Mono- And homobimetallic vanadium complexes: Borane adducts of vanada(IV)azirine complexes

Article abstract of DOI:10.1021/om049488t

The reaction between [VCp₂], BPh₃, or BCl₃ and the nitrile F₃CC₆H₄C≡N gives the borane adduct of vanada(IV)azirine complex [VCp₂{η²:C, N-F₃CC₆H

Full text of DOI:10.1021/om049488t

5488
Organometallics 2004, 23, 5488-5492
Mono- and Homobimetallic Vanadium Complexes:
Borane Adducts of Vanada(IV)azirine Complexes
Robert Choukroun,* Christian Lorber, Laure Vendier, and Bruno Donnadieu
Laboratoire de Chimie de Coordination, CNRS, 205 Route de Narbonne,
31077 Toulouse Cedex, France
Received July 8, 2004
The reaction between [VCp2], BPh3, or BCl3 and the nitrile F3CC6H4CtN gives the borane
adduct of vanada(IV)azirine complex [VCp2{η2:C,N-F3CC6H4CdN‚BR3}] (R ) Ph (2), Cl (3)).
Using B(C6F5)3 and dicyano compounds such as 1,4-benzene dicarbonitrile NtC(C6H4)CtN
and adiponitrile NtC(CH2)4CtN, an access to homobimetallic vanadium complexes was
obtained and complexes [(VCp2)2{η2:C,N-(C6F5)3B‚NdC(C6H4)CdN‚B(C6F5)3}] (6) and [(VCp2)2-
{η2:C,N-(C6F5)3B‚NdC(CH2)4CdN‚B(C6F5)3}] (8) are formed. Malononitrile NtCCH2CtN in
the presence of 2 equiv of B(C6F5)3 and 1 or 2 equiv of [VCp2] gave the monometallic complex
[(VCp2){η2:C,N-(C6F5)3B‚NdCCH2CtN‚B(C6F5)3}] (7). Complexes 2, 3, 7, and 8 were
characterized by X-ray structure determination. All these complexes are paramagnetic to
one electron per vanadium.
Scheme 1
Introduction
Adducts of nitrile RCN with Lewis acid have been
reported for a long time and widely studied.1 Recently,
we demonstrated that the coordination of a Lewis acid
to a nitrile modifies the reactivity of the -CtN bond,
and the adduct RCtN‚Lewis acid is now considered as
being a ligand containing an “activated” -CtN bond.
The Lewis acid-activated nitrile was used as a reagent
to facilitate η2:C,N interaction with the vanadocene
[VCp2] to give a borane adduct of vanada(IV)azirine
complexes [Cp2V{η2:C,N-RCdN‚B(C6F5)3}] (R ) CH3, F3-
CC6H4),2 for which EPR spectra provide evidence of a
C-F‚‚‚V intramolecular interaction. Similarly, the
titanocene [Cp2Ti(CO)2] was shown to give a borane
adduct of titana(IV)azirine complex [Cp2Ti{η2:C,N-RCd
N‚B(C6F5)3}] (R ) F3CC6H4).3
Herein, we will describe an extension of this work by
using different boranes such as BCl3 and the less acidic
borane B(C6H5)3 on trifluoro-p-tolunitrile F3CC6H4-
CtN. We shall also extend the reactivity of B(C6F5)3 to
nitrile ligands containing two -CtN nitrile functions
in order to synthesize binuclear vanadium(IV) com-
plexes in which d1-d1 interaction could be potentially
present.
Results and Discussion
Reactivity of [VCp2], Borane BR3 (R ) Ph, Cl),
and Nitrile F3CC6H4CtN. Our precedent studies on
BR3 (R ) C6F5, 2,6-F2C6H3, and 3,4,5-F3C6H2) with
R1CtN (R1 ) CH3, F3CC6H4) and [VCp2] (1) demon-
strate the facile formation of borane adducts of vanada-
(IV)azirine complexes [VCp2{η2:C,N-R1CdN‚BR3}] and,
via EPR spectroscopy, that complexes having an ortho-
fluorine atom in the borane group exhibit a V‚‚‚F
interaction between the vanadium center and the
fluorine atom in ortho-position (R ) C6F5, 2,6- F2C6H3).2
We extended this work on BPh3 and BCl3 assuming that
we could prepare other varieties of borane adducts of
vanada(IV)azirine complexes and to confirm that no
EPR interaction is observed between the vanadium
center and the hydrogen atom of the borane in the case
of R ) C6H5 as was observed in the case of R ) 3,4,5-
F3C6H2.
