B(C6F5)3 adducts of transition metal acyl compounds

Article abstract of DOI:10.1039/b514889h

The transition metal acyl compounds [Co(L)(CO)₃(COMe)] (L = PMe₃, PPhMe₂, P(4-Me-C₆H₄) ₃, PPh₃ and P(4-F-C₆H₄) ₃), [Mn(CO)₅(COMe)] and [Mo(PPh₃) (η⁵-C₅H₅)(CO)₂(COMe)] react with B(C₆F₅)₃ to form the adducts [Co(L)(CO) ₃(C{OB(C₆F₅)₃}Me)] (L = PMe ₃ 1, PPhMe₂ 2, P(4-Me-C₆H₄) ₃ 3, PPh₃ 4, P(4-F-C₆H₄)₃ 5), [Mn(CO)₅(C{OB(C₆F₅)₃}Me)] 6 and [Mo(η⁵-C₅H₅)(PPh₃)(CO) ₂(C{OB(C₆F₅)₃}Me)], 7. Addition of B(C₆F₅)₃ to a cooled solution of [Mo(η⁵-C₅H₅)(CO)₃(Me)], under an atmosphere of CO gave [Mo(η⁵-C₅H₅)(CO) ₃(C{OB(C₆F₅)₃}Me)] 8. In the presence of adventitious water, the compound [Co{HOB(C₆F ₅)₃}₂{OP(4-F-C₆H₄) ₃}₂] 9, was formed from [Co(P(4-F-C₆H ₄)₃)(CO)₃(C{OB(C₆F₅) ₃}Me)]. The compounds 4 and 9 have been structurally characterised. The use of B(C₆F₅)₃ as a catalyst for the CO-induced migratory-insertion reaction in the transition metal alkyl compounds [Co(PPh₃)(CO)₃(Me)], [Mn(CO)₅(Me)], [Mo(η⁵-C₅H₅)(CO)₃(Me)] and [Fe(η⁵-C₅H₅)(CO)₂(Me)] has been investigated. The Royal Society of Chemistry 2006.

Full text of DOI:10.1039/b514889h

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www.rsc.org/dalton | Dalton Transactions
B(C6F5)3 adducts of transition metal acyl compounds
Simon A. Llewellyn,* Malcolm L. H. Green and Andrew R. Cowley
Received 20th October 2005, Accepted 15th December 2005
First published as an Advance Article on the web 9th January 2006
DOI: 10.1039/b514889h
The transition metal acyl compounds [Co(L)(CO)3(COMe)] (L = PMe3, PPhMe2, P(4-Me-C6H4)3,
5
PPh3 and P(4-F-C6H4)3), [Mn(CO)5(COMe)] and [Mo(PPh3)(g -C5H5)(CO)2(COMe)] react with
B(C6F5)3 to form the adducts [Co(L)(CO)3(C{OB(C6F5)3}Me)] (L = PMe3 1, PPhMe2 2, P(4-Me-
5
C6H4)3 3, PPh3 4, P(4-F-C6H4)3 5), [Mn(CO)5(C{OB(C6F5)3}Me)] 6 and [Mo(g -C5H5)(PPh3)(CO)2-
5
(C{OB(C6F5)3}Me)], 7. Addition of B(C6F5)3 to a cooled solution of [Mo(g -C5H5)(CO)3(Me)], under
5
an atmosphere of CO gave [Mo(g -C5H5)(CO)3(C{OB(C6F5)3}Me)] 8. In the presence of adventitious
water, the compound [Co{HOB(C6F5)3}2{OP(4-F-C6H4)3}2] 9, was formed from [Co(P(4-F-C6H4)3)-
(CO)3(C{OB(C6F5)3}Me)]. The compounds 4 and 9 have been structurally characterised. The use of
B(C6F5)3 as a catalyst for the CO-induced migratory-insertion reaction in the transition metal alkyl
5
compounds [Co(PPh3)(CO)3(Me)], [Mn(CO)5(Me)], [Mo(g -C5H5)(CO)3(Me)] and
5
[Fe(g -C5H5)(CO)2(Me)] has been investigated.
Introduction
Results and discussion
The strong Lewis acid B(C6F5)3 has been shown to undergo a
diverse range of reactions with transition metal complexes.1 We
have recently shown that compounds of the general formula [Fe(g -
Syntheses
The cobalt(I) acyl complexes, [Co(L)(CO)3(COMe)] (L = PMe3,
PPhMe2, P(4-Me-C6H4)3, PPh3 and P(4-F-C6H4)3), react with
equimolar quantities of B(C6F5)3 at room temperature in CH2Cl2
or C6H6, to afford a series of compounds in which the Lewis
acid coordinates exclusively to the oxygen atom of the acyl
carbonyl group (Scheme 1), yielding off-white to orange-brown
solids [Co(L)(CO)3(C{OB(C6F5)3}Me)] (L = PMe3 1, PPhMe2
2, P(4-Me-C6H4)3 3, PPh3, 4, P(4-F-C6H4)3 5). Crystallographic
characterisation of the compound 4, confirms the attachment of
the B(C6F5)3 to the acyl oxygen atom. Characterising data are
summarised in Table 1.
5
C5H5)(L)(CO)(COMe)] (L = CO or tertiary phosphine), form
5
adducts of the type [Fe(g -C5H5)(CO)(L)(C{OB(C6F5)3}Me)] (L =
CO or tertiary phosphine), in which B(C6F5)3 is bound exclusively
to the acyl oxygen atom.2 Here we describe the synthesis of a series
of B(C6F5)3-bound transition metal acyl compounds, showing that
this mode of reactivity is general.
5
In contrast to the reported reaction between [Fe(g -C5H5)-
(L)(CO)(COMe)] (L = CO or tertiary phosphine) and B(C6F5)3,
5
the alkyl derivative [Fe(g -C5H5)(CO)2(Me)], has been shown to
react with B(C6F5)3 to give the unexpected product [Fe{C6F4C(O)-
5
Me-2}(g -C5H5)(CO)].3 It was postulated that the mechanism
of formation involved the transient 16 electron acyl species
5
[Fe(g -C5H5)(CO)(C{OB(C6F5)3}Me)], suggesting that B(C6F5)3
may be a suitable Lewis acid catalyst for migratory-insertion
reactions. The use of mild acids/Lewis acids to catalyse migratory-
insertion reactions in transition metal carbonyl complexes has
been well documented.4–6 Shriver et al. have shown that BF3 and
5
AlCl3 increase the rate of CO-induced carbonylation in [Fe(g -
Scheme 1 Synthesis of B(C6F5)3 adducts of cobalt(I) acyl compounds.
