Organometallic derivatives of Ni(II) with poly(pyrazolyl)borate ligands

Article abstract of DOI:10.1016/S0022-328X(97)00429-4

The reaction of the alkyl or aryl derivatives Ni(R)X(PMe₃)₂ (R=CH₂SiMe₃, CH₂CMe₃, C₆H₅; X=Cl, Br) with the potassium salt of the Bp ligand (Bp=dihydrobis(pyrazolyl)borate anion) forms the corresponding compounds BpNi(R)(PMe₃). In contrast, the reaction of the aryl derivatives Ni(C₆H₄-p-X)Br(PMe₃)₂ (X=H, Me, OMe, NMe₂) with the Bp^tBu anion (Bp^tBu=dihydrobis(3-t-butylpyrazolyl)borate) proceeds with formation of complexes of composition Bp^tBuNi(C₆H₄-p-X)(PMe₃)₂, in which the polydentate ligand is bound to the metal through only one pyrazolyl group. The Tp anion leads to only aryl derivatives; the phenyl complex TpNi(C₆H₅)(PMe₃) has been obtained, and the reaction of the alkyl complex Ni(CH₂CMe₂Ph)Cl(PMe₃)₂ with KTp furnishes the aryl TpNi(C₆H₄-o-Bu^t)(PMe₃), by means of a rearrangement of the neophyl ligand. The Tp ligand in these complexes is bonded in the η² fashion, although an X-ray analysis carried out for TpNi(Ph)(PMe₃) reveals the existence of an important Ni...N interaction with the third pz ring. Upon reaction with the bulky hydrotris(3-t-butylpyrazolyl)borate anion, the aryl derivatives Ni(C₆H₄-p-X)Br(PMe₃)₂ (X=H, Me, OMe, NMe₂) form complexes of composition Tp^tBuNi(C₆H₄-p-X)(PMe₃)₂, in which the polydentate ligand is once more bound to the metal through only one pyrazolyl group. These complexes represent the first examples of η¹ coordination of poly(pyrazolyl)borate-type ligands. The acyl and aroyl complexes BpNi(COR)(PMe₃) (R=CH₂SiMe₃, CH₂CMe₃) and TpNi(COPh)(PMe₃) have been obtained by carbonylation of the parent compounds. The aroyls Tp^tBuNi(COC₆H₄-p-X)(PMe₃) ₂ have also been obtained from the derivatives Ni(COC₆H₄-p-X)Br(PMe₃)₂ although they evolve CO slowly in solution. An X-ray analysis carried out with Tp^tBuNi(C₆H₄-p-Me)(PMe₃)₂ confirms the η¹-coordination mode of the Tp^tBu ligand, which was deduced from NMR studies.

Full text of DOI:10.1016/S0022-328X(97)00429-4

Ž
.
Journal of Organometallic Chemistry 551 1998 215–227
1
ž /
ž
/
Organometallic derivatives of Ni II with poly pyrazolyl borate ligands
b
a
b,3
Enrique Gutierrez a,2, Sarah A. Hudson , Angeles Monge , M. Carmen Nicasio
,
´
Margarita Paneque b,), Caridad Ruiz
a
a
Instituto de Ciencia de Materiales de Madrid, Consejo Superior de InÕestigaciones Cientıficas, Campus de Cantoblanco, Madrid, 28049, Spain
´
b
Instituto de InÕestigaciones Quımicas-Departamento de Quımica Inorganica, Consejo Superior de InÕestigaciones Cientıficas-UniÕersidad de
´
´
´
´
SeÕilla, Cr Americo Vespuccio srn, Isla de la Cartuja, SeÕilla, 41092, Spain
´
Received 19 May 1997; received in revised form 8 June 1997
Abstract
Ž . Ž
. Ž
.
The reaction of the alkyl or aryl derivatives Ni R X PMe3 RsCH2SiMe3, CH2CMe3, C6H5; XsCl, Br with the potassium salt
2
Ž
Ž
.
.
Ž .Ž
.
of the Bp ligand Bpsdihydrobis pyrazolyl borate anion forms the corresponding compounds BpNi R PMe3 . In contrast, the reaction
tBu
XsH, Me, OMe, NMe2 with the BptBu anion Bp sdihydrobis 3-t-
Ž
.
Ž
.
Ž
. Ž Ž
of the aryl derivatives Ni C6H4-p-X Br PMe3
2
butylpyrazolyl borate proceeds with formation of complexes of composition BptBuNi C6H4-p-X PMe3 2, in which the polydentate
.
.
Ž
.Ž
.
ligand is bound to the metal through only one pyrazolyl group. The Tp anion leads to only aryl derivatives; the phenyl complex
Ž
.Ž
.
Ž
.
Ž
.
TpNi C6H5 PMe3 has been obtained, and the reaction of the alkyl complex Ni CH2CMe2Ph Cl PMe3 with KTp furnishes the aryl
2
2
Ž
t.Ž
.
TpNi C6H4-o-Bu PMe3 , by means of a rearrangement of the neophyl ligand. The Tp ligand in these complexes is bonded in the h
Ž
.Ž
.
fashion, although an X-ray analysis carried out for TpNi Ph PMe3 reveals the existence of an important Ni . . . N interaction with the
Ž
.
Ž
.
Ž
.
third pz ring. Upon reaction with the bulky hydrotris 3-t-butylpyrazolyl borate anion, the aryl derivatives Ni C6H4-p-X Br PMe3
2
tBu
Ž
.
Ž
.Ž
.
XsH, Me, OMe, NMe2 form complexes of composition Tp Ni C6H4-p-X PMe3 2, in which the polydentate ligand is once more
bound to the metal through only one pyrazolyl group. These complexes represent the first examples of h1 coordination of
.Ž
Ž
Ž
.
Ž
.
Ž
.
poly pyrazolyl borate-type ligands. The acyl and aroyl complexes BpNi COR PMe3
R s CH2SiMe3, CH2CMe3 and
tBu
.Ž
.
Ž
.Ž
.
TpNi COPh PMe3 have been obtained by carbonylation of the parent compounds. The aroyls Tp Ni COC6H4-p-X PMe3 have also
2
Ž
.
Ž
.
2
been obtained from the derivatives Ni COC6H4-p-X Br PMe3 although they evolve CO slowly in solution. An X-ray analysis carried
out with TptBuNi C6H4-p-Me PMe3 confirms the h1-coordination mode of the TptBu ligand, which was deduced from NMR studies.
Ž
.Ž
.
2
q 1998 Elsevier Science S.A.
Keywords: Ligands; Anion; Aryl derivatives
Ž
.
1. Introduction
lished refer to the use of tris pyrazolyl borates, although
in some cases the coordination is through only two of
the three N atoms available. In some cases, maximum
coordination of the Tp ligand may be disfavoured on
T h e co o rd in atio n ch em istry o f th e
Ž
.
poly pyrazolyl borates has been extensively developed
since the ligands were initially synthesised and the first
w
x
steric grounds 4a,4b,4c,4d , although the incidence of
low coordination numbers in complexes of these ligands
appears to be restricted to late members of the transition
series such as Ag, Au, and Hg, the tendency for com-
plexes of these metals to low coordination numbers
w
x
compounds prepared, about 30 years ago 1a,1b,1c,1d .
Several reviews on the subject are available
w
x
2a,2b,2c,2d,2e,2f,2g,3a,3b . Most of the papers pub-
being well-documented. Although
poly pyrazolyl borate complexes of Pd II and Pt II
a
number of
)
Ž
.
Ž . Ž .
Corresponding author.
1 Dedicated to Prof. P.M. Maitlis, a great teacher and imaginative
w x
have been prepared 5 , related studies involving nickel
d e r i v a t i v e s a r e v e r y s c a r c e
x w
researcher, on the occassion of his 65th birthday.
2 Also a corresponding author, for x-ray studies.
w
x
6a,6b,6c,6d,6e,6f,6g,6h,7a,7b,7c 7d,7e,7f,8 . In this
paper, we report on the reactivity of alkyl and aryl
Ž .
3 New address: Departamento de Quımica y Ciencia de los Materi-
´
ales, Universidad de Huelva, 21819 Palos de la Frontera, Huelva,
Spain.
Ž
.
derivatives of Ni II , towards poly pyrazolyl borate an-
0022-328Xr98r$19.00 q 1998 Elsevier Science S.A. All rights reserved.

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216
E. Gutierrez et al.rJournal of Organometallic Chemistry 551 1998 215–227
´
Ž
.
Ž
.Ž
. Ž
.
ions. In the case of the tris pyrazolyl borate derivatives,
the effect of changes in the steric properties of the
potentially tridentate ligand upon its mode of coordina-
tion and upon the characteristic reactivity of the com-
plexes have been explored. Part of this work has been
TpNi C6 H4-o-X PMe3 XsH, 3a; Me, 3b , as brown
Ž
Ž ..
crystalline materials Eq. 3 . Analytical and spectro-
scopic data see below are in agreement with the
formulation proposed.
Ž
.
w x
briefly communicated 9 .
Ž .
3
2. Results and discussion
2.1. Synthesis of complexes
2.1.1. Alkyl and aryl deriÕatiÕes
The displacement of a halide by an anionic ligand
from the coordination sphere of a metal complex is a
commonly employed route to the synthesis of further
species, and, if the anion employed possesses poten-
tially chelating properties, a donating ligand present in
the original complex is usually eliminated together with
the halide, or otherwise the coordination number is
increased. Both possibilities can in principle be ex-
Surprisingly, we have been unable to synthesise other
derivatives of composition TpNi R PMe3 , in which R
is an alkyl group. Thus, when the complexes
Ž .Ž
.
Ž .
Ž
.
Ž
R s CH 2 SiMe3 , CH 2 CMe3 ,
Ni R X PMe3
2
.
CH2C6 H4-o-Me; XsCl or Br are treated with KTp,
following a similar procedure as described in Section 3
for complexes 1–3, analogous changes in the colour
together with formation of KX salts are observed, but
when workup of the brownish orange solutions and
product isolation are attempted, violet–pink crystals of
Ž
.
pected when a poly pyrazolyl borate is employed. The
Ž . Ž .
Ž
.
2
reaction between the Ni II compounds Ni R Cl PMe3
Ž
.
RsCH2 SiMe3, CH2CMe3, C6 H5 and KBp, pro-
ceeds smoothly at low temperatures to give complexes
Ž .Ž . Ž . Ž .
w x
the known NiTp2 were obtained in all cases 6f . For the
case of RsCH2C6 H4-o-Me, the mother liquors were
of formula BpNi R PMe3 1 , as depicted in Eq. 1 .
investigated by NMR, showing the presence of
Ž
.
Ž
Ž ..
Ni PMe3 and R–R as the only byproducts Eq. 4 .
4
The lower strength of the Ni-alkyl bond
Ž .
1
Ž .
4
compared with the Ni-aryl is invoked to explain the lack
of stability of the attempted species. It is worth men-
tioning that the analogous Cp derivatives of composi-
Compounds 1 can be isolated as reddish crystals, which
are soluble in most common organic solvents. The
microanalytical and spectroscopic data are consistent
with the formulation proposed. In contrast with that, the
Ž .Ž
.
w
x
tion CpNi R PMe3 10,11 are quite stable, which
suggests that the Tp ligand labilises the Ni–C bond.
On conducting the reaction between KTp and the
neophyl or the Me-neophyl derivatives of nickel,
Ž
.
Ž
.
reaction of the aryl derivatives Ni C6 H4-p-X Br PMe3
2
Ž
.
XsH, Me, OMe, NMe2 with the thallium salt of the
dihydrobis 3-t-butylpyrazolyl borate anion, BptBu, yields
Ž
.
Ž
.
Ž
.
Ž
Ni CH2CMe2 Ph Cl PMe3 and Ni CH2CMe2C6 H4-p-
2
crystalline materials whose elemental analyses reveal
.
Ž
.
Me Cl PMe3 2 , complexes 3c and 3d are obtained, in
the composition BptBu Ni C6 H4-p-X PMe3
Ž
.Ž
.
Ž . Ž
2 Eq.
2
which a rearrangement of the neophyl ligand has taken
Ž ..
2 , that is, no PMe3 is lost during the reaction.
Ž
Ž ..
place Eq. 5 .
Ž .
2
Ž .
5
Ž
Also, the reaction of complexes Ni C6 H4-
. Ž
.
Ž
.
XsH, Me with KTp proceeds with
-o-X Br PMe3
This was deduced from NMR studies of the products, to
be described below. This type of ligand rearrangement
2
loss of 1 equiv of PMe3 and formation of complexes

