Unexpected P-Si or P-C bond cleavage in the reaction of Li2[(C5Me4)SiMe2PR] (R = Cyclohexyl, 2,4,6-Me3C6H2) and Li[(C5H4)CMe2PHR] (R = Ph, t

Article abstract of DOI:10.1021/om990763z

The (phosphinosilyl)cyclopentadiene 1-SiMe₂PHMes-2,3,4,5-Me₄C₅H, prepared from 1-SiMe₂-Cl-2,3,4,5-Me₄C₅H and LiPHMes (Mes = 2,4,6-Me₃C₆H₂), reacts with MeLi

Full text of DOI:10.1021/om990763z

2556
Organometallics 2000, 19, 2556-2563
Un exp ected P -Si or P -C Bon d Clea va ge in th e Rea ction
of Li2[(C5Me4)SiMe2P R] (R ) Cycloh exyl, 2,4,6-Me3C6H2)
t
a n d Li[(C5H4)CMe2P HR] (R ) P h , Bu ) w ith Zr Cl4 or
[TiCl3(th f)3]: F or m a tion a n d Molecu la r Str u ctu r e of th e
a n sa -Meta llocen es [{(η-C5Me4)2SiMe2}Zr Cl2] a n d
[{(η-C5H4)2CMe2}MCl2] (M ) Ti, Zr )†
Thomas Koch, Steffen Blaurock, Fernando B. Somoza, J r., Andreas Voigt,
Reinhard Kirmse, and Evamarie Hey-Hawkins*
Institut fu¨r Anorganische Chemie der Universita¨t, D-04103 Leipzig, Germany
Received September 28, 1999
The (phosphinosilyl)cyclopentadiene 1-SiMe2PHMes-2,3,4,5-Me4C5H, prepared from 1-SiMe2-
Cl-2,3,4,5-Me4C5H and LiPHMes (Mes ) 2,4,6-Me3C6H2), reacts with MeLi to yield Li2[(C5-
Me4)SiMe2PMes] (2). The (phosphinomethyl)cyclopentadienide Li[(C5H4)CMe2PHtBu] (4) is
obtained by the reaction of LiPHtBu with 6,6-dimethylfulvene. Li2[(C5Me4)SiMe2PR] (R )
cyclohexyl (Cy; 1), Mes (2)) reacts in situ with ZrCl4 at -30 °C to give [{(η-C5Me4)2SiMe2}-
ZrCl2] (5). The formation of (PCy)4 and (PHMes)2, respectively, in these reactions was shown
t
by 31P NMR spectroscopy. In the reaction of Li[(C5H4)CMe2PHR] (R ) Ph (3), Bu (4)) with
ZrCl4 or [TiCl3(thf)3], [{(η-C5H4)CMe2PHR}2ZrCl2] (R ) Ph (6), tBu (7)) and [{(η-C5H4)CMe2-
t
PHR}2TiCl] (R ) Ph (9), Bu (10)) are formed. 6, 7, 9, and 10 slowly decompose on
recrystallization from thf, Et2O, or toluene with formation of [{(η-C5H4)2CMe2}MCl2] (M )
t
Zr (8), Ti (11)). The formation of (PR)n (R ) Ph, n ) 4-6; R ) Bu, n ) 4) and PH2R was
shown by 31P NMR spectroscopy. 2, 4, 5-8, and 11 were characterized by NMR spectroscopy
(1H, 13C, 31P) and the paramagnetic Ti(III) complexes 9 and 10 by EPR spectroscopy and
mass spectrometry. 5, 8, and 11 were also characterized by crystal structure determinations.
In tr od u ction
After the discovery of R-olefin polymerization by
Ziegler,1 a vast number of metallocene and monocyclo-
pentadienyl derivatives with different steric and elec-
tronic properties was prepared and employed as cata-
lysts in polymerization reactions.
ansa-Metallocene dichlorides of Ti, Zr, and Hf (espe-
cially chiral ones; A in Figure 1) are important catalysts
for the methylalumoxane (MAO)-promoted isotactic
polymerization of olefins. Therefore, intensive research
is being conducted toward synthesis of improved
catalysts.2-5
F igu r e 1. Selected examples of group 4 cyclopentadienyl
complexes.
