190515-99-2Relevant academic research and scientific papers
Acetone and acetophenone adducts of the zwitterionic zirconocene Cp*[η5-C5Me4CH2B(C 6F5)3]ZrC6H5
Sun, Yimin,Piers, Warren E.,Yap, Glenn P.A.
, p. 2509 - 2513 (1997)
The recently reported zwitterionic complex Cp*[η5-C5Me4CH2B(C 6F5)3]ZrC6H5, 1, reacts rapidly with 1 equiv of acetone or acetophenone to form the adducts Cp*[η5-C5Me4CH2B(C 6F5)3]Zr(C6H 5)[O=C(CH3)R] (R = CH3, 2a; C6H5, 2b) in ～85% yield. Spectroscopic evidence in favor of this assignment is presented; the adduct nature of the complexes was also confirmed in each case via an X-ray structural analysis. The ketone ligands are bound in an η1 end-on fashion (the Zr-O=C angles are near linear at 174.2° and 166.1° for 2a and 2b, respectively), allowing for a π-component to the Zr-O bonding. Unlike other fleetingly observed ketone adducts of nonzwitterionic cationic metallocenes, the ketone ligands in compounds 2 do not undergo insertion into the Zr-C bond neither upon thermolysis nor in the presence of excess ketone.