(
)
E. Gutierrez et al.rJournal of Organometallic Chemistry 551 1998 215–227
217
´
fragmentation of the TptBu ligand and byproducts con-
taining Bu-pyrazole were obtained.
w
x
has been reported 12a,12b,12c,12d,12e on previous
occasions, indeed, one nickel complex apparently un-
dergoes an analogous transformation forming the isomer
t
Ž
.
CpNi C6 H4-o-CMe3 PPh3 as
CpNi CH 2 CMe2 Ph PPh 3
a
byproduct when
is prepared from
Ž
.Ž
.
2.1.2. Carbonylation reactions. Synthesis of acyl and
aroyl deriÕatiÕes
Ž
.
Ž
.
w
x
CpNiCl PPh3 by reaction with Mg neophyl Cl 12b .
However, in the cases described herein only the rear-
ranged aryl derivatives were observed. The instability of
the Ni–C alkyl bond in this class of complex appears
to preclude the formation of the expected products,
rendering them susceptible to isomerisation via an intra-
molecular C–H bond activation process.
Compounds 1a, b undergo insertion reactions with
Ž
Ž ..
CO Eq. 9 at
Ž
.
We have also prepared and studied an analogous
phenyl derivative containing the Me-substituted Tp)
ligand, Tp Ni C6 H5 PMe3 4 which is obtained Eq.
)
Ž .
9
Ž
.Ž
. Ž .
Ž
Ž ..
6
as a red–brown crystalline material, following a
Ž .
procedure similar to that described in Eq. 3 .
Ž .
6
room temperature and 1 atmosphere of pressure to give
Ž .
w
x
Ž
.
the corresponding acyl complexes BpNi C O R PMe3
..
Ž
Ž
.
Ž
RsCH2 SiMe3 6a , RsCH2CMe3 6b .
Finally on that respect, the reaction of the aryl com-
These complexes are crystalline materials and, as
Ž
.
Ž
.
plexes Ni C6 H4-p-X Br PMe3 with the thallium salt
2
w
x
t
of the HB 3-Bu pz anion, TptBu, proceeds smoothly at
expected 11,15a,15b,15c they are somewhat less solu-
ble than the parent alkyls. In their IR spectra, the CO
stretching frequencies are observed in the region 1650–
Ž
.
3
low temperatures affording TptBu Ni C6 H4-p-X PMe3
.Ž .
2
5 as yellow crystals after workup Eq. 7 .
Ž
Ž
Ž .
Ž ..
1670 cmy1
.
We have previously shown that the 18-electron com-
Ž .Ž
.
w
x
plexes CpNi R PMe3 10,11 do not react with CO to
Ž
.Ž
.
form the acyl derivatives CpNi COR PMe3 . This was
thought to be due to the poor dissociative ability of the
PMe3 group which precludes access to an unsaturated
16-electron intermediate which would be able to interact
with CO. However, upon exposing a solution of 3a to
CO at room temperature, the acyl insertion product
Ž .
7
Once more, elemental analyses reveal the presence of
two molecules of PMe3 on the complexes. Moreover,
NMR and X-ray studies to be described below reveal
the monohapto coordination of the potentially tridentate
ligand.
w
Ž .
x
Ž
. Ž .
Ž
Ž
..
TpNi C O C6 H5 PMe3 7 is obtained Eq. 10 . This
The reaction of derivative 5c with ZnCl2 has been
carried out, in an attempt to remove one equivalent of
PMe3 and thus force the TptBu ligand to bind h2 to the
nickel atom. However, this did not meet with success,
Ž
.
10
Ž .
the reaction proceeding as depicted in Eq. 8 , with
formation of
Ž .
8
the known TptBuZnCl 13 . Also, attempts to protonate
is in accord with a mechanism that involves initial
release of the weakly coordinated pz group from the
w
x
w
x
the unbound pz rings 14a,14b with HBF4 caused

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)
218
E. Gutierrez et al.rJournal of Organometallic Chemistry 551 1998 215–227
´
metal’s coordination sphere, followed by trapping of the
resultant 16 electron square planar intermediate by CO,
the migratory insertion reaction to CO then follows
affording the acyl product. Attempts to carbonylate
Ž
t.Ž
. Ž
.
complex TpNi C6 H4-o-Bu PMe3 3c by a similar
treatment with CO lead to an appropriate change of
colour. Moreover, the solid obtained after evaporating
the solution displays an infrared absorption at 1610
cmy1, which can be assigned to n C–O of an acyl
ligand, suggesting that an analogous insertion of CO has
occurred for 3c. However, upon workup and attempted
crystallisation of the product, only complex 3c is ob-
tained. This indicates that the putative acyl product is
unstable with respect to the reverse deinsertion and
subsequent elimination of CO.
Ž
.
Scheme 1.
Ž
.Ž
. Ž
.
In contrast, the complex BpNi Ph PMe3 1c is
13
shown, by 1H and C H NMR, to exhibit a more
complicated behaviour at room temperature with only
one pz environment and lack of coupling between the
Ni–C and the P nuclei. We propose that an associative
Ä1
4
An alternative route to the acyl derivatives was ex-
plored, in which the acyl ligand is in place prior to
w
x
19 exchange of PMe3 is occurring at room tempera-
ture, which is strongly supported from the fact that the
treatment with TpX anions. Thus, the complex
31
Ä1
4
P H chemical shift at y8.0 moves to higher field,
after addition of free PMe3 to solutions of complex 1c.
As expected, on lowering the temperature to y608C,
the exchange of phosphine can be suppressed. The
)
w
Ž .
x
Ž
. Ž .
Tp Ni C O C6 H5 PMe3
8 was prepared by dis-
placement of the halide from the parent
Ž .
w
x
Ž
.
Ni C O C6 H5 Br PMe3 .
2
Similarly, the corresponding aroyls 9 can be obtained
quaternary aromatic carbon bound to nickel is then
1
tBu
Ž
.
as depicted in Eq. 11 , and they also contain an h -Tp
2
Ž
.
coupled to the phosphorus nucleus d, JCP s51 Hz ,
and both pz rings are now inequivalent. Interestingly,
the signals due to the four CH nuclei in the o- and the
m- positions of the phenyl ring also resolve into sepa-
rate peaks indicating that all important fluxional pro-
cesses that may occur in the molecule are frozen under
these conditions, included the boat-to-boat rearrange-
ment observed in complexes 1.
ligand.
Ž
.
11
In the case of the Tp derivative 3a, NMR studies
reveal again the existence of only one set of pyrazole
resonances at room temperature. In addition, the com-
plex displays the same type of phosphine exchange
mentioned above, as indicated by the observation of a
Complexes 9 slowly evolve CO in solution at room
temperature, but display sufficient kinetic stability for
full spectroscopic characterisation.
2.2. Spectroscopic studies
2.2.1. Alkyl and aryl deriÕatiÕes
The NMR data for complexes 1 are consistent with a
formulation involving a pseudo square-planar geometry
in which the bidentate N-donor ligand occupies two
w
x
mutually cis coordination positions 16a,16b . As ex-
pected, the two pz rings of 1a and 1b exhibit separate
resonances, indicating that these moieties are not ex-
changing their positions at room temperature. Neverthe-
less, the equivalence of the two methylenic protons of
the alkyl group in each compound indicates that a
fluxional process is occurring on the NMR time scale.
The equivalence of these methylenic protons would
require the coordination plane to be an effective plane
of symmetry, and it can be proposed that this occurs via
inversion of the boat configuration of the NiN4 B cycle
Ž
.
Scheme 1 . The process depicted in Scheme 1 has been
proposed to occur in complexes containing analogous
Ž
.
w x
bis pyrazolyl -methane 17 and -borate derivatives
w
x
18a,18b,18c,18d,18e .
Fig. 1. The molecular structure of compound 3a.

(
)
E. Gutierrez et al.rJournal of Organometallic Chemistry 551 1998 215–227
219
´
broad singlet in its 13C NMR spectrum assigned to
Ni–C.
fast in the case of 3a, are now slowed down, giving
C–H pyrazolyl resonances in a 1:2 ratio, which separate
into three peaks each at y608C. We presume that the
complex has a square planar structure, with one non-
bonded or weakly interacting pz) ring.
A selective exchange between the unbound and one
of the coordinated pz rings is invoked in order to
explain the observed 1:2 intensities of the NMR signals
for the pz) moieties at room temperature. A related
exchange has been recently proposed for a Tp) –Rh
We have determined the X-ray structure of 3a, which
will be discussed below, and, as can be observed in Fig.
1, complex 3a is tetracoordinated in the solid state, with
a square planar geometry, although an important inter-
action between the Ni atom and the third pz ring
˚
.
Ž
Ž
.
Ni–N 32 2.57 A exists. Although the complex is
highly fluxional in solution, we suggest that the struc-
ture found in the solid state is maintained in solution,
and hence 3a is a 16 ey species, although the existence
of the weak interaction could not be ruled out with the
data available.
w
x
w x
compound 21 . Considering the great trans effect 22
of the PR3 group as compared with the phenyl, it can be
proposed that the exchange takes place between the
uncoordinated and the pyrazolyl trans to the phosphine
ligand.
NMR studies on complex 5a provide interesting in-
1
formation about its solution structure. In the H NMR,
Ž
.
12
w
x
the appearance of a virtually coupled triplet 23 shows
the presence of two mutually trans PMe3 groups in the
molecule. This contrasts with the results obtained for
the parent Tp and Tp) described above, for which a
PMe3 is lost during the reaction. In addition, two
distinct sets of pyrazolyl resonances are observed, in a
1:2 ratio. These observations, together with the strong
As with the Bp derivative 1c, at y608C the 13C
Ž
.
NMR singlet at 154.3 ppm Ni–C splits into a doublet,
Ž2
.
Ž .
JCP s55 Hz attesting to the fact that the PMe3
tendency of Ni II to form four coordinate square-planar
exchange is slow on the NMR time-scale at this temper-
ature. The resonances due to the pz rings remain un-
changed at this temperature, but at y908C, they become
broadened although a clear separation is not observed.
The observance of only one pz environment is in-
dicative of rapid exchange of coordinated and uncoordi-
structures in complexes of this type, suggests that the
borate ligand in complex 5a is behaving as a mono-
hapto, i.e., as an one electron donor fragment. The
w
x
nated groups 20a,20b,20c,20d,20e,20f,20g,2c and this
Ž
.
13
feature has been described as a "tumbling" process
w
x
1c .
In contrast to the behaviour of 3a, the PMe3 ex-
change in 3b was slow on the NMR time-scale at room
temperature, as indicated by the presence of a doublet at
Ž2
.
152.8 ppm JCP s49 Hz for the Ni–C nucleus. Pre-
sumably, the presence of the Me group at the ortho
position of the phenyl ring blocks the axial coordination
site, thus preventing the coordination of free PMe3 at
this site and thus hindering the exchange pathway.
Spectroscopic studies of 3c and 3d in solution at
room temperature show the three pyrazole rings to be
inequivalent. The presence of the very bulky t Bu retards
significantly all the fluxional processes observed for the
related Ph derivative 3a.
coordinated and uncoordinated pz groups do not ex-
change on the NMR time scale at the temperatures
studied.
Several cases have been reported previously in which
a TpX or BpX is bound asymmetrically, with a strong
M . . . N bond and
a
weaker M...N interaction
w
x
24a,24b,24c . Such cases are usually motivated by the
electronic requirements at the metal centre, specifically
those which display a pronounced tendency to low
coordination numbers. The complexes reported in this
paper represent the first examples of a strict h1 coordi-
In the case of the Tp) derivative 4, PMe3 exchange
is judged to be slow by C H NMR, as suggested by
13
Ä1
4
Ž
.
nation of poly pyrazolyl borate-type ligands.
13
Ž2
.
Ä1
4
the doublet seen at 152 ppm JCP s45 Hz which
arises from the nickel-bound aryl carbon atom. Taking
into account the exchange of PMe3 found for the Tp-
containing complex 3a, the methyl in the 3 position of
the pz rings presumably hinders the interchange of
phosphine. Further, the other interchange processes in-
volving the pz groups, which were observed to be very
C H NMR data also provides information about
the existence of a high barrier of rotation of the phenyl
ring, and six separate resonances are found for this
group at room temperature.
NMR data for derivatives 5b–d are in agreement
with them having a square planar structure analogous to
5a. This has been confirmed by means of an X-ray