Recently, monocyclopentadienyl derivatives in which
the cyclopentadienyl ring has a heteroatom-functional-
ized side chain (B in Figure 1), were prepared and
employed in the polymerization of olefins and copolym-
erization of ethylene with propylene, 1-hexene, 1-octene
or styrene.6 These studies were also extended to phos-
pholyl ligands (C in Figure 1).7
† Parts of this work were presented as a poster at the XVIII
International Conference on Organometallic Chemistry, Munich,
Germany, Aug 16-22, 1998; Abstract No. A223.
(1) Ziegler, K.; Holzkamp, E.; Breil, H.; Martin, H. Angew. Chem.
1955, 67, 541.
(2) Schneider, N.; Huttenloch, M. E.; Stehling, U.; Kirsten, R.;
Schaper, F.; Brintzinger, H. H. Organometallics 1997, 16, 3413 and
references therein.
(3) Kaminsky, W.; Rabe, O.; Schauwienold, A.-M.; Schupfner, G. U.;
Hanss, J .; Kopf, J . J . Organomet. Chem. 1995, 497, 181.
(4) Chacon, S. T.; Coughlin, E. B.; Henling, L. M.; Bercaw, J . E. J .
Organomet. Chem. 1995, 497, 171.
(5) (a) Kaminsky, W.; Ku¨lper, K.; Brintzinger, H. H.; Wild, F. R. W.
P. Angew. Chem. 1985, 97, 507; Angew. Chem., Int. Ed. Engl. 1985,
24, 507. (b) Brintzinger, H. H.; Fischer, D.; Mu¨lhaupt, R.; Rieger, B.;
Waymouth, R. M. Angew. Chem. 1995, 107, 1255; Angew. Chem., Int.
Ed. Engl. 1995, 34, 1143. (c) Fink, G.; Mu¨lhaupt, R.; Brintzinger, H.
Ziegler CatalystssRecent Scientific Innovations and Technological
Improvements; Springer-Verlag: Berlin, Heidelberg, New York, 1995.
(6) (a) Shapiro, P. J .; Bunel, E.; Schaefer, W. P.; Bercaw, J . E.
Organometallics 1990, 9, 867. (b) Shapiro, P. J .; Cotter, W. D.; Schaefer,
W. P.; Labinger, J . A.; Bercaw, J . E. J . Am. Chem. Soc. 1994, 116,
4623. (c) Flores, J . C.; Chien, J . C. W.; Rausch, M. D. Organometallics
1994, 13, 4140. (d) Alt, H. G.; Fo¨ttinger, K.; Milius, W. J . Organomet.
Chem. 1999, 572, 21. (e) Galan-Fereres, M.; Koch, T.; Hey-Hawkins,
E.; Eisen, M. J . Organomet. Chem. 1999, 580, 145. (f) McKnight, A.
L.; Waymouth, R. M. Chem. Rev. 1998, 98, 2587. (g) Canich, J . A. M.
