Phosphavinylidene(oxo)phosphorane Mes*P(O)=C=PMes*: A diphosphaallene featuring λ5σ3- and λ3σ2-phosphorus atoms R

Article abstract of DOI:10.1002/ejic.200600384

Bis(2,4,6-tri-tert-butylphenyl)phosphavinylidene(oxo)phosphorane (1) (Mes* = 2,4,6-tri-tert-butylphenyl), the first 1λ ⁵σ³,3λ³σ²- diphosphaallene, has been synthesised by addition of the phosphaalkenyllithium Me

Full text of DOI:10.1002/ejic.200600384

FULL PAPER
DOI: 10.1002/ejic.200600384
Phosphavinylidene(oxo)phosphorane Mes*P(O)=C=PMes*: A Diphosphaallene
Featuring λ5σ3- and λ3σ2-Phosphorus Atoms
Raluca Septelean,[a] Henri Ranaivonjatovo,*[b] Gabriela Nemes,[a] Jean Escudié,*[b]
Ioan Silaghi-Dumitrescu,[a] Heinz Gornitzka,[b] Luminita Silaghi-Dumitrescu,[a] and
Stéphane Massou[c]
Keywords: Heterocumulenes / Phosphorus / Phosphaalkenes / Methylenephosphoranes
Bis(2,4,6-tri-tert-butylphenyl)phosphavinylidene(oxo)phos-
phorane (1) (Mes* = 2,4,6-tri-tert-butylphenyl), the first
which appears to be more reactive than the λ3σ2-P=C bond.
This leads to the hydrolysis compound 8 which has been
1λ5σ3,3λ3σ2-diphosphaallene, has been synthesised by ad- structurally characterised. The new bis(phosphane oxide)-
dition of the phosphaalkenyllithium Mes*P=C(Li)Cl to
dichlorophosphane oxide Mes*P(O)Cl2. Compound is
stable in the solid-state but undergoes a slow intramolecular
cyclisation in solution by addition of a C–H bond of an ortho-
tert-butyl group to the σ3-P=C double bond. Water adds
chemoselectively and regioselectively to the λ5σ3-P=C bond,
methylene 9 formed from the successive cyclisation of an
ortho-tert-butyl group to the λ5σ3-P=C bond and addition of
water to the λ3σ2-P=C bond has also been structurally char-
acterised.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2006)
1
never been described even as an intermediate. Moreover,
such a structure is comprised of a methylene(oxo)phos-
phorane unit of which only two stable –P(O)=CϽ represen-
tatives have been reported to date.[6]
Introduction
The high utility of ketenes, allenes and cumulenes has
been well established in organic synthesis.[1] Phosphaallene
derivatives, namely compounds with P=C=C or P=C=P
skeletons, are phosphorus congeners of allenes and can thus
be expected to be useful starting materials for new organo-
phosphorus compounds.