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)
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E. Gutierrez et al.rJournal of Organometallic Chemistry 551 1998 215–227
´
2
Ž
study, carried out with complex 5b, to be described
below, which confirms the square planar structure
shown.
NMR features for complexes 2 are very similar to
those encountered for the TptBu derivatives. For in-
stance, complex 2a presents a virtually coupled triplet
for the two equivalent PMe3 ligands, pztBu resonances
of the mentioned 13C acyl resonance occurs d, JCP s31
.
Hz indicating that at this temperature this process has
been stopped on the NMR timescale.
w
Ž .
x
Ž
. Ž .
In the case of the aroyl TpNi C O C6 H5 PMe3 7 ,
NMR studies again reveal that a dynamic process is
taking place at room temperature with equivalence of
the three pz rings. Cooling down to y808C, has no
effect on the signals corresponding to the pz rings. In
in 1:1 ratio and five singlets for the CH nuclei of the
13
1
13
Ä1
4
Ä1
4
phenyl, in the C H NMR spectra. All other spectro-
scopic data obtained for these complexes are in agree-
ment with the structure proposed and need no further
comment.
contrast, H and C H NMR spectroscopy show 8 to
be a rigid square-planar complex with the Tp) ligand
2
Ž
.
bound in a dihapto h mode at room temperature with
no appreciable exchange processes taking place under
these conditions.
2.2.2. Acyl and aroyl complexes
Like their parent aryl derivatives 5, the aroyls 9 have
two trans PMe3 groups and an h1-TptBu. The spectro-
scopic data are collected in Section 3 and need no
further comment.
1
13
Ä1
4
In contrast with their parent alkyls, H and C H
NMR studies demonstrate that the two acyl complexes
6a and 6b do not possess rigid stereochemistry at room
temperature. Thus, the pyrazole rings are now magneti-
cally equivalent, giving rise to just one set of signals
2.3. Structural studies
and the COR carbon produces a broad singlet at 255
13
Ä1
4
ppm in the C H NMR spectrum. This last observa-
tion is suggestive of an intermolecular exchange process
involving traces of PMe3 present in solution, and in
Single crystal X-ray studies have been carried out for
w
x
compounds 3a and 5b. Figs. 1 and 2 show ORTEP 25
representations for them while Tables 1 and 2 collect
relevant structural data. As may be seen, the molecules
of 3a have a distorted square planar structure in the
solid state with the Tp ligand coordinated through only
two of the three pz rings. Notewhorty, the distance
accord with this, in the presence of additional PMe3 at
31
Ä1
4
room temperature, the signal in the P H NMR spec-
trum of compound 6b, at y11.0 ppm shifts to higher
fields, a single resonance being observed for both the
free and bound PMe3. On cooling to y808C, a splitting
˚
Ž .
Ž
.
2.57 1 A for the Ni–N 32 contact in 3a is out of the
Table 1
Crystal and refinement data for complexes 3a and 5b
Compound
3a
5b
Formula
C18 H27 BN6 NiP
427.9
orthorhombic
P212121
C34 H59 BN6 NiP2
683.34
monoclinic
P21rn
Ž .
12.626 4
Formula weight
Crystal system
Space group
˚
Ž .
a A
Ž .
10.271 1
˚
Ž .
b A
Ž .
8.218 2
Ž .
24.298 3
˚
Ž .
c A
Ž .
24.960 8
Ž .
13.413 3
102.43 3
Ž .
4018 2
Ž .
b 8
Ž .
3
˚
Ž
.
Ž .
2106 8
V A
Z
4
4
3
Ž
.
Crystal dimensions mm
Dcalc g cm
m cm
Temperature K
Diffractometer
Monochromator
0.15=0.15=0.15
1.35
10.13
295
Enraf-Nonius
graphite
0.2=0.3=0.4
1.13
5.90
y3
Ž
.
y1
Ž
.
Ž .
˚
Ž
.
Radiation
Scan technique
u
Mo K a ls0.71069 A
vy2u
vr2u
1-u-30
1-u-25
Ž
.
Ž
.
Ž
.
Ž
.
Data collected
Unique data
0,0,0 to 14,11,35
y15,0,0 to 15,28,16
3470
1410
y
7360
Ž .
Ž .
Unique data I )3s I
Unique data I )2s I
y
3169
6.2
2
<
Ž
<
<
<
5.0
5.4
6.6

(
)
E. Gutierrez et al.rJournal of Organometallic Chemistry 551 1998 215–227
221
´
Scheme 2.
Ž
Ž .
close to other examples 1.93 1 8 for the Ni-aryl
.Ž
.
w x
bond of Ni CH CMe yoyC H PMe3
1.951 12 8 for complex Ni CH CH C H -o Cy -
17 or
.Ž
Ž
2
2
4
2
6
Ž
.
Ž
2
2
4
2
6
.
w
x.
PCH2CH2 PCy2 27a,27b .
A comparison can be drawn between the structural
geometry of compound 3a and the complexes
Ž .Ž .
TpPt L R which are square planar in the solid state
but have been proposed to be pentacoordinate in solu-
w
x
tion, by means of NMR studies 28a,28b . As can be
seen in Scheme 2, the N atom of the non-bonded pz is
oriented away from the Pt atom, unlike in complex 3a.
The nickel centre of complex 5b lies in a slightly
distorted square plane, with the phenyl ring being per-
pendicular to the coordination plane and, as expected,
the two phosphine ligands in mutually trans positions.
The borate moiety is coordinated to the nickel through
only one nitrogen, with the other two pz rings oriented
Fig. 2. The molecular structure of compound 5b.
Ž
Ž .
Ž .
normal bonding range 1.938 8 and 1.970 9 for the
.
other two distances in 3a , but reflects the existence of
an important Ni PPP N interaction. Although the be-
Ž
.
haviour of the complex in solution see above is in
agreement with a 16 electron unsaturated structure, the
geometry in the solid state could be defined as square
pyramidal, in which the square plane defined by C, P
and two pyrazolyl N atoms is capped by the third
pyrazolyl N atom, the latter interaction being weaker
than the two Ni-N equatorial bonds. The existence of an
axial pz weakly coordinated to the metal has been
Ž
.
away from the metal centre. The distance Ni–N 11 , of
˚
Ž .
1.947 6 A is in the range found for complex 3a.
˚
.
Ž . Ž
Ž .
Finally, the distance Ni–C 1 1.891 8 A is also within
the expected range of values for a Ni-aryl bond
w
x
16a,27a,27b .
w
x
reported previously 26 . The distance Ni–P for 3a
2.141 3 A fall into the range found for other Ni II –
˚
Ž
Ž .
.
Ž .
3. Experimental details
w
x
PMe3 examples 11,15a,20a,20b,20c,20d,20e,20f,20g .
The same is true of the Ni–C distance, of 1.87 1 A,
˚
Ž .
3.1. General considerations
Table 2
Mycroanalyses were performed by the Microanalyti-
cal Service of the University of Seville. Perkin–Elmer
Models 577 and 684 spectrometers were used for IR
spectra, and a Varian XL-200 instrument was used for
NMR studies. The 13C resonance of the solvent was
used as an internal reference, but chemical shifts are
reported with respect to SiMe4. 31 P NMR shifts are
relative to external 85% H3PO4. All preparations and
other operations were carried out under oxygen-free
nitrogen by conventional Schlenck techniques. Solvents
were dried and degassed before use. The petroleum
ether used had a boiling point of 40–608C. The com-
˚
Ž .
Ž .
Selected bond distances A and angles 8 for compounds 3a and 5b
3a
Ž .
Ž
.
Ž .
Ž .
106.9 4
Ni–P
Ni–N 12
Ni–N 22
Ni–N 32
2.141 3
1.938 8
1.979 9
N 32 –Ni–C 4
N 22 –Ni–C 4
N 22 –Ni–N 32
Ž .
N 12 –Ni–C 4
N 12 –Ni–N 32
N 12 –Ni–N 22
Ž
.
.
.
Ž .
Ž
.
Ž .
Ž .
170.6 4
Ž
Ž .
Ž
.
Ž
Ž .
Ž
Ž
.
Ž .
82.2 4
Ž
Ž .
Ž .
Ž .
89.9 4
2.57 1
Ž .
1.87 1
Ž
Ž
.
.
.
.
Ž .
85.7 3
Ni–C 4
Ž .
88.5 4
Ž .
Ž .
P–Ni–C 4
86.3 4
Ž
.
.
.
Ž .
P–Ni–N 32
92.8 2
Ž
Ž .
P–Ni–N 22
95.7 3
Ž
Ž .
175.3 3
P–Ni–N 12
5b
Ni–P 4
Ž .
Ž
.
Ž
.
w
x
pounds N i C H 2 S iM e 3 C l P M e
15a ,
a n d
Ž .
Ž .
Ž .
Ž .
Ž
.
.
Ž .
2.207 2
2.214 2
1.891 8
1.947 6
C 1 –Ni–N 11
178.6 3
2
1 0
w3
x
Ž .
Ž
Ž .
Ž
.
Ž
.
Ni–P 5
P 5 –Ni–N 11
93.5 2
N i C H 2 C M e C l P M e
3
Ž
3
x
2
Ž .
Ž .
Ž . Ž .
Ž .
Ni–C 1
P 5 –Ni–C 1
86.1 2
Ž
.
.
w
Ni CH2CMe2 Ph Cl PMe3
15a were obtained by
published methods, as well as the ligands KH2 B pz
2
Ž
.
Ž .
Ž .
Ž .
Ž .
Ni–N 11
P 4 –Ni–N 11
93.6 2
Ž
.
x2
Ž . Ž .
Ž .
P 4 –Ni–C 1
86.8 2
Ž .
172.7 1
w
x
Ž
.
w
x
Ž
.
w
6f,29 , KHB pz
6f,31 , KHB 3,5-Me2 pz
x
1d ,
Ž . Ž .
3
w
Ž
.
Ž
.
w
3x
P 4 –Ni–P 5
t
t
TlH2 B 3-Bu pz
7d , and TlHB 3-Bu pz
7d . The
2
3

