Phosphenium complexes 30. Supermesitylphosphenium complexes of molybdenum and tungsten: Synthesis and exchange reactions involving the P-H bond

Article abstract of DOI:10.1016/S0022-328X(98)00947-4

Deprotonation of the complex salts {Cp(OC)₃[H₂(2,4,6-tBu₃-C₆H ₂)P]M}BF₄ (M=Mo, W) (4a,b), obtained from [Cp(OC)₃M]BF₄ (2a,b) and (2,4,6-tBu₃-C₆H₂)PH₂ (3), yields the metallo-phosphanes Cp(OC)₃M-P(H)(2,4,6-tBu₃-C₆H₂) (5a,b). 5a,b are thermally decarbonylated to the PH-functionalized phosphenium complexes Cp(OC)₂M=P(H)(2,4,6-tBu₃-C₆H₂) (7a,b), which can also be obtained by the base-assisted dehydrohalogenation of the bifunctional complexes Cp(OC)₂[H₂(2,4,6-tBu₃C₆H ₂)P]M-Cl (9a,b), prepared by a ligand exchange reaction from Cp(OC)₃M-Cl (8a,b) and 3. The reaction of 7a,b with CCl₄ affords the chloro-substituted phosphenium complex Cp(OC)₂M=P(Cl)(2,4,6-tBu₃-C₆H₂) (10a,b) via H/Cl exchange at the sp²-phosphorus. Substitution of the P-bonded hydrogen by a methyl group is achieved by in situ deprotonation of 7b and subsequent treatment with methyliodide, yielding the diorgano-phosphenium complex Cp(OC)₂M=P(Me)(2,4,6-tBu₃-C₆H₂) (11).

Full text of DOI:10.1016/S0022-328X(98)00947-4

Journal of Organometallic Chemistry 572 (1999) 207–212
Phosphenium complexes 30. Supermesitylphosphenium complexes of
molybdenum and tungsten: Synthesis and exchange reactions involving
the PꢀH bondꢀ
Wolfgang Malisch *, Ulrich-Andreas Hirth, Klaus Gru¨n, Martin Schmeußer
Institut fu¨r Anorganische Chemie der Uni6ersita¨t Wu¨rzburg, Am Hubland, D-97074 Wu¨rzburg, Germany
Received 12 May 1998
Abstract
Deprotonation of the complex salts {Cp(OC)3[H2(2,4,6-tBu3-C6H2)P]M}BF4 (M=Mo, W) (4a,b), obtained from
[Cp(OC)3M]BF4 (2a,b) and (2,4,6-tBu3-C6H2)PH2 (3), yields the metallo-phosphanes Cp(OC)3MꢀP(H)(2,4,6-tBu3ꢀC6H2) (5a,b).
5a,b are thermally decarbonylated to the PH-functionalized phosphenium complexes Cp(OC)2MꢁP(H)(2,4,6-tBu3ꢀC6H2) (7a,b),
which can also be obtained by the base-assisted dehydrohalogenation of the bifunctional complexes Cp(OC)2[H2(2,4,6-
tBu3C6H2)P]MꢀCl (9a,b), prepared by a ligand exchange reaction from Cp(OC)3MꢀCl (8a,b) and 3. The reaction of 7a,b with
CCl4 affords the chloro-substituted phosphenium complex Cp(OC)2MꢁP(Cl)(2,4,6-tBu3ꢀC6H2) (10a,b) via H/Cl exchange at the
sp2-phosphorus. Substitution of the P-bonded hydrogen by a methyl group is achieved by in situ deprotonation of 7b and
subsequent treatment with methyliodide, yielding the diorgano-phosphenium complex Cp(OC)2MꢁP(Me)(2,4,6-tBu3ꢀC6H2) (11).
© 1999 Elsevier Science S.A. All rights reserved.
Keywords: Metallo-phosphanes; Phosphenium–metal complexes; PꢀH bond; Exchange reaction
1. Introduction
turally characterized complexes [(Me3SiNCH2CH2)3N]-
MoꢁP(H)Ph, (Me3CCꢂ)(Cl2)(Et3P)2WꢁP(H)Ph [5] and
C5Me5(Me3P)2MoꢁP(H)s-Mes [6] are worth mention-
ing. Usually, the insufficient shielding of the MꢁP
bond leads to serious problems concerning the isola-
tion of these compounds, especially due to a pro-
nounced tendency toward dimerization. Whereas the
tert-butyl-substituted compounds C5R5(CO2)WꢁP-
(H)tBu (R=Me, H) can only be spectroscopically
identified in solution at low temperatures [7], the aryl-
substituted species (R=Ph, Mes) have never been di-
rectly observed [8]. Therefore, we have attempted to
stabilize these MꢁP(H)R bonds by introducing the ex-
tremely bulky s-mesityl substituent to the phosphorus
with the purpose of performing, for the first time,
controlled exchange reactions at the planar phospho-
rus. Preliminary accounts of this work have been pub-
lished [7].
