Synthesis and structure of potassium and samarium phosphine(phosphinimino) methanides

Article abstract of DOI:10.1021/om049409d

The monoanionic phosphine(phosphinimino)methanide ligand (Ph ₂PCHPPh₂NSiMe₃)^- is introduced in organometallic chemistry. Starting from the established compound Ph ₂PCH₂-PPh₂NSiMe₃ (1) the potassium salt [K(Ph₂PCHPPh₂NSiMe₃)]_n (2) was prepared. The solid state structure of 2 shows a η³-N-P-C heteroallyl coordination of the ligand as well as a π-coordination of the phenyl rings to the potassium atoms, These coordination modes lead to an infinite chain in the solid state. Compound 2 was further reacted to the samarium complex [(η⁵-C₅Me₅) ₂Sm(Ph₂PCHPPh₂NSiMe₃)], in which the (Ph₂PCHPPh₂NSiMe₃)- ligand coordinates in η³-heteroallylic fashion via the N atom and the methine group to the center metal.

Full text of DOI:10.1021/om049409d

5540
Organometallics 2004, 23, 5540-5544
Synthesis and Structure of Potassium and Samarium
Phosphine(phosphinimino)methanides
Michael T. Gamer and Peter W. Roesky*
Institut fu¨r Chemie, Freie Universita¨t Berlin, Fabeckstrasse 34-36, 14195 Berlin, Germany
Received July 30, 2004
The monoanionic phosphine(phosphinimino)methanide ligand (Ph2PCHPPh2NSiMe3)- is
introduced in organometallic chemistry. Starting from the established compound Ph2PCH2-
PPh2NSiMe3 (1) the potassium salt [K(Ph2PCHPPh2NSiMe3)]n (2) was prepared. The solid
state structure of 2 shows a η3-N-P-C heteroallyl coordination of the ligand as well as a
π-coordination of the phenyl rings to the potassium atoms. These coordination modes lead
to an infinite chain in the solid state. Compound 2 was further reacted to the samarium
complex [(η5-C5Me5)2Sm(Ph2PCHPPh2NSiMe3)], in which the (Ph2PCHPPh2NSiMe3)- ligand
coordinates in η3-heteroallylic fashion via the N atom and the methine group to the center
metal.
Scheme 1
Introduction
Phosphinimines and phosphinimides have been
used as popular ligands in main group and transi-
tion metal chemistry in recent years. Lately, the
deprotonated derivatives of the well-known bis-
reported by Cavell and co-workers to form carbene-
like complexes with a series of transition metals.9,14
{CH(PPh2NSiMe3)2}- tends to show an uncommon
coordination mode. In most of the solid state structures
the methine carbon atom coordinates via a long interac-
tion onto the metal atom.8-13 Thus, the six-membered
metallacycle (N1-P1-C1-P2-N2-M), which is formed
by chelation of the two trimethlysilylimine groups to the
metal center, adopts a pseudo-boat conformation (Scheme
1). Motivated by these results we were interested to get
some insight into the coordination chemistry of the
deprotonated derivate of the related phosphine-phos-
phinimine Ph2PCH2PPh2NSiMe3 (1).15 In the heterodi-
functional compound 1 one of the phosphorus atoms is
in oxidation state +3 whereas the other one is in +5.
1 is available via a Staudinger reaction from bis-
(diphenylphosphino)methane (dppm) and trimethylsilyl
azide (Scheme 2).15 Previously 1 was used either as a
ligand in late transition metal chemistry16 or as a
precursor for the formation of phoshoranimine com-
plexes (Ph2PCH2PPh2N-M).17 The latter compounds
were obtained via the cleavage of the N-SiMe3 bond.
To the best of our knowledge no anionic derivative of
1
(phosphinimine) CH2(PPh2NSiMe3)2 have drawn the
attention by a number of research groups. It was
shown that a monoanionic2-5 and a dianionic species6,7
({CH(PPh2NSiMe3)2}- and {C(PPh2NSiMe3)2}2-, respec-
tively) can be generated by deprotonation of the pre-
cursor CH2(PPh2NSiMe3)2. The monoanionic species
was used as a ligand in main group and transition
metal chemistry,8-13 whereas the dianionic ligand was
(1) Appel, R.; Ruppert, I. Z. Anorg. Allg. Chem. 1974, 406, 131-
144.
(2) Imhoff, P.; Guelpen, J. H.; Vrieze, K.; Smeets, W. J. J.; Spek, A.