Results and Discussion
Among the possible neutral heterocumulenes featuring
the P=C=P sequence, 1σ4,3σ4-diphosphaallenes I[2] and
1σ2,3σ2-diphosphaallenes II[3,4] have been known for many
years. More recently 1σ4,3σ2-diphosphaallenes III have
been isolated.[5]
Mes*P(O)=C=PMes*, bis(2,4,6-tri-tert-butylphenyl)phos-
phavinylidene(oxo)phosphorane 1 (Mes* = 2,4,6-tri-tert-bu-
tylphenyl), was obtained by addition, at –80 °C, of one
equiv. of phosphaalkenyllithium 2[7] to a solution of dichlo-
rophosphane oxide 4.[8] 31P NMR spectroscopic analysis of
the crude mixture showed the presence of 3, 4 and 1 in a
ratio of 1:1:1. The one-pot preparation of 1 probably in-
volves the preliminary formation of phosphaalkenylphos-
phane oxide 5 followed by a rapid CCl/CLi exchange with
phosphaalkenyllithium 2 leading to the starting dichlo-
rophosphaalkene 3 and intermediate 6. The latter loses LiCl
to afford the title compound 1 (Scheme 1), which could be
easily obtained as a yellow powder from the reaction mix-
ture by precipitation with pentane. The structure of 1 was
unambiguously determined by sophisticated 1H, 13C and
31P NMR spectroscopic studies (1D selective 31P decoup-
ling experiments and 2D HSQC, HMBC) (see supporting
information). The 31P NMR spectrum of 1 displays an AX
system at δ = 261.4 (σ2-P) and 117.3 ppm (σ3-P) with a
Here we report the synthesis and the first aspects of the
chemical behaviour of a hitherto unknown 1σ3,3σ2-diphos-
phaallene IV. Despite continuing efforts over the past two
decades to synthesise low-coordinate multiply bonded
phosphorus compounds, such a functionalised molecule has
[a] Babes-Bolyai University,
Kogalniceanu 1, 400084 Cluj-Napoca, Romania
[b] Hétérochimie Fondamentale et Appliquée, UMR 5069, Uni-
versité Paul Sabatier,
118 route de Narbonne, 31062 Toulouse cedex 9, France
[c] Structure Fédérative Toulousaine en Chimie Moléculaire, FR
2599, Université Paul Sabatier,
2
coupling constant JP,P of 30.5 Hz. A large high-frequency
shift of 120 ppm can be observed for the λ3σ2-P in compari-
son with the value reported for the diphosphaallene
Mes*P=C=PMes* (δ31P = 140 ppm[4b]). The signal of the
118 route de Narbonne, 31062 Toulouse cedex 9, France
Supporting information for this article is available on the
WWW under http://www.eurjic.org or from the author.
Eur. J. Inorg. Chem. 2006, 4237–4241
© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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H. Ranaivonjatovo, J. Escudié et al.
FULL PAPER
λ5σ3-phosphorus atom is slightly lower in frequency in rela-
tion to those observed for Mes*P(O)=C(R)SiMe3 [δ31P =
153.7 ppm (R = Ph),[6a] 161.1 ppm (R = Me3Si)[6b]]. The sp
hybridised carbon atom gives rise to a doublet of doublets
1
at δ = 229.1 ppm (1JC,P(O) = 177.4, JC,P = 46.8 Hz). The
1H NMR spectrum at room temperature shows slow rota-
tion of the Mes* group bonded to the λ3σ2-phosphorus
1
atom. Dynamic H NMR spectroscopy was performed be-
tween 213 and 328 K and the coalescence temperatures for
the o-tBu groups and for the aromatic protons on the Mes*
group bonded to the λ3σ2-P are 268 and 253 K, respectively,
giving
a
rotation barrier of 12.2 kcalmol–1. Similar
values have been reported for the rotation barriers of Mes*
groups in the phosphaarsaallene Mes*P=C=AsMes*
Scheme 2. Rearrangement reaction and hydrolysis of 1.
(13.6 kcalmol–1)[9]
and
in
the
diphosphaallene
Mes*P=C=PMes* (14.0 kcalmol–1).[10] Hindered rotation coupling constant always corresponds to the E isomer
can be observed for the Mes* group bonded to the P(O) [18 Hz (Z) and 24.7 Hz (E) in Mes*P=C(H)SiMe3].[7a]
moiety even at 328 K (two singlets for the o-tBu groups Moreover ONIOM B3LYP/6-31G(d):PM3 geometry optim-
and two doublets of doublets for the aromatic protons). A isations of 7 place the Z isomer higher in energy by
molecular ion peak can be observed in the mass spectrum 3.63 kcalmol–1.
of 1 with the expected fragments at m/z = 565 [M – Me]+
and 523 [M – tBu]+.
This intramolecular cyclisation results from the addition
of a C–H bond of an ortho-tert-butyl substituent of a super-
mesityl group to the σ3-P=C double bond.[13] This re-
arrangement shows that the methylene(oxo)phosphorane
moiety is much less stable than the phosphane oxide one. In
contrast to bis(methylene)phosphoranes RP(=CRЈ2)2 which
isomerise into phosphiranes,[14] the O=P=C unit in 1 does
not undergo a similar cyclisation (which would lead to the
three-membered ring oxaphosphirane).
