M. Westerhausen et al., HETEROLEPTIC DIORGANOZINC COMPOUNDS OF TH E TYPE (ME3SI)3C-ZN-R, Journal of organometallic chemistry, 469(2), 1994, pp. 135-149
The equimolar reaction of lithium tris(trimethylsilyl)methanide with z
inc(II) chloride in a solvent mixture of THF and diethylether yields t
richloro-bis([tris(trimethylsilyl)methyl]zincate) . 2THF . Et2O. The a
ddition of organyl lithium leads to the formation of heteroleptic orga
nyl-[tris(trimethylsilyl)methyl]zinc. No ligand exchange reactions can
be observed for these compounds. Due to the steric demand of the tris
(trimethylsilyl)methyl substituent these derivatives are monomeric in
solution as well as in the solid state. ethylsilyl)methyl-[tris(trimet
hylsilyl)methyl]zinc crystallizes in the monoclinic space group P2(1)/
n (a = 910.7(2), b = 1633.0(4), c = 1863.9(4) pm, beta = 94.18(2)-degr
ees and Z = 4). The Zn-C-distances are elongated to a value of 197 pm
due to the steric demand of both the substituents. The zinc atom is wi
th an CZnC angle of 176-degrees nearly linear coordinated. Phenyl-[tri
s(trimethylsilyl)methyl]zinc with a melting point of about 24-degrees-
C crystallizes upon cooling in a nitrogen stream (P2(1), a = 908.4(3),
b = 1489.0(4), c = 1594.5(3) pm, beta = 94.68(2)-degrees and Z = 4).
Due to the small size of the phenyl group rather short Zn-C-bond lengt
hs of about 193.5 pm are formed.