L.; Elsevier, C. J. Inorg. Chim. Acta 1995, 235, 77-88.
(3) (a) Avis, M. W.; van der Boom, M. E.; Elsevier, C. J.; Smeets,
W. J. J.; Spek, A. L. J. Organomet. Chem. 1997, 527, 263-276. (b)
Avis, M. W.; Elsevier, C. J.; Ernsting, J. M.; Vrieze, K.; Veldman, N.;
Spek, A. L.; Katti, K. V.; Barnes, C. L. Organometallics 1996, 15, 2376-
2392. (c) Avis, M. W.; Vrieze, K.; Kooijman, H.; Veldman, N.; Spek, A.
L.; Elsevier, C. J. Inorg. Chem. 1995, 34, 4092-4105. (d) Imhoff, P.;
van Asselt, R.; Ernsting, J. M.; Vrieze, K.; Elsevier, C. J.; Smeets, W.
J. J.; Spek, A. L.; Kentgens, A. P. M. Organometallics 1993, 12, 1523-
1536.
(4) Gamer, M. T.; Roesky, P. W. Z. Anorg. Allg. Chem. 2001, 627,
877-881.
(5) Kamalesh Babu, R. P.; Aparna, K.; McDonald, R.; Cavell, R. G.
Inorg. Chem. 2000, 39, 4981-4984.
(6) Kasani, A.; Kamalesh Babu, R. P.; McDonald, R.; Cavell, R. G.
Angew. Chem. 1999, 111, 1580-1582; Angew. Chem., Int. Ed. 1999,
38, 1483-1484.
(13) A related ligand: (a) Hill, M. S.; Hitchcock, P. B. Dalton Trans.
2003, 4570-4571. (b) Hill, M. S.; Hitchcock, P. B. Chem. Commun.
2003, 1758-1759.
(7) Ong, C. M.; Stephan, D. W. J. Am. Chem. Soc. 1999, 121, 2939-
2940.
(8) (a) Ong, C. M.; McKarns, P.; Stephan, D. W. Organometallics
1999, 18, 4197-4208. (b) Wei, P.; Stephan, D. W. Organometallics
2002, 21, 1308-1310. (c) Wei, P.; Stephan, D. W. Organometallics
2003, 22, 601-604.
(9) (a) Kasani, A.; Kamalesh Babu, R. P.; McDonald, R.; Cavell, R.
G. Organometallics 1999, 18, 3775-3777. (b) Aparna, K.; McDonald,
R.; Fuerguson, M.; Cavell, R. G. Organometallics 1999, 18, 4241-4243.
(10) (a) Gamer, M. T.; Dehnen, S.; Roesky, P. W. Organometallics
2001, 20, 4230-4236. (b) Gamer, M. T.; Roesky, P. W. J. Organomet.
Chem. 2002, 647, 123-127.
(11) Sarsfield, M. J.; Helliwell, M.; Collison, D. Chem. Commun.
2002, 2264-2265.
(12) Leung, W.-P.; So, C.-W.; Wang, J.-Z.; Mak, T. C. W. Chem.
Commun. 2003, 248-249.
(14) (a) Kamalesh Babu, R. P.; McDonald, R.; Decker, S. A.;
Klobukowski, M.; Cavell, R. G. Organometallics 1999, 18, 4226-4229.
(b) Cavell, R. G.; Kamalesh Babu, R. P.; Kasani, A.; McDonald, R. J.
Am. Chem. Soc 1999, 121, 5805-5806. (c) Kamalesh Babu, R. P.;
McDonald, R.; Cavell, R. G. Chem. Commun. 2000, 481-482. (d)
Kasani, A.; Furguson, M.; Cavell, R. G. J. Am. Chem. Soc. 2000, 112,
726-727.
(15) (a) Katti, K. V.; Cavell, R. G. Inorg. Chem. 1989, 28, 413-416.