(
)
222
E. Gutierrez et al.rJournal of Organometallic Chemistry 551 1998 215–227
´
Ž
.
Ž
.
Ž
Ž
.
Ž
.
syntheses of Ni C6 H4-o-Me Br PMe3 2 , and Ni C6 H4-
NMR 208C, C6 D6 d 13.4 pt, JCPŽapp. s14 Hz, PMe3 ,
3
.
Ž
.
Ž
.
Ž
.
Ž
p-X Br PMe3 were carried out following the proce-
dure described previously for the phenyl derivative
Ni C6 H5 Br PMe3 30 , using THF as the solvent, at
608C. The corresponding aroyl derivatives were pre-
pared by reaction of solutions of the parent aryls with 1
atm of CO. The Cp derivative Cp Ni C6 H5 PMe3
was synthesised from Ni C6 H5 Br PMe3 by reaction
54.3 s, OCH3 , 113.6 s, 2 m-CH , 135.4 t, JCP s4
2
2
.
Ž
.
Ž
Hz, 2 o-CH , 142.3 t, JCP s34 Hz, Ni–C , 156.4 s,
31
.
Ä1
4
Ž
.
Ž .
Ž
.
Ž
.
w
x
COMe ; P H NMR 208C, C6 D6 d y14.8 s .
Anal. Calcd. for C13 H25BrNiOP2: C, 39.2; H, 6.3.
Found: C, 38.3; H, 6.6.
2
Ž
.
Ž
.
.Ž
.
(
)
(
)
Ž
Ni C6 H4-p-NMe2 Br PMe3
:
1 H NMR 208C,
2
Ž
.
Ž
.
Ž
.
C6 D6 d 0.89 pt, 18 H, JHPŽapp. s3.7 Hz, PMe3 , 2.58
2
Ž
.
Ž
.
with NaCp in THF and isolated as dark red crystals.
s, 6H, NMe2 , 6.60, 6.64, 7.15, 7.16 br, 4 H, C6 H4 ;
1
13
Ä1
4
.
Ž
Ž
.
Ž
.
Ž
(
)
(
)(
)
Ž
.
Cp Ni C6 H5 PMe3 : H NMR 208C, C6 D6 d 0.66
C H NMR 208C, C6 D6 d 13.4 br, PMe3 , 40.6 s,
2
31
.
Ž
.
Ä1
4
Ž
Ž
.
Ž
.
d, 9 H, JHP s9.6 Hz, PMe3 , 5.18 s, 5 H, Cp , 6.97
NMe2 , 113.8 s, 2 CH , 135.6 s, 2 CH ; P H NMR
Ž .
3
3
.
Ž
Ž
.
t, 1 H, JHH s7.0 Hz, p-CH , 7.03 t, 2 H, JHH s7.3
208C, C6 D6 d y15.0 s .
3
13
.
Ž
.
Ä1
4
.
Hz, m-CH , 7.57 d, 2 H, JHH s7.7 Hz, o-CH ; C H
3.2. Synthesis of complexes
1
Ž
.
Ž
NMR 208C, C6 D6 d 17.8 d, JCP s30 Hz, PMe3 ,
Ž
.
Ž
.
(
)(
) (
)
89.9 s, Cp , 122.1, 126.0, 143.0 s, 1, 2, 2 CH , 144.2
3.2.1. BpNi CH2 SiMe3 PMe3 1a
2
31
Ž
.
Ä1
4
Ž
.
d
Ž
.
Ž
.
d, JCP s39 Hz, Cq ; P H NMR 208C, C6 D6
To a stirred solution of Ni CH2 SiMe3 Cl PMe3
2
Ž
.
Ž
.
.
y3.56.
0.29 g, 0.88 mmol in THF 20 ml at y208C, was
Ž
. Ž
Ž
.
ClCH2CMe2C6 H -p-Me was prepared as reported
for neophyl chloride 31 using toluene instead of ben-
zene. Ni CH2CMe2C6 H4-p-Me Cl PMe3 was synthe-
sised as follows: to a solution of NiCl2 PMe3 0.56 g,
added KH2 B pz 0.17 g, 0.91 mmol in THF 10 ml .
4w
x
2
A turbid yellow solution was obtained which was stirred
for 4 h at room temperature. It was then evaporated in
vacuo to give a brownish solid which was extracted
with 20 ml of petroleum ether, centrifuged to remove
KCl and concentrated. Cooling to y208C provided
Ž
.
Ž
.
2
Ž
. Ž
2
.
Ž
.
2 mmol in Et2O 30 ml cooled to y608C,
Ž
.
Ž
Mg CH2CMe2C6 H4-p-Me Cl is added 1.66 ml of a
.
Ž
.
Ž
Ž
solution 1.2 M in Et2O, 2 mmol . The mixture is stirred
cream-coloured crystals; yield 0.24 g 74% . IR Nujol,
1
cmy1 : nB – H 2460–2280, nC – N 1500; H NMR 208C,
.
for 40 min at low temperature and a further period of 24
h at room temperature. The solvent is evaporated under
vacuum and the mixture extracted with petroleum ether
2
.
Ž
.
C6 D6 d 0.63 d, 9 H, JHP s9.2 Hz, PMe3 , y0.42
3
Ž
.
Ž
.
.
;
d, 2 H, JHP s11.2 Hz, CH2 , 0.22 s, 3 H, CH3 ,
Ž
.
Ž
40 ml . The resulting solution is concentrated and
5.79, 5.87, 6.94, 7.40, 7.46, 7.51 s br, 6 H, CHp z
13
1
Ä1
4
Ž
Ž
.
Ž
cooled to y208C, to yield brown–yellow needles of the
C H NMR 208C, C6 D6 d 14.2 d, JCP s29 Hz,
2
.
.
Ž
.
.
;
expected product in about 20% yield.
PMe3 , y4.2 d, JCP s33 Hz, CH2 , 2.7 s, CH3 ,
1 H NMR
(
)
(
)
:
2
Ž
Ni CH2 CMe2 C6 H4-p-Me Cl PMe3 3
104.2, 104.6, 135.2, 135.5, 138.7, 139.7 s, CHp z
31
Ä1
4
Ž
.
Ž
.
Ž
208C, CD3COCD3 d 0.72 t, 2 H, JHP s13.4 Hz,
P H NMR 208C, C6 D6 d y10.2. Anal. Calcd. for
C13 H28 N4 BNiPSi: C, 42.3; H, 7.6; N, 15.2. Found: C,
42.3; H, 7.6; N, 15.0.
.
Ž
.
Ž
.
.
Ni–CH2 , 1.15 br s, 18 H, PMe3 , 1.56 s, 6H, Me2 ,
3
Ž
Ž
.
Ž
2.25 s, 3 H, Me , 7.06 d, 2 H, JHH s7.7 Hz, 2 CH ,
3
13
.
Ä1
4
7.79 d, 2 H, JHH s7.7 Hz, 2 CH ; C H NMR
(
)( )
) (
3.2.2. BpNi CH2CMe3 PMe3 1b
This complex was prepared in the same manner as
compound 1a using 0.16
Ž
.
Ž
208C, CD3COCD3 d 13.9 pt, JCPŽapp. s12.5 Hz,
2
.
Ž
Ž
.
Ž
.
PMe3 , 17.5 t, JCP s22.4 Hz, CH2 , 20.9 s, p-Me ,
Ž .
0.44 mmol of
g
.
Ž
.
Ž
33.1 s, Me2 , 41.6 s, CMe2 , 126.6, 129.1 s, 2, 2
Ž
.
Ž
.
Ž
.
Ni CH2CMe3 Br PMe3 and 0.09 g 0.46 mmol of
31
Ä1
4
Ž
2
.
Ž
.
CH , 134.6, 150.6 s, 2 Cq ; P H NMR 208C,
Ž .
Ž
.
KH2 B pz . The product was obtained as reddish–
2
.
CD3COCD3 d y18.5 s .
y1
Ž
.
brown crystals; yield 0.85 g, 55%. IR Nujol, cm
nB – H 2480–2280, nC – N 1500; H NMR 208C, C6 D6
:
1
(
Ž
)
(
)
Ž
.
Ni C6 H4-o-Me Br PMe3 2: H NMR 208C, C6 D6 d
1
Ž
.
.
Ž
0.82 pt, 18 H, JHPŽapp. s3.7 Hz, PMe3 , 2.66 s, 3H,
2
Ž
.
Ž
d 0.68 d, 9 H, JHP s8.8 Hz, PMe3 , 0.83 d, 2 H,
13
.
Ž
.
Ä1
4
Ž
Me , 6.8–7.3 m, 4 H, C6 H4 ; C H NMR 208C,
3
.
Ž
.
.
.
JHP s10.7 Hz, CH2 , 1.20 s, 3 H, CH3 , 5.80, 5.90,
.
Ž
.
Ž
C6 D6 d 13.5 pt, JCPŽapp. s14 Hz, PMe3 , 25.9 s,
Ž
Ž
.
6.98, 7.49 s br, 4 H, CHp z , 7.55 s br, 2 H, CHp z ;
.
Ž
.
Ž
CH3 , 121.8, 124.0, 127.5, 134.1 s, CH , 141.9 t,
13
1
Ä1
4
Ž
Ž
.
C H NMR 208C, C6 D6 d 14.4 d, JCP s28 Hz,
3
2
.
Ž
)
.
JCP s4 Hz, CMe , 157.8 t, JCP s34 Hz, Ni–C .
2
.
Ž
Ž
.
PMe3 , 22.9 d, JCP s34 Hz, CH2 , 33.7 s, CH3 ,
1
(
Ž
)
(
Ž
.
Ni C6 H4-p-Me Br PMe3 2: H NMR 208C, C6 D6 d
Ž
.
Ž
34.4 s, CMe3 , 104.2, 104.5, 135.4, 139.2, 139.7 s,
.
Ž
0.85 pt, 18 H, JHPŽapp. s3.6 Hz, PMe3 , 2.16 s, 3H,
31
.
Ä1
4 Ž .
P H NMR 208C, C6 D6 d y11.8. Anal.
CHp z
;
13
.
Ž
.
Ä1
4
.
Me , 6.82, 6.86, 7.21, 7.25 br, 4 H, C6 H4 ; C H
Calcd. for C14 H28 N4 BNiP: C, 47.7; H, 7.9; N, 15.9.
Found: C, 47.7; H, 8.2; N, 16.0.
Ž
.
Ž
NMR 208C, C6 D6 d 13.3 pt, JCPŽapp. s13 Hz, PMe3 ,
31
Ž
.
Ž
.
Ž
.
Ä1
4
20.6 s, CH3 , 127.9 s, 2 CH , 135.5 s, 2 CH ; P H
Ž
.
Ž .
(
)( )
) (
NMR 208C, C6 D6 d y14.9 s . Anal. Calcd. for
3.2.3. BpNi C6 H5 PMe3 1c
Following the same procedure as for complexes 1a
and 1b, 0.66 g 1.8 mmol of Ni C6 H5 Cl PMe3 was
reacted with 0.34 g 1.8 mmol of KH2 B pz in THF
yielding complex 1c as a brown crystalline material;
C13 H25BrNiP2: C, 40.9; H, 6.6. Found: C, 40.1; H, 7.0.
1
(
)
(
)
Ž
.
.
Ž
.
Ž
.
Ž
.
2
Ni C6 H4-p-OMe Br PMe3 2: H NMR 208C, C6 D6
Ž
Ž
Ž
.
Ž
.
d 0.85 pt, 18 H, JHPŽapp. s3.7 Hz, PMe3 , 3.38 s, 3H,
2
13
.
Ž
.
Ä1
4
OMe , 6.72, 6.77, 7.13, 7.17 br, 4 H, C6 H4 ; C H

