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α-telluration of 2-acetylthiophene: electronic influence of the heteroaromatic moiety on solid state structures

Version 2 2024-06-04, 03:00
Version 1 2016-10-11, 10:12
journal contribution
posted on 2024-06-04, 03:00 authored by AKS Chauhan, P Singh, RC Srivastava, RJ Butcher, Andrew DuthieAndrew Duthie
Room temperature oxidative addition of α-bromo-2-acetylthiophene to elemental tellurium and aryltellurium(II) bromide provides direct routes to (2-thiophenoylmethyl)tellurium(IV) dibromides, (2-(C 4 H 3 S)COCH 2 ) 2 TeBr 2 (1b) and 2-(C 4 H 3 S)COCH 2 ArTeBr 2 (Ar = 1-C 10 H 7 , Npl, 2b; 2,4,6-Me 3 C 6 H 2 , Mes, 3b). The chloro analogues, 2-(C 4 H 3 S)COCH 2 ArTeCl 2 (Ar = Npl, 2a; Mes, 3a) were prepared by the condensation reaction of the parent methyl ketone with NplTeCl 3 or MesTeCl 3 . Metathesis of these products with an alkali iodide affords the iodo analogues 1c, 2c and 3c. These diorganotellurium dihalides are reduced with aqueous bisulfite to diorganotellurides 1-3, which can be oxidized readily with dihalogens to the desired diorganotellurium(IV) dihalides. Compound 1 is a rare example of a symmetrical telluroether with C sp3 -Te-C sp3 grouping that has been characterized by single-crystal diffraction techniques. Preference of the 2-thiophenoylmethyl ligand for small-bite (C, O) chelation over less strained (C, S) coordination is evident in the crystal structures of the Te(IV) compounds 1b, 2a, 2b and 3a. The unexpected transoidal orientation of the two acylmethyl ligands in the solid state molecular configuration of symmetrical diorganotellurium(IV) dibromide 1b appears to be a combined effect of electronic repulsion due to the thiophene moieties and steric repulsion of bromo ligands.

History

Journal

Journal of organometallic chemistry

Volume

695

Pagination

2532-2539

Location

Amsterdam, The Netherlands

ISSN

0022-328X

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

2010, Elsevier

Issue

23

Publisher

Elsevier