Weil, M., & Shirkhanlou, M. (2016). Crystal structure of Sr₅Te₄O₁₂(OH)₂, the first basic strontium oxotellurate(IV). Acta Crystallographica Section E Crystallographic Communications, 72(11), 1532–1535. https://doi.org/10.1107/s2056989016015577
Acta Crystallographica Section E Crystallographic Communications
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ISSN:
1600-5368
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Date (published):
2016
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Number of Pages:
4
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Peer reviewed:
Yes
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Keywords:
crystal structure; strontium tellurite; channel structure; stereoactive electron lone pair
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Abstract:
The asymmetric unit of the title basic strontium oxotellurate(IV), Sr5Te4O12(OH)2 {systematic name pentastrontium tetrakis[oxotellurate(IV)] dihydroxide}, comprises three SrII cations (one with site symmetry 2) and two TeIV atoms, as well as seven O atoms. The coordination numbers of the alkaline earth cations to nearby O atoms range from seven (2 ×) to eight, and the TeIV atoms are surrounded by three oxygen partners in the form of trigonal pyramids. The SrOx polyhedra share corners and edges to build up a three-dimensional framework structure encapsulating channels propagating along [010]. The TeIV atoms flank the framework O atoms and are situated at the outer array of the channels with the 5s2 lone electron pairs protruding into the empty space of the channels (diameter [asymptotically equal to] 4 Å). Although the H atom of the OH group could not be located, bond-valence-sum calculations and typical O...O distances (range 2.81-3.06 Å) clearly indicate hydrogen bonding of medium to weak strengths.