A 1:1 molar mixture of BPh3 and F3CC6H4CtN in
pentane is added to a pentane solution of 1 and left 2
days at room temperature; purple crystals of [VCp2-
{η2:C,N-F3CC6H4CdN‚BPh3}] (2) appear (Scheme 1),
supported by an X-ray structure determination (Figure
1). It is remarkable that the nitrile RCtN could react
with the borane BPh3, in the presence of 1. It is well
known that the presence of a phenyl group attached to
* To whom correspondence should be addressed. E-mail: choukrou@
lcc-toulouse.fr.
(1) (a) Shriver, D. F.; Swanson, B. Inorg. Chem. 1971, 10, 1354-
1365. (b) Swanson B.; Shriver, D. F. Inorg. Chem. 1969, 8, 6-1416. (c)
Hoard, J. L.; Owen, T. B.; Buzzell, A.; Salmon, N. O. Acta Crystallogr.
1950, 3, 130-137. (d) Hoard, J. L.; Geller, S.; Owen, T. B. Acta
Crystallogr. 1951, 4, 405-407. (e) Li, L.; Marks, T. J. Organometallics
1998, 17, 3996-4003. (f) Tornieporth-Oetting, I. C.; Klapo¨tke, T. M.;
Cameron, T. S.; Vallonen, J.; Rademacher, P.; Kowski, K. J. Chem.
Soc., Dalton Trans. 1992, 537-541. (g) Hoti, R.; Mihalic, Z.; Vancik,
H. Croatica Chem. Acta 1995, 2, 359-371. (h) Jacobsen, H.; Berke,
H.; Do¨ring, S.; Kehr, G.; Erker, G.; Fro¨hlich, R.; Meyer, O. Organo-
metallics 1999, 18, 1724-1735. (i) Vei, I. C.; Pascu, S. I.; Green, M. L.
H.; Green, J. C.; Schilling, R. E; Anderson, G. D. W.; Rees, L. H. Dalton
Trans. 2003, 2550-2557.
(2) Choukroun, R.; Lorber, C.; Donnadieu B. Chem. Eur. J. 2002,
8, 2700-2704.
(3) Choukroun, R.; Lorber, C.; Vendier, L. Eur. J. Inorg. Chem. 2004,
317-321.
10.1021/om049488t CCC: $27.50 © 2004 American Chemical Society
Publication on Web 10/12/2004

Borane Adducts of Vanada(IV)azirine Complexes
Organometallics, Vol. 23, No. 23, 2004 5489
Table 1. Selected Bond Lengths (Å) and Angles (deg) for 2, 3, 4, and 5
4
2
3
[F3CC6H4CtN‚B(C6F5)3]
5b
[VCp2{η2-F3CC6H4CdN‚L}]
L ) BPh3
L ) BCl3
[F3CC6H4CtN]a
L ) B(C6F5)3
V-N(1)
2.096(4)
2.033(5)
1.237(5)
2.071(3)
2.049(3)
1.248(4)
2.0922(17)
2.032(2)
1.236(3)
V-C(1)
N(1)-C(1)
1.15(2)
[1.1482(14)]
1.59(2)
1.45(3)
[1.4500(13)]
N(1)-B(1)
C(1)-C(2)
1.622(6)
1.471(6)
1.525(5)
1.459(5)
1.586(3)
C(1)-V(1)-N(1)
N(1)-C(1)-C(2)
34.83(15)
139.3(5)
35.25(12)
136.7(3)
34.83(7)
137.9(2)
177(2)
[179.59(12)]
174(2)
C(1)-N(1)-B(1)
145.7(4)
142.6(3)
138.52(18)
a The main distances and angles of the trifluoro-p-tolunitrile are reported in brackets.10 b See ref 2.
