Kristallstruktur von CF₃TeTeCF₃ – Synthese, Charakterisierung und Eigenschaften von CF₃TeI

Abstract

Te2(CF3)2 kristallisiert in der monoklinen Raumgruppe P21/a mit vier Formeleinheiten in der Elementarzelle. Die Gitterkonstanten betragen a = 10,13(1) Å, b = 11,489(7) Å, c = 6,822(8) Å und β = 101,20(8)°. Bei der Umsetzung von Te2(CF3)2 mit der äquimolaren Menge Iod entsteht CF3TeI in quantitativer Ausbeute, eine Isolierung gelingt nicht. Die NMR‐Spektren zeigen eine starke Lösungsmittelabhängigkeit. Durch Metathesereaktionen werden die Verbindungen CF3TeX (X = CCC6H5, t‐C4H9, SCN, SC6F5) synthetisiert.

A Fluent Transition from Triiodide, I3−, to Tris(trifluoromethyltellurate)(1−), [(TeCF3)3]−—A Structural Study

“…With respect to the "para-element concept", [3] [PNP][(TeCF 3 ) 3 ] resembles the analogue to [PNP]I 3 , which has been characterised by Tebbe and Krauss in 1990. [13] Comparison of these crystal structures shows evident similarities looking along the b axis, although the salts are not isostructural ( Figure 2 À , the TeÀC bond length of the central TeCF 3 unit (218.0(5) pm) matches nearly exactly the value determined for Te 2 (CF 3 ) 2 (218.6(6) and 217.5(6) pm), [17] while those of the terminal TeCF 3 moieties (213.7 (7) and 214.1(5) pm) are slightly elongated in comparison with those of the TeCF 3 anion. [18] The TeÀTe bonds of 296.9(1) and 298.3(1) pm are significantly longer than in Te 2 (CF 3 ) 2 (266.9(3) pm), [17] which might be interpreted in terms of a 3c-4e bond in this pseudotrigonal-bipyramidal anion (AB 2 CE 2 structure).…”

“…[23] Taking into account all bond lengths and angles, the anion is best described as trifluoromethyldiiodotellurate(ii) implies relations close to a two centre-two-electron (2c-2e) bond as found in Te 2 (CF 3 ) 2 (266.9(3) pm). [17] Additionally the elongation of the TeÀI bond (323.9 (1) (4), [24] 314.8(1) pm [25] ) have been found in asymmetric triiodides. À resembles "asymmetric" I 3 À .…”

Covalently bonded compounds of heavy group 15/16 elements – Synthesis, structure and potential application in material sciences

“…dimethylditellurane Te 2 Me 2 forms a chain-like structure in the solid state, [1] whereas the shortest intermolecular distance in bis(trifluormethyl)ditellurane Te 2 (CF 3 ) 2 exceed the sum of the van-der-Waals radii of the metal atoms. [2] Comparable findings were observed in tetraalkyldistibines and -dibismuthines, which often show chainlike structures in the solid state with weak intermolecular metal-metal interactions. [3,4,5] The metal-metal interactions are typically interrupted upon melting, resulting in a bathochromic shift between fluid and solid phases, the so-called ''thermochromic'' effect.…”

“…[3,4,5] The metal-metal interactions are typically interrupted upon melting, resulting in a bathochromic shift between fluid and solid phases, the so-called ''thermochromic'' effect. [6] Group 15/16 compounds such as bis(dialkylstibanyl)chalcogenanes R 2 Sb-E-SbR 2 (E = S, Se, Te) [7,8,9] and bis(dialkylbismuthanyl)chalcogenanes R 2 Bi-E-BiR 2 (E = S, Se, Te), [10,11,12,13] which are accessible by insertion reactions of elemental chalcogens into the metal-metal bonds of the corresponding distibines and dibismuthines, also exhibit weak intermolecular Scheme 1. Molecular group 15/16 compounds with potential technical applications as single source precursors in material sciences.…”

Vibrational spectra and structures of fluoroalkyl and fluoroaryl compounds of tellurium: Te2(CF3)2, Te2(C6F5)2 and Te(C6F5)2

“…7 Nevertheless, this does not necessarily prove that the same also applies to the liquid and gas phases. Therefore, we studied and report here the vibrational spectra of Te 2 (CF 3 ) 2 , the Raman spectrum of the liquid phase, the infrared spectra of the liquid phase for the mid-and far-infrared regions and of the gas phase for the mid-infrared region.…”