pounds B(C6F5)3,29 [Cr(η-C5H5)2],30 and [Co(η-C5H5)2]31 were
prepared according to the literature. The compound B(C6F5)3
was freshly sublimed before use. Water and D2O were distilled
and purged with nitrogen prior to use. The NMR spectra were
0.42 g (42%). Analysis: % calculated (% found) C 43.4 (42.8),
H 1.1 (1.3), Fe 4.3 (4.6). Selected IR data (cmϪ1, KBr): 3634
sharp weak ν(O–H), 3120 sharp v. weak ν(C–H) of C5H5.
recorded on either a 300 MHz Varian Mercury (1H, 11B, and 19
F
The compound [CO(ꢀ-C5H5)2][(F5C6)3BOH ؒ ؒ ؒ H2OB(C6F5)3]
5a. A 32 mg (0.17 mmol) portion of [Co(η-C5H5)2] was dis-
solved in 20 mL of CH2Cl2 and cooled to Ϫ78 ЊC. Two equiv-
alents of compound 2a were dissolved in 30 mL of CH2Cl2 and
added to the metallocene solution via cannula. The blue-black
colour immediately began to change to pale yellow. After one
hour at Ϫ78 ЊC the solution was allowed to warm to room
temperature. After 16 h solvents were removed in vacuo to yield
a pale yellow powder that was recrystallised from CH2Cl2 and
pentane to give pale yellow microcrystals analysing as 5a. Yield:
0.11 g (53%). Recrystallisation from CH2Cl2 layered with pen-
tane provided crystals large enough for X-ray diffraction.
Analysis: % calculated (% found) C 44.9 (44.1), H 1.0 (1.5).
Selected IR data (cmϪ1, KBr): 3634 sharp weak ν(O–H), 3126
sharp v. weak ν(C–H) of C5H5.
at 300.13, 96.25, and 282.36 MHz respectively) or a 500 MHz
Varian Unity Plus spectrometer (1H, 11B, and 19F at 499.87,
160.38, and 470.28 MHz respectively) in CD2Cl2 at room
temperature. Protio spectra were referenced internally using
residual protio-solvent and Me4Si (δ 0). Heteronuclei were
referenced externally to BF3ؒEt2O (11B, δ 0) and CFCl3 (19F,
δ 0). Elemental analyses were performed by the Inorganic
Chemistry Laboratory Microanalytical Services. Magnetic
susceptibility data were collected on a Quantum Design
SQUID Susceptometer.
Syntheses
Compound H2OؒB(C6F5)3 2a. A 900 mg portion (1.76 mmol) of
B(C6F5)3 was dissolved in 40 mL of pentane at room temper-
ature. The solution was cooled to Ϫ78 ЊC which caused some of
the borane to precipitate. One equivalent (32 µL) of distilled
water was added at low temperature and the solution allowed to
warm to room temperature whilst stirring. Initially upon warm-
ing all reagents dissolved, but after 2 h a white precipitate had
appeared. The solution volume was reduced to 15 mL, the
supernatant filtered off, and the residual white powder dried
in vacuo. The powder was recrystallised from a saturated solu-
tion of CH2Cl2 layered with pentane to give a crystalline
product. Yield: 0.75 g, 80%. Analysis: % Calculated (% found)
C 40.8 (41.0), H 0.5 (0.4), B 2.0 (2.1).
The compound [Cr(ꢀ-C5H5)2][(F5C6)3B(ꢁ-OH)B(C6F5)3] 3b. A
1:1:1 ratio of [Cr(η-C5H5)2] (0.566 mmol, 103 mg), compound
2a (0.566 mmol, 300 mg), and B(C6F5)3 (0.566 mmol, 290 mg)
was mixed in the solid state in a flask and cooled to Ϫ78 ЊC, 40
mL of CH2Cl2 were added and an immediate change from dark
red to orange was observed. After 30 min the solution was
warmed to room temperature, stirred for 2 h and the solvent
removed in vacuo. The resulting orange powder was recrystal-
lised from CH2Cl2 and pentane to give orange-yellow crystals
analysing as 3bؒCH2Cl2. Yield 0.11 g (23%). Analysis: % Calcu-
lated (% found) C 43.2 (43.0), H 1.0 (1.4), Cr 4.0 (3.6).
The compound D2OؒB(C6F5)3 2b. A portion of B(C6F5)3 (390
mg, 0.76 mmol) in 30 mL of pentane was treated as for the
synthesis of compound 2a with 14 µL of D2O. A similar white
powder precipitated from solution upon completion of the
reaction, which proved to be analytically pure. Yield: 0.30 g,
77%. Analysis: % Calculated (% found) C 40.8 (40.4), H 0.8
(0.8).