5
C5H5)(CO)2(Me)], [Mn(CO)5(COMe)] and [Mo(g -C5H5)(CO)3-
(Me)] to give the corresponding Lewis acid-coordinated acyl
5
derivatives, [Fe(g -C5H5)(CO)2(C{OAlBr3}Me)], [Mn(CO)5(C-
The analogous reactions of [Mn(CO)5(COMe)] and [Mo-
5
5
{OBF3}Me)], and [Mo(g -C5H5)(CO)3(C{OAlBr3}Me)] res-
(PPh3)(g -C5H5)(CO)2(COMe)] with B(C6F5)3 led to the for-
5
pectively. Similarly Cutler et al. have shown that the catalytic
mation of [Mn(CO)5(C{OB(C6F5)3}Me)], 6 and [Mo(g -C5H5)-
5
amounts of HBF4 allow carbonylation of [Fe(g -C5H5)(PPh3)-
(PPh3)(CO)2(C{OB(C6F5)3}Me)], 7, respectively. In a related
5
(CO)(Me)] and [Fe(g -C5H5)(CO)2(Me)] under very mild
reaction, the addition of B(C6F5)3 to a cooled solution of
conditions.6 To establish whether the bulky B(C6F5)3 would have a
similar catalytic result, the effect of the Lewis acid B(C6F5)3
on the ligand-induced migratory-insertion reactions of [Mn(CO)5-
5
[Mo(g -C5H5)(CO)3(Me)], under an atmosphere of CO gave
5
the compound [Mo(g -C5H5)(CO)3(C{OB(C6F5)3}Me)], 8. In
the presence of adventitious water, the compound [Co(P(4-F-
C6H4)3)(CO)3(C{OB(C6F5)3}Me)] decomposed to give [Co{HOB-
(C6F5)3}2{OP(4-F-C6H4)3}2], 9, which has been characterised by
X-ray crystallography. Characterising data are summarised in
Table 1.
5
5
(Me)], [Mo(g -C5H5)(CO)3(Me)], [Fe(g -C5H5)(CO)2(Me)], and
[Co(PPh3)(CO)3(Me)] has been investigated, as described below.
Inorganic Chemistry Laboratory, South Parks Road, Oxford, UK OX1 3QR
1776 | Dalton Trans., 2006, 1776–1783
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Table 1 Characterising data for compounds 1–8
Compounda
NMR Datab
1 [Co(P(CH3)3)(CO)3(C{OB(C6F5)3}CH3)]
Orange-brown solid
IR: 1644 m, 1520 m, 1998 s, 2016 s, 2076 w
1H: 1.58 [d, 2JPH = 9.8 Hz, 9H, P(CH3)3], 2.77 [s, 3H, COCH3]
1
11B{ H}: −14.71 [s, B(C6F5)3]
1
13C{ H}: 19.06 [d, 1JPC = 34.1 Hz, P(CH3)3], 49.97 [d, 3JPC = 10.4 Hz, COCH3], 117.96
[br s, B(C6F5)3, Cipso], 135.53 [d, 1JFC = 244.5 Hz, B(C6F5)3, Cmeta], 141.82 [m, B(C6F5)3,
C
para], 146.80 [d, 1JFC = 243.4 Hz, B(C6F5)3, Cortho], 195.67 [d, 2JPC = 24.2 Hz, Co(CO)3]
1
19F{ H}: 136.42 [d, 3JFF = 20.2 Hz, 6F, o-C6F5], −161.40 [t, 3JFF = 21.1 Hz, 3F, p-C6F5],
−168.13 [t, 3JFF = 18.8 Hz, 6F, m-C6F5]
31P{ H}: 18.05 [s, P(CH3)3]
1
2 [Co(P(C6H5)(CH3)2)(CO)3(C{OB(C6F5)3}CH3)]
Yellow solid
C 44.5 (44.5), H 1.7 (1.7), N 0 (0)
1H: 1.90 [br s, 6H, P(C6H5)(CH3)2], 2.76 [br s, 3H, COCH3)], 7.52 [m, 6H, ArH]
11B{ H}: −14.74 [s, B(C6F5)3]
1
13C{ H}: 18.50 [d, 1JPC = 32.7 Hz, P(C6H5)(CH3)2], 50.03 [br s, COCH3], 119.01 [br s,
1
B(C6F5)3, Cipso], 129.71 [m, P(C6H5)(CH3)2], 137.19 [d, 1JFC = 232.7 Hz, B(C6F5)3, Cmeta],
142.00 [br s, B(C6F5)3, Cpara], 147.98 [d, 1JFC = 243.9 Hz, B(C6F5)3, Cortho], 195.08 [br s,
Co(CO)3]
1
IR: 1518 m, 1644 m, 1998 s, 2016 s, 2076 w
19F{ H}: −136.42 [s, 6F, o-C6F5], −161.27 [s, 3F, p-C6F5], −168.06 [s, 6F, m-C6F5]
31P{ H}: 24.03 [s, P(C6H5)(CH3)2]
1
3 [Co(P(4-CH3–C6H4)3)(CO)3(C{OB(C6F5)3}CH3)]
Off-white solid
C 53.4 (52.7), H 2.3 (2.4), N 0 (0)
1H: 2.37 [s, 9H, 4-CH3–C6H4], 2.74 [s, 3H, COCH3], 7.31 [m, 12H, ArH]
11B{ H}: −14.70 [s, B(C6F5)3]
1
13C{ H}: 21.60 [br s, CH3–C6H4], 52.14 [br s, COCH3], 52.63 [s, CoCOCH3], 121.54 [s,
1
B(C6F5)3, Cipso], 129.72 [d, JPC = 14.5 Hz, ArC], 132.83 [d, JPC = 12.5 Hz,
P(4-CH3–C6H4)3], 146.39 [s, P(4-CH3–C6H4)3], 137.45 [d, 1JFC = 243.8 Hz, B(C6F5)3,
C
meta], 144.14 [br s, B(C6F5)3, Cpara], 146.39 [s, P(4-CH3–C6H4)3], 148.08 [d, 1JFC
=
243.8 Hz, B(C6F5)3, Cortho], 196.45 [br s, Co(CO)3]
1
IR: 1520 m, 1644 m, 1990 s, 2016 s, 2076 w
19F{ H}: −134.82 [br s, 6F, o-C6F5], −158.74 [br s 3F, p-C6F5], −165.29 [br s, 6F, m-C6F5]
31P{ H}: 48.20 [s, P(4-CH3–C6H4)3]
1
4 [Co(P(C6H5)3)(CO)3(C{OB(C6F5)3}CH3)]
Off-white solid
C 51.0 (51.3), H 2.2 (1.9), N 0 (0)
1H: 2.87 [br s, 3H, COCH3], 7.69–7.36 [m, 15H, ArH]
11B{ H}: −14.20 [s, B(C6F5)3]
1
13C{ H}: 49.80 [d, 3JPC = 9.4 Hz, COCH3], 117.67 [br s, B(C6F5)3, Cipso], 128.58 [s,
1
P(C6H5)3], 129.63 [d, JPC = 0.2 Hz, P(C6H5)3], 132.20 [s, P(C6H5)3], 133.17 [d, JPC
=
10.7 Hz, P(C6H5)3], 137.16 [d, 1JFC = 243.1 Hz, B(C6F5)3, Cmeta], 140.13 [d, 1JFC
=
246.6 Hz, B(C6F5)3, Cpara], 147.75 [d, 1JFC = 240.1 Hz, B(C6F5)3, Cortho], 195.27 [d, 2JPC
=
23.6 Hz, Co(CO)3]
1
IR: 1520 m, 1646 m, 1994 s, 2024 s, 2082 w