The reactivity of diorgano-phosphenium metal com-
plexes Cp(OC)2MꢁPR2 [2–4] of molybdenum and
tungsten is determined by the cyclo addition behaviour
of the MꢁP bond towards a series of appropriate
reagents like alcohols, diazoalkanes, organoiso-
cyanates, azides and phosphinidenes. In order to
achieve consecutive coupling reactions involving the
phosphorus atom, the functionalized systems
Cp(OC)2MꢁP(H)R that offer a reactive PꢀH bond at
the sp2-phosphorus were studied. The number of sta-
ble examples is rather limited, among which the struc-
ꢀ For part 29, see [1]
* Corresponding author. Tel.: +49-931-888-5277; fax: +49-931-
888-4618; e-mail: wolfgang.malisch@mail.uni-wuerzburg.de.
0022-328X/99/$ - see front matter © 1999 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(98)00947-4

208
W. Malisch et al. / Journal of Organometallic Chemistry 572 (1999) 207–212
Scheme 1.
2. Results
after 60 min at 120°C, respectively. In this process, the
deep blue phosphenium complexes 7a,b are generated
that show a high thermal stability and good solubility
in pentane (Scheme 2(a)).
The synthesis of the phosphenium complexes 7a,b via
dehydrohalogenation starts with the s-mesityl-phos-
phane substituted chloro complexes 9a,b, which can be
obtained from the reaction of Cp(OC)3MꢀCl (8a,b)
with (2,4,6-tBu3ꢀC6H2)PH2 (3) performed in methylcy-
clohexane at 95 or 100°C, respectively.
The complexes 7a,b with a hydroden substituted
sp2-phosphorus can be generated via a decarbonylation
as well as a dehydrochlorination reaction [2–4,7,8]. The
first process requires the corresponding secondary
metallo-phosphanes 5a,b, which can be prepared from
the hydrido-metal complexes Cp(OC)3MꢀH (M=Mo,
W) (1a,b) in several steps. Hydride abstraction from
1a,b by trityltetrafluoroborate at −60°C yields the
cationic complexes [Cp(OC)3M]BF4 [9] (2a,b), which
Besides 9a,b, the hydrido complex Cp(OC)3MꢀH
(1a,b) is formed and finally converted into [Cp(OC)3M]2
This side reaction reduces the yield of 9a,b to ca. 20%.
Due to the high lability of 9a,b, column chromatogra-
phy could not be employed for purification. Dehy-
drochlorination of 9a,b by triethylamine at r.t. leads to
the double bonded systems 7a,b in yields of 70 and
90%, respectively (Scheme 2(b)). The overall yield of 7a
could be improved from 19 to 38% when
Cp(OC)3MoꢀCl (8a) and (2,4,6-tBu3ꢀC6H2)PH2 (3) di-
rectly reacted with triethylamine in methylcyclohexane
at 55°C in a one-step procedure. The lower reaction
temperature suppresses some of the side reactions in the
formation of 9a,b.
react
with
the
primary
phosphane
(2,4,6-
tBu3ꢀC6H2)PH2 (3) to form the yellow, light-sensitive
complex salts 4a,b. These can easily be deprotonated to
give the secondary metallo-phosphanes 5a,b when using
triethylamine as a base at r.t. [10] (Scheme 1(a)).
An alternative synthetic route to the metallo-phos-
phane 5b is offered by the direct reaction of the hy-
drido-tungsten species 1b and the chloro-phosphane 6
in the presence of triethylamine (Scheme 1(b)). How-
ever, the tedious synthesis of 6 makes route (b) less
attractive than route (a).
5a,b can be isolated in yields of at least 90% and are
thermally stable at 60°C (Mo) and 90°C (W). Above
90°C, 5a decomposes and turns blue. Using DTA and
thermogravimetric techniques, the loss of one equiva-
lent of CO in the melting process has been observed.
When heated in methylcyclohexane, 1 mol of CO is
eliminated from 5a after 30 min at 75°C and from 5b
Due to their high stability and ready accessibility, the
phosphane–metal double bonded species 7a,b appear to
be well-suited for studying exchange reactions at the
phosphorus involving the PꢀH moiety.
Scheme 2.

W. Malisch et al. / Journal of Organometallic Chemistry 572 (1999) 207–212
209
Scheme 3.
