%0 Journal Article %A Castro Gausinet, Irene de %A Galakhov, Mikhail V. %A Gómez Rubio, Manuel %A Gómez Sal, Pilar %A Martín Alonso, Avelino %A Royo Gracia, Pascual %T Pentamethylcyclopentadienyl halo- and alkyl-alkoxo tantalum(V) complexes. Crystal structure of TaCp*(CH2SiMe3) 2{η2-O(2-CH2-6-MeC6H3)} %D 1996 %@ 0022-328X %U http://hdl.handle.net/10017/4554 %X Reaction of TaCp" C! 4 with MOR (M - Li, Na) in different molar ratios gives halo alkoxides TaCp" CI,(OR)4_,, (n - 3: R -tBu 1; $iPh 3 2; 2,6-Me2C6H 3 3; n -- 2: R -~Bu 4; SiPh 3 5; 2,6-Me2C6H3 6; a - !: R - SiMe 3 7) in good yields. The alkylidene complex TaCp'(CH2SiMe,02(CHSiMe ~) is hydrolyzed in the presence of traces of water to give the oxo dialkyl derivative [TaCp'(CH2SiM¢3)~O],, 8, and reacts with I equivalent of 2,6-MezC6H~NC affording a new 'q2-iminoacyi compound TaCp" (CH 2$iMe3XCHSiMe3){~ 2"C(CH 2SiMe3 ) = N(2,6"MeaC6 H 3)} 9. Reactions of TaCp "(CH 2SiMe3)a(CHSiMe3 ) with I equivalent of C6HsOH and 4-MeC6H3(OH) 2 result in the formation of the alkyl phenoxo TaCp'(CH2SiMe3)3(OC6Hs) 10 and 4-methyl pyrocatecholate TaCp'(CH2SiMe~)2(O2C6H3Me) 11, whereas the related re,",,:don with 2,6-Me2C6H 3OH leads to the cyclic alkyi-aikoxo compound TaCp (CH2SiMej)2(~2-O(2-CH2-6-MeC6H3)) 12. All the complexes were characterized by IR and NMR (tH and 13C) spectroscopy. The crystal and molecular structure of 12 has been determine~i. C~ystals of 12 are triclinic, space group P'[ with Z - 2 in a unit cell of dimensions a- 9.151(5) ~, b- 11.835(5) ~,, c- 14.045(4) A, a- 89.35(3) °, /3- 72.34(3) 0 and 'y-88.51(4) °, V- 1449(I) ~s. Final values of R -0.025 and Rw -0.0655 were obtained from 554'7 reflections measured (50'70, > 2o'(i)). %K Tantalum %K Pentamethylcyclopentadienyl derivatives %K Halo alkoxides %K Alkyl phenoxides %K Alkyl alkylidene imino acyl %K Ciencia %K Química inorgánica %K Science %K Chemistry, inorganic %~ Biblioteca Universidad de Alcala