The compound [Co(ꢀ-C5H5)2][(F5C6)3B(ꢁ-OH)B(C6F5)3] 5b. A
similar procedure to that for compound 3b was followed except
that pentane was used as the solvent. Upon warming to room
temperature a pale yellow powder precipitated. The super-
natant was removed via filtration and pale yellow crystals were
obtained via recrystallisation from CH2Cl2 and pentane. Yield:
0.04 g (10%). Analysis: % calculated (% found): C 42.9 (43.1),
H 1.0 (1.25), Co 4.5 (4.4).
The compound [Cr(ꢀ-C5H5)2][(F5C6)3BOH ؒ ؒ ؒ H2OB(C6F5)3]
3a. A portion of [Cr(η-C5H5)2] (137 mg, 0.75 mmol) was dis-
solved in 40 mL CH2Cl2 and cooled to Ϫ78 ЊC. In a separate
flask, B(C6F5)3 (770 mg, 1.5 mmol) in 20 mL CH2Cl2 was cooled
to Ϫ78 ЊC, 13.5 µL of water were added using a syringe and the
resulting mixture was subsequently added to the [Cr(η-C5H5)2]
solution via a cannula. The initially dark red metallocene solu-
tion became orange-brown over 30 min. The reaction mixture
was allowed to warm to room temperature and stirred for 4 h.
The solvents were removed in vacuo, the crude orange-brown
powder was washed with pentane, and the product recrystal-
lised from a saturated CH2Cl2 solution layered with pentane.
Orange-yellow crystals analysing for compound 3aؒCH2Cl2
were isolated and the presence of CH2Cl2 in the crystals was
confirmed by X-ray diffraction. Yield: 0.23 g (25%). Analysis:
% Calculated (% found) C 42.6 (42.8), H 1.1 (1.2), Cr 3.9
(4.5). Selected IR data (cmϪ1, KBr): for 3a: 3635.5 sharp weak
ν(O–H), 3131 sharp v. weak ν(C–H) of C5H5; for H2OؒB(C6F5)3
3384 v. strong, v. broad ν(O–H).
X-Ray crystallography
All crystals were selected under an inert atmosphere, covered
with Paratone-N oil, and mounted on the end of a glass fibre.
Data were collected on an Enraf-Nonius DIP2000 image plate
diffractometer with graphite monochromated Mo-Kα radiation
(λ = 0.71069 Å) as summarised in Table 2. The images were
processed with the DENZO and SCALEPACK programs32 and
corrections for Lorentz-polarisation effects were performed.
All solution, refinement, and graphical calculations were per-
formed using the CRYSTALS33 and CAMERON34 software
packages. The structures were solved by direct methods using
the SIR 9235 program and refined by full-matrix least squares
procedure on F. All non-hydrogen atoms were refined with
anisotropic displacement parameters. All carbon-bound hydro-
gen atoms were generated and allowed to ride on their corre-
sponding carbon atoms with fixed thermal parameters. For
compound 2a both hydrogen atoms were found in the difference
map and their positions refined. For 3a, 4a, and 5a in each case
one proton bound to oxygen was located in the difference map
but its position was not refined. The final proton of the three
in the OH ؒ ؒ ؒ H2O moiety was not part of the refinement. A
Chebychev weighting scheme was applied with the parameters
1.78, 0.414, and 1.36 for 2a, 1.18, 1.32, and 0.799 for 3a, 1.22,
1.16, and 0.763 for 4a and 2.33, 1.11, and 1.61 for 5a, as well as
an empirical absorption correction.36
The compound [Fe(ꢀ-C5H5)2][(F5C6)3BOH ؒ ؒ ؒ H2OB(C6F5)3]
4a. A portion of [Fe(η-C5H5)2] (162 mg, 0.87 mmol) in 25 mL
of pentane at room temperature was treated with a solution of
compound 2a (900 mg, 1.76 mmol) in 25 mL of pentane via
cannula. After 2 h stirring under N2 the yellow reaction mixture
was opened to air and after 8 h a large amount of blue powder
had precipitated. The pentane supernatant was removed via
filtration and the powder recrystallised from CH2Cl2 layered
with pentane to give blue-red crystals analysing as 4aؒ¹CH2Cl2,
CCDC reference number 186/1707.
graphic files in .cif format.
¯
²
which stoichiometry was confirmed crystallographically. Yield:
4328 J. Chem. Soc., Dalton Trans., 1999, 4325–4329
Doerrer, Linda H.