A chloro substituent can be introduced to the phos-
phorus using carbon tetrachloride as a reagent. The
treatment of 7a,b with one equivalent of carbon tetra-
chloride results in a complete H/Cl exchange within 3
days (7a) and 1 day (7b), respectively (Scheme 3(a)).
The PꢀCl functionalized double bonded complexes
10a,b are obtained in quantitative yield as highly ther-
mally stable purple crystals. This rare type of phosphe-
nium complex has only been realized in the case of
Cp(OC)2MoꢁP(Cl)(TMP) (TMP=2,2,2%,2%-tetramethyl-
piperidino) [11].
If a solution of 7b in THF is combined at r.t. with an
equimolar amount of KO(tBu) followed by the addi-
tion of an excess of methyliodide, the phosphenium
complex 11 is formed, which is obtained as a light
purple crystalline solid in 79% yield (Scheme 3(b)).
Compound 7b displays the typical reactivity of MꢁP
complexes towards HCl leading to the complete refor-
mation of the phosphane-substituted chloro complex
Cp(OC)2[H2(2,4,6-tBu3ꢀC6H2)P]WꢀCl (9b).
In summary, this paper shows that the s-mesityl
ligand exerts a significant stabilizing effect on PꢀH
functional phosphenium complexes, presumably due to
an efficient steric shielding of the MꢁP bond. This effect
should open the possibility of selective manipulations at
the PꢀH function, which will be used for further ex-
change reactions at the sp2-phosphorus. The results of
these investigations will be presented in forthcoming
papers.
C6H2)PH2 (3) [11] were prepared according to literature
procedures. Triethylamine, trityltetrafluoroborate,
potassium-tert-butanolate, methyliodide and carbon te-
trachloride were obtained commercially.
3.1. {Tricarbonyl(p5-cyclopentadienyl)[2,4,6-tri(tert-
butyl)-phenylphosphane]molybdenum(II)}tetrafluoro-
borate (4a)
A solution of [Cp(OC)3Mo]BF4 [9] (2a) in 6 ml of
dichloromethane, prepared from 233 mg (0.95 mmol) of
Cp(OC)3MoꢀH (1a) and 313 mg (0.95 mmol) of tritylte-
trafluoroborate, is combined with 264 mg (0.95 mmol)
of (2,4,6-tBu3ꢀC6H2)PH2 (3) at −78°C in the dark and
warmed up to r.t. After stirring for 2 h, the light red
solution is reduced in vacuo to 3 ml and 4a is precipi-
tated by dropwise addition of 10 ml of ether. 4a is
separated, washed with 3 ml of ether and pentane and
dried in vacuo. Yield 445 mg (77%), light yellow pow-
der, m.p. 186°C (decomp.). Molar conductivity [S cm2
mol−1] in acetonitrile (25°C): 136.6 (c=4.5×10−4
1
mol l−1). H-NMR (200.1 MHz, [D3]-acetonitrile): l
4
(ppm) 7.80 [d, J(PCCCH)=4.0 Hz, 2H, m-H], 6.78
3
[1J(PH)=405.0 Hz, 2H, H2P], 5.95 [d, J(PMoCH)=
0.7 Hz, 5H, H5C5], 1.57 [d, 5J(PCCCCH)=0.8 Hz,
18H, o-(H3C)C], 1.32 (s, 9H, p-(H3C)C). 31P{1H}-
NMR (36.4 MHz, [D3]-acetonitrile): l (ppm) −80.5
(s). IR (dichloromethane): w(PH)=2420 (w); w(CO)=
2063 (s), 1990 (vs, br) cm−1
.
Calc. for
C26H36BF4MoO3P (610.30): C, 51.17; H, 5.95; found:
C, 49.79; H, 5.46.
3. Experimental
3.2. {Tricarbonyl(p5-cyclopentadienyl)[2,4,6-tri(tert-
butyl)-phenylphosphane]tungsten(II)tetrafluoroborate
(4b)
All operations were performed in an atmosphere of
purified and dried nitrogen. Solvents and glassware
were prepared accordingly.