Eur. Pat. 420 436, 1991. (h) Schmidt, G. F.; Timmers, F. J .; Knight,
G. W.; Lai, S.-Y.; Nickias, P. N.; Rosen, R. K.; Stevens, J . C.; Wilson,
D. R. Eur. Pat. 416 815, 1991.
10.1021/om990763z CCC: $19.00 © 2000 American Chemical Society
Publication on Web 05/31/2000

Unexpected P-Si or P-C Bond Cleavage
Organometallics, Vol. 19, No. 13, 2000 2557
While numerous O- and N-functionalized cyclopen-
tadienyl ligands are known, the number of cyclopenta-
dienes with a P-functionalized alkyl or silyl side chain
is still small, and we have recently reported on the first
compounds in which the P atom has a reactive phos-
phorus-substituent bond (e.g., P-H).8,9 Such com-
pounds should be useful precursors for dianionic bifunc-
tional ligands in transition-metal chemistry. In addition,
the presence of a P-containing group is advantageous
for reactivity studies by 31P NMR spectroscopy.10
We now report unexpected P-Si or P-C bond cleav-
age in the reactions of Li2[(C5Me4)SiMe2PR] (R )
cyclohexyl (Cy; 1),8 2,4,6-Me3C6H2 (Mes, 2)) with ZrCl4
and of Li[(C5H4)CMe2PHR] (R ) Ph (3),8 tBu (4)) with
ZrCl4 or [TiCl3(thf)3], which give the ansa-metallocenes
[{(η-C5Me4)2SiMe2}ZrCl2] (5) and [{(η-C5H4)2CMe2}-
MCl2] (M ) Zr (8), Ti (11)). 5, 8, and 11 were character-
ized by spectroscopy and by crystal structure determi-
nation. While the ansa-metallocene 5 has been reported
before,11 its structure was unknown up to now.
(thf)2] and the dimetalated ligand in low yield (15%);11
this is a general preparative method for ansa-metal-
locenes of Ti, Zr, and Hf.2,3,4,11
In the reaction of 3 or 4 with ZrCl4 (Scheme 1) or
[TiCl3(thf)3] (Scheme 2), the formation of [{(η-C5H4)CMe2-
PHR}2ZrCl2] (R ) Ph (6), Bu (7)) as pale yellow solids
Resu lts a n d Discu ssion
t
Syn th esis. The general synthetic method for intro-
duction of a cyclopentadienyl ligand into Zr or Ti com-
plexes is salt elimination. We therefore prepared the
(phosphanidosilyl)cyclopentadienides Li2[(C5Me4)SiMe2-
PR] (R ) Cy (1),8 Mes (2)) from 1-SiMe2PHR-2,3,4,5-
Me4C5H and MeLi at -50 °C in thf. The neutral
(phosphinosilyl)cyclopentadienes were obtained from
(dimethylchlorosilyl)tetramethylcyclopentadiene and
LiPHR at -80 °C followed by distillation. The (phos-
phinomethyl)cyclopentadienides Li[(C5H4)CMe2PHR]
(R ) Ph (3),8 tBu (4)) were obtained by the reaction of
LiPHR with 6,6-dimethylfulvene in Et2O.
and of [{(η-C5H4)CMe2PHR}2TiCl] (R ) Ph (9), tBu (10))
as dark-green solids was observed. However, these
compounds decompose slowly on recrystallization from
thf, Et2O, or toluene with formation of [{(η-C5H4)2-
CMe2}MCl2] (M ) Zr (8), Ti (11)). The Ti compound that
is presumably formed in addition to 11 could not be
isolated. The decomposition is not influenced by light.
13
The formation of cyclooligophosphanes (PR)n and
PH2R in this reaction was shown by 31P NMR spectros-
copy.
For 6, the decomposition to 8 was studied in more
detail. 6 was suspended in d8-toluene (in which it is only
slightly soluble), and d8-thf was added until a clear
solution had formed. The decomposition was studied by
1H NMR spectroscopy. After 3 days at room tempera-
ture, the ratio of complexes 6 and 8 was 5:1, while at
50 °C, the ratio was 7:1 after 4 h. Complete formation
of 8 from 6 had occurred after 8 days at room temper-
ature. As the decomposition is spontaneous in methanol,
6 was dissolved in methanol, and the decomposition
products were analyzed by GC-MS. Besides products
which stem from a reaction with methanol, signals for
phenylphosphine (m/z 110, high intensity), PhPdCMe2
(m/z 150, medium intensity), and (PPh)4 (m/z 429,
medium intensity) were observed. While this experi-
ment shows that neither propene nor polypropylene is
formed, the mechanism of the formation of 5, 8, and 11
is still speculative.