Figure 2. Molecular structure of 3 with partial atom
labeling. Hydrogen atoms are omitted for clarity.
agreement with the νCdN frequencies observed for these
complexes (2, 1752 cm-1; 5, 1731 cm-1; 3, 1725 cm-1).
Both 2 and 3 are paramagnetic to one electron as VIV
species (µeff ) 1.81 and 1.65 µB, respectively). EPR
studies of 2 and 3 were carried out in THF. For 2 and
3, the formation of an octet was observed, due to the
coupling of the unpaired electron of the vanadium atom
with the 51V (I ) 7/2) nucleus (2, g ) 1.997, a(51V) 42.0
G; 3, g ) 1.999, a(51V) 41.0 G). Variable-temperature
experiments from -60 to +90 °C do not show any
change. No additional hyperfine coupling of the un-
paired electron of the vanadium atom with the hydrogen
atom of the borane BPh3 was observed for 2. This result
confirms our previous results on [VCp2{η2:C,N-F3-
CC6H4CdN‚B(3,4,5-F3C6H2)3}] in which the absence of
a fluorine atom in the ortho-position of the borane
B(3,4,5-F3C6H2)3 gives the octet EPR spectrum. In
contrast, 5 or [VCp2{η2:C,N-F3CC6H4CdN‚B(2,6-F2C6-
H3)3}], in which two fluorine atoms are in ortho-position
of the phenyl rings, give a doublet of octets due to a
C-F‚‚‚V interaction and subsequent hyperfine coupling
a(19F).2
Reactivity of [VCp2], Borane B(C6F5)3, and Dini-
trile NtC-(X)-CtN (X ) C6H4, CH2, (CH2)4). In
attempts to synthesize a bimetallic vanadium d1-d1
complex with a potential magnetic interaction between
the two centers,6 the choice of the ligand was first
reported on 1,4-benzene dicarbonitrile NtC-(C6H4)-
CtN, an aromatic unit between two nitrile groups.
Following the same experimental procedure as above,
2 equiv of 1 was reacted in a mixture of NtC-(C6H4)-
CtN in the presence of 2 equiv of B(C6F5)3 in a toluene
Figure 1. Molecular structure of 2 with partial atom
labeling. Hydrogen atoms are omitted for clarity.
the boron atom decreases the boron-donor bond strength.4
In the absence of [VCp2], IR spectra in toluene of a
mixture of nitrile F3CC6H4CtN and BPh3 (1:1 or 1:5
ratio) do not show any change in the position of the νCN
(2234 cm-1) due to an eventual formation of the borane‚
Lewis acid adduct (some rare examples of BPh3‚Lewis
base adducts are known with amine NR3 and pyridine
but to our knowledge not with nitrile). Nevertheless, it
is clear that an undetectable small amount of the adduct
is formed, which allows the formation of 3. A fast
reaction was also observed between 1, trifluoro-p-
tolunitrile, and BCl3. By mixing a hexane solution of
BCl3 and F3CC6H4CtN in toluene, followed by the
addition of 1 in toluene, blue-violet crystals were formed
and identified as [Cp2V{η2:C,N-F3CC6H4CdN‚BCl3}] (3)
(Scheme 1) by an X-ray structure determination (Figure
2). All the structural details of bonds and angles of 2
and 3 and for comparison those obtained from the X-ray
structure of the borane adduct F3CC6H4CtN‚B(C6F5)3
(4)5 (although the crystals obtained were of poor quality)
and from the previously reported [Cp2V{η2:C,N-F3-
CC6H4CdN‚B(C6F5)3}]2 (5) are collected in Table 1.
Changing the B(C6F5)3 by B(C6H5)3 or BCl3 in the borane
adduct of vanada(IV)azirine complex shows slight dif-
ferences for the VNC cycle moiety in which a CdN
double bond is now formed. In contrast, B-N distances
are modified according to the expected Lewis acidity
strength of the borane, BCl3 > B(C6F5)3 > BPh3, and in
(4) Onak, T. Organoborane Chemistry; Organometallic Chemistry
Series; Academic Press: New York, 1975.
