li4 complexes

International audienceA new lithium copper diselenite chloride hydrate, Li 2 Se 2 O 5 (H 2 O) 1.5 ·CuCl 2 , was prepared from aqueous solution

The influence of deuterium on sodium mobility and viscosity of colloidal precursor suspensions yielding template-free nanosized zeolites

The isotopic substitution in chemistry is characterized by two main effects, i.e., the kinetic isotope effect (KIE), associated with differences in the reaction rates, and the geometric isotope effect (GIE) related to crystallographic features. In this work, considering the difference in the weight of deuterium (D) compared to the weight of hydrogen (H), we use the isotopic substitution to investigate the crystallisation mechanism of template-free nanosized faujasite (FAU) type zeolite in colloidal precursors. Тhe basic hydrothermal synthesis solvent - water (H2O), is substituted with heavy water (D2O), aiming to understand the isotopic influence and the effect of H-bond networks on the zeolite crystallisation. The crystallinity, viscosity, conductivity, chemical composition, morphology and local order of the FAU zeolites synthesized in both hydrated (H) and deuterated (D) medium are evaluated with X-ray diffraction, TEM microscopy, EDX and ICP analysis, FT-IR and solid-state NMR spectroscopy. The structural directing agent - Na+, exhibits a lower mobility in the deuterated medium, because of a characteristic higher viscosity compared to hydrated medium. This leads to a slower nucleation and crystallisation in the initial stages of hydrothermal treatment in the colloidal suspensions but also to a significant difference in the Al distribution