Cyclopentadienyl yttrium complexes bearing a fluorinated aryloxide functionality

The ligand C5H5((CH2CAr2OH)-O-F) (3) (Ar-F = 3,5-C6H3(CF3)(2)) was prepared in moderate yield (65%) by ring opening of the epoxide (Ar2C)-C-F(O)CH2 (2 ) with NaCp. Epoxide 2 was accessible in two steps from commercially availa ble precursors. Reaction of the dilithium salt of 3 with YCl3 afforded the ate complex {eta (5):eta (1)-C5H4[CH2C(O)(3,5-C6H3(CF3)(2))(2)]}(2)Y- Li+{T HF}(2) (4a). Exposure of 4a to vacuum resulted in partial desolvation to {e ta (5):eta (1)-C5H4[CH2C(O)(3,5-C6H3(CF3)(2))(2)]}(2)Y-Li+{THF} (4b). The c hloride complex {eta (5): eta (1)-C5H4[CH2C(O)(3,5-C6H3(CF3)(2))(2)]}-YCl{T HF}(2) (5) could only be prepared by protonolysis of {Y[N(SiMe3)(2)](2)(THF )(2)(mu -Cl)}(2) with 1 equiv of 3. Metathesis reactions of 5 with 1 equiv of NaN(SiMe3)(2), NaCp, and LiCH(SiMe3)(2) afforded {eta (5) :eta (1)-C5H4[ CH2C(O)(3,5-C6H3(CF3)(2))(2)]}Y{N(SiMe3)(2)}{THF}(n), (6a, n = 2; 6b, n = 1 ), {eta (5): eta (1)-C5H4[CH2C(O)(3,5-C6H3(CF3)(2))(2)] }Y{eta (5)-C5H5}{TH F}(n), (8a, n = 2; 8b, n = 1), and {eta (5) :eta (1)-C5H4[CH2C(O)(3,5-C6H3( CF3)(2))(2)]}Y{CH(SiMe3)(2)}{THF}(2) (9), respectively. Metathesis of 5 wit h 2 equiv of Na[N(SiMe3)(2)] or LiCH(SiMe3)(2) afforded the anionic "ate" c omplexes {eta (5):eta (1)-C5H4[CH2C(O)(3,5-C6H3(CF3)(2))(2)]}{N(SiMe3)(2)}( 2)Y-Na+{THF}(2) (7) and {eta (5):eta (1)-C5H4[CH2C-(O)(3,5-C6H3(CF3)(2))(2) ]}{CH(SiMe3)(2)}(2)Y-Li+{THF}(2) (10), respectively. The phenoxide {eta (5) :eta (1)-C5H4[CH2C(O)(3,5-C6H3(CF3)(2))(2)]}Y{O-2,6-t-Bu2C6H3}{THF}(2) (11) could not be prepared by salt metathesis but was isolated by protonolysis of Y[O-2,6-t-Bu2C6H3] [CH(SiMe3)(2)](2)[THF](2) with 1 equiv of 3. The crys tal structures of ate complex 4a and phenoxide 11 were established by X-ray crystallography.