(5) The related borane adduct H3CC6H4CN‚B((C6F5)3 was recently
(6) Paul, F.; Lapinte, C. Coord. Chem. Rev. 1998, 178-180, 431-
509.
isolated and characterised by Erker and colleagues.1h

5490 Organometallics, Vol. 23, No. 23, 2004
Choukroun et al.
Scheme 2
Table 2. Selected Bond Lengths (Å) and Angles (deg) for 7, 8, and 9
8
7
9
V(1)-N(1)
V-C(1)
2.114(3)
2.022(4)
V(1)-N(1)
2.098(4)
2.107(4)
2.031(5)
2.042(5)
1.244(6)
1.253(6)
1.581(7)
1.594(7)
35.02(17)
35.11(17)
137.0(4)
V(2)-N(2)
V(1)-C(1)
V(2)-C(6)
N(1)-C(1)
1.236(5)
1.133(4)
1.596(5)
1.598(5)
34.68(13)
N(1)-C(1)
N(1)-C(1)
N(2)-C(3)
N(1)-B(1)
1.130(5)
1.131(6)
1.605(5)
N(2)-C(3)
N(2)-C(6)
N(1)-B(1)
N(1)-B(1)
N(2)-B(2)
N(2)-B(2)
C(1)-V(1)-N(1)
C(1)-V(1)-N(1)
C(6)-V(2)-N(2)
N(1)-C(1)-C(2)
N(1)-C(1)-C(2)
C(2)-C(3)-N(2)
131.7(4)
178.0(4)
N(2)-C(6)-C(5)
C(1)-N(1)B(1)
C(6)-N(2)-B(2)
135.1(5)
139.1(4)
138.3(4)
C(1)-N(1)-B(1)
C(3)-N(2)-B(2)
141.5(3)
177.2(4)
C(1)-N(1)-B(1)
178.2(4)
Scheme 3
Complex 8 has a dihedral angle between the VCN units
(V(1)C(1)N(1) and V(2)C6)N(2)) of nearly 76°, and only
carbon atoms C(1) to C(5) lie in the same plane. The
relevant distances and angles of the X-ray structure
elucidation of the malonitrile with one B(C6F5)3 as Lewis
acid adduct [NtCCH2CtN‚B(C6F5)3] (9) are also re-
ported in Table 2. The adduct with two borane groups
Scheme 4
solvent, to give a microcrystalline blue-violet solid.
Unfortunately, efforts to obtain suitable crystals for an
X-ray diffraction analysis have failed to date (it is
noteworthy that it is more advisable to characterize
paramagnetic isolated vanadium IV complexes by an
X-ray structure determination to assess without ambi-
guity its chemical environment around the paramag-
netic vanadium center). The formation of the solid as
[(VCp2)2{η2:C,N-(C6F5)3B‚NdC(C6H4)CdN‚B(C6F5)3}] (6)
was based on the analytical and spectroscopic data
(Scheme 2; see Experimental Section). Malononitrile
NtCCH2CtN and adiponitrile NtC(CH2)4CtN were
also investigated toward [VCp2] in the presence of
borane B(C6F5)3 to give a platform for the attachment
of two VCp2 units separated by one or four methylene
spacers, leading to the formation of a d1-d1 system.
However with malonitrile in the presence of 2 equiv of
borane, whatever the stoichiometry of 1 (1 or 2 equiv),
only the monometallic [VCp2{η2:C,N-(C6F5)3B‚NdCCH2-
CtN‚B(C6F5)3}] complex (7) was isolated (Scheme 3).
In the case of adiponitrile, a homobimetallic complex,
[(VCp2)2{η2:C,N-(C6F5)3B‚NdC(CH2)4CdN‚B(C6F5)3}] (8),
was isolated (Scheme 4). Both 7 and 8 were isolated in
crystallized forms with toluene and studied by X-ray
crystallography (Figure 3 and Figure 4). A summary of
the crystallographic data is listed in Table 2 and is
closely similar to those of compounds 2, 3, 4, and 5.