1H-NMR: Varian T60, JEOL FX 90 Q and Bruker
AC 200 (solvent used as reference). 31P-NMR: Bruker
WH 90 and JEOL FX 90 Q. IR: Perkin-Elmer, Model
283 grating spectrometer. Melting points: differential
thermo analysis (DTA); Thermal Analysis System Du
Pont 9000. Starting materials: Cp(OC)3MꢀH [M=Mo,
W (1a,b)] [12], Cp(OC)3MꢀCl [M=Mo, W (8a,b)] [13],
(2,4,6-tBu3ꢀC6H2)P(H)Cl (6) [14] and (2,4,6-tBu3ꢀ
Prepared as described for 4a from 324 mg (0.97
mmol) of Cp(OC)3WꢀH (1b), 320 mg (0.97 mmol) of
trityltetrafluoroborate and 270 mg (0.97 mmol) of
(2,4,6-tBu3ꢀC6H2)PH2 (3) in 7 ml of dichloromethane
after stirring for 3 h at r.t. Yield 557 mg (82%), light
yellow powder, m.p. 201°C (decomp.). Molar conduc-
tivity [S cm2 mol−1] in acetonitrile (25°C): 127.1 (c=

210
W. Malisch et al. / Journal of Organometallic Chemistry 572 (1999) 207–212
o-(H3C)C], 1.29 [s, 9H, p-(H3C)C]. 31P{1H}-NMR (36.4
MHz, [D6]-benzene): l (ppm) −141.0 [s, 1J(WP)=50.6
Hz]. IR (methylcyclohexane): w(PH)=2410 (w);
w(CO)=2003 (s), 1938 (vs), 1922 (vs) cm−1. Calc. for
C26H35O3PW (610.40): C, 51.16; H, 5.78; found: C,
50.73; H, 5.90.
1
4.8 10−4 mol l−1). H-NMR (60 MHz, [D3]-acetoni-
trile): l (ppm) 7.78 [d, 4J(PCCCH)=4.0 Hz, 2H, m-H],
7.05 [d, 1J(PH)=414.0 Hz, 2H, H2P], 6.00 [d,
3J(PWCH)=0.8
Hz,
5H,
H5C5],
1.52
[d,
5J(PCCCCH)=0.8 Hz, 18H, o-(H3C)C], 1.29 [s, 9H,
p-(H3C)C]. 31P{1H}-NMR (36.4 MHz, [D3]-acetoni-
trile): l (ppm) −112.8 [s, 1J(WP)=187.0 Hz]. IR
(dichloromethane): w(PH)=2420 (w); w(CO)=2062 (s),
1975 (vs br) cm−1. Calc. for C26H36BF4O3PW (698.22):
C, 44.73; H, 5.20; found: C, 44.20; H, 5.06.
3.5. Cis-dicarbonyl(chloro)(p5-cyclopentadienyl)
[2,4,6-tri(tert-butyl)-phenylphosphane]molybdenum(II)
(9a)
3.3. [Tricarbonyl(p5-cyclopentadienyl)molybdenum(II)]
[2,4,6,-tri(tert-butyl)-phenyl]phosphane (5a)
A mixture of 210 mg (0.75 mmol) of Cp(OC)3MoꢀCl
(8a) and 289 mg (1.04 mmol) of (2,4,6-tBu3ꢀC6H2)PH2
(3) in 15 ml of methylcyclohexane is stirred for 2 days
at 95°C. After cooling to r.t., the solution is reduced in
vacuo to 5 ml. Impure 9a is crystallized by cooling to
−78°C, separated by filtration and recrystallized from
3 ml of boiling methylcyclohexane. Yield 80 mg (20%),
red powder, m.p. 158°C (decomp.). 1H-NMR (200.1
MHz, [D6]-benzene): l (ppm) 7.56 [d, 4J(PCCCH)=2.9
Hz, 1H, m-H], 7.54 [d, 4J(PCCCH)=2.9 Hz, 1H,
A
suspension of 271 mg (0.40 mmol) of
{Cp(OC)3[H2(2,4,6-tBu3ꢀC6H2)P]Mo}BF4 (4a) in 12 ml
of methylcyclohexane is combined at 0°C with a solu-
tion of 45 mg (0.40 mmol) of triethylamine in 2 ml of
methylcyclohexane and the mixture is stirred for 1 h at
r.t., resulting in a yellow colour. Insoluble [Et3NH]BH4
is separated by filtration, volatiles are removed in vacuo
and the remaining 5a is washed with 4 ml of pentane
and dried in vacuo. Yield 207 mg (89%), yellow pow-
1
2
m-H], 6.49 [dd, J(PH)=329.0 Hz, J(HPH)=8.5 Hz,
1
2
1H, HP], 6.15 [dd, J(PH)=389.0 Hz, J(HPH)=8.5
Hz, 1H, HP], 4.88 (s, 5H, H5C5), 1.40 [s, 18H, o-
(H3C)C], 1.20 [s, 9H, p-(H3C)C]. 31P{1H}-NMR (36.4
MHz, [D6]-benzene): l (ppm) −46.5 (s). IR (benzene):
1
der, m.p. 85°C (decomp.). H-NMR (90 MHz), [D6]-
4
benzene): l (ppm) 7.72 [d, J(PCCCH)=2.0 Hz, 2H,
1
m-H], 5.13 [d, J(PH)=213.0 Hz, 1H, HP], 4.80 [d,
3J(PMoCH)=1.6 Hz, 5H, H5C5], 1.68 [s, 18H, o-
(H3C)C], 1.25 [s, 9H, p-(H3C)C]. 31P{1H}-NMR (36.4
MHz, [D6]-benzene): l (ppm) −120.3 (s). IR (methyl-
cyclohexane): w(PH)=2409 (w); w(CO)=2005 (s), 1946
w(PH)=2388 (w); w(CO)=1974 (vs), 1898 (vs) cm−1
.