(b) Schmidtbaur, H.; Bowmaker, G. A.; Kumberger, O.; Mu¨ller, G.;
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10.1021/om049409d CCC: $27.50 © 2004 American Chemical Society
Publication on Web 10/05/2004

Phosphine(phosphinimino)methanides
Organometallics, Vol. 23, No. 23, 2004 5541
Table 1. Crystallographic Details of
[K(Ph2PCHPPh2NSiMe3)]n (2) and
Scheme 2
[(η5-C5Me5)2Sm(Ph2PCHPPh2NSiMe3)] (3)a
2‚(toluene)
2 3‚(toluene)
formula
fw
space group
a, Å
b, Å
c, Å
C
63H68K2N2P4Si2
C
103H128N2P4Si2Sm2
1111.45
P1h (No. 2)
12.087(2)
12.676(3)
20.777(4)
77.86(3)
86.31(3)
85.86(3)
3100.2(11)
2
1874.84
P21/c (No. 14)
22.4232(8)
14.8800(8)
14.846(2)
composition (Ph2PCHPPh2NSiMe3)- has been reported.
On the other hand the coordination chemistry of some
main group metals of the somewhat related ligand
(Me3SiCHPPh2NSiMe3)- was reported by Lappert et
al.18 Herein we describe the synthesis of the potas-
sium compound [K(Ph2PCHPPh2NSiMe3)]n and a fur-
ther reaction to the samarium complex [(η5-C5Me5)2Sm-
(Ph2PCHPPh2NSiMe3)].
R, deg
â, deg
γ, deg
V, Å3
109.289(8)
4675.4(6)
4
1.332
Ag KR
(λ ) 0.56086 Å)
0.743
Z
density (g/cm3)
radiation
1.191
Ag KR
(λ ) 0.56086 Å)
0.176
none
18 293
µ, mm-1
absorp corr
no. of reflns
collected
no. of unique
reflns
no. of obsd reflns
GOF on F2
R1b; wR2c
none
27 984
Experimental Section
10 479 [Rint
0.1271]
4052
0.873
0.0824; 0.1890
)
12 919 [Rint
0.0523]
9135
1.036
0.0421; 0.1170
)
General Procedures. All manipulations of air-sensitive
materials were performed with the rigorous exclusion of
oxygen and moisture in flame-dried Schlenk-type glassware
either on a dual manifold Schlenk line, interfaced to a high-
vacuum (10-4 Torr) line, or in an argon-filled M. Braun
glovebox. Ether solvents (THF and ethyl ether) were predried
over Na wire and distilled under nitrogen from K (THF) or
Na wire (ethyl ether) as well as benzophenone ketyl prior to
use. Hydrocarbon solvents (toluene and n-pentane) were
distilled under nitrogen from LiAlH4. All solvents for vacuum
line manipulations were stored in vacuo over LiAlH4 in
resealable flasks. Deuterated solvents were obtained from
Chemotrade Chemiehandelsgesellschaft mbH (all g 99 atom
% D) and were degassed, dried, and stored in vacuo over
Na/K alloy in resealable flasks. NMR spectra were recorded
on a Bruker AC 250 or JNM-LA 400 FT-NMR spectrometer.
Chemical shifts are referenced to internal solvent resonances
and are reported relative to tetramethylsilane and 85%
phosphoric acid (31P NMR), respectively.
c
a All data collected at 203 K. bR1 ) ∑|Fo| - |Fc||/∑|Fo|. wR2 )
{∑[w(Fo - Fc )2]/∑[w(Fo2)2]}1/2
.
2
2
[K(Ph2PCHPPh2NSiMe3)]n (2). To a suspension of 0.69 g
(17.2 mmol) of KH in THF was slowly added 5.37 g (11.4 mmol)
of 1 dissolved in 40 mL of THF at room temperature. The
mixture was refluxed for 6 h. Then, the unreacted KH was
filtered off and the filtrate was concentrated in vacuo to
dryness. The remaining residue was crystallized from toluene.
1
Yield: 3.86 g (67%), colorless powder. H NMR (d8-THF, 400
MHz, 20 °C): δ -0.21 (s, 9H, SiMe3), 1.59 (dd, 1H, P2CH,
2J(H,PIII) ) 14.13 Hz, 2J(H,PV) ) 6.79 Hz), 6.98-7.02 (m, 2H,
Ph), 7.07-7.14 (m, 10H, Ph), 7.50-7.54 (m, 4H, Ph), 7.70-
7.76 (m, 4H, Ph). 13C{1H} NMR (d8-THF, 100.4 MHz, 20 °C):
δ 4.3 (dd, SiMe3, J(C,PV) ) 4.0 Hz, J(C,PIII) ) 0.9 Hz), 21.2
3
5
(dd, PCP, J(C,PV) ) 138.4 Hz, J(C,PIII) ) 3.5 Hz), 126.2 (s,
p-PhPIII), 127.7 (d, m-PhPV, 3J(C,PV) ) 10.7 Hz), 128.0 (d,
m-PhPIII, 3J(C,PIII) ) 5.8 Hz), 128.6 (d, p-PhPV, 4J(C,PV) ) 2.5
1
1
Ph2PCH2PPh2NSiMe3 (1). To a suspension of 5.0 g (13.0
mmol) of bis(diphenylphosphino)methane in 15 mL of toluene
was added 2 mL (1.72 g, 14.9 mmol) of trimethylsilyl azide.