The structure of 1 was also established unambiguously
from its hydrolysis products. The λ5σ3-P=C double bond is
much more reactive than the λ3σ2-P=C bond since one
equiv. of water adds only to this double bond to afford the
two geometric isomers 8a and 8b (Scheme 2). Again,
ONIOM B3LYP/6-31G(d):PM3 optimisations show that 8b
Scheme 1. Synthesis of Mes*P(O)=C=PMes* (1).
Compound 1 is stable for months at room temperature (E isomer) is lower in energy by 5.27 kcalmol–1.
in the solid-state but attempts to crystallise it in various
The 31P NMR spectra of 8a and 8b exhibit characteristic
2
solvents at low temperatures did not afford satisfactory sin- signals of phosphaalkenes [δ31P 8a = 305.5 ppm (dd, JP,P
gle crystals for X-ray diffraction studies. Compound 1 = 47.3 Hz, 2JP,H = 24.4 Hz, P=C), 8b = 335.4 ppm (dd, 2JP,P
2
slowly rearranges within one day at room temperature in = 68.5 Hz, JP,H = 24.4 Hz, P=C] and phosphinic acids
2
solution. The rearrangement affords the phosphaalkenyl- [δ31P 8a = 24.6 ppm {d, JP,P = 47.3 Hz, P(O)}; 8b =
2
phosphane oxides 7a and 7b in near quantitative yield 34.9 ppm {d, JP,P = 68.5 Hz, P(O)}].
in the form of two geometric isomers in the ratio of
This addition is regioselective and gives, as expected, the
85:15 (Scheme 2). B3LYP/6-31G(d)//ONIOM B3LYP/6- derivative with the hydrogen atom bonded to the central sp2
31G(d):PM3 calculations support this easy isomerisation carbon atom. However, since the reaction of water with 1
and 7 was found to be lower in energy than 1 by about is slow in solution (about one day in pentane at room tem-
54 kcalmol–1.
perature), the competitive cyclisation products 7a,b are also
The 31P NMR spectra of 7a and 7b exhibit signals in the formed. Compounds 7 and 8 are obtained in the ratio 7a
typical range for phosphalkenes[11a–11d] [δ31P for P=C in 7a (25%), 7b (5%), 8a (20%) and 8b (50%). The X-ray struc-
2
2
at δ = 339.1 ppm (dd, JP,P = 70.2 Hz, JP,H = 24.4 Hz) and ture of the Z isomer 8b has been determined (Figure 1) and
in 7b at δ = 353.0 ppm (dd, 2JP,P = 73.3 Hz, 2JP,H = 21.4 Hz, displays standard bond lengths and angles.
P=C)] and phosphane oxides[11e] [δ31P for P(O) in 7a at δ =
Addition of water to the Z/E mixture of 7 afforded, after
2
49.3 ppm (d, JP,P = 70.2 Hz) and in 7b at δ = 38.7 ppm one week, the new bis(phosphane oxide)methylene 9 in the
2
(d, JP,P = 73.3 Hz)]. Similar chemical shifts at 327 and form of only one diastereoisomer, which was isolated as
10 ppm have been reported for Mes*P=CH–P(O)- pale yellow crystals in 85% yield. The 31P NMR spectrum
HMes*.[12] The E structure has been tentatively assigned to of 9 displays two doublets at δ = 52.1 and 4.8 ppm (small
2
the major isomer 7a on the basis of the JP,H coupling con- coupling constant 2JP,P of 2.7 Hz). In the nondecoupled 31
P
stant. For example, in the Mes*P=CHR system, the larger NMR spectrum, derivative 9 exhibits a doublet of doublets
4238
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© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2006, 4237–4241

1λ5σ3,3λ3σ2-Diphosphaallene
FULL PAPER
Solvents were dried and freshly distilled from sodium benzo-
phenone ketyl and carefully deoxygenated on a vacuum line by
several “freeze-pump-thaw” cycles. NMR spectra were recorded in
CDCl3 on the following spectrometers: 1H, Bruker Avance 300
(300.13 MHz) and Avance 400 (400.13 MHz); 13C{1H}, Bruker
Avance 300 (75.47 MHz) and Avance 400 (100.62 MHz) (reference
TMS); 31P, Bruker AC200 (81.02 MHz) and Avance 400
(162.04 MHz) (reference H3PO4). Melting points were determined
on a Wild Leitz-Biomed apparatus. Mass spectra were obtained on
a Hewlett–Packard 5989A spectrometer by EI at 70 eV.
