Cationic half-sandwich complexes, [CpM{P(C7H7) 2(η2-C7H7)}]BF4 (M=Ni, Pd, Pt), containing a bidentate tri(1-cyclohepta-2,4,6-trienyl)phosphane ligand

Article abstract of DOI:10.1016/S0020-1693(02)00747-8

Displacement of η⁴-cycloocta-1,5-diene (cod) from [CpM(cod)]BF₄ by the olefinic phosphane P(C₇H ₇)₃ (1) leads to complexes [CpM{P(C₇H ₇)₂(η²-C₇H₇)}]BF ₄ (M=Ni (4), Pd (5)) in which one of the cyclohepta-2,4,6-trienyl substituents is symmetrically η²-coordinated to the metal in addition to phosphorus. The platinum analogue (M=Pt (6)) was obtained from [PtCl₂(cod)] by consecutive reactions with 1, TlCp and AgBF ₄. The homologous series 4-6 was studied by multinuclear ( ¹H, ¹³C, ³¹P and ¹⁹⁵Pt) NMR spectroscopy, and related tetrafluoroborates such as the pentaphenyl- cyclopentadienyl analogue of 5 and the tert-butylisocyanide adduct of 4, [CpNi(CN^tBu){P(C₇H₇)₃}]BF ₄ (11), were considered for comparison. An X-ray crystallographic structure determination of 4 has been carried out.

Full text of DOI:10.1016/S0020-1693(02)00747-8

Inorganica Chimica Acta 334 (2002) 10ꢁ16
/
www.elsevier.com/locate/ica
Cationic half-sandwich complexes, [CpM{P(C7H7)2(h2-C7H7)}]BF4
(Mꢀ
/
Ni, Pd, Pt), containing a bidentate tri(1-cyclohepta-2,4,6-
trienyl)phosphane ligand
Max Herberhold *, Thomas Schmalz, Wolfgang Milius, Bernd Wrackmeyer *
Laboratorium fur Anorganische Chemie der Universitat Bayreuth, Postfach 10 12 51, D-95440 Bayreuth, Germany
¨ ¨
Received 22 June 2001; accepted 28 August 2001
Dedicated to Professor Andrew Wojcicki
Abstract
Displacement of h4-cycloocta-1,5-diene (cod) from [CpM(cod)]BF4 by the olefinic phosphane P(C7H7)3 (1) leads to complexes
[CpM{P(C7H7)2(h2-C7H7)}]BF4 (MꢀNi (4), Pd (5)) in which one of the cyclohepta-2,4,6-trienyl substituents is symmetrically h2-
coordinated to the metal in addition to phosphorus. The platinum analogue (MꢀPt (6)) was obtained from [PtCl2(cod)] by
consecutive reactions with 1, TlCp and AgBF4. The homologous series 4ꢁ
6 was studied by multinuclear (1H, 13C, 31P and 195Pt)
/
/
/
NMR spectroscopy, and related tetrafluoroborates such as the pentaphenyl-cyclopentadienyl analogue of 5 and the tert-
butylisocyanide adduct of 4, [CpNi(CNtBu){P(C7H7)3}]BF4 (11), were considered for comparison. An X-ray crystallographic
structure determination of 4 has been carried out. # 2002 Elsevier Science B.V. All rights reserved.
Keywords: Nickel; Palladium; Platinum; Phosphane complexes; Olefin complexes; NMR; X-ray crystallogaphy
1. Introduction
cyclopentadienyl rings (h5-C5H4t Bu (3a), h5-C5Me5) or
an indenyl ring (h5-C9H7) are used to form the half-
sandwich complex instead of the unsubstituted Cp
ligand [3] (Scheme 2). The molecular structures in the
solid state have been determined for 1, 2, 3 and 3a by X-
The tertiary phosphane tri(1-cyclohepta-2,4,6-
trienyl)phosphane, P(C7H7)3 (1) [1], is a versatile ligand,
which is able to use its olefinic cycloheptatrienyl side
arms as coordinating centers in addition to the firmly
bound phosphorus atom. If all three C7H7 substituents
ray crystallography [1ꢁ
We now present a comparative study of the tetra-
fluoroborate salts 4ꢁ6 (Scheme 2), in which the half-
/
3].
are attached to the metal as*
(2) [2,3] or in the corresponding iridium(I) complex
[2]*a highly symmetrical (C3v) molecule is formed in
/
in [RhCl{P(h2-C7H7)3}]
/
sandwich cation is isoelectronic and isostructural with
the neutral complex 3. In a formal sense, the coordina-
tion number 5 can be assigned to these complexes, if the
Cp ring occupies three and the 4-electron ligand
{P(C7H7)2(h2-C7H7)} two coordination sites. A similar
4-electron ligand is found in the osmium complex
[(mesitylene)OsCl{P(C7H7)2(h2-C7H7)}]PF6 (7) [4],
/
which 1 acts as an 8-electron ligand (Scheme 1).