The mixture was refluxed for 12 h. Then, the solvent and
unreacted trimethylsilyl azide were removed in vacuo at 100
°C. The remaining oily residue was treated with 20 mL of
pentane and dried in vacuo. Then, the resulting suspension
was filtered and the solvent removed. The remaining solid was
washed with n-pentane (2 × 10 mL) and dried in vacuo.
Usually the resulting raw product can be used for subsequent
reactions without further purification. A pure product is
obtained by crystallization from hot toluene (in this case the
yield decreases by about 30%). Yield: 5.37 g (88%), colorless
powder. 1H NMR (C6D6, 250 MHz, 25 °C): δ 0.14 (s, 9H,
SiMe3), 2.95 (dd, 1H, CH2, 2J(H,P) ) 11.85 Hz, 2J(H,P) ) 11.86
Hz), 7.00-7.05 (m, 12H, Ph), 7.38-7.45 (m, 4H, Ph), 7.60-
Hz), 132.4 (d, o-PhPIII, J(C,PIII) ) 9.9 Hz), 132.6 (d, o-PhPV,
2
2J(C,PV) ) 17.7 Hz), 147.1 (dd, i-PhPV, 1J(C,PV) ) 90.7 Hz,
3J(C,PIII) ) 3.6 Hz ), 151.4 (dd, i-PhPIII, J(C,PIII) ) 12.0 Hz,
1
3J(C,PV) ) 9.1 Hz ). 29Si NMR (d8-THF, 79.4 MHz, 20 °C): δ
-15.6. 31P{1H} NMR (d8-THF, 161.7 MHz, 20 °C): δ -15.2 (d,
2J(P,P) ) 136.3 Hz), 21.7 (d, 2J(P,P) ) 136.3 Hz). Anal. Calcd
for C28H30KNP2Si (509.68): C 65.98, H 5.93, N 2.75. Found:
C 65.77, H 6.12, N 2.78.
[(η5-C5Me5)2Sm(Ph2PCHPPh2NSiMe3)] (3). THF (20 mL)
was condensed at -196 °C onto a mixture of 250 mg (1.0 mmol)
of SmCl3 and 500 mg (1.0 mmol) of 2. The mixture was stirred
for 18 h at room temperature. The solvent was then evaporated
in a vacuum, and 349 mg (2.0 mmol) KC5Me5 was added to
the remaining solid. Again, 20 mL of THF was condensed at
-196 °C onto the mixture, and the suspension was stirred for
18 h at room temperature. The solvent was then evaporated
in a vacuum and toluene (20 mL) condensed onto the mixture.
Then, the solution was shortly heated under reflux and
filtered, and the solvent was removed. The remaining solid
was washed with n-pentane (10 mL) and dried in a vacuum.
Finally, the product was crystallized from hot toluene. Yield:
7.69 (m, 4H, Ph). 29Si NMR (C6D6, 49.7 MHz, 25°C):
δ
-11.8. 31P{1H} NMR (C6D6, 101.3 MHz, 25 °C): δ -26.7 (d,
2
2J(P,P) ) 56.4 Hz), -2.1 (d, J(P,P) ) 56.4 Hz). Anal. Calcd
for C28H31NP2Si (471.59): C 71.31, H 6.63, N 2.97. Found: C
71.22, H 6.55, N 2.89. EI/MS (70 eV) m/z (%): 471 ([M]+, rel
int 90), 456 ([M- Me]+, 100), 394 ([C22H26NP2Si]+, 93), 272
([C15H19NPSi]+, 72), 199 ([C13H12P]+, 64).
72 mg (23%). Anal. Calcd for C48H60NP2SiSm (891.40):
64.68, H 6.78, N 1.57. Found: C 64.39, H 6.63, N 1.61.
X-ray Crystallographic Studies of 2 and 3. Crystals of
2 and 3 were grown from hot toluene. A suitable crystal was
covered in mineral oil (Aldrich) and mounted onto a glass fiber.
