Synthesis and characterization of bulky cationic arylalkylaluminum compounds
Tomasz Kliś , Douglass R. Powell , Łukasz Wojtas , Rudolph J. Wehmschulte
AbstractABSTRACT: The cationic m-terphenyl-substituted organoaluminum compounds [Dipp*AlEt][CH6B11Cl6] (3; Dipp* = 2,6-(2,6-i-Pr2C6H3)2C6H3), [DcpAlEt][CH6B11Cl6] (4; Dcp = 2,6-(2,6-Cl2C6H3)2C6H3), [Dipp*AlEt][CH6B11I6] (5), and [DcpAlEt][CH6B11I6] (6) have been obtained by ethide elimination through trityl or preferably silylium salts from the precursors Dipp*AlEt2 (1) and DcpAlEt2 (2). The crystal structures of compounds 35 reveal the presence of cationanion adducts involving two halides of the carborane anions, and the NMR spectroscopic data and solubility properties indicate such an interaction for 6. The interactions of the hexaiodocarborane anion with the [Dipp*AlEt]þ cation are stronger than those of the hexachlorocarborane anion. Interestingly, cation 3 3 3 anion contacts are preferred to intramolecular Al 3 3 3 Cl interactions in the Dcp species 4. Compound 4 forms the bisamine adduct [DcpAlEt(NH2t-Bu)2][CH6B11I6] (8) upon exposure to tBuNH2, and compounds 3 and 4 slowly catalyze the alkylation of benzene with 1-hexene. The compounds have been characterized by 1H, 13C, and 11B NMR spectroscopy and by X-ray crystallography in the case of 15, 7, and 8.
|Journal series||Organometallics, ISSN 0276-7333|
|Keywords in English||cationic aluminum compounds, carboranes|
|Publication indicators||: 2011 = 3.963 (2) - 2011=3.786 (5)|
|Citation count*||17 (2015-06-30)|
* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.