In half-sandwich cyclopentadienyl complexes such as
[CpRh{P(C7H7)2(h2-C7H7)}] (3) [3], the olefinic phos-
phane 1 plays the part of a 4-electron ligand, bearing
only one h2-coordinated and two free cyclohepta-2,4,6-
trienyl substituents at the phosphorus atom. An analo-
gous structure of type 3 is formed if substituted
* Corresponding authors. Tel.: ꢂ
157.
E-mail
Herberhold), b.wrack@uni-bayreuth.de (B. Wrackmeyer).
/
49-921-552 540; fax: ꢂ
/
49-921-552
addresses:
max.herberhold@uni-bayreuth.de (M.
Scheme 1.
0020-1693/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved.
PII: S 0 0 2 0 - 1 6 9 3 ( 0 2 ) 0 0 7 4 7 - 8

M. Herberhold et al. / Inorganica Chimica Acta 334 (2002) 10ꢁ
/16
11
Scheme 5.
Scheme 2.
for the synthesis of the half-sandwich cation in 6
(Scheme 6).
A palladium complex 10 which contains a voluminous
h5-pentaphenyl-cyclopentadienyl ring ligand (Scheme 7)
instead of the unsubstituted Cp ring in 5, was obtained
through the known reaction sequence starting from
palladium acetate and diphenylacetylene [9,10]. The
intermediate [(h5-C5Ph5)2Pd2(m-C2Ph2)] [9] was con-
verted into the salt [(h5-C5Ph5)Pd(cod)]BF4 [10] from
which the cycloocta-1,5-diene chelate ligand could be
eliminated by the action of P(C7H7)3 (1) in the usual
way.
Scheme 3.
whereas the phosphane is a 6-electron system in [(h7-
C7H7)Mo{P(C7H7)2(h4-C7H7)}]BF4 (8) [5] (Scheme 3).
The cations of the tetrafluoroborate salts 4ꢁ6 remain
/
intact in the presence of an excess of P(C7H7)3. Model
experiments with [CpNi{P(C7H7)2(h2-C7H7)}]BF4 (4)
have shown that phosphanes and phosphites (such as
PPh3 or P(OMe)3) do not open the chelate ring,
although tert-butyl isocyanide reacts to give the adduct
11 (Scheme 7).
2. Results and discussion
2.1. Syntheses
The general strategy for the introduction of P(C7H7)3
(1) as a four-electron ligand is to displace a chelating
cycloocta-1,5-diene (cod) chelate ligand by 1. The
synthetic routes to the tetrafluoroborate salts 4,5,
therefore, involve the initial formation of the cy-
cloocta-1,5-diene precursors [CpM(cod)]BF4. In the
case of nickel, the 20e sandwich complex nickelocene
(NiCp2) can be easily converted into the 18e cation
[CpNi(cod)]ꢂ [6]. In the cases of palladium and
platinum, the 16e dichlorides, [MCl2(cod)], were used
as starting materials [7]. Conversion of [PdCl2(cod)] into
a dinuclear, chloro-bridged, methoxy-cyclooctenyl (16e)
complex and subsequent reaction with thallium cyclo-
pentadienide (TlCp) gave the 18e cation [CpPd(cod)]ꢂ
[8] (Scheme 4).
In 11, the P(C7H7)3 system acts as a simple two-
electron phosphane ligand. The cations [CpM-
{P(C7H7)2(h2-C7H7)}]ꢂ (Mꢀ
/
Ni, Pd, Pt) in 4ꢁ
related to the cations [CpM(L)(C2H4)]ꢂ (Mꢀ
Ni, Lꢀ
PPhMe2 [11]; MꢀPd and Pt, LꢀPPh3 [11ꢁ13]) which
/
6 are
/
/
/
/
/
were studied by Kurosawa and coworkers.