19F{ H}: −134.27 [d, 3JFF = 21.4 Hz, 6F, o-C6F5], −156.42 [t, 3JFF = 18.6 Hz, 3F,
p-C6F5], −163.81 [d, 3JFF = 20.2 Hz, 6F, m-C6F5]
31P{ H}: 50.60 [s, PPh3]
1
5 [Co(P(4-F-C6H4)3)(CO)3(C{OB(C6F5)3}CH3)]
Off-white solid
C 48.5 (48.6), H 1.5 (1.5), N 0 (0)
1H: 2.87 [s, 3H, COCH3], 6.55 [t, 3JHH = 8.5 Hz, 6H, ArH], 6.99 [br s, 6H, ArH]
11B{ H}: −14.09 [br s, B(C6F5)3]
1
13C{ H}: 50.03 [s, COCH3], 117.40 [m, P(4-F–C6H4)3], 126.71 [m, P(4-F-C6H4)3], 135.77
1
[s, P(4-F-C6H4)3], 138.62 [s, B(C6F5)3, Cmeta], 141.89 [s, B(C6F5)3, Cpara], 149.42 [d, 1JFC
=
236.14 Hz, B(C6F5)3, Cortho], 163.20 [s, P(4-F-C6H4)3], 166.56 [s, P(4-F-C6H4)3], 195.39 [s,
Co(CO)3]
1
IR: 1514 m, 1644 m, 2004 s, 2022 s, 2080 w
19F{ H}: −106.48 [s, 3F, P(4-F-C6H4)3], −134.07 [s, 6F o-C6F5], −158.65 [s, 3F, p-C6F5],
−166.46 [s, 6F, m-C6F5]
1
31P{ H}: 49.17 [s P(4-F-C6H4)3]
6 [Mn(CO)5(C{OB(C6F5)3}CH3)]
Off-white solid
IR: 1520 m,1646 m, 2004 s, 2086 s, 2116 s
1H: 2.87 [s, 3H, COCH3]
1
11B{ H}: 1.48 [br s, B(C6F5)3]
1
13C{ H}: 50.91 [s, COCH3], 118.96 [br s, B(C6F5)3, Cipso], 137.42 [d, 1JFC = 229.3 Hz,
B(C6F5)3, Cmeta], 140.55 [s, 1JFC = 249.3 Hz, B(C6F5)3, Cpara], 147.78 [d, 1JFC = 240.2 Hz,
B(C6F5)3, Cortho], 205.05 [s, Mn(CO)5]
1
19F{ H}: −134.84 [d, 3JFF = 21.8 Hz, 6F, o-C6F5], −157.56 [s, 3F, p-C6F5], −164.35 [t,
3JFF = 17.8 Hz, 6F, m-C6F5]
5
5
7 [Mo(g -C5H5)(P(C6H5)3)(CO)2(C{OB(C6F5)3}CH3)]
1H: 2.75 [s, 3H, COCH3], 5.27 [s, 5H, g -C5H5], 7.15–7.50 [m, 15H, P(C6H5)3]
1
Yellow solid
11B{ H}: 3.175 [s, B(C6F5)3]
1
5
C 51.7 (52.2), H 2.4 (2.2), N 0 (0)
13C{ H}: 50.41 [s, COCH3], 97.86 [s, g -C5H5], 119.50 [br s, B(C6F5)3, Cipso], 129.32 [d,
JPC = 10.3 Hz, P(C6H5)3], 131.68 [m, P(C6H5)3], 133.15 [m, P(C6H5)3], 137.22 [d, 1JFC
228.9 Hz, B(C6F5)3, Cmeta], 140.12 [m, B(C6F5)3, Cpara], 147.99 [d, 1JFC = 243.0 Hz,
B(C6F5)3, Cortho], 235.3 [d, 2JPC = 25.7 Hz, Mo(CO)2]
=
1
IR: 1520 m, 1644 m, 1898 s, 1970 s
19F{ H}: −134.60 [d, 3JFF = 21.4 Hz, 6F, o-C6F5], −159.34 [t, 3JFF = 18.6 Hz, 3F,
p-C6F5], −165.50 [d, 3JFF = 20.2 Hz, 6F, m-C6F5]
1
31P{ H}: 57.6 [s, P(C6H5)3]
5
5
8 [Mo(g -C5H5)(CO)3(C{OB(C6F5)3}CH3)]
1H: 2.79 [s, 3H, COCH3], 5.65 [s, 5H, g -C5H5]
1
Orange solid
11B{ H}: 4.84 [br s, B(C6F5)3]
1
5
C 41.7 (42.0), H 1.1 (1.0), N 0 (0)
13C{ H}: 51.19 [s, COCH3], 96.99 [s, g -C5H5], 137.10 [d, 1JFC = 244.5 Hz, B(C6F5)3,
C
meta], 141.79 [s, B(C6F5)3, Cpara], 147.58 [d, 1JFC = 244.4 Hz, B(C6F5)3, Cortho], 225.97 [s,
Mo(CO)3]
1
IR: 1515 m, 1646 m, 1929 s, 2020 s
19F{ H}: 135.53 [s, 6F, o-C6F5], 156.66 [s, 3F, p-C6F5], 163.20 [s, 6F, m-C6F5]
a Analytical data are given as found (calculated) in %. Selected IR data (cm−1) were recorded as either Nujol mulls between KBr plates, 1–5, or as CH2Cl2
solutions, 6–8. b NMR data given as chemical shift (d = 0 ppm) [multiplicity, relative intensity, J in Hz, assignment] and were obtained in C6D6/CD2Cl2.
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The reaction of cooled solutions (−78 ◦C) of the transition
metal alkyl compounds, [Co(PPh3)(CO)3(Me)], [Mn(CO)5(Me)],
5
5
[Mo(g -C5H5)(CO)3(Me)] and [Fe(g -C5H5)(CO)2(Me)] with
B(C6F5)3 and CO gave the B(C6F5)3-coordinated acyl adducts:
[Co(PPh3)(CO)3(C{OB(C6F5)3}Me)], [Mn(CO)5(C{OB(C6F5)3}-
5
5
Me)], [Mo(g -C5H5)(CO)3(C{OB(C6F5)3}Me)] and [Fe(g -
C5H5)(CO)2(C{OB(C6F5)3}Me)], in yields of 40–99%. By con-
trast, under the same pressures of CO, but in the absence of
5
5
B(C6F5)3, [Mo(g -C5H5)(CO)3(Me)] and [Fe(g -C5H5)(CO)2(Me)]
were inactive towards carbonylation. However, the compounds
[Co(PPh3)(CO)3(Me)] and [Mn(CO)5(Me)] underwent carbony-
lation even in the absence of B(C6F5)3 to give the acyl derivatives
in yields of 70–99%. The effect of B(C6F5)3 on the migratory-
insertion may be rationalised in terms of the formation of an
intermediate acyl species, [M(C{OB(C6F5)3}Me)], on reacting
with the metal alkyl compound, [M(CO)(Me)]. The vacant
site formed during this migration, possibly stabilised by a M–F
interaction, would then be filled by CO, to give the observed Lewis
acid bound acyl derivatives (Scheme 2). Such M–F interactions
have recently been reported by Roesky et al. in the compound
[LAlB(C6F5)3] (L = HC(CMeNAr)2; Ar = 2,6-iPr2C6H3].7
Scheme 2 Proposed pathway in B(C6F5)3 catalysed migratory-insertion.
