Kinetic and Donor Stabilization of Organotellurenyl Iodides and Azides^†

The first tellurium compounds containing the extremely bulky tris(phenyldimethylsilyl)methyl (Tpsi) and 2,6-bis(2,4,6-triisopropylphenyl)phenyl (2,6-Trip2C6H3) moieties have been synthesized and isolated. Careful oxidation of the tellurolate TpsiTeLi (1) resulted in the formation of the crowded ditellane (TpsiTe)2 (2), and iodination of 2 gave the alkanetellurenyl iodide TpsiTeI (3). In a similar fashion, the terphenyl-substituted ditellane (2,6-Trip2C6H3Te)2 (9) and the arenetellurenyl iodide 2,6-Trip2C6H3TeI (10) were prepared. Reaction of the iodides TpsiTeI (3) and 2,6-Trip2C6H3TeI (10), as well as TripTeI, Mes*TeI (Trip = 2,4,6-triisopropylphenyl, Mes* = 2,4,6-tri-tert-butylphenyl), and the donor-stabilized 2-Me2NCH2C6H4TeI, with AgN3 resulted in the formation and isolation of the corresponding tellurenyl azides TpsiTeN3 (4), TripTeN3 (7), Mes*TeN3 (8), 2,6-Trip2C6H3TeN3 (11), and 2-Me2NCH2C6H4TeN3 (12). Furthermore, the corresponding tris(ethyldimethylsilyl)methyl-containing (Tesi) tellurium compounds (TesiTe)2, TesiTeI (5), and TesiTeN3 (6) have been prepared but could not be isolated in pure form. The crystal structures of TpsiTeLi (1), (TpsiTe)2 (2), TpsiTeN3 (4), 2,6-Trip2C6H3TeI (10), 2,6-Trip2C6H3TeN3 (11), and 2-Me2NCH2C6H4TeN3 (12) have been determined by X-ray diffraction. Additionally, computational studies of the molecules for which experimental structural data were available were performed.