178674-20-9Relevant academic research and scientific papers
Pentamethylcyclopentadienyl halo- and alkyl-alkoxo tantalum(V) complexes. Crystal structure of taCp*(CH2SiMe3) 2{η2-O(2-CH2-6-MeC6H3)}
De Castro, Irene,Galakhov, Mikhail V.,Gomez, Manuel,Gomez-Sal, Pilar,Martin, Avelino,Royo, Pascual
, p. 51 - 58 (2007/10/03)
Reaction of TaCp*Cl4 with MOR (M = Li, Na) in different molar ratios gives halo alkoxides TaCp*Cln(OR)4-n (n = 3: R = tBu 1; SiPh3 2; 2,6-Me2C6H3 3; n = 2: R = tBu 4; SiPh3 5; 2,6-Me2C6H3 6; n = 1: R = SiMe3 7) in good yields. The alkylidene complex TaCp*(CH2SiMe3)2(CHSiMe3) is hydrolyzed in the presence of traces of water to give the oxo dialkyl derivative [TaCp*(CH2SiMe3)2O]n 8, and reacts with 1 equivalent of 2,6-Me2C6H3NC affording a new η2-iminoacyl compound TaCp*(CH2SiMe3)(CHSiMe3){η2-C(CH2SiMe3)=N(2,6-Me2C6H3)} 9. Reactions of TaCp*(CH2SiMe3)2(CHSiMe3) with 1 equivalent of C6H5OH and 4-MeC6H3(OH)2 result in the formation of the alkyl phenoxo TaCp*(CH2SiMe3)3(OC6H5) 10 and 4-methyl pyrocatecholate TaCp*(CH2SiMe3)2(O2C6H3Me) 11, whereas the related reaction with 2,6-Me2C6H3OH leads to the cyclic alkyl-alkoxo compound TaCp*(CH2SiMe3)2{η2-O(2-CH2-6-MeC6H3)} 12. All the complexes were characterized by IR and NMR (1H and 13C) spectroscopy. The crystal and molecular structure of 12 has been determined. Crystals of 12 are triclinic, space group P1 with Z = 2 in a unit cell of dimensions a = 9.151(5) A, b = 11.835(5) A, c = 14.045(4) A, α = 89.35(3)°, β = 72.34(3)° and γ = 88.51(4)°, V = 1449(1) A3. Final values of R = 0.025 and Rw = 0.0655 were obtained from 5547 reflections measured (5070, > 2σ(I)).