2.2. NMR spectra
The 1H, 13C and 31P NMR data obtained for the
tetrafluoroborate salts 4ꢁ6, 10 and 11 are collected in
/
Table 1. The 18e cations [CpM{P(C7H7)2(h2-C7H7)}]ꢂ
(Mꢀ/Ni, Pd, Pt) apparently possess rigid structures in
The [CpM(cod)]BF4 salts (MꢀNi, Pd) were then
/
treated with 1 to give [CpM{P(C7H7)2(h2-C7H7)}]BF4
(4,5) (Scheme 5).
In the case of platinum, the ligand P(C7H7)3 (1) was
introduced first to give [PtCl2{P(C7H7)2(h2-C7H7)}] (9),
before the reaction with TlCp and AgBF4 was applied
Scheme 4.
Scheme 6.

12
M. Herberhold et al. / Inorganica Chimica Acta 334 (2002) 10ꢁ16
/
solution, which is in contrast to neutral 16e complexes
such as [PtCl2{P(C7H7)2(h2-C7H7)}] (9) [14].
In general, acetone-d6 served as the solvent for
measuring the NMR spectra. Only in the case of the
platinum complex 6 which was used for many NMR
experiments, advantage was taken of the better solubi-
1
lity in CD2Cl2. The assignments of the various H and
13C signals are supported by two-dimensional (2D)
Scheme 7.
Table 1
a
NMR spectra of the ligand P(C7H7)3 (1) and of the half-sandwich cations in the tetrafluoroborate salts 4ꢁ
/6, 10 and 11
b
Compound
P(C7H7)3
[CpM{P(C7H7)2(h2-C7H7)}]BF4
MꢀNi (4) MꢀPd (5)
[(C5Ph5)Pd{P(C7H7)2(h2- [CpNi(CNtBu)-
C7H7)}]BF4
{P(C7H7)3}]BF4
a
(1)
/
/
Mꢀ
/
Pt (6)
(10)
(11)
c,e
1H NMR
H1
2.34dt [7.1]
(2.4)
5.20m
2.24dt [8.2]
(6.7)
2.35dt [9.0]
(6.7)
2.18dt [9.6]
2.14dt [7.8]
(6.9)
2.56dt [11.3]
(6.0)
5.42m
{16.4} (6.9)
4.92m/4.99m
6.34m
H2,H7
H3,H6
H4,H5
H1?
5.37m/5.47m
6.37m
6.71m
5.10m/5.20m
6.36m
6.62m
4.72m/5.14m
5.95m/6.25m
6.69m
6.17m
6.52m
6.41m
6.70m
6.58m
4.81dt [15.2]
(8.2)
6.33m
4.96dt [14.8]
(8.5)
6.31m
4.59dt [12.4]
{65.6}, (8.6)
6.04m
5.25dt [14.2]
(8.5)
6.47m
H2?,H7?
H3?,H6?
H4?,H5?
Ph
6.76m
6.69m
6.67m
6.29m
6.63m
5.34m {74.2}
7.05ꢁ7.15m
/
5.84m
g
Cp
5.95s
6.25d [2.0]
6.07 [1.5]
{16.0}
-
5.88s
1.42s
CMe3
d,e
13C NMR
C1
36.7d [17.4]
120.0d [12.3]
127.3d [7.4]
131.6s
37.9d [27.7]
36.7 [25.9]
111.8s
35.2 [36.3]
{52.8}
37.3d [24.3]
37.3d [31.6]
116.2s
C2,C7
C3,C6
C4,C5
C1?
116.8s
117.3s
112.0s {18.4}
112.6s {19.2}
128.5d [16.0]
128.6d [15.3]
131.35s
113.7s
114.3s
128.1d [12.1]
128.2d [10.4]
131.8s
128.2d [11.3]
128.3d [10.3]
131.1s
128.2d [10.2]
128.7d [12.5]
131.1s
128.4d [11.6]
131.9s
132.0s
35.1d [17.3]
131.3s
35.3d [19.3]
131.38s
30.0d [27.5]
{11.4}
131.3s
38.8d [19.8]
C2?,C7?
C3?,C6?
133.3d [2.8]
133.9d [12.0]
68.5s
133.5d [2.8]
131.4d [10.8]
77.1s
132.2d [1.3]
{76.6}
132.2s
131.3d [11.4]
{44.2}
52.1s {190.2}
131.4d [11.0]
C4?,C5?