Fig. 1 The molecular structure of [Co(PPh3)(CO)3(C{OB(C6F5)3}Me)]
4, thermal ellipsoids are drawn at 40% probability.
Reaction conditions and yields obtained for the CO-
induced migratory-insertions are summarised in Table 2.
The lower yields observed for the carbonylation of [Fe(g -
and molecular parameters are presented in Table 7. The cobalt
centre has a trigonal bipyramidal geometry, typical of cobalt
acyl complexes of this type,8 with a bis-axial arrangement of
the acyl and phosphine groups. The X-ray structure confirms
the connection of the B(C6F5)3 to the O atom of the acyl group
5
C5H5)(CO)2(Me)] may be attributed to a higher reactivity of
5
the compound [Fe(g -C5H5)(CO)2(Me)] with B(C6F5)3 (with
regards to C–F activation) when compared with that of
5
[Mn(CO)5(Me)] and [Mo(g -C5H5)(CO)3(Me)]. The formation
˚
with a B–O bond length of 1.561(3) A, and shows a distorted
5
of [Mo(g -C5H5)(CO)3(C{OB(C6F5)3}Me)] represents a stabili-
tetrahedral coordination about the boron centre. The Co–Cacyl
5
sation of the otherwise thermodynamically unstable [Mo(g -
˚
˚
length of 1.931(3) A is 0.057 A shorter than is found in the parent
C5H5)(CO)3(COMe)] system. Shriver et al. have noted a similar
acyl compound [Co(PPh3)(CO)3(COMe)]9 (see Table 4), and is
5
effect in the compound [Mo(g -C5H5)(CO)3(C{OAlBr3}Me)].5
˚
approaching the 1.912 A Co–C distance found in the Fischer-
The products of all carbonylation reactions were unambiguously
identified by comparison of the NMR and IR spectroscopic data
with reference samples of the compounds in question.
carbene complexes [(Ph3Ge)(CO)3Co( C(OEt)Et)].10 This is con-
=
sistent with a strengthening of the Co–Cacyl upon coordination of
the Lewis acid. Thus the Co–Cacyl bond length may be described
=
as intermediate between the single Co–C and the double Co
bond lengths. The coordination of B(C6F5)3 to the O acyl atom
in the compound [Co(PPh3)(CO)3(COMe)] leads to an increase in
C
X-Ray crystallography
The molecular structure of the compound 4 is given in Fig. 1.
Selected bond lengths (A) and angles ( ) are summarised in Table 3
◦
˚
˚
=
C Oacyl bond length from 1.195 A, in the parent acyl compound,
Table 2 Results for the carbonylation of transition metal alkyl compounds
Starting material
Conditions
Product
Yield (%)
[Co(PPh3)(CO)3(Me)]
CO
CO, B(C6F5)3
CO
CO, B(C6F5)3
CO
CO, B(C6F5)3
CO
[Co(PPh3)(CO)3(COMe)]
99
99
0
40
72
99
0
[Co(PPh3)(CO)3(C{OB(C6F5)3}Me)]
5
5
[Fe(g -C5H5)(CO)2(Me)]
[Fe(g -C5H5)(CO)2(COMe)]
5
[Fe(g -C5H5)(CO)2(C{OB(C6F5)3}Me)]
[Mn(CO)5(Me)]
[Mn(CO)5(COMe)]
[Mn(CO)5(C{OB(C6F5)3}Me)]
5
5
[Mo(g -C5H5)(CO)3(Me)]
[Mo(g -C5H5)(CO)3(COMe)]
5
CO, B(C6F5)3
[Mo(g -C5H5)(CO)3(C{OB(C6F5)3}Me)]
99
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◦
˚
Table 3 Selected bond lengths (A) and angles ( ) for compounds 4 and 9
4
Co(1)–C(22)
Co(1)–P(1)
C(22)–C(23)
O(4)–B(1)
C(22)–O(4)
CO terminala
9
1.931(3)
2.2640(7)
1.497(4)
1.561(3)
1.268 (3)
1.136 (3)
O(4)–B(1)–C(24)
C(2)–Co(1)–C(3)
Co(1)–C(22)–C(23)
111.17(19)
114.57(13)
121.69(17)
Co(1)–O(1)
Co(1)–O(3)
O(1)–P(1)
O(3)–B(1)
Co(1)–O(2)
Co(1)–O(4)
O(2)–P(2)
O(4)–B(2)
O(4)–H(2)
1.920(2)
1.933(2)
1.499(2)
1.484(4)
1.941(2)
2.022(19)
1.493(2)
1.532(3)
0.72(8)
O(1)–Co(1)–O(2)
O(1)–Co(1)–O(3)
O(2)–Co(1)–O(3)
O(3)–Co(1)–O(4)
Co(1)–O(1)–P(1)
O(3)–B(1)–C(37)
O(3)–B(1)–C(43)
Co(1)–O(3)–H(1)
Co(1)–O(4)–H(2)
100.9(1)
118.8(1)
118.5(1)
102.7(8)
169.4(16)
103.3(2)
112.4(2)
103.5(2)
100(7)
a Average of 3 bond lengths.
˚
to 1.268(3) A in 4. This is longer than has been observed for any
other reported cobalt(I) acyl compound (Table 4).
˚
The 1.561(3) A O–B bond length observed for the com-
pound is comparable with those seen for the related
Fig. 2 The molecular structure of [Co{HOB(C6F5)3}2{OP(4-F-C6H4)3}2]
9, thermal ellipsoids are drawn at 40% probability.
4
5
5
compounds [Fe(g -C5H5)(CO)2(C{OB(C6F5)3}Me)], and [Fe(g -
C5H5)(PMe3)(CO)(C{OB(C6F5)3}Me)],2 in which O–B bond
The O–B bond lengths in compound 9 are 1.484(4) A and
˚
˚
˚
˚
lengths are 1.570(3) A, and 1.559(3) A respectively. The O–B bond
length observed for the compound 4 is shorter than those seen
in organic analogues of general formula [PhC{OB(C6F5)3}R]: see
1.532(3) A. The second of these values is similar to those re-
5
ported for the related compounds [Fe(g -C5H5)(PPh3)(CO){HOB-
5
18
˚
(C6F5)3}], 1.508(2) A, [Ti(g -C5H5)2][HOB(C6F5)3], 1.519(3)
17
˚
˚
˚
Table 4, in which the average O–B bond length is 1.593(6) A. The
A, [InMe{HOB(C6F5)3}{1,2-(NiPr)2C8H5}], 1.528(3) A, and
average Cco–Co–Cacyl bond angle observed for the compound 4 is
88.82◦.