Calc. for C25H36ClMoO2P (530.91): C, 56.56; H, 6.83;
found: C, 56.19; H, 6.48.
(vs), 1930 (vs) cm−1. Thermogravimetry (10°C min−1
;
3.6. Cis-dicarbonyl(chloro)(p5-cyclopentadienyl)
[M]-CO 85–113°C, melt): CO calc. 5.36; found, 4.80.
Calc. for C26H35MoO3P (522.51): C, 59.77; H, 6.75;
found: C, 58.81; H 6.53.
[2,4,6-tri(tert-butyl)-phenylphosphane]tungsten(II) (9b)
Prepared as described for 9a from 183 mg (0.52
mmol) of Cp(OC)3WꢀCl (8b) and 236 mg (0.85 mmol)
of (2,4,6-tBu3ꢀC6H2)PH2 (3) in 15 ml of methylcyclo-
hexane after 2 days at 100°C. Yield 72 mg (23%), red
powder, m.p. 161°C (decomp.). 1H-NMR (60 MHz,
3.4. [Tricarbonyl(p5-cyclopentadienyl)tungsten(II)]
[2,4,6-tri(tert-butyl)-phenyl]phosphane (5b)
4
(a) Prepared as described for 5a from 269 mg (0.42
mmol) of {Cp(OC)3[H2(2,4,6-tBu3ꢀC6H2)P]W}BF4 (4b)
and 43 mg (0.42 mmol) of triethylamine in 10 ml of
methylcyclohexane after stirring for 1.5 h. Yield 241 mg
(94%).
benzene): l (ppm) 7.50 [d, J(PCCCH)=2.7 Hz, 1H,
m-H], 7.46 [d, 4J(PCCCH)=2.7 Hz, 1H, m-H], 7.20 [d,
1
1J(PH)=365.0 Hz, 1H, HP], 7.05 [d, J(PH)=347.0
Hz, 1H, HP], 5.00 (s, 5H, H5C5), 1.40 [s, 18H, o-
(H3C)C], 1.20 [s, 9H, p-(H3C)C]. 31P{1H}-NMR (36.4
MHz, [D6]-benzene): l (ppm) −71.4 [s, 1J(WP)=272.4
Hz]. IR (benzene): w(PH)=2380 (w); w(CO)=1956
(vs), 1882 (vs) cm−1. Calc. for C25H36ClO2PW (618.79):
C, 48.52; H, 5.86; found: C, 49.19; H, 5.80.
(b) A mixture of 257 mg (0.77 mmol) of Cp(OC)3WꢀH
(1b), 242 mg (0.77 mmol) of (2,4,6-tBu3ꢀC6H2)P(H)Cl
(6) and 105 mg (1.04 mmol) of triethylamine in 10 ml of
benzene is stirred for 1 h at r.t. The solution changes
from pink to brown and insoluble [Et3NH]Cl is formed.
Insolubles are separated by filtration and the filtrate is
evaporated in vacuo to yield 5b, which is washed with
8 ml of cold pentane and dried in vacuo. Yield 253 mg
(54%), yellow powder, m.p. 117°C. 1H-NMR (200.1
MHz, [D6]-benzene): l (ppm) 7.67 [d, 4J(PCCCH)=2.0
3.7. Dicarbonyl(p5-cyclopentadienyl)[2,4,6-tri(tert-
butyl)-phenyl-u4-phosphandiyl]molybdenum(II) (7a)
(a)
A
solution of 122 mg (0.23 mmol) of
Cp(OC)3MoꢀP(H)(2,4,6-tBu3ꢀC6H2) (5a) in 10 ml of
methylcyclohexane is heated to 75°C for 30 min, where
upon the colour changes from yellow to deep blue.
1
Hz, 2H, m-H], 5.30 [d, J(PH)=221.0 Hz, 1H, HP],
3
4.82 [d, J(PWCH)=1.6 Hz, 5H, H5C5], 1.69 [s, 18H,

W. Malisch et al. / Journal of Organometallic Chemistry 572 (1999) 207–212
211
Volatiles are removed in vacuo and the remaining 7a is
w(PH)=2299 (w); w(CO)=1953 (vs), 1881 (vs) cm−1
.
washed with 3 ml of pentane and dried in vacuo. Yield
108 mg (93%).
