Kristallstruktur des Tellurtetrajodids TeJ₄

Abstract

The crystal structure of tellurium tetraiodide TeL was determined from three-dimensional X-ray diffractometer data and was refined by full-matrix least-squares methods to an R index of 5.1%. The crystals are orthorhombic, space group Pnma, with a= 13.635 (5), b= 16.798 (5), c= 14.624 (5)/~, Z= 16TeI4. The structure is built of tetrameric (TeI4)4 molecules which are not isomorphous with the (TeCl4)4 molecular structure, but form a novel binary X4Y16 structure type composed of edge-sharing TeI6 octahedra. Mean Te-I bond lengths are 2.769, 3.108 and 3.232 ,~ for bonds to terminal, doubly and triply bridging iodine atoms, respectively. Intermolecular I...I distances as short as 3.870, 3"893, 3.932 ,~ indicate weak bonding interactions between the Te4116 molecules. Within the series of the TeF4, TeCL and TeL crystal structures, a strong decrease of the stereochemical activity of the non-bonding electron pair on tellurium(IV) is observed.

Theoretical Prediction of Bond-Valence Networks. II. Comparison of the Graph-Matrix and Resonance-Bond Approaches

“…All observed interatomic distances were converted to bond valences using the form V --exp{-(R-Ro)/b } and the parameters of either Krebs & Paulat (1976), for YeI4 only, or Brown & Altermatt (1985). For each example the methods were compared by calculation of the standard deviation of the predicted bond valence from their observed values; the equivalent standard deviation of an arbitrary 'best-fit' Valence-Sum Rule model was also calculated as a benchmark.…”

“…This structure (Krebs & Paulat, 1976) is included because it was used by Brown (1977) as one of his examples. Although it is a binary compound with a very unusual range of connectivities and iodine coordination numbers, it is perhaps out-of-place in being a molecular (We4116) rather than an infinite lattice complex.…”

[Fe(phen)3]2Sb6l22·2CH3CN: Ein Iodoantimonat mit zentralem [Sb6I6]-Doppelwürfel (phen = 1,10-Phenanthrolin)/ [Fe(phen)3]2Sb6I22 · 2 CH3CN: An Iodoantimonate with Central [Sb6I6]-Double Cube (phen = 1,10-Phenanthrolin)

“…In den bisher charakterisierten Sbl 3 -reichen Iodoantimonaten (mit SbI 3 :I" > 1) [(Me 2 N) 3 C 3 ]Sb 3 I 10 [2], (Ph 4 P)Sb 3 I 10 und (Ph 4 P) 4 Sb 8 I 28 [3] lassen sich die kantenverknüpften SbI 6 -Oktaeder als -jeweils unterschiedliche -Ausschnitte aus einer Schicht der Cdl 2 -Struktur beschreiben (s. [3]). …”

Solvatisierte HalogenochaLkogen(IV)säuren, I Darstellung und Struktur des Hexabromoselen(IV)säure-Hydrats (H5O2)2SeBr6 · 4H2O / Solvated Halogeno-Chalcogen(IV) Acids, I Preparation and Structure of the Hexabromoselenium(IV) Acid Hydrate (H5O2)2SeBr6 · 4H2O

“…Die isotypen Tetrahalogenide SeCU [1], TeCLj [2,3] und TeBr4 [1] bilden im festen Zustand tetramere M4Xi6-Moleküle mit einem zentralen cubanartigen M4X4-Gerüst (M = Se, Te; X = Cl, Br). Ihr isostruktureller Aufbau äußert sich in sehr ähnlichen, charakteristischen Schwingungsspektren [4][5][6].…”