2 research outputs found
Pentamethylcyclopentadienyl halo- and alkyl-alkoxo tantalum(V) complexes. Crystal structure of TaCp*(CH2SiMe3) 2{η2-O(2-CH2-6-MeC6H3)}
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;
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))
Monocyclopentadienyl alkyl alkylidene niobium(V) and tantalum(V) complexes. X-ray crystal-structure of Ta(η5-CP')(CH2SiMe3)2(CHSiMe3)
Reactions of monocyclopentadienyl complexes M(η5-Cp′)Cl4 with trimethylsilylmethyl lithium leads to the formation of alkylidene derivatives M(η5-Cp′)(CH2SiMe3)2(CHSiMe3), where M = Nb (1); Ta (2); Cp′= C5Me5 and M = Ta; Cp′ Me3Si(C5H4) (3), 1,3-(Me3Si)2(C5H3) (4). The new complexes were characterized by 1H and 13C NMR spectroscopy and the molecular structure of 2 was studied by X-ray diffraction methods