Calc. for C25H35O2PW (582.43): C, 51.56; H, 6.06;
found: C, 51.89; H, 5.69.
(b)
A
solution of 187 mg (0.35 mmol) of
Cp(OC)2[H2(2,4,6-tBu3ꢀC6H2)P]MoꢀCl (9a) is treated
with 36 mg (0.35 mmol) of triethylamine and stirred for
20 min at r.t., whereupon the solution turns blue.
Insoluble [Et3NH]Cl is separated and volatiles are re-
moved in vacuo. The remaining 7a is washed with 3 ml
of pentane and dried in vacuo. Yield 162 mg (94%).
(c) A solution of 72 mg (0.70 mmol) of Et3N in 2 ml of
methylcyclohexane is added dropwise at r.t. to a mix-
ture of 198 mg (0.70 mmol) of Cp(OC)3MoꢀCl (8a) and
197 mg (0.70 mmol) of (2,4,6-tBu3ꢀC6H2)PH2 (3) in 10
ml of methylcyclohexane. The solution is stirred for 90
min at 55°C, whereupon it turns blue. [Et3NH]Cl is
separated, the filtrate is evaporated in vacuo and the
remaining blue residue is purified by column chro-
matography (column 10×1.5 cm; Al2O3, activity IV,
neutral; pentane). 7a is obtained by evaporation of the
first blue fraction in vacuo. Yield 121 mg (35%), blue
microcrystalline powder, m.p. 102°C (decomp.). 1H-
NMR (200.1 MHz, [D6]-benzene): l (ppm) 9.95 [d,
3.9. Dicarbonyl(p5-cyclopentadienyl){[2,4,6-tri(tert-
butyl)-phenyl](chloro)-u4-phosphanediyl}molybdenum(II)
(10a)
A
solution of 84 mg (0.17 mmol) of
Cp(OC)2MoꢁP(H)(2,4,6-tBu3ꢀC6H2) (7a) in 5 ml of
pentane is treated with 26 mg (0.17 mmol) of CCl4 at
r.t. After 3 days, a change of colour from blue to violet
is observed. Volatiles are removed in vacuo and the
remaining 10a is washed with 3 ml of pentane and dried
in vacuo. Yield 89 mg (99%), red–violet powder, m.p.
1
116°C (decomp.). H-NMR (90 MHz, [D6]-benzene): l
4
(ppm) 7.63 [d, J(PCCCH)=4 Hz, 2H, m-H], 5.07 (s,
5H, C5H5), 1.65 [d, 5J(PCCCCH)=1.1 Hz, 18H, o-
(H3C)C], 1.12 [s, 9H, p-(H3C)C]. 31P{1H)-NMR (36.4
MHz, [D6]-benzene): l (ppm) 259.1 (s). IR (pentane):
w(CO)=1972 (vs), 1909 (vs) cm−1. UV (cyclohexane):
umax=193.6, 240.0, 303.4 nm (m=57 956, 17 057,
15 261) (c=2.3×10−4 mol·l−1), 507.6 nm (m=208.7)
(c=2.3×10−3 mol·l−1). Calc. for C25H34ClMoO2P
(528.89): C, 56.77; H, 6.48; Cl, 6.70; found: C, 56.46; H,
6.82; Cl, 6.68.
1J(PH)=408.0 Hz, 1H, HP], 7.44 [d, J(PCCCH)=2.0
4
Hz, 2H, m-H], 5.08 (s, 5H, H5C5), 1.35 [d,
5J(PCCCCH=0.9 Hz, 18H, o-(H3C)C], 1.12 [s, 9 H,
p-(H3C)C]. 31P{1H}-NMR (36.4 MHz [D6]-benzene): l
(ppm) 266.2 ppm (s). IR (pentane): w(PH)=2294 (w);
3.10. Dicarbonyl(p5-cyclopentadienyl){[2,4,6-tri(tert-
butyl)phenyl](chloro)-u4-phosphanediyl}tungsten(II)
(10b)
w(CO)=1960 (vs), 1890 (vs) cm−1
.
Calc. for
C25H35MoO2P (494.51): C, 60.73; H, 7.13; found: C,
60.77; H, 7.17.