The crystal was transferred directly to the -73 °C cold N2
C
(17) (a) Katti, K. V.; Cavell, R. G. Inorg. Chem. 1989, 28, 3033-
3036. (b) Katti, K. V.; Cavell, R. G. Organometallics 1991, 10, 539-
541. (c) Katti, K. V.; Santarsiero, B. D., Pickerton, A. A.; Cavell, R. G.
Inorg. Chem. 1993, 32, 5919-5925.
(18) (a) Hitchcock, P. B.; Lappert, M. F.; Wang, Z.-X. Chem.
Commun. 1997, 1113-1114. (b) Hitchcock, P. B.; Lappert, M. F.;
Uiterweerd, P. G. H.; Wang, Z.-X. Dalton Trans. 1999, 3413-3417.

5542 Organometallics, Vol. 23, No. 23, 2004
Gamer and Roesky
Scheme 3
Table 2. Selected Bond Lengths (Å) and Angles
(deg) of [K(Ph2PCHPPh2NSiMe3)]n (2)
stream of a Stoe IPDS diffractometer. Subsequent computa-
tions were carried out on a Intel Pentium III PC.
Bond Lengths
Bond Angles
All structures were solved by the Patterson method
(SHELXS-9719). The remaining non-hydrogen atoms were
located from successive difference Fourier map calculations.
The refinements were carried out by using full-matrix least-
squares techniques on F, minimizing the function (Fo - Fc)2,
N1-K1
2.799(6)
3.166(7)
3.170(7)
3.233(8)
3.218(8)
3.414(8)
1.724(6)
1.739(7)
1.574(6)
2.798(6)
3.002(7)
3.496(7)
3.394(8)
3.329(9)
3.384(9)
3.424(9)
3.491(8)
1.697(7)
1.752(7)
1.587(5)
N1-P1-C1
118.1(3)
56.2(2)
C1-K1
C14-K1
C15-K1
C34-K1
C35-K1
C1-P1
N1-K1-C1
P1-C1-P2
N2-P3-C29
N2-K2-C29
P3-C29-P4
122.5(4)
115.9(3)
57.3(2)
2
2
where the weight is defined as 4Fo /2(Fo ) and Fo and Fc are
the observed and calculated structure factor amplitudes using
the program SHELXL-97.20 In the final cycles of each refine-
ment, all non-hydrogen atoms except C4-C6, C22-C24,
C39-C41, C53-C56, and the toluene molecules in 2 and the
toluene molecules in 3 were assigned anisotropic temperature
factors. Carbon-bound hydrogen atom positions were calcu-
lated and allowed to ride on the carbon to which they are
bonded assuming a C-H bond length of 0.95 Å. The hydrogen
atom contributions were calculated, but not refined. The final
values of refinement parameters are given in Table 1. The
locations of the largest peaks in the final difference Fourier
map calculation as well as the magnitude of the residual
electron densities in each case were of no chemical significance.
Positional parameters, hydrogen atom parameters, thermal
parameters, bond distances, and angles have been deposited
as Supporting Information. Crystallographic data (excluding
structure factors) for the structures reported in this paper have
been deposited with the Cambridge Crystallographic Data
Centre as supplementary publication nos. CCDC-245811 (2)
and 245812 (3). Copies of the data can be obtained free of
charge on application to CCDC, 12 Union Road, Cambridge
CB21EZ, UK (fax: (+(44)1223-336-033; e-mail: deposit@
ccdc.cam.ac.uk).
124.8(4)
C1-P2
N1-P1
N2-K2
C29-K2
C2-K2’
C3-K2’
C4-K2’
C5-K2’
C6-K2’
C7-K2’
C29-P3
C29-P4
N2-P3
N-P-C backbone in a heteroallylic fashion onto the
potassium atom. Thus, K1 is η3-coordinated by the
N1-P1-C1 and K2 by the N2-P3-C29 unit. Inside
these units the angles are N1-P1-C1 118.1(3)° and
N2-P3-C29 115.9(3)°. The distances of these units to
the potassium atoms are N1-K1 2.799(6) Å, N2-K2
2.798(6) Å, C1-K1 3.166(7) Å, and C29-K2 3.002(7) Å
and the N-K-C bite angles are N1-K1-C1 56.2(2)°
and N2-K2-C29 57.3(2)°.
