Eder Felix, Weil Matthias
Institute for Chemical Technologies and Analytics, Division of Structural Chemistry, TU Wien, Getreidemarkt 9/164-SC, A-1060 Vienna, Austria.
Acta Crystallogr E Crystallogr Commun. 2020 May 15;76(Pt 6):831-834. doi: 10.1107/S2056989020006283. eCollection 2020 Jun 1.
Single crystals of cadmium penta-oxidoditellurate(IV), CdTeO, were obtained as by-products in a hydro-thermal reaction of Cd(NO)·4HO, TeO, HTeO and NH (molar ratios 2:1:1:6) at 483 K for seven days. The crystals represent a different polymorph (henceforth referred to as the -form) than the -CdTeO crystals grown from the melt, and are isotypic with hydro-thermally grown -CaTeO. The asymmetric unit of -CdTeO comprises one Cd, two Te and five O sites, all of which are located in general positions (Wyckoff position 4 ). The cadmium(II) atom is coordinated by seven oxygen atoms, forming [CdOO] (100) layers. Both tellurium sites are surrounded by four oxygen atoms with one of them being at a significantly longer distance than the other three. The resulting bis-phenoidal [TeO] units also form layers propagating parallel to (100) by sharing edges with each other. The stereochemically active 5 lone pair of the Te atoms leads to the formation of large channels extending along [011] and smaller ones along [010]. A qu-anti-tative comparison between the crystal structures of -CdTeO and ∊-CaTeO is made.
五氧化二碲（IV）镉单晶CdTeO是在Cd(NO)·4HO、TeO、HTeO和NH（摩尔比2:1:1:6）于483 K下进行水热反应7天的过程中作为副产物获得的。这些晶体代表了一种与从熔体中生长的-CdTeO晶体不同的多晶型（以下称为-型），并且与水热生长的-CaTeO同型。-CdTeO的不对称单元包含一个Cd、两个Te和五个O位点，所有这些位点都位于一般位置（Wyckoff位置4）。镉（II）原子由七个氧原子配位，形成[CdOO]（100）层。两个碲位点都被四个氧原子包围，其中一个氧原子的距离明显长于其他三个。由此产生的双棱柱状[TeO]单元也通过相互共享边缘形成平行于（100）传播的层。Te原子的立体化学活性5孤对电子导致形成沿[011]延伸的大通道和沿[010]延伸的较小通道。对-CdTeO和∊-CaTeO的晶体结构进行了定量比较。
