Thallium benzotriazenide has been prepared from benzotriazole, thallium(I) acetate, and triethylamine in ethanol. The compound serves as a convenient starting material for the synthesis of organometallic benzotriazenides. It reacts with [Ir(CO) (acetone) (PPhxy3)2][PF6] to yield the tetramer [Ir(BTA) (CO) (PPh3)]4, where Ph = phenyl and BTA = benzotriazenido. A similar reaction with RhCl(CO) (PPh3)2 yields the hexamer [Rh(BTA) (CO) (PPh3)]6. Direct reaction of Tl(BTA) with IrCl(CO) (PPh3)2 yields Ir(BTA)2(CO) (PPh3)Tl-C6H6. A methanol solution of this material rapidly changes color from violet to yellow and from this solution the compound Ir(BTA) (CO) (PPh3)2 is obtained. On the basis of an X-ray crystal structure, the Ir atom in Ir(BTA) (CO) (PPh3)2 is coordinated by trans P atoms, the CO ligand, and the BTA ligand in nearly a square-planar arrangement. Despite the symmetric nature of the N3 portion of the BTA ligand, the ligand is coordinated to the Ir atom through atom N(l). The ligand makes an angle of approximately 78° with the Ir(CO)P2 plane. The compound crystallizes with four molecules in space group C2h5-P21/n of the monoclinic system in a cell of dimensions [Formula Ommited] The structure has been refined by full-matrix least-squares methods to a final R index of 0.035 for 199 variables, based on 6321 observations.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry