Platinum(II) complexes with 1-cyclohepta-2,4,6-trienyl-diphenylphosphane, Ph2P(C7H7), and alkyn-1-yl ligands

Article abstract of DOI:10.1002/zaac.200500078

[1-Cyclohepta-2,4,6-trienyl-diphenylphosphane]platinum(II) dichloride (4) was prepared by the 1:1 reaction of (cod)PtCl₂ (cod = η⁴-cycloocta-1,5-diene) with the phosphane. The reaction of 4 with di(alkyn-1-yl)dimethylstannanes, Me₂Sn(C=C-R)₂ [R = H (a), Me (b), Ph (c), SiMe₃ (d)], in boiling THF gave selectively in high yield the monoalkynyl complexes [Ph₂P(C₇H ₇)]Pt(Cl)C≡C-R (6b,c,d), in which the alkyn-1-yl group is arranged in cis position with respect to the phosphorus atom, and the C ₇H₇ ring is η²-coordinated to platinum through the central C=C bond. The same-reaction at room temperature afforded, again selectively and in high yield, the dialkynyl complexes [Ph ₂P(C₇H₇)]Pt(C≡C-R)2 (7a-d). The new complexes were characterised in solution by ¹H, ¹³C, ²⁹Si, ³¹P and ¹⁹⁵Pt NMR spectroscopy, and the molecular structures of 4 and 7d were determined by X-ray crystallography.

Full text of DOI:10.1002/zaac.200500078

Platinum(II) Complexes with 1-Cyclohepta-2,4,6-trienyl-diphenylphosphane,
Ph2P(C7H7), and Alkyn-1-yl Ligands
Bernd Wrackmeyer*, Bettina Ullmann, Rhett Kempe, Max Herberhold*
Bayreuth, Laboratorium für Anorganische Chemie der Universität
Received February 24th, 2005.
Dedicated to Professor Herbert W. Roesky on the Occasion of his 70th Birthday
Abstract. [1-Cyclohepta-2,4,6-trienyl-diphenylphosphane]platinum(II)
dichloride (4) was prepared by the 1:1 reaction of (cod)PtCl2
(cod ϭ η4-cycloocta-1,5-diene) with the phosphane. The reaction
of 4 with di(alkyn-1-yl)dimethylstannanes, Me2Sn(CϵC-R)2 [R ϭ H
(a), Me (b), Ph (c), SiMe3 (d)], in boiling THF gave selectively in
high yield the monoalkynyl complexes [Ph2P(C7H7)]Pt(Cl)CϵC-R
(6b,c,d), in which the alkyn-1-yl group is arranged in cis position
with respect to the phosphorus atom, and the C7H7 ring is η2-
coordinated to platinum through the central CϭC bond. The same
reaction at room temperature afforded, again selectively and in high
yield, the dialkynyl complexes [Ph2P(C7H7)]Pt(CϵC-R)2 (7a-d).
The new complexes were characterised in solution by 1H, 13C, 29Si,
31P and 195Pt NMR spectroscopy, and the molecular structures of
4 and 7d were determined by X-ray crystallography.
Keywords: Platinum; Tin; Alkynes; Phosphanes; NMR spectro-
scopy; Crystal structures
Introduction
num. This is evident from NMR spectra [4Ϫ6] and, there-
fore, one aim of this work was to replace the P(C7H7)3
ligand by 1-cyclohepta-2,4,6-trienyl-diphenylphosphane,
Ph2P(C7H7), in order to facilitate NMR spectroscopic stud-
ies. Another problem remained to be addressed, considering
the current interest in alkyn-1-ylplatinum chemistry [7],
namely the selectivity by which the complexes 2 are formed
[5] in the exchange reaction of 1 with di(alkyn-1-yl)di-
methylstannanes. Thus, the complex 4, analogous to 1 [4],
was prepared (Scheme 1a) and characterised, and its
Among chelating phosphanes coordinated to a metal by
both the phosphorus atom and a CϭC bond [1, 2], 1-cyclo-
hepta-2,4,6-trienylphosphanes [3] deserve special attention.
In the case of the complexes 2 and 3, the nature of the
platinum-ligand bonds in cis- and trans-positions relative to
the phosphorus atom is remarkably different. It has been
shown, that the complexes 2 are accessible selectively by the
reaction of the platinum dichloride 1 [4] with di(alkyn-1-yl)-
dimethylstannanes, Me2Sn(CϵC-R)2, in boiling THF [5],
whereas the complexes 3 have been prepared [5] from the
corresponding dialkyn-1-yl(cod)Pt complexes by the reac-
tion with tri(cyclohepta-2,4,6-trienyl)phosphane, P(C7H7)3
[3].
reactivity
towards
di(alkyn-1-yl)dimethylstannanes,
Me2Sn(CϵC-R)2 [R ϭ H (a), Me (b), Ph (c), SiMe3 (d)],
was studied.
