Publikationsserver der RWTH Aachen University
Synthese, Stereochemie und Eigenschaften einiger organischer Tellurate(VI)
Abstract
dc:description2 known and 15 new organic tellurates(VI) were synthesised starting from Te(OH)6. Their stereochemistries were investigated by spectroscopic methods (IR, UV, CD, MCD, NMR, MS) and by X-ray analysis. Orthotellurates Te(OAlk)6 Alk = Me, Et and the binuclear tellurate [(EtO)5Te]2O were made by alkylations with trialkylorthoformiates. Cyclic tellurates were synthesised by the reaction of Te(OH)6 with neat 1,2-diols, by the reaction of diols or triols with the reaction mixture of the alkylation of Te(OH)6 with trialkylorthoformiates or by the transesterification of the tartaric ester function of {[(R)-MeOOCCHO]2}3Te with alcohols (EtOH, i-PrOH, n-BuOH). (Mononuclear) orthotellurates were synthesised from ethanediol; rac- and S-1,2-propanediol; meso-, rac- and (R,R)-2,3-butanediol; [(R)-AlkOOCCHOH]2 Alk = Me, Et, i-Pr; AlkC(CH2OH)3 Alk = Me, Et. Binuclear tellurates of the type (L2Te)2O2 were synthesised from LH2 = ethanediol; meso-, rac- and (R,R)-2,3-butanediol; 2,3-dimethyl-2,3-butanediol. X-ray analysis in the solid state exhibit a distorted TeO6-octahedron with (R,R)-dimethyltartrate as a diolato ligand for {[(R)-MeOOCCHO]2}3Te, an almost perfect TeO6-octahedron for [EtC(CH2O)3]2Te, 2 distorted TeO6-octahedra which are connected by edge-sharing oxygen atoms for the binuclear tellurate from rac-2,3-butanediol. The racemisations and epimerisations at the octahedral centers of 7 organic tellurates were investigated by polarimetry and NMR spectroscopy. Half-lives at room temperature of ca. 1 s up to several hours were found. By the reaction of Te(OH)6 with (R,R)-tartaric acid and DMSO, a product with the composition Te2O14C8H4 4 DMSO was isolated.
Degree
thesis:*- Grantor dc:publisher
- Publikationsserver der RWTH Aachen University
- Year dc:date
- 2001
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Bausch, Stephan
- Contributors dc:contributor
-
- Laur, Peter
Subjects
dc:subject × 4Rights
dc:rights- Statement dc:rights
-
- info:eu-repo/semantics/openAccess
- Language dc:language
- ger
Identifiers
dc:identifier.*- OAI identifier oai:identifier
- oai:publications.rwth-aachen.de:61919