Ph
Cp
92.3s
g
97.8d [1.7]
102.1d [2.1]
96.6d [2.3]
121.9d [2.3]
{16.3}
96.2s
CMe3
31P NMR
195Pt NMR
29.6s; 61.0s
51.5s
f
ꢃ
/
12.3s
153.6s
164.8s
120.8s {5149}
127.0s
ꢃ1786.1d
/
f
{5149}
a
Measured at 25 8C; d values (ppm); solvent acetone-d6 (except CD2Cl2 in the case of 6).
b
The numbers of the H and C atoms (1ꢁ7) refer to the positions in the uncoordinated cyclohepta-2,4,6-trienyl substituents, the primed numbers
/
(1’ꢁ
/
7’) to the (via 4?ꢁ
5?) h2-coordinated cyclohepta-2,4,6-trienyl substituent.
/
c
Coupling constants (3J(1H,1H)) and [nJ(31P,1H)] in Hz.
d
e
f
Coupling constants [nJ(31P,13C)] in Hz.
Coupling constants {nJ(195Pt,1H)} and {nJ(195Pt,13C)} in Hz.
Coupling constant {1J(195Pt,31P)} in Hz.
g
The phenyl substituents of the h5-C5Ph5 ring in 10 are observed at d(1H) 6.98 m (o), ca 7.10 m (m), 7.30m (p) and d(13C) 128.9 (m), 129.5 (p),
132.6 (o), 134.9 (i).

M. Herberhold et al. / Inorganica Chimica Acta 334 (2002) 10ꢁ
/16
13
Fig. 1. Contour plot of the 250 MHz 1H/1H COSY NMR spectrum of
[CpPt{P(C7H7)2(h2-C7H7)}]BF4 (6), saturated solution in CD2Cl2. The
negative tilt of the 195Pt satellites for the cross peaks H1?/H2?,7?, and for
H4?,5?/H3?,6? indicate opposite signs of the coupling constants
3 J(195Pt,1H1?)/4 J(195Pt,1H2?,7?) and 2 J(195Pt,1H4?,5?)/3 J(195Pt,1H3?,6?).
1H/1H and 13C/1H shift correlations, as shown for
[CpPt{P(C7H7)2(h2-C7H7)}]BF4 (6) in Fig. 1 and Fig.
2. The assignments agree well with our earlier studies
[2,3,5].
Fig. 2. Contour plot of the 62.8 MHz 13C/1H HETCOR NMR
spectrum [based on 1 J(13C,1H)] of [CpPt{P(C7H7)2(h2-C7H7)}]BF4
(6), saturated solution in CD2Cl2. The expansion for C1/H1 clearly
shows a negative tilt of the doublet owing to 1 J(31P,13C1) and a
positive tilt for the 195Pt satellites owing to 2 J(195Pt,13C1). Thus, the
signs of 1 J(31P,13C1) and 2 J(31P,1H1) are opposite whereas the signs of
2 J(195Pt,13C1) and 3 J(195Pt,1H1) are alike. In the case of C4?,5?, the
negative tilt of the 195Pt satellites shows that 1 J(195Pt,13C4?,5?) and
2 J(195Pt,1H4?,5?) possess opposite signs.
Due to the additional coupling with 195Pt, many of the
1H and 13C nuclei in 6 can be easily identified by their
195Pt satellites. Thus, spinꢁ
/
spin coupling with 195Pt (Iꢀ
1/2, natural abundance 33.8%) is observed for the
/
protons H1 and H1?ꢁ
/
H7?, for the carbon atoms (C2?ꢁ
/
C7?) of the h2-coordinated cycloheptatrienyl substituent,
and also for C1 and C2/C7 of the free C7H7 groups, as
1
well as for the H and 13C nuclei of the h5-cyclopenta-
dienyl ring. It is remarkable that the magnitude of the
1
coupling constant J(195Pt,31P) (5149 Hz) is consider-
ably larger than the corresponding value in the related
cation [CpPt(PPh3)(C2H4)]ꢂ (4343 Hz) [13] or in the
neutral precursor complex [PtCl2{P(C7H7)3}] (9) (3932
Hz) [14]. In the 2D 13C/1H experiments based on
1J(13C,1H), the tilt of the respective cross peaks [15,16]
reveals the relative signs of coupling constants
Scheme 8. Some 2D shift correlations (experiments) allow for
comparison of coupling signs; the resultꢀ
of the relevant cross peaks (alike signs), and B
tilt of the cross peaks (opposite signs).