The presence of two pending C7H7 rings in the complexes
1 Ϫ 3 causes fast intramolecular exchange between the
three C7H7 rings with respect to their coordination to plati-
Results and Discussion
Synthesis of the [1-cyclohepta-2,4,6-trienyl-
diphenylphosphane]platinum dichloride (4)
The reaction of (cod)PtCl2 with one equivalent of 1-cyclo-
hepta-2,4,6-trienyl-diphenylphosphane proved to be the
most straightforward route to the platinum dichloride 4
(Scheme 1a). The complex 4 was formed in essentially
quantitative yield as a yellowish solid, crystallised from
* Prof. Dr. B. Wrackmeyer, Prof. Dr. M. Herberhold
Anorganische Chemie II, Universität Bayreuth
D-95440 Bayreuth/Germany
Fax: Int. Code ϩ(921)552157
E-mail: b.wrack@uni-bayreuth.de
1
max.herberhold@uni-bayreuth.de
CH2Cl2/hexane, and was characterised in solution by H,
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B. Wrackmeyer, B. Ullmann, R. Kempe, M. Herberhold
13C, 31P and 195Pt NMR spectroscopy (Table 1) and in the
solid state by X-ray structural analysis (vide infra). An ex-
cess of the phosphane gave the complex 5, in which the two
phosphane ligands are in cis-positions and coordinated to
platinum by the phosphorus atoms (Scheme 1b). The pro-
posed structure of 5 is based on a consistent set of 1H, 13C,
31P and 195Pt NMR data (Table 1). Thus, the coupling con-
stant 1J(195Pt,31P) ϭ 3666 Hz is observed in the typical
range known for the cis-arrangement of phosphane ligands
in platinum(II) dichlorides [8]. It should be noted that a
complex analogous to 5 with the P(C7H7)3 ligand is not
accessible by this route [4]. The complex trans-
[(C7H7)3P]2PtCl2 has been identified in solution when
[PtCl4]2Ϫ reacts with two equivalents of P(C7H7)3; however,
even trans-[(C7H7)3P]2PtCl2 rearranges slowly into 1 by
elimination of phosphane [4].
tion using 31P NMR spectroscopy it became evident that
the dialkynyl complexes 7, analogues of 3, are formed.
These complexes 7 could be isolated when the reactions
were carried out at room temperature (Scheme 2b). Except
of the complex 7a (R ϭ H) which was found to decompose
in CD2Cl2 solution after several hours at room temperature,
all other complexes 6 and 7 could be kept in solution for
1
prolonged periods. The H, 13C, 29Si, 31P and 195Pt NMR
data of 6 and 7 are listed in Table 2, and the molecular struc-
ture of 7d was determined by X-ray analysis (vide infra).
Scheme 2 Selective synthesis of the complexes 6 and 7, depending
on the reaction conditions.
The known reaction of 1 with Me2Sn(CϵC-R)2 (R ϭ
Me, Ph, SiMe3) [5] was then reinvestigated, and the same
selectivity, depending on the reaction conditions, was ob-
served. Thus, the complexes 3 and 7 can be obtained di-
rectly from the dichlorides 1 and 4, respectively, avoiding
the preparation of the intermediates (cod)Pt(CϵC-R)2 [5].
In the case of bis(phosphane)palladium dichlorides, it
has been found that exchange reactions with alkyn-1-yltin
compounds lead to complexes containing Pd-Sn bonds, and
this was explained by assuming short-lived Pd(IV) inter-
mediates as a result of oxidative addition of the di(alkyn-1-
yl)tin compounds [9]. A similar mechanism is proposed here
(Scheme 3) for the alternative formation of 6 or 7, starting
from 4. Fast reductive elimination of Me2Sn(Cl)CϵC-R in
the intermediate A at elevated temperatures gives 6 or, at
room temperature, A has time to rearrange into B by intra-
molecular exchange, followed by elimination of Me2SnCl2
to give 7. It is also conceivable that at elevated temperatures
the elimination of Me2Sn(Cl)CϵC-R from B to give 6 is
preferred over the elimination of Me2SnCl2. These assump-
tions are supported by experimental observations. In equili-
brated mixtures containing 7, Me2Sn(Cl)CϵC-R and an ex-
cess of Me2Sn(CϵC-R)2, obtained at room temperature in
THF, the formation of 6 at the cost of 7 starts at 40 °C.
