An Aluminum Telluride with a Terminal Al=Te Bond and its Conversion to an Aluminum Tellurocarbonate by CO 2 Reduction.

Facile access to dimeric heavier aluminum chalcogenides [(NHC)Al(Tipp)-μ-Ch] 2 (NHC=IiPr (1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene, IMe 4 (1,3,4,5-tetramethylimidazol-2-ylidene); Tipp=2,4,6-iPr 3 C 6 H 2 ; Ch=Se, Te) by treatment of NHC-stabilized aluminum dihydrides with elemental Se and Te is reported. The higher affinity of IMe 4 in comparison with IiPr toward the Al center in [(NHC)Al(Tipp)-μ-Ch] 2 can be used for ligand exchange. Additionally, the presence of excess IMe 4 allows for cleavage of the dimers to form a rare example of a neutral multiply bonded heavier aluminum chalcogenide in the form of a tetracoordinate aluminum complex, (IMe 4 ) 2 (Tipp)Al=Te. This species reacts with three equivalents of CO 2 across two Al-C NHC and the Al=Te bond affording a pentacoordinate aluminum complex containing a dianionic tellurocarbonate ligand [CO 2 Te] 2- , which is the first example of tellurium analogue of a carbonate [CO 3 ] 2- .