Figure 3. Molecular structure of 7 with partial atom
labeling. Hydrogen atoms are omitted for clarity.
Figure 4. Molecular structure of 8 with partial atom
labeling. Hydrogen atoms are omitted for clarity.

Borane Adducts of Vanada(IV)azirine Complexes
Organometallics, Vol. 23, No. 23, 2004 5491
resonances and are reported relative to tetramethylsilane (δ
) 0 ppm). 19F NMR (188.298 MHz) spectra were recorded on
a Bruker AC-200 spectrometer (reference CF3CO2H). 11B NMR
(128.378 MHz) spectra were recorded on a Bruker AC-400
spectrometer (reference BF3‚Et2O). Elemental analyses were
performed in the laboratory (C,H,N). Magnetic susceptibilities
were determined by Faraday’s method and a Squid suscep-
tometer within the temperature range 2-300 K. EPR spectra
were obtained by using a Bruker ESP300E spectrometer.
[VCp2{η2-(F3CC6H4)CdN‚B(C6H5)3}] (2). In a typical ex-
periment, F3CC6H4CtN (42 mg, 0.24 mmol) in 10 mL of
pentane was added to a solution of borane B(C6H5)3 (65 mg,
0.27 mmol) in pentane (5 mL) and the freshly resulting
solution added to Cp2V (45 mg, 0.25 mmol) in pentane (5 mL).
The solution was left for 2-3 days at room temperature to give
purple crystals of 2. Yield of 2: 105 mg (72%). Anal. Calcd for
2, C36H29BF3NV (594.3): C 72.75, H 4.92, N 2.36. Found: C
72.63,H 5.05, N 2.42.
on malonitrile [(C6F5)3B‚NtCCH2CtN‚B(C6F5)3] (10)
was also isolated (see Experimental Section).
IR spectroscopy shows νCdN frequencies at 1735 cm-1
for 6, two bands νC≡N and νCdN at 2356 and 1740 cm-1
,
respectively, for 7, and two bands νC)N at 1744 and 1734
cm-1 for 8. X-band EPR spectra of 6, 7, and 8 were
carried out in THF. The formation of a doublet of octets
was observed and confirmed by Q-band EPR experi-
ments. Coupling of the unpaired electron of the vana-
dium atom with the 51V (I ) 7/2) nucleus and the ortho-
fluorine atoms of the borane B(C6F5)3 via a C-F‚‚‚V
interaction give rise to these spectra (6, g ) 1.997, a(51V)
43.6 G, a(19F) 17.7 G; 7, g ) 1.996, a(51V) 43.4 G, a(19F)
17.4 G; 8, g ) 1.996, a(51V) 43.6 G, a(19F) 17.7 G).
Mononuclear complex 7 is paramagnetic to one electron
as VIV species (µeff ) 1.72 µB). Complexes 6 and 8 have
been studied by variable-temperature magnetic suscep-
tibility measurements resulting from homobimetallic
d1-d1 situations. The effective magnetic moment µeff per
vanadium is nearly the same from 300 to 2 K (1.63-
1.66 µB for 6 and 1.60-1.55 µB for 8) and denotes two
noninteracting d1 vanadium atoms in both complexes.
Unfortunately, these paramagnetic d1-d1 systems do
not present any antiferromagnetism interaction due to
the presence of a long sp3 alkyl chain when adiponitrile
is used (in 8) and to a suggested disfavored orientation
of the VCp2CN units within the NC-(C6H4)-CN ligand
(in 6). This latter situation was already observed in the
case of [(VCp2)2(1-2η:3-4η-Me3SiCdC-CdCSiMe3)] and
[(VCp2)2(1-2η:7-8η-PhCdC-(CtC)2CdCPh)], where the
dihedral angle between both Cp2VC2 units is nearly
110-120° and prevents a favorable “in-plane π type”
geometry in the molecule.7
[VCp2{η2-(F3CCdN‚BCl3}]‚toluene (3). By using a pro-
cedure identical to that described above for 2 and using toluene
as solvent, compound 3 was synthesized starting from [Cp2V]
(18 mg, 0.1 mmol), F3CC6H4CN (19 mg, 0.11 mmol), and BCl3
(0.3 mL, 1 M in hexane). A slight excess (0.015 mmol) of the
nitrile or borane gives also microcrystalline products directly
from the solution. Yield of 3: 44 mg (79%). Anal. Calcd for
3‚toluene, C25H22BCl3F3NV (561.55): C 53.47, H 3.95, N 2.49.