Addition of Me2SnCl2 to the reaction solution at room tem-
perature shifts the equilibria from 7 towards 6. In this con-
text it is interesting to note that the reaction of (dppe)PtCl2
with Me2Sn(CϵC-R)2 in THF gave selectively the dialkyn-
1-yl complexes (dppe)Pt(CϵC-R)2 under all experimental
conditions studied [10].
Scheme 1 Synthesis of the complexes 4 and 5, starting from
(cod)PtCl2.
Table 1 13C, 31P and 195Pt NMR data of the platinum(II) comple-
xes [Ph2P(C7H7)]PtCl2 (4) and [Ph2P(C7H7)]2PtCl2 (5).
4a),c)
5b),c)
13C NMR
C1
38.3 [31.4]
130.7 [1.7]
38.4 [15.9] [40.7]
117.5
125.8 [12.8]
130.4
128.4 [52.0]
134.0 [9.3]
128.2 [10.6]
131.3
C2,7
C3,6
130.4 [11.2] {36.7}
80.9 {143.7}
125.0 [60.1]
133.8 [9.4]
128.6 [11.1]
132.3 [2.9]
C4,5
Phi
Pho
Phm
Php
31P NMR
97.3 {4137}
549.4 [4137]
14.0 {3666}
134.2 [3666]
195Pt NMR
a) In CD2Cl2 at 25 °C; b) in CDCl3 at 25 °C; c) Coupling constants [nJ(31P,X)],
{nJ(195Pt,X)} in Hz.
Reaction of [Ph2P(C7H7)]PtCl2 (4) with
di(alkyn-1-yl)dimethylstannanes, Me2Sn(CϵC-R)2
The reaction of the dichloride 4 with Me2Sn(CϵC-R)2
[R ϭ Me (b), Ph (c), SiMe3 (d)] in boiling THF proceeds
in the same way as has been reported for 1 [5], and the
monoalkynyl complexes 6, analogous to 2, were isolated in
high yield (Scheme 2a). However, by monitoring this reac-
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Platinum(II) Complexes with 1-Cyclohepta-2,4,6-trienyl-diphenylphosphane
Table 2 13C, 31P, 195Pt and 29Si NMR data a),b) of the platinum(II) complexes [Ph2P(C7H7)]Pt(Cl)CϵC-R (6) and [Ph2P(C7H7)]Pt(CϵC-R)2 (7).
(R)
6b (Me)
6c (Ph)
6d (SiMe3),c)
7a (H)
7b (Me)
7c (Ph)
7d (SiMe3),d)
13C NMRb)
C1
39.6 [30.5] {4.9}
128.5
130.3 [10.6]
95.1 {60.2}
126.5 [62.7]
134.3 [8.7] {25.2} 134.0 [10.0] {25.4} 134.2 [9.3] {27.5}
128.7 [11.7]
132.0
39.4 [30.9] {5.3}
127.7
129.9 [10.6]
96.4 {58.3}
128.5 [69.9]
39.2 [30.7] {5.0}
128.5
130.0 [10.2]
96.9 {53.6}
126.3 [62.3]
39.4 [26.0] {11.0} 39.1 [24.9] {9.1}
39.8 [25.4] {10.8} 39.6 [25.2] {11.0}
C2,7
129.8 [3.3]
130.0 [11.3]
91.8 {58.2}
129.2 [36.0]
128.8 [3.8]
130.3 [11.3]
89.5 {59.1}
128.9 [24.8]
130.2 [3.3]
130.7 [11.4]
91.5 {59.0}
128.7 [50.7]
130.1 [3.6]
130.4 [11.2]
92.7 {54.0}
128.4 [50.2]
C3,6
C4,5
Phi
Pho
134.2 [9.8] {18.0} 134.2 [9.9] {18.4} 134.6 [9.8] {18.3} 134.6 [10.0] {18.1}
Phm
Php
128.6 [11.0]
131.8 [2.8]
128.4 [11.0]
131.7 [2.9]
128.5 [10.4]
131.4 [2.5]
128.3 [10.2]
130.9 [2.5]
128.9 [10.5]
131.6 [2.6]
128.7 [10.4]
131.5 [2.5]
Pt-CϵC- 76.8 [18.3] {1523.8} 92.1 [16.7] {1543.5} 107.1 [15.9] {1468.4} 96.8 [29.2] {n.o.} 76.7 [15.3] {1457.0} 90.6 [15.5] {1562.2} 108.1 [14.4] {1433.2}
e)
cis; trans
104.2 [162.1] {n.o.} 97.6 [167.8]
{1140.6}
111.5 [166.2]
{1142.9}
131.6 [152.8]
{1086.4}
-CϵC-R
cis; trans
107.4 {402.0}
6.5 {26.3}
110.6 {424.5}
117.1 {336.5}
0.2
99.1 [2.2] {425.1} 108.4 [1.9] {427.7} 113.9 [2.3] {421.6} 119.1 [1.7] {409.5}
89.9 [33.7] {296.5} 98.1 [34.7] {301.4} 105.1 [34.0] {295.5} 108.4 [27.2] {259.8}
e)
R
126.2, 126.4
129.0, 131.1
Ϫ
6.0 [3.2] {24.1}
6.1 [1.5] {26.7}
126.3, 126.5, 127.2 0.4 [0.6] {3.4}
[1.5], 127.7 [3.6],
128.3, 128.5,
131.5, 132.1
1.2 {2.8}
31P NMR 85.6 {4210}
195Pt NMR 92.1 [4210]
87.3 {4156}
92.4 [4156]
86.5 s {4192}
97.7 d [4192]
99.7 {2745}
99.0 {2745}
100.1 {2727}
99.6 {2688}
Ϫ51.3 [2745]
Ϫ18.9[2745]
Ϫ25.5 [2727]
Ϫ3.9 [2688]
a) In CD2Cl2 at 25 °C; n.o. means not observed. b) Coupling constants [nJ(31P,X)], {nJ(195Pt,X)} in Hz. c) 29Si NMR: δ ϭ Ϫ20.7 [0.7], {33.9}. d) 29Si NMR:
δ ϭ Ϫ22.1 [3.5] {24.4} (trans); Ϫ21.3 [1.4] {37.1} (cis). e) Relative to the phosphorus atom (cf. Figure 1).
Scheme 3 Proposed mechanism for the selective formation of the complexes 6 and 7.
The NMR data of the complexes 6 and 7 (Table 2) corre-
spond closely to those obtained for the comparable com-
plexes 2 and 3 [5]. This indicates that the influence of the
phosphane ligands Ph2P(C7H7) and P(C7H7)3 on the elec-
tronic structure of the platinum(II) complexes is very simi-
lar. Clearly, any fluxional character associated with the
C7H7 groups in 2 and 3 is absent in 6 and 7. Therefore, the
assignments of the NMR data for the C7H7 ring in 4, 6 and
7 are straightforward. As for 3, the different 13C NMR data
for the alkyny-1-yl groups in cis- and trans-positions relative
to the phosphorus atom in 7 are noteworthy. The 29Si NMR
spectrum of 7d (Figure 1) shows the sensitivity of the 29Si
NMR parameters to the influence exerted by the other li-
gands in trans-positions although they are removed by four
bonds from the 29Si nuclei. The fast nuclear spin relaxation of
195Pt is also evident from the significantly broadened 195Pt sat-
X-Ray structure determinations of 4 and 7d
The molecular structures of the platinum dichloride
[Ph2P(C7H7)]PtCl2 (4) and of the dialkynyl complex
[Ph2P(C7H7)]Pt(CϵC-SiMe3)2 (7d) were determined by
X-ray analysis (Figures 2 and 3). Selected bond lengths and
angles are listed in the Tables 3 and 4. Both complexes are
typical 16e platinum(II) complexes with “square-planar”
coordination geometry. The phosphane is a chelating ligand
with the lone pair of electrons and the central CϭC bond
of the C7H7 ring. The CϭC bond axis of the η2-coordinated
double bond is arranged almost exactly perpendicular to
the coordination plane (dihedral angles are 88.7° in 4 and
84.6° in 7d). Expectedly, this CϭC bond with 138.9(11) pm
in 4 and 140.8(9) pm in 7d is found to be shorter than a
typical single (154 pm) and longer than a typical double
bond (134 pm). The data compare well with the data for
the η2-coordinated CϭC bonds in numerous platinum com-
ellites. The relaxation times T1,2(
195Pt) become short in Pt(II)
complexes because of the efficient relaxation mechanism due
to chemical shift anisotropy, depending on B02 [11].
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B. Wrackmeyer, B. Ullmann, R. Kempe, M. Herberhold
Figure 1 49.7 MHz 29Si{1H} NMR spectrum (INEPT [18]) of
[Ph2P(C7H7)]Pt(CϵC-SiMe3)2 (7d) dissolved in CD2Cl2 (saturated
solution at 23 °C). Note the broadening of the 195Pt satellites (mar-
ked by arrows) as a result of short 195Pt nuclear spin relaxation
caused by the chemical shift anisotropy mechanism. A weak signal
belonging to an impurity is marked by an asterisk.
Figure 3 Molecular structure of [Ph2P(C7H7)]Pt(CϵC-SiMe3)2
(7d) (ellipsoids correspond to the 50 % probability level).
Table
3
Selected bond lengths/pm and angles/° for
plexes containing the P(C7H7)3 ligand [4Ϫ6] and also with
[Ph2P(C7H7)]PtCl2 (4) (see Figure 2).
data for(cod)PtCl2 (137.5(8)/138.7(8) pm [12]).