A
solution of 85 mg (0.15 mmol) of
3.8. Dicarbonyl(p5-cyclopentadienyl)[2,4,6-tri(tert-
butyl)-phenyl-u4-phosphanediyl]tungsten(II) (7b)
Cp(OC)2WꢁP(H)(2,4,6-tBu3ꢀC6H2) (7b) in 5 ml of ben-
zene is treated with 22 mg (0.15 mmol) of CCl4 and
stirred for 22 h at r.t. Volatiles are removed in vacuo,
the remaining 10b is washed with 3 ml of pentane and
dried in vacuo. Yield 86 mg (96%), violet microcrys-
(a)
A
solution of 241 mg (0.39 mmol) of
Cp(OC)3WꢀP(H)(2,4,6-tBu3ꢀC6H2) (5b) in 12 ml of
methylcyclohexane is stirred for 1 h at 120°C. After
removal of volatiles in vacuo the purple residue is
extracted with 10 ml of pentane. Evaporation of the
extract in vacuo yields pure 7b. Yield 216 mg (95%).
1
talline solid, m.p. 120°C. H-NMR (200.1 MHz, [D6]-
benzene): l (ppm) 7.65 [d, J(PCCCH)=4.0 Hz, 2H,
4
5
m-H], 5.07 (s, 5H, H5C5), 1.60 [d J(PCCCCH)=1.0
Hz, 18H, o-(H3C)C], 1.08 [s, 9H, p-(H3C)C]. 31P-NMR
1
(b)
A
solution of 80 mg (0.13 mmol) of
(36.4 MHz, [D6]-benzene): l (ppm) 201.8 [s, J(WP)=
Cp(OC)2[H2(2,4,6-tBu3ꢀC6H2)P]WꢀCl (9b) in 0.5 ml of
benzene is combined with 79 mg (0.78 mmol) of triethy-
lamine at r.t., whereupon the solution turns violet
immediately. After 10 min, insoluble [Et3NH]Cl is sepa-
rated and the solvent is removed in vacuo. The remain-
ing residue is extracted with 2 ml of pentane and the
extract is evaporated in vacuo to yield 7b. Yield 52 mg
711.6 Hz]. IR (pentane): w(CO)=1969 (vs), 1904 (vs)
cm−1. UV (cyclohexane): umax=193.7, 243.2, 303.8 nm
(m=65 638, 24 628, 21 383) (c=1.9×10−4 mol·l−1),
490.3 nm (m=340) (c=1.9×10−3 mol·l−1). Calc.
C25H34ClO2P2W (616.80): C, 48.68; H, 5.56; Cl, 5.75;
found: C, 48.72; H, 5.74; Cl, 5.82.
1
(69%), violet powder, m.p. 108°C. H-NMR (60 MHz,
3.11. Dicarbonyl(p5-cyclopentadienyl){[2,4,6-tri(tert-
butyl)-phenyl](methyl)-u4-phosphanediyl}tungsten(II)
(11)
1
[D6]-benzene): l ppm) 12.8 [d, J(PH)=379.0 Hz, 1H,
4
HP], 7.44 [d, J(PCCCH)=2.0 Hz, 2H, m-H], 5.08 [d,
3J(PWCH)=0.3
Hz,
5H,
H5C5],
1.37
[d,
5J(PCCCCH)=0.7 Hz, 18H, o-(H3C)C], 1.15 [s, 9H,
p-(H3C)C]. 31P{1H}-NMR (36.4 MHz, [D6]-benzene): l
(ppm) 211.8 [s, 1J(PW)=604.0 Hz]. IR(pentane):
To
a
solution of 85 mg (0.15 mmol) of
Cp(OC)2WꢁPH(2,4,6-tBu3ꢀC6H2) (7b) in 10 ml of THF
19 mg (0.15 mmol) of KO(tBu) is added at 0°C where-

212
W. Malisch et al. / Journal of Organometallic Chemistry 572 (1999) 207–212
[2] (a) W. Malisch, K. Jo¨rg, E. Groß, M. Schmeußer, A. Meyer,
Phosphorus Sulfur 26 (1986) 25. (b) D. Gudat, E. Niecke, W.
Malisch, U. Hofmockel, S. Quashie, A.H. Cowley, A.M. Arif, B.
Krebs, M. Dartmann, J. Chem. Soc. Chem. Commun. (1985)
1687. (c) E. Groß, K. Jo¨rg, K. Fiederling, A. Go¨ttlein, W.
Malisch, R. Boese, Angew. Chem. 96 (1984) 705; Angew. Chem.
Int. Ed. Engl. 23 (1984) 738. (d) K. Jo¨rg, W. Malisch, W. Reich,
A. Meyer, U. Schubert, Angew. Chem 98 (1986) 103; Angew.
Chem. Int. Ed. Engl. 25 (1986) 92. (e) H.H. Karsch, H.-U.
Reisacher, K. Jo¨rg, W. Malisch, B. Huber, G. Mu¨ller, New J.
