inorganic compounds
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Single-crystals of the title compound, nonapotassium triyttrium dodecasilicate difluoride, were obtained from flux synthesis experiments in the system SiO2-Y2O3-KF. The crystal structure belongs to the group of single-layer silicates and is based on silicate sheets parallel to (110). A single layer contains secondary (Q2) and tertiary (Q3) silicate tetrahedra in the ratio 1:2 and is build up from six-, eight- and twelve-membered rings. The linkage between neighboring layers is achieved by two crystallographically independent Y3+ cations, which are coordinated by six oxygen ligands in form of distorted octahedra. Charge compensation is accomplished by incorporation of additional F- anions and K+ cations in the structural channels, forming anion-centred [F2K7] groups. Apart from one K+ and one Y3+ cation (each with site symmetry -1), the 30 crystallographically independent atoms reside on general positions.
inorganic compounds
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Single crystals of Rb2Lu[Si4O10]F (dirubidium lutetium tetrasilicate fluoride) were obtained in flux-synthesis experiments in the system SiO2-Lu2O3-RbF. The compound belongs to the group of tubular chain silicates, i.e. it is based on multiple chains of condensed [SiO4] tetrahedra forming closed columns. The periodicity of the unbranched multiple chains is four and corresponds to the length of the b axis. Adjacent columns are connected by Lu3+ cations, which are coordinated by four oxide and two fluoride anions in the form of slightly distorted octahedra. By sharing common fluoride corners, the single octahedra are linked into chains running parallel to the silicate tubes. Electroneutrality is achieved by the incorporation of additional Rb+ cations. All four symmetrically independent rubidium ions, four out of twelve oxide as well as the two fluoride anions are located on mirror planes. The remaining atoms reside on general positions.
inorganic compounds
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Single crystals of dithulium disilicate, Tm2Si2O7, were obtained in flux synthesis experiments in the system SiO2-Tm2O3-LiF at ambient pressure. The compound belongs to the group of sorosilicates, i.e. it is based on [Si2O7]-units and crystallizes in the thortveitite (Sc2Si2O7) structure type. The Tm3+ cation (site symmetry .2.) occupies a distorted octahedral site, with Tm-O bond lengths in the range 2.217 (4)-2.289 (4) Å. Each of the octahedra shares three of its edges with adjacent [TmO6] groups, resulting in the formation of layers parallel to (001). The individual [SiO4] tetrahedra are more regular, i.e. the differences between the bond lengths between Si and the bridging and non-bridging O atoms are not very pronounced. The layers containing the octahedra and the sheets containing the [Si2O7] groups (point group symmetry 2/m) form an alternating sequence. Linkage is provided by sharing common oxygen vertices.
data reports
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The title compound, C9H10N4O, was obtained unintentionally by hydrolysis of 4-amino-1-benzyl-5-methylsulfanyl-1,2,4-triazolium tetrafluoroborate in the presence of sodium azide. In the crystal, alternating layers of polar aminotriazolinone and apolar benzene moieties are observed. N—HO hydrogen bonds between the amino and carbonyl groups form infinite chains along [010]. These infinite chains are linked by additional C—HO contacts.