/
0 indicates a positive tilt
/0 indicates a negative
n
nJ(31P,13C) and nꢂ1J(31P,1H) and of J(195Pt,13C) and
signs are in general expected for two- and three-bond
couplings in the absence of lone pairs of electrons at the
intervening nuclei or at the coupled nuclei. Therefore, a
2D 31P/1H shift correlation was carried out in order to
nꢂ1J(195Pt,1H) (Fig. 2). Scheme 8 shows the isotopo-
mers and some experiments relevant to the determina-
tion of absolute coupling signs. The absolute signs are
based on the positive signs of 1J(195Pt,13C) [16] and
1J(195Pt,31P) [17]. An interesting case is the observation
that the signs of 2J(195Pt,13C1) and 3J(195Pt,1H1) are
alike (see Fig. 2) which is unexpected, since alternating
3
obtain the absolute sign of J(195Pt,1H1) by comparison
with 1J(195Pt,31P) (known to be positive [17]). This
shows that the sign of 3J(195Pt,1H1) is positive, and,
2
therefore, J(195Pt,13C1) must also be ꢀ
/0.

14
M. Herberhold et al. / Inorganica Chimica Acta 334 (2002) 10ꢁ
/16
The 31P chemical shifts of 4ꢁ
6 and 10 are all observed
/
in the range between d(31P) 120 and 170, typical of
tri(cyclohepta-2,4,6-trienyl)phosphane complexes con-
taining one (and only one) h2-cyclohepta-2,4,6-trienyl
substituent [cf. [3,5,18]. For 11 the d(31P) value (51.5)
indicates that all three cyclopentadienyl substituents are
freely pending side-arms in solution.
1
In the H NMR spectra of 4ꢁ/6 and 10, generally two
multiplets are observed for the protons H2/H7 of the
uncoordinated cyclohepta-2,4,6-trienyl substituents: the
shift difference (Dd) is particularly large in the case of
the pentaphenyl cyclopentadienyl complex 10 (Fig. 3).
In the 13C NMR spectra, two slightly separated signals
are recorded for the diastereotopic pairs C2/C7, C3/C6
and C4/C5 of the two free C7H7 substituents; only the
13C(C3/C6) signals show significant splitting into doub-
Fig. 4. Molecular structure of [CpNi{P(C7H7)2(h2-C7H7)}]BF4 (4) in
lets due to 31P-13C spinꢁ
spin-coupling.
/
the crystal. Selected bond distances (pm) and bond angles (8): NiÃ
216.28(11), PÃC(6) 185.5(5), PÃC(13) 187.6(5), PÃC(20) 183.1(4), BÃ
137.090.1; NiÃPÃC(6) 107.42(17), NiÃPÃC(13) 113.91(18), NiÃPÃ
C(20) 113.47(15), C(6)ÃPÃC(13) 101.8(3), C(13)ÃPÃC(20) 111.2(2),
C(6)ÃPÃC(20) 108.1(2), FÃBÃF 109.590.1. See also Table 2.
/P
/
/
/
/F
11B NMR spectra show the 11B NMR signal at d
/
/
/
/
/
/
/
ꢃ
/
0.8 typical of the [BF4]ꢃ anion [19]. These signals are
/
/
/
/
sharp and do not show resolved coupling 1J(19F,11B). In
the case of 4, the line width is less than 0.4 Hz, indicating
a perfect tetrahedral symmetry at the site of the
quadrupolar 11B nucleus in solution. Therefore, the
ions must be separated by the solvent, and there are no
/
/
/
/
/
(h2(C7H7)}). Relevant distances and angles of the three
related complexes 3,4 and 12 are compared in Table 2.
In the rhodium and nickel complexes 3 and 4,
respectively, the metal is coplanar with the P atom, the
midpoint of the coordinated double bond (olefin(m))
and the centre of the cyclopentadienyl ring (Cp(Z)). As
expected, the distances between the metal and the ligand
centres (P, olefin(m) and Cp(Z)) in the coordination
sphere are significantly shorter in the cation than in the
neutral compounds 3 and 12 (cf. Table 2).
appreciable cationꢁanion interactions in solution.