Chem. 13 (1989) 319. (f) W. Malisch, K. Hindahl, R. Schemm,
Chem. Ber. 125 (1992) 2027.
[3] (a) H. Lang, Phosphorus Sulfur 77 (1993) 9. (b) H. Lang, M.
Leise, L. Zsolnai, Organometallics 12 (1993) 2393. (c) H. Lang,
M. Winter, M. Leise, L. Zsolnai, M. Bu¨chner, G. Huttner, J.
Organomet. Chem. 533 (1997) 167. (d) H. Lang, M. Leise, W.
Imhof, Z. Naturforsch. 46B (1991) 1650. (e) H. Lang, M. Leise,
L. Zsolnai, Organometallics 12 (1993) 2393.
[4] (a) H.-U. Reisacher, E.N. Duesler, R.T. Paine, Chem. Ber. 129
(1996) 279. (b) H.-U. Reisacher, W.F. McNamara, E.N. Duesler,
R.T. Paine, Organometallics 16 (1997) 449. (c) L.D. Hutchins,
R.T. Paine, C.F. Campana, J. Am. Chem. Soc. 102 (1980) 4521.
(d) D.A. Dubois, E.N. Duesler, R.T. Paine, Organometallics 2
(1983) 1903. (e) L.D. Hutchins, E.N. Duesler, R.T. Paine,
Organometallics 3 (1984) 399.
[5] (a) N.C. Zanetti, R. Schrock, W.M. Davis, Angew. Chem. 107
(1995) 2184; Angew. Chem. Int. Ed. Engl. 34 (1995) 2044. (b)
S.M. Rocklage, R.R. Schrock, M.P. Churchill, H.J. Wasser-
mann, Organometallics 1 (1982) 1332.
upon the colour of the solution turns from violet to
dark green immediately. Addition of 114 mg (0.80
mmol) of methyliodide results in a change of colour
back to violet. After removal of volatiles in vacuo, the
remaining solid is dissolved in 2 ml of pentane and
purified by column chromatography (column 10×1.5
cm; Al2O3, activity IV, neutral; pentane). 11 is isolated
by evaporation of the violet fraction in vacuo. Yield 69
mg (79%), violet microcrystalline solid, m.p. 135°C
(decomp.). 1H-NMR (200.1 MHz, [D6]-benzene): l
4
(ppm) 7.47 [d, J(PCCCH)=2.3 Hz, 2H, m-H], 5.12 (s,
2
5H, H5C5), 1.58 [d, J(PCH)=15.1 Hz, 3H, (H3C)P],
5
1.52 [d, J(PCCCCH)=1.0 Hz, 18H, o-(H3C)C], 1.24
[s, 9H, p-(H3C)C]. 31P{1H}-NMR (36.4 MHz, [D6]-ben-
1
zene): l (ppm) 262.8 [s, J(WP)=617.8 Hz]. IR (pen-
tane): w(CO)=1940 (vs), 1868 (vs); (benzene): 1928
(vs), 1850 (vs) cm−1. Calc. for C26H37O2PW (596.40):
C, 52.36; H, 6.25; found: C, 51.68; H, 6.44.
3.12. Reaction of 7b with etherial HCl
A
solution of 87 mg (0.15 mmol) of
Cp(OC)2WꢁP(H)(2,4,6-tBu3ꢀC6H2) (7b) in 5 ml of di-
ethyl ether is combined at r.t. with an etherial solution
of 6 mg (0.16 mmol) of hydrogen chloride. The colour
of the solution turns from blue to red. After removal of
volatiles in vacuo, the remaining 9b is washed with 3 ml
pentane, dried in vacuo and spectroscopically identified
by comparison with an authentic sample. Yield 88 mg
(92%).
[6] E. Hey-Hawkins, K. Fromm, Polyhedron 14 (1995) 2825.
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Weis, Angew. Chem. 107 (1995) 2717; Angew. Chem. Int. Ed.
Engl. 34 (1995) 2500.
[8] W. Malisch, U.-A. Hirth, T.A. Bright, H. Ka¨b, T.S. Ertel, S.
Hu¨ckmann, H. Bertagnolli, Angew. Chem. 104 (1992) 1537;
Angew. Chem. Int. Ed. Engl. 31 (1992) 1525.
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Chem. 42 (1972) 145.
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[12] E.O. Fischer, W. Hafner, Z. Naturforsch. 10B (1955) 140.
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[14] C. Couret, J. Escudie, H. Ranaivonjatovo, J. Satge,
Organometallics 5 (1986) 113.
References
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Weis, C. Kru¨ger, Z. Naturforsch., submitted.
.