Pt(1)-C(1)
Pt(1)-C(2)
Pt(1)-P(1)
Pt(1)-Cl(1)
Pt(1)-Cl(2)
C(1)-C(2)
C(1)-C(7)
C(2)-C(3)
218.6(6)
219.4(7)
C(1)-Pt(1)-P(1)
C(2)-Pt(1)-P(1)
C(1)-Pt(1)-Cl(1)
C(2)-Pt(1)-Cl(1)
P(1)-Pt(1)-Cl(1)
C(1)-Pt(1)-Cl(2)
C(2)-Pt(1)-Cl(2)
P(1)-Pt(1)-Cl(2)
Cl(1)-Pt(1)-Cl(2)
91.94(19)
93.0(2)
158.0(2)
165.0(2)
86.21(7)
91.64(19)
88.5(2)
221.35(17)
232.40(17)
239.38(16)
138.9(11)
146.6(10)
144.7(11)
175.81(6)
91.28(6)
Table
4
Selected bond lengths/pm and angles/° for
[Ph2P(C7H7)]Pt(CϵC-SiMe3)2 (7d) (see Figure 3).
C(1)-C(2)
C(1)-Pt(1)
C(2)-Si(2)
C(3)-C(4)
C(3)-Pt(1)
C(4)-Si(1)
C(5)-C(6)
C(5)-C(11)
C(5)-Pt(1)
C(6)-C(7)
C(6)-Pt(1)
120.5(9)
196.8(7)
181.6(7)
118.9(10)
201.4(7)
181.3(8)
140.8(9)
145.1(8)
226.5(6)
145.2(10)
229.4(6)
C(2)-C(1)-Pt(1)
C(1)-C(2)-Si(2)
C(4)-C(3)-Pt(1)
C(3)-C(4)-Si(1)
C(6)-C(5)-C(11)
C(6)-C(5)-Pt(1)
C(11)-C(5)-Pt(1)
C(5)-C(6)-C(7)
C(5)-C(6)-Pt(1)
C(7)-C(6)-Pt(1)
175.1(6)
174.1(7)
178.6(6)
174.1(7)
125.5(6)
73.1(4)
112.5(4)
125.0(6)
70.9(3)
Figure 2 Molecular structure of [Ph2P(C7H7)]PtCl2 (4) (ellipsoids
correspond to the 50 % probability level).
115.8(5)
In the complex 4, the Pt-Cl distances are significantly dif-
ferent, the one for the chloro ligand trans to the coordinated
CϭC bond (232.40(17) pm) being shorter than the other
one in trans-position to the phosphorus atom
(239.38(16)pm). This effect is comparable to that found for
the Pt-I distances in [P(C7H7)3]PtI2 [4].
The Pt-Cϵ distance trans to the coordinated CϭC bond
(and cis to the phosphorus atom) in 7d (196.8(7) pm) is ob-
served in the normal range of 193-198 pm, expected for
such compounds [13]. However, the Pt-Cϵ bond trans to
phosphorus is significantly enlarged to 201.4(7) pm. This
appears to be compensated to some extent by opposite
changes in the CϵC bond lengths with 118.90(10) pm for
the alkynyl group trans to phosphorus, and 120.5 (9) pm
for the alkynyl group trans to the CϭC bond.
By comparing Pt-P distances [13], the Pt-P bond length
(221.35(17) pm) in 4 (chloro ligand trans to phosphorus)
appears to be short, and also Pt-P ϭ 229.60(17) pm in 7d
(alkynyl ligand trans to phosphorus) is more on the short
side of the known range. In the case of 7d, there may be a
relation between shortening of the Pt-P bond and elon-
gation of the Pt-Cϵ bond in trans-position to phosphorus.
Conclusions
1-Cyclohepta-2,4,6-trienyl-diphenylphosphane, Ph2P(C7H7),
is a useful chelating ligand for complexes of platinum(II)
bearing chloro and/or alkyn-1-yl ligands. As already shown
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Platinum(II) Complexes with 1-Cyclohepta-2,4,6-trienyl-diphenylphosphane
rated, recrystallised from CH2Cl2/hexane, and dried in a high vac-
uum to give the products 6 as yellow powders.
6b: 254 mg (93 %).
1H NMR (CD2Cl2, 25 °C): δ ϭ 1.70 (s, 3H, 4J(195Pt,1H) ϭ 19.1 Hz, Me),
4.83 (dt, 1H, H1 2J(31P,1H) ϭ 13.3 Hz, 3J(1H,1H) ϭ 8.5 Hz), 5.60 (m, 2H,
H2,7), 5.99 (m, 2H, H4,5 2J(195Pt,1H) ϭ 40.3 Hz), 6.45 (m, 2H, H3,6),
7.38Ϫ7.46 (m, 4H, Ph), 7.82Ϫ7.87 (m, 6H, Ph).
in previous studies [5, 9, 10], di(alkyn-1-yl)dimethylstan-
nanes serve as versatile alkynyl transfer reagents in reac-
tions with platinum(II) dichlorides. The unique dependence
on reaction conditions, opening selective routes to the
transfer of one or two alkyn-1-yl groups, indicates that
short-lived intermediates formed by oxidative addition are
involved.
6c: m. p. 172 °C (dec.), 258 mg (85 %).
1H NMR (CD2Cl2, 25 °C): δ ϭ 4.97 (dt, 1H, H1, 2J(31P,1H) ϭ 13.2 Hz,
3J(1H,1H) ϭ 8.8 Hz), 5.70 (m, 2H, H2,7), 6.11 (m, 2H, H4,5 2J(195Pt,1H) ϭ
,
42.5 Hz), 6.54 (m, 2H, H3,6), 6.81Ϫ7.07, 7.42-7.55, 7.87-7.94 (m, m,
Experimental Section
m,15H, Ph).
IR: ν(CϵC) ϭ 2092 cmϪ1
.
General and starting materials
Preparation and handling of all compounds were carried out in an
atmosphere of dry argon, and carefully dried solvents were used
throughout. Starting materials were prepared according to litera-
ture procedures, e.g. (cod)PtCl2 [14], Ph2P(C7H7) [15],
Me2Sn(CϵC-H)2 [16], Me2Sn(CϵC-R)2 (R ϭ Me, Ph, SiMe3) [17],
or were used as commercial products without further purification,
e.g. Me-CϵC-H, Ph-CϵC-H, Me3Si-CϵC-H. NMR spectroscopy:
Bruker ARX 250 or DRX 500 (1H, 13C, 29Si, 31P, 195Pt NMR);
direct single pulse measurements were used, or in the case of some
13C and 29Si NMR spectra, the refocused INEPT pulse sequence
with 1H decoupling [18], based on nJ(13C,1H) ഠ 3 Ϫ 5 Hz, and
2J(29Si,1H) ഠ 7 Hz) was applied. Chemical shifts are given relative
to Me4Si [δ 1H (CD(H)Cl2) ϭ 5.33; δ 13C (CD2Cl2) ϭ 53.8; δ 29Si ϭ
0 for Ξ(29Si) ϭ 19.867184 MHz]; external aqueous H3PO4 (85 %)
with δ 31P ϭ 0 for Ξ(31P) ϭ 40.480747 MHz, and δ 195Pt ϭ 0 for
Ξ(195Pt) ϭ 21.400000 MHz. IR spectra: Perkin Elmer Spectrum
2000 FTIR.
6d: 224 mg (74 %).
1H NMR (CD2Cl2, 25 °C): δ ϭ Ϫ0.29 (s, 9H, SiMe3), 4.85 (dt, 1H, H1,
2J(31P,1H) ϭ 13.3 Hz, 3J(1H,1H) ϭ 8.6 Hz), 5.62 (m, 2H, H2,7), 6.11 (m, 2H,
H4,5 2J(195Pt,1H) ϭ 36.5 Hz), 6.48 (m, 2H, H3,6), 7.36Ϫ7.52 (m, 4H, Ph),
,
7.84Ϫ7.92 (m, 6H, Ph).
General procedure for the synthesis of [Ph2P(C7H7)]Pt(CϵC-R)2
(7)
The complex [Ph2P(C7H7)]PtCl2 (4) (271 mg; 0.50 mmol) was sus-
pended in THF (20 ml), and then Me2Sn(CϵC-R)2 (R ϭ H, Me,
Ph, SiMe3) (0.55 mmol) was added. When the mixture had been
kept stirring at room temperature for 1 h, a clear yellow solution
was formed. After removing all volatile materials in a high vacuum,
hexane (30 ml) was added. The insoluble precipitate was separated,
recrystallised from CH2Cl2/hexane, and dried in a high vacuum to
give the products as yellow powders.
7a: m. p. 140 °C (dec.), 235 mg (90 %).