Synthesis of Mes*P(O)=C=PMes* (1): To
Mes*P=CCl2 3 (3.15 g, 8.67 mmol) in THF (20 mL) cooled to
–80 °C was added a solution of n-butyllithium (5.7 mL, 1.6  in
a solution of
Figure 1. Structure of 8 (E) (50% probability level). Selected bond
lengths [Å] and angles [°]: P1–C1 1.650(4), P2–C1 1.822(3), P2–C2
1.828(4), P1–C20 1.847(5), P2–O1 1.510(3), P2–O2 1.550(3), P1–
C1–P2 122.3(3), O1–P2–C1 108.72(17), O2–P2–C1 107.32(18), O1– hexane, 9.1 mmol). After stirring for 1 h, the solution of
P2–C2 108.39(17), O2–P2–C2 105.60(18), C1–P2–C2 116.26(19),
C20–P1–C1–P2 168.0.
Mes*P=C(Cl)Li was transferred by cannula to a solution of
Mes*P(O)Cl2 4 (3.00 g, 8.67 mmol) in THF (30 mL) at –80 °C. The
reaction mixture became dark brown and after 15 min stirring and
subsequent warming to –20 °C, the solvent was removed under vac-
uum. Pentane (30 mL) was added to the residue and 3 and 4 dis-
solved. However 1 and LiCl precipitated due to both being very
poorly soluble in pentane. After filtration, 1 was extracted with
CH2Cl2. Removal of the solvent gave a pale yellow powder of 1
(2.01 g, 40%, m.p. 125 °C, dec.).
2
of triplets for the signal at 4.8 ppm (1JP,H = 517.4 Hz, JP,H
= 2.8 Hz, 2JP,P = 2.7 Hz), the very large 1JP,H coupling con-
stant being characteristic of a hydrogen bonded to a λ5σ4-
1
phosphorus atom. The H and 13C NMR spectra display
1
hindered rotation of the Mes* group. Dynamic H NMR
spectroscopy was performed between 253 and 323 K. The
coalescence temperatures for the o-tBu groups and for the
aromatic protons on the Mes* group bonded to the P(H)
atom are 288 K in both cases, corresponding to a rotation
barrier of 14.2 kcalmol–1 which is 2 kcalmol–1 higher than
that of the Mes* group bonded to the λ3σ2-phosphorus
atom in 1.
The carbon and phosphorus atoms are numbered as follows:
The X-ray structure of 9 (Figure 2) displays standard
bond lengths and angles.
In order to assign all the signals observed in the 1H and 13C NMR
spectra, HSQC, HMBC and selective 31P decoupling experiments
1
were performed. H NMR (CDCl3, 400.13 MHz, 213 K): δ = 1.10
(s, 9 H, H on C27–29), 1.23 (s, 9 H, H on C17–19), 1.34 (s, 9 H,
H on C13–15), 1.36 (s, 9 H, H on C31–33), 1.65 (s, 9 H, H on C35–
37), 1.79 (s, 9 H, H on C9–11), 7.27 (broad s, 1 H, H on C22), 7.37
(broad d, 4JH,P = 5.2 Hz, 1 H, H on C6), 7.46 (broad s, 1 H, H on
C24), 7.48 (broad d, 4JH,P = 6.1 Hz, 1 H, H on C4) ppm. 13C NMR
(CDCl3, 100.62 MHz): δ = 31.3 (C13–15), 31.5 (C31–33), 32.8
4
(C17–19), 33.1 (d, JC,P1 = 6.5 Hz, C27–29), 33.3 (C9–11), 33.9
3
(C35–37), 35.2 (C30), 35.5 (C12), 37.4 (C26), 38.1 (d, JC,P2
=
3
Figure 2. Structure of 9 (50% probability level). Selected bond
lengths [Å] and angles [°]: P1–C1 1.827(3), P2–C1 1.822(3), P2–C2
1.819(3), P2–C9 1.794(4), P1–C20 1.818(4), P1–O1 1.482(2), P2–
O2 1.481(2), P1–C1–P2 115.14(18), O1–P1–C1 112.78(15), O2–P2–
C1 111.13(14), O2–P2–C2 119.96(16), O1–P1–C20 120.11(14).