/
2.3. X-ray structure analysis of [CpNi{P(C7H7)2(h2-
C7H7)}]BF4 (4)
The molecular geometry of the cation of the tetra-
fluoroborate salt 4 is depicted in Fig. 4. The structure is
similar to that of the neutral analogues [CpRh{P}] (3)
The cyclopentadienyl ligand is unsymmetrically at-
tached to the central metal in all three complexes. In the
[3] and [CpMn(CO){P}] (12) [20] ({P}ꢀ{P(C7H7)2-
/
case of 4, the shortest distance NiÃ
opposite to the coordinated double bond, whereas the
longer bond distances (NiÃC(1) 212.8(6) and NiÃC(2)
212.2(7) pm) are those opposite to the phosphorus atom.
C(Cp) bond lengths
/
C(4) (204.2(7) pm) is
/
/
Analogous differences in the MÃ
/
have been observed for 3 and 12.
3. Experimental
All reactions were carried out under argon in carefully
dried solvents. The starting compounds P(C7H7)3 (1) [1],
[CpNi(cod)]BF4 [6], [CpPd(cod)]BF4 [8], [(C5Ph5)Pd-
(cod)]BF4 [10] and [PtCl2(cod)] [7] were synthesized
according to the literature.
NMR Instrumentation: Bruker ARX 250 (1H: 250
MHz; 11B: 80.3 MHz; 13C: 62.8 MHz; 31P: 101.3 MHz;
195Pt: 53.5 MHz). Solvents for NMR measurements and
chemical shift references: CHCl3/CDCl3: d(1H) 7.24,
d(13C) 77.0; CD2Cl2: d(1H) 5.32, d(13C) 55.8;
(CD3)2CO: d(1H) 2.04, d(13C) 29.8; d(11B)ꢀ
/0 for
Fig. 3. 250 MHz 1H NMR spectrum of [(h5-C5Ph5)Pd{P(C7H7)2(h2-
C7H7)}]BF4 (10), saturated solution in acetone-d6.
external Et2Oꢁ 32.083971 MHz,
/
BF3 with J (11B)ꢀ
/

M. Herberhold et al. / Inorganica Chimica Acta 334 (2002) 10ꢁ
/16
15
d(31P)ꢀ
/
0 for external (85% aq) H3PO4 with J(31P)ꢀ
/
CH2Cl2ꢁ
272 8C). EIꢁ
ꢂ ꢁCl), 91 (100%, C7H7ꢂ).
A solution of 9 (170 mg; 0.30 mmol) in CH2Cl2 (20
/
hexane to give 520 mg (91%) of 9 (dec.
40.480747 MHz, and d(195Pt)ꢀ
21.400000 MHz.
/
0 for J (195Pt)ꢀ
/
/
MS: m/eꢀ
/
569 (1%, Mꢂ), 534 (2%,
M
/
ml) was first treated with 80 mg (0.30 mmol) TlCp. After
stirring for 1 h at 0 8C, a solution of AgBF4 (60 mg;
0.31 mmol) in acetone (5 ml) was added, and the
reaction mixture was stirred for additional 20 min at
r.t. Insoluble material was filtered off, and the yellow
filtrate was brought to dryness. The residue was
3.1. Syntheses
3.1.1. [CpNi{P(C7H7)2(h2-C7H7)}]BF4 (4)
A solution of 155 mg (0.51 mmol) P(C7H7)3 (1) in 20
ml of dichloromethane was added dropwise during 15
min to
a
solution of 160 mg (0.50 mmol)
dissolved in CH2Cl2 (2ꢁ3 ml). Addition of diethylether
/
[CpNi(cod)]BF4 in 30 ml of dichloromethane. The
reaction mixture was stirred at room temperature (r.t.)
for 5 h and then brought to dryness. The remaining
green solid was dissolved in a small amount of CH2Cl2.
Addition of diethylether produced a dark-green pre-
cipitate which was filtered off and dried. Recrystallisa-
to the cooled (0 8C) solution gave 155 mg (80%) of 6 as
a yellow powder which was dried in a high vacuum (dec.
183 8C).
3.1.4. [(h5-C5Ph5)Pd{P(C7H7)2(h2-C7H7)}]BF4 (10)
The phosphane P(C7H7)3 1 (100 mg; 0.33 mmol),
dissolved in CH2Cl2 (10 ml), was added to a solution of
[(h5-C5Ph5)Pd(cod)]BF4 (225 mg; 0.30 mmol) in CH2Cl2
(30 ml). The mixture was heated under reflux (40 8C)
for 20 h. Then the solvent was evaporated, and the
tion from acetoneꢁ
/
ether mixtures gave 210 mg (83%) of
MS: m/eꢀ428 (1%,
C7H7),
a green powder, dec. 178 8C. EIꢁ
/
/
Mꢂ cation), 363 (1%, Mꢂ ꢁ
/
Cp), 337 (2%, Mꢂ ꢁ
/
304 (2%, P(C7H7)3ꢂ), 91 (100%, C7H7ꢂ).