1H NMR (CD2Cl2, 25 °C): δ ϭ 2.32 (d, 1H, ϵC-Htrans
,
3J(195Pt,1H) ϭ
3J(195Pt,1H) ϭ 67.3 Hz,
4J(31P,1H) ϭ 2.3 Hz), 4.98 (dt, 1H, H1, 2J(31P,1H) ϭ 13.7 Hz, 3J(1H,1H) ϭ
8.6 Hz), 5.63 (m, 2H, H2,7), 6.29 (m, 2H, H4,5 2J(195Pt,1H) ϭ 44.4 Hz), 6.45
43.8 Hz, 4J(31P,1H) ϭ 7.0 Hz), 2.60 (d, 1H, ϵC-Hcis
,
Synthesis of [Ph2P(C7H7)]PtCl2 (4)
,
The phosphane Ph2P(C7H7) (187 mg; 0.5 mmol), dissolved in
CH2Cl2 (10 ml), was added dropwise to a solution of (cod)PtCl2
(0.5 mmol) in CH2Cl2 (25 ml). The reaction mixture was stirred at
room temperature for 2h, and then brought to dryness in a high
vacuum. The remaining solid was washed with hexane (30 ml).
Recrystallisation from CH2Cl2/hexane and drying under high vac-
uum gave pure 4 [m. p. 279 °C (dec.); 255 mg; 94 %], as a yellow
powder.
(m, 2H, H3,6), 7.42Ϫ7.51 (m, 4H, Ph), 7.85Ϫ7.93 (m, 6H, Ph). IR:
ν(CϵC) ϭ 2057 cmϪ1
.
7b: 236 mg (86 %).
1H NMR (CD2Cl2, 25 °C): δ ϭ 1.80 (d, 3H, Metrans
5J(31P,1H) 2.1 Hz), 2.01 (d, 3H, Mecis 4J(195Pt,1H)
5J(31P,1H) ϭ 2.1 Hz), 4.85 (dt, 1H, H1, 2J(31P,1H) ϭ 13.2 Hz, 3J(1H,1H) ϭ
8.5 Hz), 5.51 (m, 2H, H2,7), 6.11 (m, 2H, H4,5 2J(195Pt,1H) ϭ 42.2 Hz), 6.32
(m, 2H, H3,6), 7.30Ϫ7.44 (m, 4H, Ph), 7.86Ϫ7.94 (m, 6H, Ph). IR
ν(CϵC) ϭ 2146 cmϪ1
,
4J(195Pt,1H) ϭ 21.5 Hz,
ϭ
,
ϭ
13.3 Hz,
,
1H NMR (CD2Cl2, 25 °C): δ ϭ 4.73 (dt, 1H, H1, 2J(31P,1H) ϭ 13.6 Hz,
.
3J(1H,1H) ϭ 8.4 Hz), 5.83 (m, 2H, H2,7), 5.95 (m, 2H, H4,5 2J(195Pt,1H) ϭ
,
18.6 Hz), 6.53 (m, 2H, H3,6), 7.47 (m, 4H, Ph), 7.78Ϫ7.86 (m, 6H, Ph).
7c: m. p. 105 °C (dec.), 246 mg (73 %).
1H NMR (CD2Cl2, 25 °C): δ ϭ 4.96 (dt, 1H, H1, 2J(31P,1H) ϭ 13.7 Hz,
Synthesis of [Ph2P(C7H7)]2PtCl2 (5)
3J(1H,1H) ϭ 8.7 Hz), 5.62 (m, 2H, H2,7), 6.37 (m, 2H, H4,5 2J(195Pt,1H) ϭ
,
45.2 Hz), 6.45 (m, 2H, H3,6), 6.95Ϫ7.05, 7.13-7.21, 7.32-7.51, 7.89-7.97 (m,
The phosphane Ph2P(C7H7) (276 mg; 1.0 mmol), dissolved in
CH2Cl2 (10 ml), was added dropwise to a solution of [(cod)PtCl2]
(0.5 mmol) in CH2Cl2 (25 ml). The reaction mixture was stirred at
room temperature for 2 h, and then all volatiles were removed in a
high vacuum. The remaining solid was washed with hexane (30 ml).
Recrystallisation from CH2Cl2/hexane and drying under high vac-
uum gave pure 5 (368 mg; 91 %) as a yellow powder.
m, m, m, 20H,Ph). IR ν(CϵC) ϭ 2118 cmϪ1
.
7d: 296 mg (89 %).
1H NMR (CD2Cl2, 25 °C): δ ϭ Ϫ 0.21, 0.15 (s, s, 9H, 9H, SiMe3), 4.92 (dt,
1H, H1 2J(31P,1H) ϭ 13.3 Hz, 3J(1H,1H) ϭ 8.6 Hz), 5.55 (m, 2H, H2,7), 6.22
(m, 2H, H4,5, 2J(195Pt,1H) ϭ 43.8 Hz), 6.36 (m, 2H, H3,6), 7.30Ϫ7.45 (m, 4H,
Ph), 7.85Ϫ7.93 (m, 6H, Ph). IR ν(CϵC) ϭ 2060 cmϪ1
.