Found: C 53.56, H 3.97, N 2.77.
[(Cp2V)2{η2-(C6F5)3B‚NdC(C6H4)CdN‚B(C6F5)3}] (6). By
using a procedure identical to that described above for 2 and
using toluene as solvent, compound 6 was synthesized starting
from [Cp2V] (36 mg, 0.2 mmol) and NC(C6H4)CN (13 mg, 0.1
mmol). The presence of toluene in 6 as solvate molecule was
observed by 1H NMR. Yield of 6: 85 mg (53%). Anal. Calcd
for 6‚1toluene, C71H32B2F30N2V2 (1606.48): C 53.08, H 2.01,
N 1.74. Found: C 53.45, H 2.09, N 1.70.
[(VCp2)2{η2-(C6F5)3B‚NdCCH2CtN‚B(C6F5)3}]‚1.5tolu-
ene (7). By using a procedure identical to that described above
for 2 and using toluene as solvent, compound 7 was synthe-
sized starting from [Cp2V] (18 mg, 0.1 mmol), NCCH2CN (6
mg, 0.1 mol), and B(C6F5)3 (105 mg, 0.2 mmol). Yield of 7: 110
mg (78%). Anal. Calcd for 7‚1.5toluene, C59.5H24B2F30N2V
(1409.11): C 50.71, H 1.72, N 1.99. Found: C 50.42, H 1.52,
N 2.02.
Conclusion
It has been demonstrated that a Lewis-acid-activated
nitrile reacts with [VCp2] to give a large variety of
vanada(IV)azirine complexes; BPh3 as a soft Lewis acid
is a rare example of an interaction with a nitrile. This
reaction was extended to dinitrile compounds activated
with the borane B(C6F5)3 to access a new synthetic route
for d1-d1 homobimetallic vanadium complexes. Regard-
ing the lack of ferromagnetic interaction observed on
d1-d1 homobimetallic complexes 6 and 8, efforts on the
structure of the organic bridge between the unpaired
electron on each vanadium center would be the next
step.
[(VCp2)2{η2-(C6F5)3B‚NdC(CH2)4CdN‚B(C6F5)3}]‚tolu-
ene (8). By using a procedure identical to that described above
for 2 and using toluene as solvent, compound 8 was synthe-
sized starting from [Cp2V] (18 mg, 0.1 mmol), NC(CH2)4CN
(10 mg, 0.1 mmol), and B(C6F5)3 (105 mg, 0.2 mmol). Yield of
8: 100 mg (63%). Anal. Calcd for 8‚toluene, C69H36B2F30N2V2
(1586.49): C 52.24, H 2.29, N 1.77. Found: C 52.65, H 2.17,
N 1.65.
[F3CC6H4CtN‚B(C6F5)3] (4). F3CC6H4CtN (34 mg, 0.2
mmol) in 5 mL of toluene was added to a solution of borane
B(C6F5)3 (102 mg, 0.2 mmol) in pentane (5 mL), and the
solution was left for 2-3 days at room temperature to give
crystals of 4. Yield of 4: 60 mg (44%). Anal. Calcd for 4: C26H4-
BF18N (683.10): C 45.71, H 0.59, N 2.05. Found: C 45.62,H
Experimental Section
All experiments were performed under an inert atmosphere
of argon using standard Schlenk and glovebox techniques. All
solvents were dried by conventional methods, distilled under
argon, and degassed before use. [VCp2] was prepared according
to the method given in ref 8 and B(C6F5)3 according to that in
ref 9. 1H NMR data were recorded using an AC-200 spectrom-
eter and referenced internally to residual protio solvent (1H)
1
5.05, N 2.12. IR: ν(CtN) (KBr) 2321 cm-1. H NMR (C6D6):
6.73, 6.61 (AB system, dd, C6H4). 11B NMR (C6D6): -9.3. 19F
NMR (376.41 MHz, 298 K, C6D6): 12.0 (s, CF3), -58.6 (dd, 6
o-F, C6F5), -78.53 (t, 3 p-F, C6F5), -86.6 (m, 6 m-F, C6F5).