3.1 Hz, C16), 38.5 (C34), 38.7 (d, JC,P2 = 3.6 Hz, C8), 119.7 (d,
1JC,P2 = 127.5 Hz, C2), 121.7 (C22), 122.6 (d, JC,P2 = 13.8 Hz,
3
3
1
C6), 122.7 (C24), 122.9 (d, JC,P2 = 15.6 Hz, C4), 138.3 (dd, JC,P1
= 74.6 Hz, JC,P2 = 28.5 Hz, C20), 150.3 (C23), 152.0 (C21), 153.6
(d, JC,P2 = 6.7 Hz, C7), 153.9 (C25), 154.2 (d, JC,P2 = 11.0 Hz,
C3), 154.6 (d, JC,P2 = 2.9 Hz, C5), 227.3 (dd, JC,P1 = 47.1 Hz,
3
2
2
4
1
In conclusion, the first phosphavinylidene(oxo)phos-
1JC,P2 = 184.7 Hz, C1) ppm.
phorane 1, a derivative with three “cumulated formal
2
double bonds”, was obtained as a stable compound in the 31P NMR (CDCl3, 81.02 MHz, 298 K): δ = 117.3 (d, JP,P
=
30.5 Hz, P2), 261.4 (d, 2JP,P = 30.5 Hz, P1) ppm. MS (EI = 70 eV):
m/z (%) = 580 (1) [M]+, 565 (3) [M – Me]+, 523 (20) [M – tBu]+,
467 (5) [M – 2 tBu + 1]+, 335 (30) [M – Mes*]+, 57 (100) [tBu]+.
C37H58OP2 (580.81): calcd. C 76.51, H 10.07; found C 76.76, H
9.75. At 253 K, the signals of C21, 22, 24–26, 27–29, 34, and 35–
37 (13C NMR) and the signals of H on C22, 24, 27–29, 35–37 (1H
NMR) are too broad to be observed. At 328 K, the free rotation
of Mes* bonded to P1 occurs and the following signals may be
solid-state in a one-pot procedure. The ability of 1 to form
transition metal complexes is now under investigation.
Experimental Section
General: All experiments were carried out in flame-dried glassware
under an argon atmosphere using high-vacuum-line techniques.
Eur. J. Inorg. Chem. 2006, 4237–4241
© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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4239

H. Ranaivonjatovo, J. Escudié et al.
FULL PAPER
observed: 33.8 (C27–29 and C35–37), 37.8 (C26 and C34), 121.9
(C27–29 and C35–37), 35.3 (C30), 35.4 (C12), 37.7 (C16), 38.7 (d,
(C22 and C24) and 153.2 ppm (C21 and C25) in the 13C NMR 2JC,P2 = 6.2 Hz, C8), 39.2 (C26 and C34), 39.6 (d, 1JC,P2 = 72.1 Hz,
1
1
spectrum; 1.39 (s, C27–29 and C35–37) and 7.32 ppm (s, C22 and
C9), 40.6 (dd, JC,P1 = 55.1 Hz, JC,P2 = 50.5 Hz, C1), 118.9 (d,
1
3
C24) in the H NMR spectrum.
