Crystal structure of Zn₂(HTeO₃)(AsO₄)

Abstract

Single crystals of Zn 2 (HTeO 3 )(AsO 4 ), dizinc(II) hydroxidodioxidotellurate(IV) oxidoarsenate(V), were obtained as one of the by-products in a hydrothermal reaction between Zn(NO 3 ) 2 ·6H 2 O, TeO 2 , H 3 AsO 4 and NH 3 in molar ratios of 2:1:2:10 at 483 K for seven days. The asymmetric unit of Zn 2 (HTeO 3 )(AsO 4 ) contains one Te (site symmetry m ), one As ( m ), one Zn (1), five O (three m , two 1) and one H ( m ) site. The Zn II atom exhibits a coordination number of 5 and is coordinated by four oxygen atoms and a hydroxide group, forming a distorted trigonal bipyramid. The hydroxide ion is positioned at a significantly larger distance on one of the axial positions of the bipyramid. The [ZnO 4 OH] polyhedra are connected to each other by corner-sharing to form ∞ 2 [ZnO 3/2 (OH) 1/2 O 1/1 ] layers extending parallel to (001). The Te IV atom is coordinated by three oxygen atoms and a hydroxide group in a one-sided manner in the shape of a bisphenoid, revealing stereochemical activity of its 5 s 2 electron lone pair. The As V atom is coordinated by four oxygen atoms to form the tetrahedral oxidoarsenate(V) anion. By corner-sharing, [TeO 3 OH] and [AsO 4 ] groups link adjacent ∞ 2 [ZnO 3/2 (OH) 1/2 O 1/1 ] layers along [001] into a three-dimensional framework structure.