The anion
[H2B2(μ-H)(μ-C4H8)2]-,
II, reacts with zirconocene dichloride and with hafnocene
dichloride to form
(η5-C5H5)2ZrCl{(μ-H)2BC4H8},
III, and
(η5-C5H5)2HfCl{(μ-H)2BC4H8},
IV, complexes, which contain a
boracyclopentane ring that is bound to the metal through hydrogen
bridges. In these reactions, 0.5 mol of the
transannular hydrogen-bridged 10-membered ring compound
B2(μ-H)2(μ-C4H8)2
is also formed. A possible reaction
pathway for the formation of these complexes is proposed on the basis
of time-lapse 11B NMR spectroscopy.
The methyl-substituted complex
(η5-C5H5)2Zr(CH3){(μ-H)2BC4H8},
V, is prepared from the reaction of III
with
CH3Li. The molecular structure of III
was reported earlier. The structures of IV and V
are reported here. Crystal
data for IV: space group
P21/n (No. 14), a =
8.565(1) Å, b = 14.786(3) Å, c =
11.120(3) Å, β = 96.17(2)°, Z
= 4. Crystal data for V: space group
Pbca (No. 61), a = 8.436(1) Å,
b = 16.343(2) Å, c = 20.827(2) Å,
Z =
8.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.