3JC,P2 = 14.4 Hz, C4), 123.3 (d, JC,P2 = 10.2 Hz, C6), 123.6 (d,
3JC,P1 = 11.9 Hz) and 124.1 (d, JC,P1 = 13.4 Hz) (C22 and C24),
3
Synthesis of Cyclisation Products 7a and 7b: A solution of Mes*-
P(O)=C=PMes* 1 (1.20 g, 2.01 mmol) in toluene (10 mL) was
heated at 80 °C for 1 h. NMR analysis showed the conversion of 1
into 7a and 7b in the ratio 85:15. Removal of solvent in vacuo led to
a powder of 7a,b. Attempts at fractional crystallisation in various
solvents (pentane, Et2O, CHCl3) did not allow the complete separa-
1
3
1
125.2 (dd, JC,P2 = 96.5 Hz, JC,P1 = 3.9 Hz, C2), 128.2 (d, JC,P1
= 99.0 Hz, C20), 153.6 (d, JC,P1 = 3.1 Hz, C23), 154.2 (d, JC,P2
8.1 Hz, C7), 156.0 (d, JC,P1 = 5.7 Hz, C21), 156.3 (d, JC,P2
4
2
=
=
=
2
2
4
2
33.0 Hz, C3), 156.6 (d, JC,P2 = 2.4 Hz, C5), 157.4 (d, JC,P1
11.9 Hz, C25) ppm. 31P NMR (CDCl3, 81.02 MHz, 298 K): δ = 4.8
2
1
2
(ddt, JP,P = 2.7 Hz, JP,H = 517.4 Hz, JP,H = 2.8 Hz, P1), 52.1 (d,
2JP,P = 2.7 Hz, P2) ppm. MS (EI = 70 eV): m/z (%) = 599 (2)
[M + 1]+, 581 (1) [M – O – 1]+, 541 (100) [M – tBu]+, 353 (85)
[M – Mes*]+, 57 (70) [tBu]+ C37H60O2P2 (598.82): calcd.C 74.21,
H 10.10; found C 74.56, H 9.85.
1
tion of the two isomers 7a and 7b. Selective 31P decoupled H and
13C NMR experiments were performed. At 283 K, signals of some
tBu groups were too broad to be observed by 1H NMR spec-
troscopy.
1
7a [(E) isomer]: H NMR (CDCl3, 400.13 MHz, 283 K): δ = 1.31,
Synthesis of 8a and 8b by Hydrolysis of the P(O)=C Double Bond
of 1: An excess of degassed water was added to a solution of 1
(1.15 g, 1.98 mmol) in pentane (20 mL). After stirring for 2 d at
room temperature, NMR analysis showed the formation of a mix-
ture of 7a,b and 8a,b. Attempts at crystallisation from various sol-
vents did not allow complete separation of the two derivatives and
only some single crystals of 8, suitable for an X-ray structure deter-
mination, could be obtained by crystallisation from CHCl3 and
cyclohexane. 31P NMR (CDCl3, 81.02 MHz, 298 K) 8a (30%), δ =
2
1.48 and 1.56 (3s, 27 H, H from tBu groups), 2.36 [ddd, JH,H
=
2
4
15.0 Hz, JH,P2 = 19.3 Hz, JH,P1 = 3.9 Hz, 1 H, H on C9 (carbon
atom bonded to P2)], 2.50 (dd, JH,H = 15.0 Hz, JH,P2 = 7.1 Hz,
1 H, H on C9), 7.16, 7.28, 7.36 and 7.40 (4 broad s, 4 × 1 H, arom
H), 7.58 (dd, JH,P1 = 22.3 Hz, JH,P2 = 13.8 Hz, 1 H, H on
C1) ppm. 13C NMR (CDCl3, 100.62 MHz, 283 K): δ = 31.2, 31.3
and 32.5 (C13–15, C17–19, C31–33), 34.2 (d, 4JC,P1 = 7.0 Hz, C27–
2
2
2
2
2
29, C35–37), 37.5 (C30), 38.3 (C26, C34), 39.0 (d, JC,P2 = 5.8 Hz,
C8), 40.0 (d, JC,P2 = 2.8 Hz) and 40.8 (d, JC,P2 = 3.6 Hz) (C12,
2
2
24.6 (d, 2JP,P = 47.3 Hz, PO), 305.5 ppm (dd, JP,P = 47.3 Hz, JP,H
1
3
C16), 43.7 (dd, JC,P2 = 75.9 Hz, JC,P1 = 6.0 Hz, C9), 118.7 (d,
= 24.4 Hz, P=C) 8b (70%), δ = 34.9 (2JP,P = 68.5 Hz, PO),
335.4 ppm (dd, JP,P = 68.5 Hz, JP,H = 24.4 Hz, P=C).