1H NMR (CD2Cl2, 25 °C): δ ϭ 2.23 (m, 2H, H1), 5.27 (m, 4H, H2,7), 6.13
(m, 4H, H3,6), 6.44 (m, 4H, H4,5), 7.36 (m, 8H, Ph), 7.46 (m, 12H, Ph).
X-ray structural analyses of the complexes 4 and 7d
General procedure for the synthesis of [Ph2P(C7H7)]Pt(Cl)CϭC-R
(6)
Single crystals of 4 and 7d were mounted directly out of the mother
liquid under N2 atmosphere at low temperature. Relevant experi-
mental details of the crystal structure analyses [19] are given in
Table 5.
The intensity data were collected on a STOE IPDS II dif-
fractometer with MoKα-radiation (λϭ71.073 pm, graphite mono-
chromator) at 193(2) K. The hydrogen atoms are in calculated posi-
A suspension of the complex [Ph2P(C7H7)]PtCl2 (4) (271 mg;
0.50 mmol) in THF (20 ml) was prepared, then Me2Sn(CϵC-R)2
(R ϭ Me, Ph, SiMe3) (0.28 mmol) was added, and the mixture was
heated at reflux for 30 min. During this time a clear yellow solution
was formed. The volume of the solution was reduced under vacuum
to 5 ml, and hexane (50 ml) was added. The precipitate was sepa-
Z. Anorg. Allg. Chem. 2005, 631, 2629Ϫ2634
zaac.wiley-vch.de
 2005 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
2633

B. Wrackmeyer, B. Ullmann, R. Kempe, M. Herberhold
Table 5 Crystal structure data (at 193(2) K) for the complexes [Ph2P(C7H7)]PtCl2 (4), and [Ph2P(C7H7)]Pt(CϵC-SiMe3)2 (7d).
[Ph2P(C7H7)]PtCl2 (4)
[Ph2P(C7H7)]Pt(CϵC-SiMe3)2 (7d)
Crystal system
Space group
Unit cell dimensions
orthorhombic
P212121
monoclinic
P21/c
a ϭ 1284.1(1) pm,
b ϭ 2334.0(1) pm,
c ϭ 3284.3(1) pm,
9.82(1) nm3
a ϭ 1040.7(1) pm,
b ϭ 1220.3(1) pm,
c ϭ 1401.5(2) pm,
1.7799(3) nm3
4
α ϭ 90.000°.
β ϭ 90.000°.
γ ϭ 90.000°.
α ϭ 90.000°.
β ϭ 94.276(5)°.
γ ϭ 90.000°.
Volume
Z
Density (calculated)
Absorption coefficient
F(000)
Crystal size
Theta range for data collection
Index ranges
Reflections collected
Independent reflections
Absorption correction
Max. and min. transmission
Refinement method
Data / restraints / parameters
Goodness-of-fit on F2
Final R indices [I>2sigma(I)]
R indices (all data)
Largest diff. peak and hole
12
2.024 Mg/m3
8.269 mmϪ1
1032
1.460 Mg/m3
4.535 mmϪ1
4260
0.32 x 0.23 x 0.19 mm3
2.21 to 26.18°.
0.79 x 0.47 x 0.17 mm3
1.07 to 24.01°.
Ϫ12<ϭh<ϭ12, Ϫ15<ϭk<ϭ14, Ϫ17<ϭl<ϭ17
24338
14<ϭh<ϭ14, Ϫ26<ϭk<ϭ26, 0<ϭl<ϭ37
29126
3501 [R(int) ϭ 0.0669]
Numerical
15313 [R(int) ϭ 0.0227]
Numerical
0.26 and 0.13
0.58 and 0.16
Full-matrix least-squares on F2
3501 / 0 / 208
Full-matrix least-squares on F2
15313 / 0 / 920
1.340
1.038
R1 ϭ 0.0187, wR2 ϭ 0.0620
R1 ϭ 0.0199, wR2 ϭ 0.0756
0.879 and Ϫ1.603 e·A
R1 ϭ 0.0355, wR2 ϭ 0.0926
R1 ϭ 0.0448, wR2 ϭ 0.0956
2.129 and Ϫ1.817 e·A
Ϫ3
Ϫ3
˚
˚
tions. All non-hydrogen atoms were refined with anisotropic tem-
perature factors.
R. (eds.), NMR Ϫ Basic Principles and Progress, Vol. 16,
Springer, Berlin, 1979.
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Acknowledgements. Support of this work by the Deutsche
Forschungsgemeinschaft is gratefully acknowledged.
[10] A. Sebald, B. Wrackmeyer, Z. Naturforsch. 1983, 38b, 1156.
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216Ϫ263.
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Z. Anorg. Allg. Chem. 2005, 631, 2629Ϫ2634