Issue Date: January 15, 2007
Hafnocene Puts N2 And CO2 To Work
If chemists could take N2 and CO2 out of the air and convert them into value-added chemicals, they would really have something. Wesley H. Bernskoetter, Emil Lobkovsky, and Paul J. Chirik of Cornell University have opened a door to that possibility by preparing a substituted hydrazine from N2 and CO2 in a reaction mediated by hafnocene, a hafnium bis(cyclopentadienyl) complex (Angew. Chem. Int. Ed., DOI: 10.1002/anie.200604099). Chirik's group has previously shown that hafnocene and zirconocene can preferentially bind N2 side-on (rather than end-on) between two of the metallocene molecules, an orientation that sets up N2 for further reaction (Dalton Trans. 2007, 16). For hafnocene, they now report that reacting the hafnocene-N2 complex with CO2 leads to insertion of CO2 into the Hf-N bonds (shown). Addition of Me3SiI (Me = methyl) liberates the N2-CO2 core by forming the substituted dicarboxyl hydrazine (Me3Si)2N-N(CO2SiMe3)2 mixed with iodinated hafnocene, which can be recycled.
- Chemical & Engineering News
- ISSN 0009-2347
- Copyright © American Chemical Society