X-ray Structure Determinations
3JC,P2 = 13.8 Hz) and 122.8 (d, JC,P2 = 10.0 Hz, C4, C6), 122.2
(C22, C24), 127.1 (d, JC,P2 = 95.6 Hz, C2), 138.8 (dd, JC,P1
67.5 Hz, JC,P2 = 17.7 Hz, C20), 150.1 (C23), 153.4 (C21, C25),
154.2 (d, JC,P2 = 7.2 Hz) and 157.0 (d, JC,P2 = 20.2 Hz, C3, C7),
3
2
2
1
1
=
3
2
2
Crystal Data for 8 and 9. Compound 8: C43H73Cl3O2P2, M = 790.30
4
1
1
155.7 (d, JC,P2 = 2.5 Hz, C5), 165.3 (dd, JC,P2 = 74.8 Hz, JC,P1
¯
(CHCl3 and cyclohexane in the lattice), triclinic, P1, a = 13.998(2),
= 63.2 Hz, C1) ppm. 31P NMR (CDCl3, 81.02 MHz, 298 K): δ =
b = 14.106(2), c = 14.348(2) Å, α = 91.531(4), β = 119.170(3), γ =
108.678(3)°, V = 2285.6(6) Å3, Z = 2, T = 173(2) K. 9004 reflec-
tions (5491 independent, Rint = 0.0740) were collected. Largest elec-
tron density residue: 0.341 eÅ–3, R1 [for I Ͼ 2σ(I)] = 0.0565 and
2
2
2
49.3 (d, JP,P = 70.2 Hz, P2), 339.1 (dd, JP,P = 70.2 Hz, JP,H
=
24.4 Hz P1) ppm. MS (EI = 70 eV): m/z (%) = 565 (8) [M – 15]+,
523 (15) [M – tBu]+, 335 (100) [M – Mes*]+, 57 (90) [tBu]+.
1
wR2 = 0.1433 (all data) with R1 = Σ||Fo| – |Fc||/Σ|Fo| and wR2
=
7b [(Z) isomer]: H NMR (CDCl3, 400.13 MHz, 283 K): δ = 7.82
[Σw (Fo – Fc ) /Σw(Fo2)2]0.5. Compound 9: C37H60O2P2, M =
598.79, monoclinic, P21/c, a = 10.275(1), b = 25.939(2), c =
14.342(1) Å, β = 110.884(2)°, V = 3571.4(6) Å3, Z = 4, T =
173(2) K. 15676 reflections (5066 independent, Rint = 0.1213) were
collected. Largest electron density residue: 0.250 eÅ–3, R1 [for I Ͼ
2σ(I)] = 0.0558 and wR2 = 0.0943 (all data).