[Pt{HOB(C6F5)3}(bu2bpy)Me]16 (bu2bpy = 4,4-di-tert-butyl-2,2-
˚
bipyridine), 1.526(3) A. The O–B bond length in all of these
The reaction of B(C6F5) with water has been well documented,14
and the presence of adventitious water has given rise to some
unusual complexes.2 During the attempted crystal growth of the
compound 5, crystals of [Co{HOB(C6F5)3}2{OP(4-F-C6H4)3}2]
that were suitable for structural characterisation were formed. The
molecular structure of compound 9 is shown in Fig. 2. Selected
bond lengths (A) and angles ( ) are given in Table 3 and molecular
parameters are presented in Table 7. Bond lengths of similar
compounds are given in Table 5, for comparison. The cobalt centre
shows a distorted tetrahedral geometry, with Co–O bond lengths
compounds is longer than the 1.487(3) A O–B bond length that
˚
has been reported for the anion [HOB(C6F5)3]−.16 However, the
shorter O–B bond in 7, at 1.484(4) A, is similar.
˚
In each of the two [HOB(C6F5)3] moieties, short O · · · F
bond distances between one of the ortho-fluorine atoms and the
˚
˚
appropriate OB oxygen atom (2.686 A and 2.739 A) are observed.
These values are significantly smaller than the sum of the van der
Waals radii (O 1.52 A and F 1.47 A), and suggest an interaction
between the ortho-fluorine atom of the C6F5 group and the oxygen
atom of the B–O–Co bond. In each case, the C–F bond of the
ortho-fluorine was observed to be the longest of the five C–F bonds
◦
˚
˚
˚
˚
˚
of between 1.920(2) A and 2.022(19) A. These values are similar
to those reported for [Co4(PO4)4]-containing complexes.15
˚
in the C6F5 group (by ca. 0.05 A). Similar interactions have been
˚
Table 4 Selected bond lengths (A)
a
Co–C
C–Oacyl
1.268(3)
C–Oterminal
O–B
[Co(PPh3)(CO)3(C{OB(C6F5)3}Me)]
1.931(3)
1.988(6)
1.976b
1.999 (5)
1.967(2)
1.912b
1.919(2)
1.904(2)
—
1.136(3)
1.145b
1.138b
1.142(3)
1.141(2)
1.13
1.141(3)
—
—
1.561(3)
—
—
—
—
[Co(PPh3)(CO)3(COMe)]9
1.195(7)
[Co(PPh3)(CO)3(C(O)OMe)]11
[Co(PPh3)(CO)3(C(O)CH2Cl)]8
[Co(PPh3)(CO)3(C(O)OnBu)]12
1.196b
1.180b
120.1(2)
10
=
[(Ph3Ge)(CO)3Co( C(OEt)Et)]
—
—
5
[Fe(g -C5H5)(CO)2(C{OB(C6F5)3}Me)]2
1.254(3)
1.297(3)
1.241(7)
1.242(5)
1.253(5
1.570(3)
1.559(3)
1.610(8)
1.576(5)
1.594(6)
5
[Fe(g -C5H5)(PMe3)(CO)(C{OB(C6F5)3}Me)]2
PhC{OB(C6F5)3}H13
PhC{OB(C6F5)3}OEt13
13
PhC{OB(C6F5)3}CH3
—
—
—
—
a Average for 3 terminal CO groups. b esd not given.
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−
˚
Table 5 Selected bond lengths (A) from compounds containing [HOB(C6F5)3]
Compound
Co–O
O–B
O–P
[Co{HOB(C6F5)3}2{OP(4-F-C6H4)3}2]
1.920(2), 2.022(19)
1.484(4), 1.532(3)
1.508(2)
1.526(3)
1.528(3)
1.519(3)
1.487(3)
1.597 (2)
1.499(2), 1.493(2)
5
[Fe(g -C5H5)(PPh3)(CO){HOB(C6F5)3}]2
—
—
—
—
—
—
—
—
—
—
—
—
16
[Pt{HOB(C6F5)3}(bu2bpy)Me]a
[InMe{HOB(C6F5)3}{1,2-(NiPr)2C8H5}]17
5
[Ti(g -C5H5)2][HOB(C6F5)3]18
[NEt3H][HOB(C6F5)3]16
[H2O·B(C6F5)3]19
a bu2bpy = 4,4ꢀ-di-tert-butyl-2,2ꢀ-bipyridine.
5
noted in the compounds [Fe(g -C5H5)(PPh3)(CO){HOB(C6F5)3}]2
of free B(C6F5)3, that is most emphasised for the para resonances.
Typically, these para resonances show an up-field shift of ca.
and [Ti(g -C5H5)2][HOB(C6F5)3].18 Two short Co · · · F (from C6F5)
5
1
15 ppm. Table 6 lists 19F{ H} NMR data for B(C6F5)3 containing
˚
˚
bond distances of 2.752 A and 2.750 A were also observed.
compounds in which a 4-coordinate boron centre is present (data
1
for B(C6F5)3 is also included). Comparison of the 19F{ H} data for
NMR Spectroscopy
the compounds 1–8 with these data, suggests a 4-coordinate boron
1
centre is present in these compounds. The 11B{ H} NMR spectra
The 1H NMR spectra for the B(C6F5)3 adducts 1–5 show a
downfield shift of the singlet resonance, assigned to the acyl
methyl protons, whencompared withtheir parent acylcompounds.
This is consistent with a reduction in the electron density at
the methyl group, caused by coordination of the Lewis acid.
For the compounds 1–5 these methyl resonances are broad
(ca. 30–200 Hz). The corresponding resonances in the parent
acyl compounds are much sharper (ca. 10 Hz).20 Addition of
1 equivalent of B(C6F5)3 to solutions of compounds 1–5, led
for the compounds 1–5 show broad resonances (Table 1) that
are typically 70 ppm up-field from the un-coordinated B(C6F5)3.
These resonances fall into the typical range d + 5 to d − 25 seen
for organometallic compounds containing coordinated B(C6F5)3.
