Two tetraalkoxy‐λ4‐telluranes were prepared from tellurium tetrachloride and the sodium salts of methanol and 2,2,2‐trifluoroethanol, respectively. Their molecular structures which were determined by single‐crystal X‐ray diffraction show dipolar intermolecular contacts. NBO analyses for the title compounds were conducted to assess the role of the stereochemically active lone pair on the tellurium atoms.

Crystals of the bis(tert‐butyl)silylene (DTBS) derivatives of the tartaric acids were synthesized from D‐, L‐, rac‐, and meso‐tartaric acid and DTBS bis(trifluoromethanesulfonate): two polymorphs of Si2tBu4(L‐Tart1,2;3,4H–4) (L‐1a and L‐1b), the mirror image of the denser modification (D‐1b) as well as the racemate (2), and the meso analogue Si2tBu4(meso‐Tart1,3;2,4H–4) (3). The structures were determined by single‐crystal X‐ray diffraction. The threo‐configured D‐ and L‐ (and rac‐) tartrates were coordinated by two tBu2Si units forming five‐membered chelate rings, whereas the erythro‐configured meso‐tartrate formed six‐membered chelate rings. The new compounds were analyzed by NMR techniques, including 29Si NMR spectroscopy, and single‐crystal X‐ray crystallography.

The symmetric spiro‐selenurane derived from ethylene glycol, 1,4,6,9‐tetraoxa‐5λ4‐selena‐spiro[4.4]nonane, was prepared from selenium tetrachloride and ethylene glycol and its molecular structure was determined by single crystal X‐ray diffraction. NBO analyses for the title compound and a related compound were conducted to assess the role of the stereochemical active lone pair on the selenium atom on the structure.