3.1.2. [CpPd{P(C7H7)2(h2-C7H7)}]BF4 (5)
residue was dissolved in CH2Cl2 (2ꢁ
hexane led to the precipitation of 10 as a dark green
powder which was recrystallised from acetoneꢁether.
/3 ml). Addition of
In analogy to the preparation of 4, two equimolar
solutions of P(C7H7)3 (1) (95 mg, 0.31 mmol, in 10 ml of
CH2Cl2) and [CpPd(cod)]BF4 (110 mg, 0.30 mmol, in 20
ml of CH2Cl2) were slowly combined, and the mixture
stirred for 2 h under ambient conditions. Recrystallisa-
/
Yield 210 mg (74%); dec. 163 8C.
3.1.5. [CpNi(CN-tBu){P(C7H7)3}]BF4 (11)
tion of the violet product 5 from acetoneꢁether gave 123
/
mg (74%) as a violet powder, dec. 165 8C.
Tert-Butylisocyanide (0.02 ml; 0.2 mmol) was added
to a solution containing 4 (60 mg; 0.12 mmol) in CH2Cl2
(10 ml). While the solution was stirred for 4 h at 25 8C,
its colour gradually changed from green to dark red.
3.1.3. [CpPt{P(C7H7)2(h2-C7H7)}]BF4 (6)
A solution containing the phosphane P(C7H7)3 1 (304
mg; 1 mmol) and [PtCl2(cod)] (374 mg; 1 mmol) in
CH2Cl2 (100 ml) was stirred for 1 h. The complex
[PtCl2{P(C7H7)2(h2-C7H7)}] (9) was formed in almost
quantitative yield. The product was recrystallised from
The solution was concentrated to a volume of 2ꢁ
pentane was added and the mixture kept at ꢃ78 8C
over night. The brownish red precipitate was collected,
recrystallised from acetoneꢁether and dried in a high
/3 ml,
/
/
Table 2
Structural data of h5-cyclopentadienyl halfsandwich complexes containing a {P(C7H7)2(h2-C7H7)} (ꢀ
/{P}) chelate ligand
[CpNi{P}]BF4
4
[CpRh{P}] [3]
3
[CpMn(CO){P}] [20]
12
Unit cell
monoclinic
orthorhombic
triclinic
Space group; Z
Distances (pm)
P21; Zꢀ
/2
P212121; Zꢀ
/
4
P/
1; Zꢀ2
/
MÃ
MÃ
MÃ
MÃ
CÄ
/
P
216.28(11)
208.1(5); 208.7(5)
196.5
220.1(1)
221.49(6)
220.0(2); 221.2(2)
208.8
/
C (olefin)
C (olefin(m))
Cp(Z)
213.4(3); 213.6(3)
200.7
191.9
/
/
173.9
178.9
/
C
138.8(10)
145.5(4)
142.1(3)
Angles (8)
CÃMÃC (olefin)
PÃMÃ
PÃMÃ
Cp(Z)Ã
/
/
38.9(3)
39.9(1)
37.58(9)
/
/
C (olefin)
Cp(Z)
95.56(17); 94.98(16)
131.0
133.4
89.5(1); 90.7(1)
136.4
133.4
88.22(6); 91.69(7)
128.5
126.5
/
/
/
MÃ
/
(olefin(m))
Abbreviations: Cp, h5-cyclopentadienyl, C5H5, {P}, tri(1-cyclohepta-2,4,6-trienyl)phosphane, {P(C7H7)2(h2-C7H7)}; Cp(Z), center of the Cp ring;
olefin(m), midpoint of the h2-coordinated olefinic double bond (C4?ÄC5?).
/

16
M. Herberhold et al. / Inorganica Chimica Acta 334 (2002) 10ꢁ16
/
vacuum to give 11 as a dark red powder (65 mg, 93%),
dec. 151 8C. IR (CsI): 2197 cmꢃ1, n(NÅ
C).
Acknowledgements
/
Support of this work by the Deutsche Forschungsge-
meinschaft and the Fonds der Chemischen Industrie is
gratefully acknowledged.
