Carbon dioxide fixation with dialkyltellurium(IV) dihydroxides

Aqueous solutions of Me 2 Te(OH) 2 and (CH 2 ) 4 Te(OH) 2 readily absorb carbon dioxide giving rise to the formation of the dialkyltelluroxane carbonates (Me 2 TeOTeMe 2 CO 3 )., (1) and HO(CH 2 ) 4 TeOTe(CH 2 ) 4 CO 3 Te(CH 2 ) 4 OH.·2H 2 O (2·2H 2 O), which were characterised by 13 C MAS and 125 Te MAS NMR spectroscopy as well as X-ray crystallography. The spatial arrangement of the tellurium atoms is defined by C 2 O 2 donor sets in the primary coordination sphere and one or two secondary Te....O contacts, which involve coordination of the carbonate moieties. In turn, the different Te-O coordination modes render a lack of symmetry to the carbonate moieties, which show significantly different C-O bond lengths, an important feature when contemplating the C-O bond activation in carbonates. The structural and spectroscopic parameters of 1 and 2 are discussed in comparison with other heavy p-block element carbonates. In solution, electrolytic dissociation of 1 and 2 takes place. © 2010 WTLEY-VCH Verlag GmbH & Co. KGaA.