Results and Discussion
Besides the heteroallyl coordination of the ligand,
π-coordination of the phenyl rings to the potassium
atoms is observed. The coordination number of the
potassium atom depends strongly on the considered
length of the C-K interaction. In Figure 1 all C-K
interactions up to a range of 3.5 Å are marked as
dotted lines. By using the criteria, K1 is η2-coordi-
nated in an intramolecular fashion by one of the phenyl
rings, which is bound to P2. Furthermore a η3-coordina-
tion is observed to a phenyl ring of a neighboring
(Ph2PCHPPh2NSiMe3)- ligand. In contrast K2 is in-
tramolecular η1-coordinated by one of the phenyl rings,
which is bound to P4. Additionally, an intramolecular
η6-coordination to one of the phenyl rings, which is
attached to P1, is seen. Here, the average C-K distance
of these interactions is 3.420(8) Å.
Next, we were interested to learn about the coordina-
tion behavior of the (Ph2PCHPPh2NSiMe3)- ligand in
lanthanide chemistry. To get a reliable comparison with
other ligands in lanthanide chemistry, we wanted to
synthesize a metallocene complex. In a one-pot reaction
starting from SmCl3 and the potassium salt 2 followed
by an addition of KC5Me5 the metallocene complex
[(η5-C5Me5)2Sm(Ph2PCHPPh2NSiMe3)] (3) was obtained
(Scheme 3). Compound 3 is an air- and moisture-
The neutral phosphine-phosphinimine ligand
Ph2PCH2PPh2NSiMe3 (1), was prepared as described in
the literature from bis(diphenylphosphino)methane
(dppm) and trimethylsilyl azide (Scheme 2). However,
compared to the reported procedure15 we used different
reaction conditions to obtain a pure product in high
yields. Treatment of 1 with KH in boiling THF followed
by crystallization from hot toluene leads to the desired
potassium reagent [K(Ph2PCHPPh2NSiMe3)]n (2) in
moderate yields (Scheme 3). The new complex has been
characterized by standard analytical/spectroscopic tech-
niques, and the solid state structure was established
by single-crystal X-ray diffraction. Data collection pa-
rameters and selected bond lengths and angles are
given in Tables 1 and 2. Compound 2, which crystal-
lizes in the triclinic space group P1h with two mole-
cules of toluene, forms infinite chains in the solid
state (Figure 1). In the unit cell there are two different
[K(Ph2PCHPPh2NSiMe3)] units. In both units the
(Ph2PCHPPh2NSiMe3)- ligand coordinates via the
(19) Sheldrick, G. M. SHELXS-97, Program of Crystal Structure
Solution; University of Go¨ttingen: Germany, 1997.
(20) Sheldrick, G. M. SHELXL-97, Program of Crystal Structure
Refinement; University of Go¨ttingen: Germany, 1997.

Phosphine(phosphinimino)methanides
Organometallics, Vol. 23, No. 23, 2004 5543
Figure 1. Perspective ORTEP view of the molecular structure of 2. Thermal ellipsoids are drawn to encompass 30%
probability. Hydrogen atoms are omitted for clarity. Shown is one unit out of an infinite chain.
atom in a chelating heteroallylic (η3) fashion. Whereas
compound 3 is to the best of our knowledge the first
lanthanide compound having a η3-N-P-C heteroallyl
ligand, other heteroallyl systems such as benzamidi-
nates,21 diiminosulfates,22 and diiminophosphinates23
are established in lanthanide chemistry.24 The unusual
point in compound 3 is the phosphorus atom (P2) in
oxidation state +3, which points away from the center
metal. It may be possible to attach other transition
metals at this position onto 3. The bite angle of the
ligand in 3 (N-Sm-C1 63.41(10)°) is in the ex-
pected range (62.94(13)° in [{Ph2P(NSiMe3)2}2Sm-
(µ-I)2Li(THF)2]).23b The corresponding bond distances
C1-Sm (2.698(3) Å) and N-Sm (2.478(3) Å) differ
by more than 0.2 Å. Both distances are in agreement
with other samarium amido (e.g., Sm-N in [(η5-C5Me5)2-
Sm{η2-N(PPh2)2}], 2.430(3) Å)25 and allyl complexes
Figure 2. Perspective ORTEP view of the molecular
(e.g., Sm-C in the allyl complex [(η5-C5Me5)2Sm-
structure of 2. Thermal ellipsoids are drawn to en-
(η3-CH2CHCH2)] (2.63(2) and 2.64(2) Å).26 The Cg-Sm
compass 50% probability. Hydrogen atoms are omitted for
clarity.