(
)
E. Gutierrez et al.rJournal of Organometallic Chemistry 551 1998 215–227
223
´
3
y1
Ž
.
Ž
.
Ž
.
Ž
yield 0.49 g 71% . IR Nujol, cm : nB – H 2430–2170,
s, 6H, NMe2 , 5.88, 6.36, 7.26, 8.00 d, JHH s2.2 Hz,
1
Ž
.
Ž
.
Ž
.
nC – N 1500; H NMR 208C, C6 D6 d 0.55 d, 9 H,
1, 1, 1 and 1 H, CHp z , 6.5–7.25 br m, 4H, C6 H4 ;
2
3
13
Ä1
4
Ž
.
Ž
.
Ž
JHP s7.3 Hz, PMe33 , 5.80 t, 2 H, JHH s2.1 Hz,
C H NMR 208C, C6 D6 d 12.3 pt, JCPŽapp. s14
.
Ž
.
.
Ž
.
Ž
.
CHp z , 6.86 d, 2 H, JHH s2.1 Hz, CHp z , 6.94–7.55
Hz, PMe3 , 31.5 s, C Me3 , 40.4 s, NMe2 , 99.3,
Ž . Ž .
13
Ž
.
Ä1
4
Ž
.
Ž
.
m, 7 H, CHp z and CHAr
;
C H NMR 208C, C6 D6
104.1, 134.8, 135.5 s, CHp z , 112.7 s , 112.7 s ,
1
2
Ž
.
Ž .
Ž . Ž
.
Ž
d 13.6 d, JCP s26 Hz, PMe3 , 104.3, 135.0, 140.6,
135.5 s , 139.1 s C6 H4 , 130.1 t, JCP s38 Hz,
Ž
.
Ž
.
.
Ž
.
.
Ž
.
139.7 s, CHp z , 122.6, 126.3, 136.6 s, CHAr , 154.3
Ni–C , 147.5 s, CNMe2 , 158.3, 162.3 s, Cq p z ;
31
31
Ä1
4 Ž .
P H NMR 208C, C6 D6 d y11.5. Anal.
Ä1
4
Ž
Ž .
Ž
.
s, Cq Ar
;
P H NMR 208C, C6 D6 d y17.0 s . Anal. Calcd.
for C28 H52 N5BNiP2: C, 57.0; H, 8.9; N, 11.8. Found:
C, 57.6; H, 9.5; N, 11.2.
Calcd. for C15 H22 N4 BNiP: C, 50.2; H, 6.2; N, 15.6.
Found: C, 50.1; H, 6.3; N, 15.9.
(
)
( )
3.2.4. BptBuNi C6 H4-p-X PMe3
)
2
3.2.5. TpNi C6 H5 PMe3 3a
(
)(
Ž
.
Ž
. Ž
To a stirred solution of Ni C6 H5 Cl PMe3 0.2 g,
2
The Bpt derivatives can be prepared in 65–80%
yields as orange crystalline materials following the pro-
cedure described above for complexes 1.
.
Ž
.
0.54 mmol in THF 20 ml at y208C, was added
Ž
.
Ž
. Ž .
0.14 g, 0.56 mmol in THF 10 ml . The
KHB pz
3
reaction mixture was stirred for 4 h at room tempera-
ture. The solvent was then evaporated in vacuo to give a
brownish solid which was extracted with 20 ml of
petroleum ether, centrifuged to remove KCl and concen-
1
3.2.4.1. BptBuNi C6 H5 PMe3
2a . H NMR 208C,
(
)(
) (
)
Ž
2
.
Ž
.
C6 D6 d 0.76 pt, 18 H, JHPŽapp. s3.8 Hz, PMe3 , 1.54
Ž
.
Ž
.
s, 9 H, CMe3 , 1.58 s, 9 H, CMe3 , 5.87, 6.37, 7.25,
3
trated. Cooling to y208C provided brown crystals of
Ž
.
8.0 d, JHH s2.2 Hz, 1, 1, 1 and 1 H, CHp z , 6.8–7.4
y1
13
Ž
.
Ž
.
:
Ž
.
Ä1
4
Ž
.
Ž
complex 3a; yield 0.14 g 61% . IR Nujol, cm
m, 5 H, Ph ; C H NMR 208C, C6 D6 d 12.2 pt,
1
Ž
.
nB – H 2450, nC – N 1500; H NMR 208C, C6 D6 d 0.64
s br, 9 H, PMe3 , 5.94 s br, 3 H, CHp z , 7.25 s br, 3
.
Ž
.
JCPŽapp. s14 Hz, PMe3 , 31.5 s, C Me3 , 99.3, 104.3,
Ž
.
Ž
.
Ž
Ž
.
Ž . Ž .
134.8, 135.5 s, 1, 1, 1, 1 CHp z , 122.1 s , 125.6 s ,
.
Ž
.
Ž
H, CHp1z3 , 7.55 s br, 3 H, CHp z , 6.9–7.7 m, 5 H,
Ž .
Ž .
Ž . Ž . Ž
5 CHPh , 151.5 t,
31
125.7 s , 138.5 s , 139.1
s
1
2
.
Ä1
4
Ž
.
Ž
.
Ž
.
Ä1
4
P H
CHAr
.
26 Hz, PMe3 , 104.3, 135.0, 140.6, 139.7 s, CHp z ,
;
C H NMR 208C, C6 D6 d 13.6 d, JCP
s
JCP s38 Hz, Ni–C , 158.3, 162.2 s, Cq p z
;
.
Ž
Ž
.
Ž .
NMR 208C, C6 D6 d y16.4 s . Anal. Calcd. for
C26 H47 N4 BNiP2: C, 57.1; H, 8.6; N, 10.2. Found: C,
57.0; H, 8.8; N, 10.1.
31
Ž
.
Ž
.
Ä1
4
P H
122.6, 126.3, 136.6 s, CHAr , 154.3 s, Cq Ar
NMR 208C, C6 D6
C18 H24 N6 BNiP: C, 50.9; H, 5.7; N, 19.8. Found: C,
51.0; H, 5.6; N, 19.8.
;
Ž
.
d
y11.5. Anal. Calcd. for
3.2.4.2. BptBuNi C6 H4-p-Me PMe3 2b . 1H NMR
)( ) ( )
2
(
Ž
.
Ž
Ž
208C, C6 D6 d 0.78 pt, 18 H, JHPŽapp. s3.7 Hz,
(
)
( )
3.2.6. TpNi C6 H4-o-CH3 PMe3 3b
The reaction procedure followed was the same as for
.
.
Ž
.
PMe3 , 1.48 s, 9 H, CMe3 , 1.53 s, 9 H, CMe3 , 2.16
Ž
.
Ž
s, 3H, Me , 5.87, 6.37, 7.23, 7.98 br s, 1, 1, 1 and 1 H,
CHp z , 6.7–7.4 m, 4H, C6 H4 ; C H NMR 208C,
Ž
Ž
.
.
Ž
compound 3a using 0.46 g 1.2 mmol of Ni C6 H4-o-
CH3 Br PMe3 and 0.3 g 1.2 mmol of KHB pz .
The product was obtained as a light orange crystalline
material; yield 0.28 g 56% . IR Nujol, cm : nB – H
13
.
.
Ž
.
Ä1
4
Ž
.
Ž
.
Ž
.
2
3
Ž
.
Ž
C6 D6 d 12.2 pt, JCPŽapp. s14 Hz, PMe3 , 20.6 s,
.
Ž
.
.
Ž
Me , 31.3 s, C Me3 , 99.3, 104.3, 134.7, 135.3 s, 1, 1,
Ž . Ž . Ž . Ž .
y1
Ž
.
Ž
Ž
.
1
1, 1 CHp z , 126.8 s , 127.2 s , 138.4 s , 138.9 s
.
Ž
2450, nC – N 1500; H NMR 208C, C6 D6 d 0.61 s br,
2
Ž
.
Ž
.
Ž
C6 H4 , 130.9 br s, CMe , 145.5 t, JCP s38 Hz,
.
Ž
.
Ž
.
9 H, PMe3 , 2.96 s, 3 H, CH3 , 6.0 s br, 3 H, CHp z ,
31
.
.
Ž
.
Ä1
4 Ž
P H NMR 208C,
13
Ni–C , 158.3, 162.2 s, Cq p z
;
Ž
.
Ä1
4
6.87–7.65 m, 10 H, CHp z and CHAr
;
C H NMR
Ž .
1
C6 D6 d y16.7 s . Anal. Calcd. for C27 H49 N4 BNiP2:
Ž
.
Ž
.
Ž
208C, C6 D6 d 14.0 d, JCP s31 Hz, PMe3 , 25.4 s,
C, 57.8; H, 8.7; N, 10.0. Found: C, 58.4; H, 9.3; N, 9.8.
.
Ž
.
CH3 , 104.5, 135.0, 140.7 s, CHp z , 126.7, 126.8,
2
Ž
.
Ž
.
Ž
137.6 s, CHAr , 143.4 s, Cq Ar–Me , 152.8 d, JCP
51 Hz, Cq Ar
Anal. Calcd. for C19 H26 N6 BNiP: C, 52.0; H, 6.0; N,
19.1. Found: C, 51.8; H, 6.4; N, 19.1.
s
1
3.2.4.3. BptBuNi C6 H4-p-OMe PMe3
2c . H NMR
(
)(
) (
)
31
Ä1
4 Ž .
P H NMR 208C, C6 D6 d y12.2.
2
.
;
Ž
.
Ž
208C, C6 D6 d 0.77 pt, 18 H, JHPŽapp. s3.7 Hz,
.
Ž
.
Ž
.
PMe3 , 1.54 s, 9 H, CMe3 , 1.59 s, 9 H, CMe3 , 3.37
3
Ž
.
Ž
s, 3H, OMe , 5.87, 6.37, 7.25, 8.00 d, JHH s2.2 Hz,
.
Ž
Ž
.
(
)( ) ( )
3.2.7. TpNi C6 H5-o-CMe3 PMe3 3c
2
1, 1, 1 and 1 H, CHp z , 6.6–7.4 m, 4H, C6 H4 ;
13
Ä1
4
Ž
.
Ž
.
Ž
. Ž
C H NMR 208C, C6 D6 d 12.2 pt, JCPŽapp. s14
To a solution of Ni CH2CMe2 Ph Cl PMe3 0.15 g,
2
.
Ž
.
Ž
.
.
Ž
.
Hz, PMe3 , 31.4 s, C Me3 , 54.1 s, OMe , 99.4, 104.3,
Ž . Ž .
0.39 mmol in THF 20 ml at y208C, was added a
Ž
.
Ž
.
134.8, 135.5 s, 1, 1, 1, 1 CHp z , 112.1 s , 113.1 s ,
. Ž
solution of KHB pz . A turbid, orange solution was
3
Ž
.
Ž
.
138.4 br s , 139.0 br s C6 H4 , 157.0, 158.3, 159.6
obtained which was left stirring at room temperature for
3 h, after which the solvent was evaporated under
vacuum. The solid residue was extracted with petroleum
31
Ž
.
Ä1
4
Ž
.
Ž .
s, Cq ; P H NMR 208C, C6 D6 d y16.8 s .
1
3.2.4.4. BptBuNi C6 H4-p-NMe2 PMe3 2d . H NMR
(
)(
) ( )
2
Ž
.
ether 20 ml and centrifuged. On concentration of the
Ž
.
Ž
Ž
208C, C6 D6 d 0.82 pt, 18 H, JHPŽapp. s3.8 Hz,
solution, and cooling to y208C overnight, yellow–
.
.
Ž
.
Ž
.
PMe3 , 1.54 s, 9 H, CMe3 , 1.62 s, 9 H, CMe3 , 2.57
orange crystals were obtained; yield 0.12 g 64% . IR

