Peter C Ho, Justin Lomax, Valerie Tomassetti, James F Britten, Ignacio Vargas-Baca
Chemistry (Weinheim an der Bergstrasse, Germany) 2021 Jul 26Chlorination of 3-methyl-5-phenyl-1,2-tellurazole-2-oxide yielded the λ4 Te dichloro derivative. Its crystal structure demonstrates that the heterocycle retains its ability to autoassociate by chalcogen bonding (ChB) forming macrocyclic tetramers. The corresponding Te⋅⋅⋅O ChB distances are 2.062 Å, the shortest observed to date in aggregates of this type. DFT-D3 calculations indicate that while the halogenated molecule is stronger as a ChB donor it also is a weaker ChB acceptor; the overall effect is that the ChBs in the chlorinated homotetramer are not significantly stronger. However, partial halogenation or scrambling selectively yield the 2 : 2 heterotetramer with alternating λ4 Te and λ2 Te centers, which calculations identified as the thermodynamically preferred arrangement. © 2021 Wiley-VCH GmbH.
Peter C Ho, Justin Lomax, Valerie Tomassetti, James F Britten, Ignacio Vargas-Baca. Competing Effects of Chlorination on the Strength of Te⋅⋅⋅O Chalcogen Bonds Select the Structure of Mixed Supramolecular Macrocyclic Aggregates of Iso-Tellurazole N-Oxides. Chemistry (Weinheim an der Bergstrasse, Germany). 2021 Jul 26;27(42):10849-10853
PMID: 34018275
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