(Cg
) C5Me5-ring centroids) distances (Cg1-Sm
2.514(9) Å, Cg2-Sm 2.509(6) Å, respectively) and the
angle Cg1-Sm-Cg2 (130.77(10)°) are in the expected
range.25-27
Table 3. Selected Bond Lengths (Å) and Angles
(deg) of [(η5-C5Me5)2Sm(Ph2PCHPPh2NSiMe3)] (3)a
Bond Lengths Bond Angles
Summary
C1-P1
1.753(3)
1.820(3)
2.698(3)
1.612(3)
1.738(3)
2.478(3)
2.514(9)
2.509(6)
N-Sm-C1
63.41(10)
108.2(2)
116.0(2)
88.49(12)
138.2(2)
133.0(2)
99.85(12)
127.1(2)
130.77(10)
116.04(10)
114.68
C1-P2
C1-Sm
N-P1
N-P1-C1
In summary, we have introduced the (Ph2PCHPPh2-
NSiMe3)- ligand in organometallic chemistry. Start-
ing from Ph2PCH2PPh2NSiMe3 the potassium salt
[K(Ph2PCHPPh2NSiMe3)]n was prepared and further
reacted to the samarium complex [(η5-C5Me5)2Sm-
(Ph2PCHPPh2NSiMe3)]. The (Ph2PCHPPh2NSiMe3)-
P1-C1-P2
P1-C1-Sm
P2-C1-Sm
P1-N-Si
P1-N-Sm
Si1-N-Sm
Cg1-Sm-Cg2
Cg1-Sm-N
Cg1-Sm-C1
N-Si
N-Sm
Cg1-Sm
Cg2-Sm
(21) Edelmann, F. T. Coord. Chem. Rev. 1994, 137, 403-481.
(22) Kno¨sel, F.; Noltemeyer, M.; Edelmann, F. T. Z. Naturforsch, B
1989, 44, 1171-1174.
a
Cg ) C5Me5-ring centroid.
(23) (a) Reissmann, U.; Poremba, P.; Noltemeyer, M.; Schmidt, H.-
G.; Edelmann, F. T. Inorg. Chim. Acta 2000, 303, 156-162. (b)
Recknagel, A.; Steiner, A.; Noltemeyer, M.; Brooker, S.; Stalke, D.;
Edelmann, F. T. J. Organomet. Chem. 1991, 414, 327-335. (c)
Recknagel, A.; Witt, M.; Edelmann, F. T. J. Organomet. Chem. 1989,
371, C40-C44.
sensitive compound, which has been characterized by
single-crystal X-ray diffraction and elemental analysis.
The solid state structure of 3 was investigated by
single-crystal X-ray diffraction (Figure 2). Data collec-
tion parameters and selected bond lengths and angles
are given in Tables 1 and 3. The structure reveals a
pseudo 4-fold coordination sphere of the ligands around
the samarium atom. The (Ph2PCHPPh2NSiMe3)- ligand
is coordinated via the atoms N-P1-C1 to the samarium
(24) Edelmann, F. T. Top. Curr. Chem. 1996, 179, 113-148.
(25) Gamer, M. T.; Canseco-Melchor, G.; Roesky, P. W. Z. Anorg.
Allg. Chem. 2003, 629, 2113-2116.
(26) Evans, W. J.; Ulibarri, T. A.; Ziller, J. W. J. Am. Chem. Soc.
1990, 112, 2314-2324.
(27) Evans, W. J.; Ulibarri, T. A. J. Am. Chem. Soc. 1987, 109,
4292-4297.

5544 Organometallics, Vol. 23, No. 23, 2004
Gamer and Roesky
ligand always coordinates in η3-heteroallylic fashion via
the N atom and the methine group.
port from Prof. Dr. D. Fenske (Universita¨t Karlsruhe)
is gratefully acknowledged.
Supporting Information Available: X-ray crystallo-
graphic files in CIF format for the structure determinations
of 2 and 3 are available free of charge via the Internet at
http://pubs.acs.org.
Acknowledgment. This work was supported by the
Deutsche Forschungsgemeinschaft (DFG Schwerpunk-
tprogramm 1166: Lanthanoidspezifische Funktionali-
ta¨ten in Moleku¨l und Material) and the Fonds der
Chemischen Industrie. Additionally, the generous sup-
OM049409D