(
)
224
E. Gutierrez et al.rJournal of Organometallic Chemistry 551 1998 215–227
´
1
y1
Ž
.
Ž
Ž
.
Ž
. Ž
To a solution of Ni C6 H5 Br PMe3 0.19 g, 0.51
2
Nujol, cm : nB – H 2444, nC – N 1500; H NMR 208C,
2
.
Ž
.
Ž
.
Ž
.
C6 D6 d 0.43 d, 9 H, JHP s10.0, PMe3 , 2.05 s, 9 H,
mmol in THF 20 ml cooled to y208C was added
TlTptBu 0.30 g, 0.51 mmol dissolved in THF 10 ml .
A white precipitate of TlBr was formed immediately.
The mixture was stirred for 4 h at room temperature and
the solvent was evaporated under vacuum. The residue
.
Ž
Ž
.
Ž
.
CH3 , 5.63, 5.96, 6.40, 7.56, 7.12, 7.41, 6.66, 7.70 s
13
.
Ž
.
Ä1
4
br, 9 H, CHp z , 6.8–7.9 m, 4 H, CHAr
;
C H NMR
1
Ž
.
Ž
.
Ž
208C, C6 D6 d 13.9 d, JCP s29 Hz, PMe3 , 33.9 s,
.
Ž
.
CH3 , 36.5 s, CMe3 , 104.4, 104.6, 105.0, 133.2,
Ž
.
Ž
.
136.3, 137.8, 140.7, 142.0, 142.8 s, CHp z , 123.0,
was extracted with petroleum ether 20 ml , the suspen-
sion centrifuged and the resulting solution concentrated
under vacuum and cooled to y208C overnight. Yellow
2
Ž
Ž
.
Ž
123.2, 126.5, 137.0 s, CHAr , 146.3 d, JCP s47 Hz,
31
.
.
Ä1
4 Ž
P H NMR 208C,
CAr–CMe3 , 155.5 s, Cq Ar
;
.
Ž
.
C6 D6 d y16.4. Anal. Calcd. for C22 H32 N6 BNiP: C,
needles 0.21 g, 65% yield of complex 5a were ob-
54.7; H 6.7; N 17.1. Found: C, 54.9; H 6.7; N 17.5.
tained.
3.2.10.1. TptBuNi C6 H5 PMe31
5a . IR Nujol,
(
)
( )
(
)(
)
(
)
Ž
3.2.8. TpNi 1-C6 H4-2-CMe3-5-Me PMe3 3d
Using the same method as for 7 and 8, 0.14 g 0.36
2
cmy1 : nB – H 2330, nC – N 1500; H NMR 208C, C6 D6
Ž
.
Ž
.
.
Ž
Ž
.
.
Ž
.
Ž
.
Ž
mmol of Ni CH2C CH3 2C6 H4-p-CH3 Cl PMe3 was
reacted with 0.09 0.36 mmol of KHB pz giving 3d
d 0.64 pt, 18 H, JHPŽapp. s3.8 Hz, PMe3 , 1.48 s, 18
2
Ž
.
Ž
.
.
Ž
.
H, CMe3 , 1.54 s, 9 H, CMe3 , 5.88, 6.22, 7.40, 7.64
3
3
Ž
.
Ž
Ž
Ž
.
Ž
as red–brown crystals; yield 0.2 g 67% . IR Nujol,
d, JHH s2.2 Hz, 1, 2, 2 and 1 H, CHp z , 6.91 br m,
1
3
cmy1 : nB – H 2450, nC – N 1500; H NMR 208C, C6 D6
.
.
.
Ž
.
Ž
3H, Ph , 7.22 br d, 1 H, JHH s7.5 Hz, Ph , 7.63 br d,
2
3
13
Ä1
4
Ž
Ž
.
Ž
.
Ž
.
d 0.48 d, 9 H, JHP s9.7 Hz, PMe3 , 2.05 s, 9 H,
1 H, JHH s7.5 Hz, Ph ; C H NMR 208C, C6 D6 d
Ž
. .
Ž
.
Ž
Ž
.
.
C CH3 , 2.10 s, 3 H, CAr–CH3 , 5.63–7.89 br s, 10
12.2 pt, JCPŽapp. s14 Hz, PMe3 , 31.3 s, C Me3 , 31.8
3
3
.
Ž
.
Ž
Ž
.
Ž
.
H, CHp z and 1 CHAr , 6.74 d, 1H, JHH s7.4, CHAr ,
s, CMe3 , 32.2 s, 2CMe3 , 100.2, 104.5, 133.2, 137.5
Ž . Ž . Ž .
3
13
Ž
.
.
Ä1
4 Ž
C H NMR 208C,
.
7.08 d, 1H, JHH s7.4, CHAr
;
s, 2, 1, 2, 1 CHp z , 122.2 s , 125.6 s , 126.0 s ,
1
2
Ž
.
Ž
Ž
.
Ž
. Ž
.
Ž
C6 D6 d 13.9 d, JCP s30 Hz, PMe3 , 31.1 s,
138.3 br s , 139.1 br s 5 CHPh , 150.8 t, JCP s37
31
.
Ž
.
Ä1
4 Ž
P H NMR 208C,
Ž
. . . .
Ž
Ž
Ž
.
C Me , 34.0 s, C CH3 , 36.1 s, CMe3 , 104.3,
Hz, Ni–C , 159.8, 162.1 s, Cq p z
;
2
3
.
Ž .
104.6, 105.0, 133.4, 136.3, 138.2, 140.7, 142.0, 142.9
s, CHp z , 124.1, 126.3, 137.0 3 CHAr , 131.4, 152.5
C6 D6 d y18.3 s . Anal. Calcd. for C33H57 N6 BNiP2:
C, 59.2; H, 8.6; N, 12.6. Found: C, 60.0; H, 8.6; N,
13.3.
Ž
Ž
Ž
.
Ž
.
2
31
.
Ž
.
.
Ä1
4
s, Cq , 145.8 d, JCP s50 Hz, Ni–C ; P H NMR
208C, C6 D6
d
y17.9 s. Anal. Calcd. for
3.2.10.2. TptBuNi C6 H4-p-Me PMe3
5b . IR Nujol,
(
)(
) (
)
Ž
C23 H34 N6 BNiP: C, 56.0; H 6.7; N 17.0. Found: C,
55.9; H 7.0; N 17.1.
2
1
cmy1 : nB – H 2330, nC – N 1500; H NMR 208C, C6 D6
.
Ž
.
Ž
.
Ž
d 0.66 pt, 18 H, JHPŽapp. s3.8, PMe3 , 1.49 s, 18 H,
)
(
)(
) ( )
.
Ž
.
Ž
.
3.2.9. Tp Ni C6 H5 PMe3
4
CMe3 , 1.55 s, 9 H, CMe3 , 2.17 s, 3H, Me , 5.88,
3
Ž
.
Ž
. Ž
2
Ž
To a stirred solution of Ni C6 H5 Cl PMe3 0.31 g,
6.22, 7.41, 7.65 d, JHH s2.2 Hz, 1, 2, 2 and 1 H,
.
Ž
.
.
Ž
.
Ž
.
0.84 mmol in THF 20 ml at y208C, was added
CHp z , 6.84 br m, 2H, C6 H4 , 7.16 br s, 1 H, C6 H4 ,
3
13
Ä1
4
Ž
) . Ž
. Ž .
0.28 g, 0.84 mmol in THF 10 ml . The
Ž
.
KHB pz
7.54 br d, 1H, JHH s7.8 Hz, C6 H4 ; C H NMR
3
Ž
Ž
.
Ž
.
reaction mixture was stirred for 4 h at room tempera-
ture. It was then evaporated in vacuo to give a brownish
solid which was extracted with 20 ml of petroleum
ether, centrifuged to remove KCl and concentrated.
208C, C6 D6 d 12.2 pt, JCPŽapp. s14 Hz, PMe3 , 20.6
.
Ž
.
Ž
.
s, Me , 31.3 s, C Me3 , 32.2 s, CMe3 , 100.3, 104.5,
Ž . Ž .
Ž
.
.
133.2, 137.5 s, 2, 1, 2, 1 CHp z , 126.8 s , 127.2 s ,
. Ž
Ž
.
Ž
Ž
.
.
138.1 br s , 139.0 br s C6 H4 , 131.2 br s, CMe ,
2
Ž
.
Ž
Cooling to y208C provided red–brown crystals of
144.9 t, JCP s40 Hz, Ni–C , 159.8, 162.1 s, Cq p z ;
31
y1
Ä1
4
Ž
.
Ž .
Ž
.
Ž
.
complex 4; yield 0.14 g 61% . IR Nujol, cm : nB – H
P H NMR 208C, C6 D6 d y18.5 s . Anal. Calcd.
for C34 H59 N6 BNiP2: C, 59.8; H, 8.7; N, 12.3. Found:
C, 59.7; H, 8.8; N, 12.3.
1
Ž
.
Ž
2460, nC – N 1550; H NMR 208C, C6 D6 d 0.57 d, 9
H,2 JHP s10.3, PMe3 , 1.45, 2.16, 2.19, 1.32 s, 18 H,
.
Ž
.
Ž
.
Ž
Mep z , 5.33, 5.84, 7.14 s, 3 H, CHp z , 6.9–7.6 m, 5
13
.
Ä1
4
Ž
.
Ž
3.2.10.3. TptB uNi C6 H4-p-OMe PMe3
5c . IR
(
)(
)
(
)
H, CHAr
;
C H NMR 208C, C6 D6 d 13.4 d,
2
1
1
y1
.
Ž
.
.
Ž
.
Ž
JCP s30 Hz, PMe3 , 12.4, 13.3, 13.9, 14.6 s, Mep z
,
,
Nujol, cm : nB – H 2330, nC – N 1500; H NMR 208C,
Ž
.
Ž
.
Ž
.
Ž
105.9, 106.9 s, CHp z , 122.4, 125.2, 139.0 s, CHAr
C6 D6 d 0.65 pt, 18 H, JHPŽapp. s3.7, PMe3 , 1.49 s,
2
Ž
.
Ž
.
Ž
.
Ž
.
144.8, 147.3, 150.6 s, Cq p z , 151.3 d, JCP s54 Hz,
18 H, CMe3 , 1.55 s, 9 H, CMe3 , 3.37 s, 3H, OMe ,
31
3
.
Ä1
4 Ž .
P H NMR 208C, C6 D6 d y13.6. Anal.
Ž
Cq Ar
;
5.88, 6.22, 7.41, 7.63 d, JHH s2.2 Hz, 1, 2, 2 and 1
.
Ž
.
Ž
Calcd. for C24 H36 N6 BNiP: C, 56.6; H, 7.1; N, 16.5.
Found: C, 56.8; H, 7.4; N, 16.4.
H, CHp z , 6.71 m, 2H, C6 H4 , 7.05 br d, 1 H,
3
3
.
Ž
JHH s8.1 Hz, C6 H4 , 7.44 br d, 1H, JHH s8.0 Hz,
13
.
Ä1
4
Ž
Ž
.
Ž
C6 H4 ; C H NMR 208C, C6 D6 d 12.2 pt, JCPŽapp.
3.2.10. TptBuNi C6 H4-p-X PMe3
5
)( ) ( )
2
These complexes were prepared starting from the
aryls Ni C6 H4-p-X Br PMe3 following the procedure
(
.
.
Ž
.
s14 Hz, PMe3 , 31.2 s, C Me3 , 31.3 s, C Me3 , 31.8
Ž
.
Ž
.
Ž
.
s, CMe3 , 32.2 s, CMe3 , 54.2 s, OMe , 100.2,
Ž .
Ž
.
Ž
.
Ž
.
104.5, 133.2, 137.5 s, 2, 1, 2, 1 CHp z , 112.4 s , 113.0
2
2
Ž .
Ž
.
Ž
. Ž
.
Ž
described below for the phenyl derivative:
s , 138.1 br s , 139.0 br s C6 H4 , 135.3 t, JCP s39

(
)
E. Gutierrez et al.rJournal of Organometallic Chemistry 551 1998 215–227
225
´
.
Ž
.
Ž
.
Hz, Ni–C , 157.1 s, COMe , 159.8, 162.2 s, Cq p z ;
insertion with CO to give the product as yellow crystals
in nearly quantitative yield. IR Nujol, cm : nB – H
31
Ä1
4
Ž
.
Ž .
y1
Ž
.
P H NMR 208C, C6 D6 d y18.5 s . Anal. Calcd.
for C34 H59 N6 BNiOP2: C, 58.4; H, 8.5; N, 12.0. Found:
C, 57.6; H, 8.9; N, 11.8.
1
Ž
2480–2280, nC – N 1500, nC – O 1600; H NMR 208C,
2
.
Ž
.
Ž
C6 D6 d 0.66 d, 9 H, JHP s9.0 Hz, PMe3 , 2.96 s,
3
.
Ž
.
Ž
CH2 , 0.91 s, 9 H, CH3 , 5.82 d, 2H, JHH s2.1 Hz,
3
3.2.10.4. TptBuNi C6 H4-p-NMe2 PMe3
5d . IR
(
)(
)
(
)
Ž
.
Ž
.
Ž
CHp z , 7.12 s br, 2 H, CHp z , 7.49 d, 2 H, JHH s2.1
2
1
13
y1
.
Ä1
4 Ž . Ž
C H NMR 208C, C6 D6 d 13.3 d,
Ž
.
Nujol, cm : nB – H 2340, nC – N 1500; H NMR 208C,
Hz, CHp z
;
1
.
Ž
.
Ž
.
Ž
.
Ž
.
.
Ž
C6 D6 d 0.69 pt, 18 H, JHPŽapp. s3.7, PMe3 , 1.46 s,
JCP s28 Hz, PMe3 , 63.2 s, CH2 , 29.2 s, CH3 ,
.
Ž
.
Ž
Ž
.
Ž
18 H, CMe3 , 1.59 s, 9 H, CMe3 , 2.58 s, 6 H,
30.9 s, CMe3 , 104.5, 135.3, 139.6 s, CHp z , 256.9 s
3
31
.
Ä1
4
Ž
.
.
Ž
NMe2 , 5.88, 6.18, 7.37, 7.61 d, JHH s2.2 Hz, 1, 2, 2
br, CsO ; P H NMR 208C, C6 D6 d y11.0.
Anal. Calcd. for C15 H28 N4 BNiOP: C, 47.3; H, 7.4; N,
14.7. Found: C, 47.4; H, 7.6; N, 14.9.
.
Ž
.
.
Ž
.
and 1 H, CHp z , 6.57 m, 2 H, C6 H4 , 7.01 br d, 1 H,
3
13
Ž
Ä1
4
JHH s8.1 Hz, C6 H4 , 7.42 br, 1 H, C6 H4 ; C H
Ž
.
Ž
.
NMR 208C, C6 D6 d 12.4 pt, JCPŽapp. s14 Hz, PMe3 ,
[ ( ) ( )
]
3.2.13. TpNi C O C6 H5 PMe3 7
Ž
.
Ž
.
Ž
.
31.3 s, C Me3 , 31.4 s, C Me3 , 31.8 s, CMe3 , 32.2
Ž
.Ž
. Ž
A solution of TpNi C6 H5 PMe3 0.12 g, 0.28
Ž
Ž
.
Ž
.
s, CMe3 , 40.4 s, NMe2 , 100.1, 104.4, 133.1, 137.3
Ž . Ž .
.
mmol in 40 ml of a 1:1 mixture of diethyletherrpetro-
.
.
Ž
.
s, 2, 1, 2, 1 CHp z , 112.4 s , 112.9 s , 138.2 br s ,
. Ž ..
leum ether was bubbled with CO for 5 min at room
temperature during which the solution took on an or-
ange hue. The solvent was then removed under vacuum
leaving an orange solid which was extracted with di-
Ž
Ž
Ž
139.1 br s C6 H4 , 147.5 s, Cq C6 H4 , 159.8, 162.0
31
Ž
.
Ä1
4 Ž . Ž .
P H NMR 208C, C6 D6 d y18.6 s .
s, Cq p z
;
Anal. Calcd. for C35 H62 N7 BNiP2: C, 59.0; H, 8.8; N,
13.7. Found: C, 59.2; H, 9.0; N, 13.6.
Ž
.
ethyl ether 15 ml . On cooling, orange crystals of 7
y1
Ž
.
Ž
.
were obtained; yield 0.1 g 79% . IR Nujol, cm
:
3.2.10.5. Reaction of complex 5c with ZnCl2. To a
solution of complex 5c 0.07 g, 0.1 mmol in Et2O 15
1
Ž
nB – H 2450, nC – N 1510, nC – O 1620; H NMR 208C,
Ž
Ž
.
Ž
2
.
Ž
.
C6 D6 d 0.68 d, 9 H, JHP s9.7 Hz, PMe3 , 5.94,
.
ml a solution of ZnCl2 0.06 ml, 1 M solution in Et2O,
Ž
.
Ž
Ž
.
7.25, 7.55 m, 9 H, CHp z , 7.0–8.4 m, 5 H, CHAr ;
.
0.06 mmol was added. A white precipitate was formed
13
1
Ä1
4
Ž
.
C H NMR 208C, C6 D6 d 14.1 d, JCP s30 Hz,
and after 1 h of stirring, the solution was filtered and
the solvent evaporated under vacuum. The residue was
extracted with Et2O, concentrated and cooled at y208C
.
Ž
.
PMe3 , 104.3, 134.8, 141.1 s, CHp z , 128.0, 128.7,
Ž
4
.
Ž
.
Ž
.
131.1 s, CHAr , 138.3 s, Cq Ar , 253.7 s, CsO ;
31
Ä1
Ž
.
P H NMR 208C, C6 D6 d y10.5. Anal. Calcd. for
C19 H24 N6 BNiOP: C, 50.4; H 5.3; N 18.6. Found: C,
50.6; H 5.3; N 18.6.
Ž
to yield orange crystals of the complex Ni C6 H4-p-
.
Ž
.
OMe Cl PMe3 2. From the mother liquors a white solid
identified as TptBuZnCl was crystallised. Anal. Calcd.
for C21H34 N6 BZnCl: C, 52.3; H, 7.1; N, 17.4. Found:
C, 52.5; H, 7.4; N, 17.6.
)
[ ( )
]
( )
8
3.2.14. Tp Ni C O C6 H5 PMe3
Ž
Following the same procedure as for 7, 0.25 g 0.66
.
w
Ž .
x
Ž
.
mmol of the complex Ni C O C6 H5 Br PMe3 was
[ ( ) ) ( )
](
3.2.11. BpNi C O CH2 SiMe3 PMe3 6a
2
)
Ž
.
Ž
.
reacted with 0.23 g 0.68 mmol of KHB pz
giving
Ž
.
A solution of 1a 0.24 g, 0.65 mmol in 30 ml of
petroleum ether was bubbled with CO for 5 min at room
temperature during which the appearance of a yellow
microcrystalline solid was observed. The solvent was
evaporated under reduced pressure leaving a yellow
solid residue which crystallised from a 1:1 petroleum
etherrdiethyl ether mixture at y208C to give an orange
3
orange crystals of the expected product; yield 0.2 g
y1
Ž
.
Ž
.
55% . IR Nujol, cm : nB – H 2460, nC – N 1530,
nC – O 1610; 1H NMR 208C, C6 D6 d 0.78 d, 9
Ž
.
Ž
H,2 JHP s9.9, PMe3 , 1.95 s, 3 H, Mep z , 2.17 s, 6 H,
.
Ž
.
Ž
.
Ž
.
Ž
Mep z , 2.33 s, 9 H, Mep z , 5.21, 5.57 s br, 3 H,
13
.
Ž
.
Ä1
4 Ž
C H NMR 208C,
CHp z , 6.2–8.0 m, 5 H, CHAr
;
1
.
Ž
.
.
Ž
C6 D6 d 13.4 d, JCP s29 Hz, PMe3 , 12.6–15.0 m,
crystalline material in essentially quantitative yield. IR
Nujol, cm : nB – H 2460–2280, nC – N 1500, nC – O
y1
.
Ž
Mep z , 105.3, 106.5, 107.1 s, CHp z , 127.9, 128.5,
Ž
.
1
2
Ž
.
Ž
131.0 s, CHAr , 143.7, 145.7, 146.0, 146.8, 149.7 s,
Ž
.
Ž
1625; H NMR 208C, C6 D6 d 0.67 d, 9 H, JHP s9.3
2
.
Ž
.
Ž
.
Cq p z , 139.0 s, Cq Ar , 254.0 d, JCP s38 Hz, CsO ;
.
Ž
.
Ž
.
Hz, PMe3 , 2.83 s, CH2 , y0.06 s, 9 H, CH3 , 5.81
31
Ä1
4
Ž
.
3
P H NMR 208C, C6 D6 d y11.1. Anal. Calcd. for
C25 H36 N6 BNiOP: C, 55.9; H, 6.7; N, 15.7. Found: C,
55.3; H, 6.9; N, 15.7.
Ž
.
4
Ž
t, 2H, CHp z , 7.18, 7.50 d, 4 H, JHH s2.1 Hz,
13
1
.
Ä1
Ž
.
Ž
.
CHp z
;
C H NMR 208C, C6 D6 d 13.9 d, JCP
s
.
Ž
.
Ž
Ž
28 Hz, PMe3 , 43.6 s, CH2 , y0.9 s, CH3 , 34.4 s,
.
.
Ž
.
Ž
CMe3 , 104.4, 135.4, 139.7 s, CHp z , 255.5 s br,
3.2.15. TptBuNi COC6 H4-p-X PMe3
)( )
2
(
31
Ä1
4
Ž
.
CsO ; P H NMR 208C, C6 D6 d y10.6. Anal.
Calcd. for C14 H28 N4 BNiOPSi: C, 42.4; H, 7.1; N, 14.1.
Found: C, 42.7; H, 7.0; N, 14.3.
The aroyls 9 can be synthesised similarly. A typical
procedure is as follows:
Ž
.
Ž
. Ž
A solution of Ni COC6 H5 Br PMe3 0.17 g, 0.43
2
[ ( ) ) ( )
](
.
Ž
.
3.2.12. BpNi C O CH2CMe3 PMe3 6b
mmol in THF 20 ml cooled to y208C, was treated
with a solution of TlTptBu 0.25 g, 0.43 mmol dis-
Ž
.
Employing the same method for compound 6a, 0.16
.Ž
Ž
.
Ž
.
Ž
.
g 0.45 mmol of BpNi CH2CMe3 PMe3 underwent
solved in THF 10 ml . The mixture was stirred at low