[NtCCH2CtN‚B(C6F5)3] (9). To NCCH2CN (13 mg, 0.2
mmol) dissolved in 2 mL of CH2Cl2 was added B(C6F5)3 (102
mg, 0.2 mmol) in 1 mL of CH2Cl2. After 1 h stirring, 3 mL of
pentane was added and the solution left at -30 °C, giving 9
as a colorless and white crystalline product. Yield of 9: 70 mg
(62%). Anal. Calcd for 9, C21H2BF15N2 (578.01): C 43.63, N
(7) (a) Choukroun, R.; Donnadieu, B.; Malfant, I.; Haubrich, S.;
Frantz, R.; Guerin, C.; Henner, B. Chem. Commun. 1997, 2315-2316.
(b) Choukroun, R.; Donnadieu, B.; Lorber, C.; Pellny, P.-M.; Baumann,
W.; Rosenthal, U. Chem. Eur. J. 2000, 6, 4505-4509.
(8) Eisch, J. J.; King, R. B. Organometallic Synthesis of Transition
Metal Compounds; Academic Press: New York, 1965; pp 64-66.
(9) (a) Massey, A. G.; Park, A. J. J. Organomet. Chem. 1964, 2, 245-
250. (b) Massey, A. G.; Park, A. J. J. Organomet. Chem. 1966, 5, 218-
225.
4.85. Found: C 43.49, N 4.81. IR: ν(CtN) 2377, 2285 cm-1
.
1H NMR (C6D6): 1.19 (CH2). 11B NMR (C6D6): -3.2. 19F NMR
(376.41 MHz, 298 K, C6D6): -58.3 (d, 6 o-F, C6F5), -77.5 (t, 3
p-F, C6F5), -86.1 (m, 6 m-F, C6F5).

5492 Organometallics, Vol. 23, No. 23, 2004
Choukroun et al.
Table 3. Summary of Crystal Data, Data Collection, and Structure Refinement Parameters for 2, 3, 4, 7, 8,
and 9
2
3‚toluene
4
7‚1.5toluene
8‚toluene
9
formula
fw
C
36H29BF3NV
C25H22BCl3F3NV
561.55
C26H4BF18
N
C59.5H24B2F30NV
1409.11
C69H36B2F30N2V2
1586.50
10.170(5)
17.885(5)
34.917
C
21H2BF15N2
594.35
683.11
578.06
a (Å)
9.059(5)
9.743(5)
17.635(5)
83.292(5)
79.672(5)
70.255(5)
1438.6(12)
2, 1.372
P1h
9.168(5)
8.897(5)
12.017(5)
13.367(5)
65.416(5)
11.6741(12)
13.0802(13)
19.202(2)
71.067(11)
86.025(13)
71.755(11)
2777.7(5)
2, 1.630
19.502(4)
10.866(2)
19.177(4)
b(Å)
11.104(5)
24.741(5)
c (Å)
R (deg)
â (deg)
95.704(5)
7551.510(5)
83.317(5)
1232.3(10)
2, 1.841
P1h
97.893(5)
92.11(3)
γ (deg)
V (Å3)
2506.2(18)
4, 1.488
P21/n
6291(4)
4, 1.675
P21/c
4061.2(14)
8, 1.891
C2/c
Z, dcalc (g/cm3)
space group
linear abs coeff
P1h
0.391
0.391
0.753
0.204
0.433
0.209
(mm-1
)
T (K)
180
180
180
180
180
180
wavelength (Å)
F(000)
2 θ range (deg)
no. of indep reflns
no. of params
R1, wR2 (all data)
R1, wR2 (>2σ)
0.71073
614
2.23-24.25
6460
379
0.0713, 0.1442
0.0498, 0.1325
0.71073
1140
2.01-26.10
19 299
362
0.0853, 0.1543
0.0556, 0.1382
0.71073
668
1.86-21.96
7826
415
0.2319, 0.3041
0.0830, 0.1978
0.71073
1346
1.65-23.05
10 254
885
0.1334, 0.1210
0.0460, 0.0919
0.71073
3160
2.02-24.20
39 785
1011
0.1140, 0.1554
0.0533, 0.1180
0.71073
2256
2.09-24.71
13 826
352
0.0833, 0.0850
0.0370, 0.0722
[(C6F5)3B‚NtCCH2CtN‚B(C6F5)3] (10). To NCCH2CN (7
