ANSA-TITANOCENE AND ANSA-ZIRCONOCENE ETA(2)-ALKYNE COMPLEXES - SYNTHESIS, SPECTRAL CHARACTERISTICS, AND X-RAY CRYSTAL-STRUCTURE

The reduction of the complex [(eta(5)-C5H4)-ansa-(eta(5)-C5H4)]TiCl2 W ith magnesium in the presence of Me(3)SiC(2-)SiMe(3) in THF at room te mperature gives the ansa-titanocene alkyne complex -ansa-(eta(5)-C5H4) ]Ti(eta(2)-Me(3)SiC(2)-SiMe(3)) (ansa = Me(2)Si-O-SiMe(2), 1). The sim ilar pyridine stabilized zirconium complexes could be obtained by anal ogous reactions and addition of pyridine: nsa-(eta(5)-C5H4)]Zr(L)(eta( 2)-Me(3)SiC(2)SiMe(3)) (ansa = Me(2)Si-O-SiMe(2), L = pyridine: 2; ans a = SiMe(2), L = pyridine: 3). All complexes were characterized by spe ctroscopic methods. An X-ray structure determination of complex 3 was conducted, and the data were compared to those of the complexes rac-(E B-HI)Zr(L)(eta(2)-Me(3)SiC(2)SiMe(3)) [L = (S)-(-)-nicotine: 6, EBHI = ethylenebis(tetrahydroindenyl)] and Cp(2)Zr(py)(Me(3)SiC(2-)SiMe(3)).