(
)
226
E. Gutierrez et al.rJournal of Organometallic Chemistry 551 1998 215–227
´
temperature for 2 h. The solvent was removed in vacuo
at 08C and the residue extracted with petroleum ether
Kappa diffractometer. The cell dimensions were refined
by least-squares fitting the u values of 25 reflections.
The intensities were corrected for Lorentz and polarisa-
tion effects. Scattering factors for neutral atoms and
anomalous dispersion corrections for Ni and Pd were
Ž
.
20 ml and filtered off. After concentration and cooling
at y208C yellow crystals of complex 9a were obtained
Ž
.
yield 67% .
w
x
taken from the literature 32 . The structure was solved
by Patterson and Fourier methods in the centrosymetric
P21rn space group. An empirical absorption correction
3.2.15.1. TptBuNi COC6 H5 PMe3
)(
9a . IR Nujol,
(
)
(
)
Ž
1
2
cmy1 : nB – H 2390, nC – N 1510, nC – O 1610; H NMR
.
Ž
.
Ž
w
x
208C, C6 D6 d 0.69 pt, 18 H, JHPŽapp. s3.6 Hz,
33 was applied at the end of the isotropic refinements.
.
Ž
.
Ž
.
.
PMe3 , 1.47 s, 18 H, CMe3 , 1.61 s, 9 H, CMe3 , 5.85
As can be seen in the values of the thermal parameters
for 5b, there exists some non resolvable disorder in the
C atoms of the t-Butyl groups due to their thermal
motions. A final refinement was undertaken with unit
weight and anisotropic thermal motion for all atoms
except the hydrogen atoms that have been refined
isotropically. The hydrogen atoms were included with
fixed isotropic contributions at their calculated posi-
tions. No trend in DF vs. Fo or sin url was observed.
Ž
Ž
.
Ž
.
Ž . Ž
br s , 6.21 br s , 7–8 m 1, 2 and 3 H, CHp z , 7–8
13
.
Ä1
4
Ž
.
Ž
m, C6 H5 ; C H NMR 208C, C6 D6 d 12.9 pt,
.
Ž
.
Ž
Ž
JCPŽapp. s13 Hz, PMe3 , 31.2 s, C Me3 , 31.4 s,
.
Ž
.
C Me3 , 32.1 s, CMe3 , 100.4, 104.5, 132.9, 137.0 s,
Ž . Ž . Ž . Ž
.
.
.
2, 1, 2, 1 CHp z , 128.2 s , 131.7 s , 134.0 s C6 H5 ,
3
Ž
.
Ž
138.9 t, JCP s7 Hz, COC , 160.1, 162.2 s, Cq p z ,
2
31
Ž
.
Ä1
4
Ž
254.2 t, JCP s27 Hz, CO ; P H NMR 208C,
.
Ž .
C6 D6 d y19.5 s . Anal. Calcd. for C34 H57 N6 BNiOP2:
C, 58.6; H, 8.2; N, 12.1. Found: C, 58.6; H, 8.3; N,
12.1.
Final difference synthesis showed no significant elec-
tron density no greater than 0.40 e A for 5b . Most
of the calculations were carried out with the X-Ray 80
y3
˚
Ž
.
3.2.15.2. TptBuNi COC6 H4-p-Me PMe3
9b . IR
(
)(
)
(
)
w
x
system 34 . Atomic coordinates for these structures
have been deposited with the Cambridge Crystallo-
graphic Data Centre. The coordinates can be obtained,
on request, from the Director, Cambridge Crystallogra-
phyC Data Centre, 12 Union Road, Cambridge CB2
1EZ, UK.
2
Nujol, cm : nB – H 2390, nC – N 1510, nC – O 1600; 1H
y1
Ž
.
Ž
.
.
Ž
NMR 208C, C6 D6 d 0.72 pt, 18 H, JHPŽapp. s3.9 Hz,
Ž
.
Ž
.
PMe3 , 1.99 s, 3 H, Me , 1.47 s, 18 H, CMe3 , 1.62
Ž . Ž . Ž .
Ž
.
Ž
.
s, 9 H, CMe3 , 5.86 d , 6.23 d , 7.49 d , 7.52 br s
Ž3
.
Ž
JHH s2.2 Hz, 1, 2, 2, 1 H, CHp z , 7.0–7.7 m,
13
.
Ä1
4
Ž
.
Ž
C6 H4 ; C H NMR 208C, C6 D6 d 13.0 pt, JCPŽapp.
.
Ž
.
Ž
.
Ž
s13 Hz, PMe3 , 21.1 s, Me , 31.2 s, C Me3 , 31.5 s,
.
Ž
Ž
.
Ž
.
C Me3 , 31.7 s, CMe3 , 32.2 s, CMe3 , 100.3, 104.5,
Acknowledgements
.
Ž
.
132.9, 137.0 s, 2, 1, 2, 1 CHp z , 128.9 br s, C6 H4 ,
Ž
.
Ž
.
Ž
.
Ž
137.0 s, Cq , 142.1 s, Cq , 160.1 s, Cq p z , 162.1 s,
The Direccion General de Investigacion Cientıfica y
´
´
´
2
31
.
Ž
.
.
Ä1
4
Cq p z , 253.3 t, JCP s26 Hz, CO ; P H NMR
Ž
.
Tecnica Proyectos PB93-0921 and PB94-1445 and the
´
Ž
Ž .
208C, C6 D6
d
y19.5 s . Anal. Calcd. for
Junta de Andalucıa are thanked for financial support.
Thanks are also due to the University of Sevilla for free
access to its NMR facilities and to the Spanish Ministry
of Science and the EU for research grants M.C.N. and
S.A.H. . Dr. E. Carmona and Dr. M.L. Poveda are
´
C35 H59 N6 BNiOP2: C, 59.1; H, 8.3; N, 11.8. Found: C,
58.9; H, 8.4; N, 11.6.
Ž
3.2.15.3. TptBuNi COC6 H4-p-OMe PMe3
(
)(
)
( )
9c . IR
.
2
Nujol, cm : nB – H 2390, nC – N 1510, nC – O 1605; 1H
y1
Ž
.
thanked for help and encouragement and Ms. I.
Sanchez-Medina is thanked for some experimental help.
´
Ž
.
.
Ž
NMR 208C, C6 D6 d 0.74 pt, 18 H, JHPŽapp. s3.9 Hz,
Ž
.
Ž
.
PMe3 , 3.22 s, 3H, OMe , 1.49 s, 18 H, CMe3 , 1.63
Ž . Ž . Ž .
Ž
.
Ž
.
s, 9 H, CMe3 , 5.87 d , 6.22 d , 7.43 d , 7.46 br s
Ž3
.
Ž
JHH s2.2 Hz, 1, 2, 2, 1 H, CHp z , 6.5–7.0 m,
References
13
.
Ä1
4
Ž
Ž
.
Ž
C6 H4 ; C H NMR 208C, C6 D6 d 13.7 pt, JCPŽapp.
.
.
Ž
.
s14 Hz, PMe3 , 54.8 s, OMe , 31.3 s, C Me3 , 31.4
w
w
w
w
w
w
x
Ž
.
1a S. Trofimenko, J. Am. Chem. Soc. 91 1969 588.
Ž
.
Ž
.
Ž
.
x
Ž
.
s, C Me3 , 31.7 s, CMe3 , 32.2 s, CMe3 , 100.4,
1b S. Trofimenko, J. Am. Chem. Soc. 88 1966 1842.
x
Ž
Ž
.
.
1c S. Trofimenko, J. Am. Chem. Soc. 91 1969 3183.
Ž
.
Ž
104.5, 132.9, 136.7 s, 2, 1, 2, 1 CHp z , 112–140 br,
3
x
1d S. Trofimenko, J. Am. Chem. Soc. 89 1967 6288.
.
Ž
Ž
Ž . .
Ž
.
C6 H4 , 133.3 t, JCP s6 Hz, C O C , 162.6 s, COMe ,
x
Ž
.
2a S. Trofimenko, Chem. Rev. 93 1993 943.
2
.
Ž
.
Ž
160.3 s, Cq p z , 162.2 s, Cq p z , 251.1 t, JCP s27
x
2b A. Shaver, in: R.D. Gillard, J.A. McCleverty, G. Wilkinson
31
.
Ä1
4
Ž
.
Ž .
Hz, CO ; P H NMR 208C, C6 D6 d y19.3 s .
Anal. Calcd. for C35 H59 N6 BNiO2 P2: C, 57.8; H, 8.2;
N, 11.6. Found: C, 56.9; H, 8.0; N, 11.2.
Ž
.
Eds. , Comprehensive Coordination Chemistry, Vol. 2, Perga-
mon, Oxford, 1987.
w
w
w
w
w
w
x
Ž
.
2c K. Niedenzu, S. Trofimenko, Top. Curr. Chem. 131 1986 1.
x
Ž
.
2d S. Trofimenko, Prog. Inorg. Chem. 34 1986 115.
x
Ž
.
3.3. X-ray structure determinations of 3a and 5b
2e S. Trofimenko, Adv. Chem. Ser. 150 1976 289.
x
Ž
.
2f S. Trofimenko, Chem. Rev. 72 1972 497.
Ž
Ž
.
Ž
..
Crystals red 3a or yellow 5b of prismatic shape
x
Ž
.
2g S. Trofimenko, Acc. Chem. Res. 4 1971 17.
x
Ž
.
were coated with an epoxi resin and mounted in a
3a N. Kitajima, W.B. Tolman, Prog. Inorg. Chem. 43 1995 419.