1
The 13C{ H} NMR spectra of the compounds 1–5 show a
characteristic change of the carbonyl resonances on coordination
of B(C6F5)3. In the parent acyl compounds, the terminal carbonyl
resonances are observed as broad singlets at ca. d 200, and the acyl
carbonyl resonance occurs at ca. d 240. This later resonance shows
to a sharpening of the 1H and 31P{ H} NMR resonances in
1
1
1
coupling of the 13C{ H} nucleus to the 31P{ H} nucleus of the
tertiary phosphine ligand. In the corresponding adducts, the com-
pounds 1–5, the terminal carbonyl resonances are also observed at
ca. d 200. On coordination to B(C6F5)3, the carbonyl resonances
of the [COMe] moiety were no longer detectable. This may be due
to exchange between B(C6F5)3 and the oxygen atom of the acyl
all instances, suggesting an equilibrium between the B(C6F5)3-
coordinated and free acyl compounds. Similar equilibria have
been suggested to exist between benzaldehyde/acetophenone and
B(C6F5)3.21 The exchange equilibria between the Lewis acid
adducts 1–5 and the non-coordinated parent acyl compounds
were explored further by a series of variable temperature (VT)
NMR studies. Typically, as the temperature was reduced from
25 ◦C to −60 ◦C, the resonance assigned to the methyl acyl group
sharpened, indicating that as the temperature decreased, both the
relative amount of B(C6F5)3-coordinated adduct increases, and
the rate of exchange decreases, leading to sharper resonances. By
contrast, the compounds 6–8, showed sharp methyl resonances.
1
group. Similarly, the 13C{ H} spectra of the compounds 6–8 show
only carbonyl resonances assignable to terminal carbonyl groups.
Conclusion
The reaction between B(C6F5)3 and the compounds [Co(L)-
The 19F{ H} NMR chemical shifts of the B(C6F5)3 moiety in
(CO)3(COMe)] (L = PMe3, PPhMe2, P(4-Me-C6H4)3, PPh3 and
1
5
the compounds 1–8 (Table 1) show a characteristic up-field shift
of the ortho, meta and para resonances, when compared with those
P(4-F-C6H4)3), [Mn(CO)5(COMe)] and [Mo(PPh3)(g -C5H5)(CO)2-
(COMe)] gave the adducts [Co(L)(CO)3(C{OB(C6F5)3}Me)]
1
1
Table 6 Comparison of 11B{ H} and 19F{ H} NMR resonances
19F{ H} (d)
1
1
Compound
B(C6F5)3
11B{ H} (d)
ortho
para
meta
65.47
−128.6
−134.0
−133.5
−134.2
—
−144.3
−158.6
−156.8
−163.9
—
−164.6
−164.7
−163.8
−169.0
—
5
[Fe{(l-CN)B(C6F5)3}(g -C5H5)(CO)2]22
−22.4 (br)
−14.1 (br)
−6.5 (br)
2.4 (br)
2.5 (br)
4.6 (br)
1.6 (s)
5
[Fe(g -C5H5)(PMe3)(CO)(C{OB(C6F5)3}Me)]2
[Mo[NB(C6F5)3(SCNMe2)3]23
[MoO{OB(C6F5)3}(g -ONEt2)2]24
2
[Mo{OB(C6F5)3}{HB(dmpz)3}(S2CNMe2)]a
—
—
—
25
[Re{OB(C6F5)3}{HB(pz)3}(OCH2CH2O)]b
25
5
[W(g -C5H5)2{OB(C6F5)3}]26
[Mo(C5H4Me)2{OB(C6F5)3}]26
2.3 (s)
—
—
—
a dmpz = 3,5-dimethylpyrazolyl. b pz = pyrazolyl.
1780 | Dalton Trans., 2006, 1776–1783
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(L = PMe3 1, PPhMe2 2, P(4-Me-C6H4)3 3, PPh3 4, P(4-
reduced pressure, to yield 2 as a sticky orange solid, which was
then dried under vacuum. Yield of 2 = quantitative.
5
F-C6H4)3 5), [Mn(CO)5(C{OB(C6F5)3}Me)]
6
and [Mo(g -
C5H5)(PPh3)(CO)2(C{OB(C6F5)3}Me)] 7. Addition of B(C6F5)3
5
to a cooled solution of [Mo(g -C5H5)(CO)3(Me)], under an
Preparation of [Co(P(4-Me-C6H4)3(CO)3(C{OB(C6F5)3}Me)] 3
5
atmosphere of CO gave [Mo(g -C5H5)(CO)3(C{OB(C6F5)3}Me)],
A solution of B(C6F5)3 (187 mg, 0.366 mmol) in benzene
(20 ml) was added dropwise to a yellow solution of [Co(P(4-Me-
C6H4)3)(CO)3(COMe)] (180 mg, 0.366 mmol) in benzene (20 ml).
The resulting solution was left stirring at room temperature for
48 h, forming an orange solution. Solvents were removed under
reduced pressure leaving 3 as an off-white solid, which was then
dried under vacuum. Yield of 3 = quantitative.
8. The use of B(C6F5)3 as a catalyst for the CO-induced migratory-
insertion has been demonstrated.
Experimental
All manipulations of air- and/or moisture-sensitive compounds
were carried out under an inert atmosphere of dinitrogen, in
either an inert-atmosphere box or using standard Schlenk line
techniques. Solvents used in the preparation of air- and/or
moisture-sensitive compounds were dried by passage through
an alumina column under a positive pressure of dinitrogen.
Dinitrogen was passed through the dried solvents for twenty
minutes before use. Deuterated solvents were degassed using
three freeze–pump–thaw cycles and were vacuum distilled
from potassium or sodium (d6-benzene, d8-toluene) or CaH2
(CD2Cl2). Solution NMR spectra were recorded with either
a Varian UNITYplus (1H: 500.0 MHz, 13C: 125.7 MHz, 31P:
202.4 MHz, 19F: 470.4, 11B: 160.4 MHz) or a Varian Mercury
300 (1H: 300.2 MHz, 13C: 75.5 MHz, 31P: 121.5 MHz, 19F
282.3 MHz,) spectrometer. The spectra were either internally
referenced relative to the residual protio-solvent (1H) and solvent
(13C) resonances relative to trimethylsilane (1H, 13C, d = 0
ppm), or were referenced externally, relative to H3PO4 (31P,
d = 0 ppm), CFCl3 (19F, d = 0 ppm), or BF3.Et2O (11B, d =
0 ppm). Infrared spectra were recorded on either a Perkin-
Elmer 1710 FTIR spectrometer or a Perkin-Elmer 1600 FTIR
instrument in the range 4000–400 cm−1. Samples were prepared
either as Nujol mulls between KBr plates, or as solutions in
CH2Cl2. Data are quoted in wavenumbers (cm−1). The following
compounds were synthesised according to literature methods:
Preparation of [Co(PPh3)(CO)3(C{OB(C6F5)3}Me)] 4
A solution of B(C6F5)3 (285 mg, 0.557 mmol) in benzene (20 ml)
was added dropwise to a yellow solution of [Co(PPh3)(CO)3-
(COMe)] (250 mg, 0.557 mmol) in benzene (20 ml). The resulting
solution was left stirring at room temperature for 2 h to give a
pale yellow/green solution. Solvents were removed under reduced
pressure and the resulting solid was dried under vacuum to
yield 4 as an off white solid. Crystals suitable for structural
characterisation were grown by slow diffusion of pentane into
a saturated benzene solution. Yield of 4 = quantitative.