mg, 0.1 mmol) dissolved in 2 mL of CH2Cl2 was added B(C6F5)3
(102 mg, 0.2 mmol). After 1 h stirring, 3 mL of pentane was
added and the solution left at -30 °C, giving 10 as a colorless
and white crystalline product. Yield of 10: 40 mg (36%). Anal.
calcd for 10, C39H2B2F30N2 (683.10): C 42.97, N 2.57. Found:
WinGX (version 1.63).12 All hydrogen atoms were located on
a difference Fourier map and refined with a riding model, and
all remaining non-hydrogen atoms was anisotropically refined.
In the last cycles of refinement a weighting scheme was used
for each structure where weights are calculated from the
2
2
following formula: w ) 1/[σ2(Fo ) + (aP)2+ bP] where P ) (Fo
C 42.63, N 2.42. IR: ν(CtN) (KBr) 2370 cm-1
.
1H NMR
+ 2Fc2)/3. The high R factor obtained for 4 is due to the poor
quality of the crystal. The crystallographic data for all
compounds are summarized in Table 3.
(C6D6): 1.17 (CH2). 11B NMR (C6D6): 3.7. 19F NMR (376.41
MHz, 298 K, C6D6): -57.5 (d, 6 o-F, C6F5), -75.1 (t, 3 p-F,
C6F5), -85.7 (m, 6 m-F, C6F5).
Crystallographic Data for 2, 3, 4, 7, 8, and 9. The
selected crystals, sensitive to air and moisture, were suspended
in oil on a glass slide. Under a microscope, a single block was
isolated. Data were collected on a Stoe imaging plate diffrac-
tion system (IPDS) using Mo ΚR radiation (λ ) 0.71073 Å).
The final unit cell parameters were obtained by least-squares
refinement of a set of 5000 reflections, and crystal decay was
monitored by measuring 200 reflections by image. No signifi-
cant fluctuation of the intensity was observed over the course
of the data collection. All structures were solved by means of
direct methods using SIR9210 and refined by least-squares
procedures on F2 with the aid of SHELXL9711 included in
Supporting Information Available: Crystallographic
data for compounds 2, 3, 4, 7, 8, and 9 including ORTEP
diagrams, tables of crystal data and data, collection param-
eters, atomic coordinates, anisotropic displacement param-
eters, and all bond lengths and bond angles. This material is
available free of charge via the Internet at http://pubs.acs.org.
OM049488T
(11) Altomare, A.; Cascarano, G.; Giacovazzo, G.; Guagliardi, A.;
Burla, M. C.; Polidori, G.; Camalli, M. J. Appl. Crystallogr. 1994, 27,
435.
(12) Sheldrick, G. M. SHELX97 [includes SHELXS97, SHELXL97,
CIFTAB], Programs for Crystal Structure Analysis (Release 97-2);
Institu¨t fu¨r Anorganische Chemie: Go¨ttingen, Germany, 1998.
(13) Farrugia, L. J. J. Appl. Crystallogr. 1999, 32, 837-838.
(10) Boitsov, S.; Songstad, J.; To¨rnroos, K. W. Acta Crystallogr. 2002,
C58, 66-68.