(
)
E. Gutierrez et al.rJournal of Organometallic Chemistry 551 1998 215–227
227
´
w
w
w
x
Ž
.
w
w
x
Ž
.
3b G. Parkin, Adv. Inorg. Chem. 42 1995 291.
15c H.F. Klein, Angew. Chem., Int. Ed. Engl. 12 1973 402.
x
Ž
.
x
4a D.L. Reger, Y. Ding, Organometallics 12 1993 4485.
16a E. Carmona, E. Gutierrez-Puebla, J.M. Marın, A. Monge, M.
´
´
x
Ž
.
4b E. Kime-Hunt, K. Spartalian, M. DeRusha, C.M. Nunn, C.J.
Paneque, M.L. Poveda, C. Ruiz, J. Am. Chem. Soc. 111 1989
2883.
Ž
.
Carrano, Inorg. Chem. 28 1989 4399.
w
w
x
w
x
4c D.M. Collins, F.A. Cotton, C.A. Murillo, Inorg. Chem. 15
16b R. Neidlein, A. Rufinska, H. Schwager, G. Wilke, Angew.
Ž
.
Ž
.
1976 1861.
Chem., Int. Ed. Engl. 25 1986 640.
x
w
x
Ž
.
4d U.E. Bucher, A. Currao, R. Nesper, H. Ruegger, L.M. Ve-
17 P.K. Byers, A.J. Canty, Organometallics 9 1990 210.
¨
Ž
.
w
w
w
w
w
x
nanzi, E. Younger, Inorg. Chem. 34 1995 66.
18a D.L. Reger, S.J. Knox, M.F. Huff, A.L. Rheingold, B.S.
w x
Ž
.
5 P.K. Byers, A.J. Canty, R.T. Honeyman, Adv. Organomet.
Heggerty, Inorg. Chem. 30 1991 1754.
Ž
.
x
Chem. 34 1992 1.
18b F.G. Herring, D.J. Patmore, A. Storr, J. Chem. Soc., Dalton
w
w
w
x
Ž
.
6a S. Trofimenko, J.C. Calabrese, J.S. Thompson, Inorg. Chem.
Trans. 1975 711.
Ž
.
x
31 1992 974.
18c J.L. Calderon, F.A. Cotton, A. Shaver, J. Organomet. Chem.
x
Ž
.
6b J.C. Calabrese, P.J. Domaille, S. Trofimenko, G.J. Long, Inorg.
37 1972 127.
Ž
.
x
Chem. 30 1991 2795.
18d J.L. Calderon, F.A. Cotton, A. Shaver, J. Organomet. Chem.
x
Ž
.
6c M. Cano, J.V. Heras, S. Trofimenko, A. Monge, E. Gutierrez,
38 1972 105.
´
x
C.J. Jones, J.A. McCleverty, J. Chem. Soc., Dalton Trans.
18e J.L. Calderon, F.A. Cotton, A. Shaver, J. Organomet. Chem.
Ž
.
Ž
.
1990 3577.
42 1972 419.
w
w
x
x
Ž
.
w
x
Ž
.
6d E. Frauendorfen, G. Agrifoglio, Inorg. Chem. 21 1982 4122.
6e J.P. Jesson, S. Trofimenko, D.R. Eaton, J. Am. Chem. Soc. 89
19 H.F. Klein, H.H. Karsch, Chem. Ber. 105 1972 2628.
w
w
w
x
20a M. Onishi, K. Hiraki, T. Itoh, Y. Ohama, J. Organomet. Chem.
Ž
.
Ž
.
1967 3148.
254 1983 381.
w
w
x
x
Ž
.
x
Ž
.
6f S. Trofimenko, J. Am. Chem. Soc. 89 1967 3170.
6g H. Kokusen, Y. Sohrin, M. Matsui, Y. Hata, H. Hasegawa, J.
20b M. Onishi, T. Itoh, K. Hiraki, J. Organomet. Chem. 209 1981
123.
Ž
.
x
Chem. Soc., Dalton Trans. 1996 195.
20c M. Cocivera, T.J. Desmond, G. Ferguson, B. Kaitner, F.J.
w
x
Ž
.
6h P. Cecchi, G. Gioia-Lobbia, F. Marchetti, G. Valle, S. Calogero,
Lalor, D.J. Sullivan, Organometallics 1 1982 1125.
Ž
.
w
w
x
x
Ž
.
Polyhedron 13 1994 2173.
20d K.D. Gallicano, N.L. Paddock, Can. J. Chem. 60 1982 521.
20e O.M. Abu-Salah, M.I. Mruce, P.J. Lohmeyer, C.L. Raston,
w
w
w
x
Ž
.
7a J.C. Calabrese, S. Trofimenko, Inorg. Chem. 31 1992 4810.
7b I.B. Gorrel, G. Parkin, Inorg. Chem. 29 1990 2452.
7c S. Trofimenko, J.C. Calabrese, P.J. Domaille, J.S. Thompson,
x
Ž
.
B.W. Shelton, A.H. White, J. Chem. Soc., Dalton Trans.
x
Ž
.
1981 962.
Ž
.
w
w
x
x
Ž
.
Inorg. Chem. 28 1989 1091.
20f N.F. Borkett, M.I. Bruce, Inorg. Chim. Acta 12 1975 L33.
20g A.J. Canty, N.J. Minchin, J.M. Patrick, A.H. White, Aust. J.
w
w
w
x
7d S. Trofimenko, J.C. Calabrese, J.S. Thompson, Inorg. Chem.
Ž
.
Ž
.
26 1987 1507.
Chem. 36 1983 1107.
x
w
w
w
x
7e S. Trofimenko, J.C. Calabrese, J.K. Kochi, S. Wolowiec, F.B.
21 V. Chauby, C. Serra Le Berre, Ph. Kalck, J.-C. Daran, G.
Ž
.
Ž
.
Hulsbergen, J. Reedijk, Inorg. Chem. 31 1992 3943.
Commenges, Inorg. Chem. 35 1996 6354.
x
x
7f D. Carmona, F.J. Lahoz, R. Atencio, A.J. Edwards, L.A. Oro,
22 F.A. Cotton, G. Wilkinson, Advanced Inorganic Chemistry,
M.P. Lamata, M. Esteban, S. Trofimenko, Inorg. Chem. 35
Chap. 29, Wiley, New York, 1988, pp. 1297–1300.
Ž
.
x
Ž
.
1996 2549.
23 R.K. Harris, Can. J. Chem. 42 1964 2275.
w x
w
w
w
x
8 H. Lehmkuhl, J. Naser, G. Mehler, T. Keil, F. Danowski, R.
24a A.J. Canty, B.W. Skelton, A.H. White, Aust. J. Chem. 40
¨
Ž
.
Benn, R. Mynott, G. Schroth, B. Gabor, C. Kruger, P. Betz,
¨
1987 1609.
Ž
.
x
Chem. Ber. 124 1991 441.
24b M.I. Bruce, J.D. Walsh, B.W. Skelton, A.H. White, J. Chem.
w x
Ž
.
9 E. Gutierrez, S.A. Hudson, A. Monge, M.C. Nicasio, M.
Soc., Dalton Trans. 1981 956.
´
Ž
.
x
Paneque, E. Carmona, J. Chem. Soc., Dalton Trans. 1992
24c G.G. Lobbia, P. Cecchi, F. Bonati, G. Rafaiani, Synth. React.
Ž . Ž
.
2651.
Inorg. Met.-Org. Chem. 22 6 1992 775.
w
w
x
Ž
.
w
w
x
10 E. Carmona, M. Paneque, M.L. Poveda, Polyhedron 3 1984
25 C.K. Johnson, ORTEP II, Oak Ridge National Laboratory,
317.
Tennessee, 1971.
x
x
11 E. Carmona, J.M. Marın, M. Paneque, M.L. Poveda,
26 A.J. Canty, N.J. Minchin, P.C. Healy, A.H. White, J. Chem.
´
Ž
.
Ž
.
Organometallics 6 1987 1757.
Soc., Dalton Trans. 1982 p. 1795.
w
x
Ž
.
w
w
x
12a A. Akermark, A. Ljungkist, J. Organomet. Chem. 149 1978
27a M.A. Bennett, T.W. Hambley, N.K. Roberts, G.B. Robertson,
Ž
.
97.
Organometallics 4 1985 1992.
w
w
w
x
Ž
.
x
12b S.I. Black, G.B. Young, Polyhedron 8 1989 585.
12c B.P. Clearly, R. Eisenberg, Organometallics 11 1992 2335.
12d D.C. Griffiths, L.G. Joy, A.C. Skapski, D.J. Wilkes, G.B.
27b D.D. VanderLende, K.A. Abboud, J.M. Boncella, Inorg. Chem.
x
Ž
.
Ž
.
34 1995 5319.
x
w
w
x
x
Ž
.
28a H.C. Clark, L.E. Manzer, Inorg. Chem. 1974 1291.
28b J.D. Oliver, P.E. Rush, J. Chem. Soc., Chem. Commun. 1974
Ž
.
Ž
.
.
Young, Organometallics 5 1986 1744.
w
x
Ž
.
12e A. Akermark, A. Ljungkist, J. Organomet. Chem. 182 1979
966.
w
w
x
Ž
.
47.
29 S. Trofimenko, Inorg. Synth. 12 1970 99.
w
x
x
Ž
13 I.B. Gorrell, A. Looney, G. Parkin, J. Chem. Soc., Chem.
30 E. Carmona, M. Paneque, M.L. Poveda, Polyhedron 8 1989
Ž
.
Commun. 1990 220.
285.
w
w
x
w
w
x
14a R.G. Ball, C.K. Ghosh, J.K. Hoyano, A.D. McMaster, W.A.G.
31 F.C. Whitmore, C.A. Weisgerber, A.C. Shabica Jr., J. Am.
Ž
.
Ž
.
Graham, J. Chem. Soc., Chem. Commun. 1989 341.
Chem. Soc. 65 1943 1469.
x
x
14b P.K. Byers, A.J. Canty, N.J. Minchin, J.M. Patrick, B.W.
32 International Tables for X-Ray Crystallography, Vol. 4,
Ž
.
Skelton, A.H. White, J. Chem. Soc., Chem. Commun. 1985
Kynoch, Birmingham, 1974, pp. 72–98.
w
w
x
Ž
.
1183.
33 N. Walker, D. Stuart, Acta Crystallogr., Sect. A 39 1983 158.
w
w
x
x
15a E. Carmona, F. Gonzalez, M.L. Poveda, J.L. Atwood, R.D.
Rogers, J. Chem. Soc., Dalton Trans. 1980 2108.
15b H.F. Klein, H.H. Karsch, Chem. Ber. 99 1976 2501.
34 J.M. Stewart, X-RAY 80 System, Computer Science Center,
´
Ž
.
Universty of Maryland, College Park, MD, 1985.
x
Ž
.