Preparation of [Co(P(4-F-C6H4)3)(CO)3(C{OB(C6F5)3}Me)] 5
A solution of B(C6F5)3 (181 mg, 0.352 mmol) in benzene
(20 ml) was added slowly to a yellow solution of [Co(P(4-F-
C6H4)3)(CO)3(COMe)] (180 mg, 0.352 mmol) in benzene (20 ml).
The resulting solution was left stirring at room temperature
overnight, forming an orange solution. Solvents were removed
under reduced pressure to yield 5 as an off-white solid that was
dried under vacuum. Yield of 5 = quantitative.
Preparation of [Mn(CO)5(C{OB(C6F5)3}Me)] 6
B(C6F5)3,27
[Co(PPh3)(CO)3(Me)],28
[Co(L)(CO)3(COMe)]
(L = PMe3, PPhMe2, P(4-Me-C6H4)3, and P(4-F-C6H4)3),20
A sample of [Mn(CO)5(COMe)], (100 mg, 0.420 mmol) was
dissolved in toluene (20 ml) and was cooled to −78 ◦C. A
solution of B(C6F5)3, (215 mg, 0.420 mmol) in toluene (20 ml)
was then added. The resulting solution was allowed to warm to
room temperature under stirring for 1 h. During this time the
solution changed colour from pale yellow to colourless. Removal
of solvents under reduced pressure left 6 as an off-white solid,
which was dried under vacuum. Yield of 6 = quantitative.
[Co(PPh3)(CO)3(COMe)],29 [Fe(g -C5H5)(CO)2(Me)],30 [Fe(g -
5
5
C5H5)(PPh3)(CO)(COMe)],31
[Mn(CO)5(COMe)],32
[Mo(g -
5
C5H5)(PPh3)(CO)2(COMe)],33 [Mo(g -C5H5)(CO)3(Me)].30
5
Preparation of [Co(PMe3)(CO)3(C{OB(C6F5)3}Me)] 1
A solution of B(C6F5)3 (580 mg, 1.14 mmol) in dichloromethane
(10 ml) was added slowly to
a
yellow solution of
Preparation of [Mo(g5-C5H5)(PPh3)(CO)2(C{OB(C6F5)3}Me)] 7
[Co(PMe3)(CO)3(COMe)] (300 mg, 1.14 mmol) in dichloro-
methane (20 ml). The resulting solution was left stirring at room
temperature for 2 h, giving a pale yellow solution. Solvents were
removed under reduced pressure, to yield 1 as a sticky yellow solid,
which was then dried under vacuum. Yield of 1 = quantitative.
5
[Mo(g -C5H5)(PPh3)(CO)2(COMe)] (200 mg, 0.381 mmol) was
dissolved in dichloromethane (20 ml). A solution of B(C6F5),
(195 mg, 0.381 mmol) in dichloromethane (20 ml) was then added
dropwise and the solution stirred at room temperature for 2 h.
Removal of solvents under reduced pressure gave 7 as a yellow
solid, which was dried under vacuum. Yield of 7 = quantitative.
Preparation of [Co(PPhMe2)(CO)3(C{OB(C6F5)3}Me)] 2
A solution of B(C6F5)3 (47 mg, 0.09 mmol) in dichloromethane
(20 ml) was added slowly to a yellow solution of [Co(PPhMe2)-
(CO)3(COMe)] (30 mg, 0.09 mmol) in dichloromethane (20 ml).
The resulting solution was left stirring at room temperature for
2 h to give a pale yellow solution. Solvents were removed under
Preparation of [Mo(g5-C5H5)(CO)3(C{OB(C6F5)3}Me)] 8
5
[Mo(g -C5H5)(CO)3(Me)] (250 mg, 0.961 mmol) was dissolved in
dichloromethane (20 ml) and cooled to −78 ◦C. A solution of
B(C6F5)3 (291 mg, 0.961 mmol) in dichloromethane (20 ml) was
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then added dropwise. The cooled Schlenk was then quickly pump-
filled 5 times with 0.5 bar CO. This was then stirred under a 0.5
bar CO atmosphere at −78 ◦C for 1 h, and at room temperature
for 17 h. During this time the solution darkened from yellow to
orange. Removal of volatiles yielded a pale orange solid. This was
washed with pentane (3 × 20 ml) to give 8 as a pale orange solid
that was dried under vacuum. Yield of 8 = 472 mg (61.4%).
bath was then removed and the solution stirred for a further 24 h.
Removal of solvents under reduced pressure left an orange solid.
1H NMR and IR spectroscopies indicated that only unreacted
5
[Fe(g -C5H5)(CO)2(Me)] was present.
Reaction of [Mn(CO)5(Me)] with B(C6F5)3 under a CO atmosphere
A solution of [Mn(CO)5(Me)] (100 mg, 0.476 mmol) in dry
dichloromethane (10 ml) was cooled to −78 ◦C. A solution
of B(C6F5)3 (195 mg, 0.476 mmol) in dichloromethane (10 ml)
was then added, and the reaction vessel purged with CO. A
0.5 atm pressure of CO was then introduced, and the solution
allowed to warm to room temperature under stirring. Stirring
was continued at room temperature for 1 h. Removal of solvents
Preparation of [Co{HOB(C6F5)3}2{OP(4-F-C6H4)3}2] 9
A 50 mg sample of [Co(P(4-F-C6H4)3)(CO)3(C{OB(C6F5)3}Me)]
was dissolved in benzene (10 ml) and was introduced into one half
of a crystallisation bridge. The other half was filled with pentane
(10 ml). After 3 weeks blue crystals of 9 suitable for structural
characterisation were isolated.
1
under reduced pressure yielded a white solid. 1H, 13C{ H}
NMR and IR data indicated the quantitative formation of
Reaction of [Co(PPh3)(CO)3(Me)] with B(C6F5)3 under a CO
atmosphere
[Mn(CO)5(C{OB(C6F5)3}Me)].
The compound [Co(PPh3)(CO)3(Me)] (100 mg, 0.238 mmol) was
dissolved in dichloromethane (10 ml) and cooled to −78 ◦C. A
solution of B(C6F5)3 (121 mg, 0.238 mmol) in dichloromethane
(10 ml) was then added. A 1 atm pressure of CO was then
introduced, and the resulting mixture stirred for 1 h. Solvents
were removed under reduced pressure to leave a yellow powder.
Reaction of [Mn(CO)5(Me)] under a CO atmosphere in the
absence of B(C6F5)3
A solution of [Mn(CO)5(Me)] (100 mg, 0.476 mmol) in dry
dichloromethane (10 ml) was cooled to −78 ◦C. The reaction
vessel was then purged with CO. A 0.5 atm pressure of CO was then
introduced, and the solution allowed to warm to room temperature
under stirring. Stirring was continued at room temperature for
17 h. Removal of solvents under reduced pressure yielded a white
1
1
1H, 31P{ H}, 19F{ H} NMR and IR spectroscopies indicated the
quantitative formation of [Co(PPh3)(CO)3(C{OB(C6F5)3}Me)].