3.2. Crystal structure of [CpNi{P(C7H7)2(h2-
C7H7)}]BF4 (4)
The intensity data were collected on a Siemens P4
71.073 pm,
References
diffractometer with Mo Ka radiation (lꢀ
/
graphite monochromator) at r.t. The hydrogen atoms
are in calculated positions. All non-hydrogen atoms
were refined with anisotropic temperature factors. The
hydrogen atoms were refined applying the riding model
with fixed isotropic temperature factors.
[1] M. Herberhold, K. Bauer, W. Milius, Z. Anorg. Allg. Chem. 620
(1994) 2108.
[2] M. Herberhold, K. Bauer, W. Milius, J. Organomet. Chem. 502
(1995) C1.
[3] M. Herberhold, W. Milius, S. Eibl, Z. Anorg. Allg. Chem. 625
(1999) 341.
[4] M. Herberhold, M. Muller, Th. Daniel, W. Milius, to be
¨
4, [C26H26NiP]ꢂBF4ꢃ, green prism of dimensions
0.18ꢄ
space group P21; aꢀ
1170.77(11) pm, bꢀ
mmꢃ1; 6749 reflections collected in the range 2ꢁ
in q, 5311 reflections independent, 5055 reflections
assigned to be observed (I ꢀ2s(I)); full matrix least
/
0.15ꢄ
/
0.12 mm, crystallises in the monoclinic
906.31(8), bꢀ1095.48(12), cꢀ
91.586(5)8, Zꢀ2, mꢀ1.472
27.508
published.
[5] M. Herberhold, K. Bauer, W. Milius, J. Organomet. Chem. 545/
/
/
/
546 (1997) 267.
[6] A. Salzer, T.L. Court, H. Werner, J. Organomet. Chem. 54 (1973)
325.
/
/
/
/
[7] D. Drew, J.R. Doyle, Inorg. Synth. 13 (1972) 47ꢁ
/
55.
/
[8] D.A. White, Inorg. Synth. 13 (1972) 55.
[9] T.R. Jack, C.J. May, J. Powell, J. Am. Chem. Soc. 99 (1977) 4707.
[10] K. Broadley, N.G. Connelly, G.A. Lane, W.E. Geiger, J. Chem.
Soc., Dalton Trans. (1986) 373.
squares refinement with 270 parameters, R1/vR2-values
0.068/0.199, absorption correction (c-scans), min./max.
transmission factors 0.3183/0.3417; max./min. residual
[11] T. Majima, H. Kurosawa, J. Organomet. Chem. 134 (1977) C45.
[12] H. Kurosawa, T. Majima, N. Asada, J. Am. Chem. Soc. 102
(1980) 6996.
electron density 1.23/ꢃ .
0.702 e 10ꢃ6 pmꢃ3
/
[13] H. Kurosawa, N. Asada, A. Urabe, M. Emoto, J. Organomet.
Chem. 272 (1984) 321.
[14] M. Herberhold, Th. Schmalz, W. Milius, B. Wrackmeyer, Z.
Anorg. Allg. Chem. 628 (2002) 437.
4. Supplementary material
[15] A. Bax, R. Freeman, J. Magn. Reson. 45 (1981) 177.
[16] B. Wrackmeyer, Z. Naturforsch. Teil. B 52 (1997) 1019.
[17] M. Herberhold, K. Bauer, W. Milius, J. Organomet. Chem. 563
Crystallographic data (excluding structure factors) for
the structure reported in this paper have been deposited
with the Cambridge Crystallographic Data Centre as
supplementary publication no. CCDC-165484 (4). Co-
pies of the data can be obtained free of charge on
application to CCDC, 12 Union Road, Cambridge CB2
(1998) 227ꢁ
/
233.
[18] W. McFarlane, J. Chem. Soc. (A) (1967) 1922.
[19] H. Noth, B. Wrackmeyer, Nuclear Magnetic Resonance Spectro-
¨
scopy of Boron Compounds, in: P. Diehl, E. Fluck, R. Kosfeld
(Eds.), NMR-Basic Principles and Progress, vol. 14, Springerꢁ
Verlag, Berlin, 1978, pp. 387ꢁ388.
[20] W. Milius, A. Pfeifer, M. Herberhold, to be published.
/
1EZ, UK [fax (internat.): ꢂ
/
44-1223-336-033; e-mail:
/
deposit@ccdc.cam.ac.uk].