2
2 2
2
2
(dd, JH,P2 = 212.0 Hz, JH,P1 = 17.6 Hz, 1 H, CH=P) ppm (other
1H signals and 13C signals of the minor isomer could not be as-
signed unambiguously). 31P NMR (CDCl3, 81.02 MHz, 298 K): δ
= 38.7 (d, JP,P = 73.3 Hz, PO), 353.0 (dd, JP,P = 73.3 Hz, JP,H
21.4 Hz P=C) ppm.
2
2
2
=
Hydrolysis of 7a and 7b. Synthesis of 9: An excess of degassed water
was added to the mixture of 7a,b (0.60 g, 1.04 mmol) in Et2O. After
stirring for a week at room temperature, NMR analysis showed the
formation of 9. Et2O was removed under vacuum and recrystalli-
sation from pentane afforded pure 9 as pale yellow crystals (0.48 g,
78%, m.p. 203 °C). HSQC, HMBC, NOESY and selective 31P de-
All data for structures reported in this paper were collected at low
temperature using an oil-coated shock-cooled crystal on a Bruker-
AXS CCD 1000 diffractometer with Mo-Kα radiation (λ =
0.71073 Å). The structures were solved by direct methods
(SHELXS-97)[15] and all non-hydrogen atoms were refined aniso-
tropically using the least-squares method on F2 (SHELXL-97).[16]
1
coupled 1H and 13C NMR experiments were performed. H NMR
2
2
(CDCl3, 400.13 MHz, 253 K): δ = 0.46 (dd, JH,P2 = 6.2 Hz, JH,H
= 15.3 Hz, 1 H, H on C9, carbon atom bonded to P2), 0.90 and
1.21 (2s, 2 × 3 H, H on C10,11), 1.30 (s, 9 H, H on C13–15), 1.38
CCDC-605519 (for 8) and -605520 (for 9) contain the supplemen-
tary crystallographic data for this paper. These data can be ob-
tained free of charge from The Cambridge Crystallographic Data
Centre via www.ccdc.cam.ac.uk/data_request/cif.
(s, 9 H, H on C31–33), 1.52 and 1.65 (2s, 2 × 9 H, H on C27–29
2
and C35–37), 1.53 (s, 9 H, H on C17–19), 1.54 (dd, JH,P2
=
=
Supporting Information: (for details see the footnote on the first
page of this article): variable temperature 1H NMR, 2D HSQC and
2D HMBC, 13C{1H,31P} and 13C{1H} Jmod spectra of diphos-
phaallene Mes*P(O)=C=PMes* (1), variable-temperature 1H
NMR spectra of bis(phosphane oxide)methylene 9.
2
2
20.4 Hz, JH,H = 15.3 Hz, 1 H, H on C9), 2.43 (dddd, JH,P1
2
2
3
15.0 Hz, JH,P2 = 7.2 Hz, JH,H = 15.3 Hz, JH,H = 7.1 Hz, 1 H, H
2
2
2
on C1), 3.30 (dt, JH,P1 and JH,P2 = 16.6 Hz, JH,H = 15.3 Hz, 1
H, H on C1), 7.07 (dd, 4JH,P2 = 2.0 Hz, JH,H = 1.0 Hz, 1 H, H on
4
C4), 7.41 (dd, 4JH,P2 = 5.2 Hz, 4JH,H = 1.0 Hz, 1 H, H on C6), 7.45
4
4
(dd, JH,P1 = 2.0 Hz, JH,H = 1.0 Hz, 1 H, H on C22), 7.54 (dd,
4JH,P1 = 4.1 Hz, JH,H = 1.0 Hz, 1 H, H on C24), 8.52 (ddd, JH,P1
4
1
Acknowledgments
3
3
= 517.4 Hz, JH,P2 = 2.8 Hz, JH,H = 7.1 Hz, 1 H, H on P1) ppm.
13C NMR (CDCl3, 100.62 MHz, 253 K): δ = 31.2 (C13–15), 31.4 We thank the CNRS and the Ministry of Foreign Affairs [AI Bran-
(C31–33), 31.9 and 33.5 (C10–11), 32.2 (C17–19), 33.6 and 34.3 cusi no. 08581TK (Fr) and 18015 (Ro)]. R. S. thanks ERASMUS/
4240
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Eur. J. Inorg. Chem. 2006, 4237–4241

1λ5σ3,3λ3σ2-Diphosphaallene
FULL PAPER
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Received: April 27, 2006
Published Online: August 7, 2006
Eur. J. Inorg. Chem. 2006, 4237–4241
© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
4241