Reaction of [Co(PPh3)(CO)3(Me)] under a CO atmosphere in the
absence of B(C6F5)3
1
solid. The 1H and 13C{ H} NMR and IR data of this solid
indicated the formation of [Mn(CO)5(COMe)] in a yield of 72%
as judged by integration of CH3 resonances.
The compound [Co(PPh3)(CO)3(Me)] (100 mg, 0.238 mmol) was
dissolved in dichloromethane (10 ml) and cooled to −78 ◦C. A
1 atm pressure of CO was then introduced. and the resulting
mixture stirred for 1 h. Solvents were removed under reduced
Reaction of [Mo(g5-C5H5)(CO)3(Me)] with B(C6F5)3 under a CO
atmosphere
1
1
1
pressure to leave a yellow powder. H, 31P{ H}, 19F{ H} NMR
and IR spectroscopies indicated the quantitative formation of
[Co(PPh3)(CO)3(COMe)].
5
The compound [Mo(g -C5H5)(CO)3(Me)] (100 mg, 0.385 mmol)
was dissolved in dichloromethane (10 ml) and the resulting
solution cooled to −78 ◦C. A solution of B(C6F5)3 (195 mg,
0.385 mmol) in dichloromethane (10 ml) was then added. The
reaction vessel was then purged with CO. A 0.5 atm pressure
of CO was then introduced and the solution stirred for 1 h, then
allowed to warm to room temperature under stirring. The solution
was then stirred at room temperature for a further 1 h. Removal
of solvents under reduced pressure yielded a yellow solid. The 1H,
13C{H} NMR and IR spectra indicated the quantitative formation
Reaction of [Fe(g5-C5H5)(CO)2(Me)] with B(C6F5)3 under a CO
atmosphere
5
A solution of [Fe(g -C5H5)(CO)2(Me)] (25 mg, 0.13 mmol) in
toluene (10 ml) was cooled to −78 ◦C. A solution of B(C6F5)3
(66 mg, 0.13 mmol) in toluene (10 ml) was then added, and the
reaction vessel purged with CO. A 0.5 atm pressure of CO was
then introduced, and the solution stirred at −78 ◦C for 1 h.
The cardice/acetone bath was then removed and the solution
stirred for a further 24 h. Removal of solvents under reduced
5
of [Mo(g -C5H5)(CO)3(C{OB(C6F5)3}Me)]
Reaction of [Mo(g5-C5H5)(CO)3(Me)] under a CO atmosphere in
the absence of B(C6F5)3
1
1
1
pressure left an orange solid. H, 19F{ H}, 11B{ H} NMR and
5
IR spectroscopies indicated that the solid contained 40% [Fe(g -
C5H5)(CO)2(C{OB(C6F5)3}Me)], as judged by integration of the
5
The compound [Mo(g -C5H5)(CO)3(Me)] (100 mg, 0.385 mmol)
5
(g -C5H5) environments from the 1H NMR spectrum.
was dissolved in dichloromethane (10 ml) and was cooled to
−78 ◦C. The reaction vessel was then purged with CO. A 0.5
atm pressure of CO was then introduced and the solution allowed
to warm to room temperature under stirring. The solution was
then stirred at room temperature for 1 h. Removal of solvents
under reduced pressure yielded a yellow solid. The 1H NMR and
IR spectra of this residue indicated that only unreacted starting
materials were present
Reaction of [Fe(g5-C5H5)(CO)2(Me)] under a CO atmosphere in
the absence of B(C6F5)3
5
A solution of [Fe(g -C5H5)(CO)2(Me)] (25 mg, 0.13 mmol) in
toluene (10 ml) was cooled to −78 ◦C, and the reaction vessel
purged with CO. A 0.5 atm pressure of CO was then introduced,
◦
and the solution stirred at −78 C for 1 h. The cardice/acetone
1782 | Dalton Trans., 2006, 1776–1783
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Table 7 Crystallographic data for compounds 4 and 9
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4
9
Chemical formula
Formula weight
Crystal system
Space group
C41H18BCoF15O4P
960.28
Monoclinic
P 21/c
12.5164(3)
17.0794(5)
18.0656(4)
90
99.4628(11)
150
3809.4
4
C72H26B2CoF36O4P2
1781.43
Monoclinic
P 21/c
20.2640(2)
13.0854(2)
25.3366(2)
90
˚
a/A
˚
b/A
˚
c/A
c /◦
b/◦
93.9521(5)
150
6702.3
T/K
3
˚
10 F. Carre, G. Cerveau, E. Colomer, R. J. P. Corriu, J. C. Young, L. Ricard
and R. Weiss, J. Organomet. Chem., 1979, 179, 215–226.
11 D. Milstein and J. L. Huckaby, J. Am. Chem. Soc., 1982, 104, 6150–
6152.
V/A
Z
4
l/mm−1
0.610
37239
0.458
87004
Reflections measured
12 T. Bartik, T. Kruemmling, C. Krueger, L. Marko, R. Boese, G. Schmid,
P. Vivarelli and G. Palyi, J. Organomet. Chem., 1991, 421, 323–333.
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Organometallics, 1998, 17, 1369–1377.
Unique reflections
8941
0.073
5530
568
15818
0.042
10011
1062
Rint
Observed reflections
Parameters refined
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2000, 39, 1426–1433.
R
wR
0.0390
0.0480
0.0504
0.0599
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Crystallography
Data collections were performed by Dr A. R. Cowley, us-
ing an Enraf-Nonius KappaCCD diffractometer (graphite-
˚
monochromated MoKa radiation, k = 0.71073 A). Intensity data
19 L. H. Doerrer and M. L. H. Green, J. Chem. Soc., Dalton Trans., 1999,
were processed using the DENZO-SMN package.34 The crystal
structures were solved using direct-methods program SIR92,35
which located all non-hydrogen atoms. Subsequent full-matrix
least-squares refinement was carried out using the CRYSTALS36
program suite. Coordinates and anisotropic thermal parameters
of all non-hydrogen atoms were refined. Hydrogen atoms were
positioned geometrically after each cycle of refinement. A 3-term
Chebychev polynomial weighting scheme was applied. Crystal
structure diagrams were produced using the CRYSTALS36 pro-
gram suite. Molecular parameters are presented in Table 7.
CCDC reference numbers 287089 and 287090.
4325–4329.
20 S. A. Llewellyn, M. L. H. Green and A. R. Cowley, J. Organomet.
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25 L. H. Doerrer, J. R. Galsworthy, M. L. H. Green and M. A. Leech,
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26 J. R. Galsworthy, J. C. Green, M. L. H. Green and M. Muller, J. Chem.
Soc., Dalton Trans., 1998, 15–20.
For crystallographic data in CIF or other electronic format see
DOI: 10.1039/b514889h
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Acknowledgements
We thank the EPSRC for a grant (S.A.L).
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The Royal Society of Chemistry 2006
Dalton Trans., 2006, 1776–1783 | 1783
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