100485-46-9Relevant academic research and scientific papers
Dimeric (η2-benzophenone)zirconocene: Its remarkable structure and chemistry
Erker, Gerhard,Dorf, Ulrich,Czisch, Peter,Petersen, Jeffrey L.
, p. 668 - 676 (2008/10/08)
(η2-Benzophenone)zirconocene has been obtained by the thermolysis of (η2-benzoyl)phenylzirconocene. In the solid state this (η2-ketone)metallocene complex adopts a dimeric structure and crystallizes in the monoclinic space group P21/n with lattice parameters a = 13.765 (4) A?, b = 18.220 (3) A?, c = 14.182 (5) A?, β = 93.20 (2)°, V = 3551.3 (1.6) A?3, and Z = 4. In [(η5-C5H5)2Zr(η 2-OC(C6H5)2)]2 (3), the two independent three-membered Zr-O-C rings, which contain short zirconium-oxygen bonds (Zr1-O1 = 2.109 (2), Zr2-O2 = 2.112 (2) A?) and long zirconium-carbon distances (Zr1-C1 = 2.346 (3), Zr2-C2 = 2.350 (3) A?), are linked together by relatively weak Zr1-O2 (2.304 (2) A?) and Zr2-O1 (2.287 (2) A?) bonds. In contrast to many other oligomeric (η2-ketone)- and (η2-aldehyde)MCp2 complexes, the central four-membered Zr2O2- unit in 3 is nonplanar with a folding angle of 17.2°. In solution 3 reacts with electron-deficient transition metal or main-group metal hydrides to form 1:1 adducts containing the monomeric (η2-benzophenone)zirconocene unit. The reaction of 3 with (Cp2ZrH2)x yields the binuclear complex Cp2Zr(μ-η1(O):η2-OC(C 6H5)2)(μ-H)ZrCp2H (17). The corresponding 1:1 adduct between Cp2Zr(η2-OC(C6H5)2) and hafnocene dihydride undergoes a thermally induced "dyotropic" rearrangement to give an equilibrium mixture of Cp2Zr(μ-η1(O):η2-OC(C 6H5)2)(μ-H)HfCp2H (18) and Cp2Hf(μ-η1(O):η2-OC(C 6H5)2)(μ-H)ZrCp2H (19). The reaction of 3 with methylenetriphenylphosphorane proceeds with ring opening of the metallaoxirane structural subunit. Transfer of one ylide hydrogen to the carbonyl carbon atom of the former η2-ketone ligand leads to the formation of the metallocene-substituted phosphorus ylide Cp2Zr(OCHPh2)(CHPPh3) (25).