After treating 1 and 2 with ZrCl4 (ratio 1:1), we were,
however, unable to isolate the expected cyclopentadienyl
derivatives [{(η-C5Me4)SiMe2PR}MCl2]; instead, the
ansa-metallocene [{(η-C5Me4)2SiMe2}ZrCl2] (5) was ob-
tained after recrystallization from thf in good yield. The
12,13
14
formation of (PCy)4
or (PHMes)2 in this reaction
(eq 1) was shown by 31P NMR spectroscopy. The Si
compound which must have been formed could not be
characterized by 29Si NMR spectroscopy. These results
are contrary to what was originally described by Dow
Chemical Co. in a patent application. There, the reaction
between the related dilithio salt Li2[(C5Me4)SiMe2PPh]
and TiCl4 or ZrCl4 was reported to give the expected
products [{(η-C5Me4)SiMe2PPh}MCl2], but no analytical
or spectroscopic data were reported to support this
assumption.6h 5 was previously prepared from [ZrCl4-
The Ti(III) complexes 9 and 10 are highly air-
sensitive. Brief exposure of toluene solutions to minute
traces of oxygen apparently also triggers the quantita-
tive formation of 11.
A stable zirconocene derivative with [(diarylphosphi-
no)isopropyl]cyclopentadienyl ligands, namely, [{(η-
C5H4)CMe2PR2}2ZrCl2] (R ) p-tolyl, Ph), has been
reported.15
(7) (a) Brown, S. J .; Gao, X.; Harrison, D. G.; Koch, L.; Spence, R.
E. V. H.; Yap, G. P. A. Organometallics 1998, 17, 5445. (b) Mathey, F.
Chem. Rev. 1998, 88, 429. (c) J aniak, C.; Lange, K. C. H.; Versteeg,
U.; Lentz, D.; Budzelaar, P. Chem. Ber. 1996, 129, 1517. (d) J aniak,
C.; Versteeg, U.; Lange, K. C. H.; Weimann, R.; Hahn, E. J . Organomet.
Chem. 1995, 501, 219.
(8) Koch, T.; Hey-Hawkins, E. Polyhedron 1999, 18, 2113 and
references therein.
(9) Slone, C. S.; Weinberger, D. A.; Mirkin, C. A. Prog. Inorg. Chem.
1999, 48, 233.
(10) Berger, S.; Braun, S.; Kalinowski, H. D. NMR Spectroscopy;
Thieme Verlag: Stuttgart, Germany, 1993; Vol. 3 (31P NMR Spectros-
copy).
(11) J utzi, P.; Dickbreder, R. Chem. Ber. 1986, 119, 1750.
(12) Bart, J . C. J . Acta Crystallogr. 1969, 25B, 762.
(13) Baudler, M.; Glinka, K. Chem. Rev. 1993, 93, 1623.
(14) Kurz, S.; Oesen, H.; Sieler, J .; Hey-Hawkins, E. Phosphorus,
Sulfur Silicon Relat. Elem. 1996, 117, 189.
The complexes 6, 7, 9, and 10 were characterized by
IR and 31P NMR spectroscopy (the signals are only
slightly broadened for 9 and 10), 6 and 7 were also
(15) Bosch, B. E.; Erker, G.; Fro¨hlich, R.; Meyer, O. Organometallics
1997, 16, 5449.

2558 Organometallics, Vol. 19, No. 13, 2000
Koch et al.
Sch em e 1
F igu r e 2. Experimental (a) and simulated (b) X-band EPR
spectra of 10 in toluene at 295 K. The low-field part is
additionally increased in intensity by a factor of 5.
Sch em e 2
F igu r e 3. Experimental (a) and simulated (b) X-band EPR
spectra of 10 in toluene at 130 K.
spectrum (in C6D6), which is shifted to low field relative
to 3 and 4 (6, 17.1 ppm (1J P-H ) 206.0 Hz); 7, 42.3 ppm
1
(1J P-H ) 193.8 Hz); 9, 18.4 ppm (d, J P-H ) 212.0 Hz);
1
10, 38.6 ppm (d, J P-H ) 195.0 Hz); 3, -1.20 ppm (d of
1
3
3
two q, J P-H ) 207.5 Hz, J P-H ) 11.4 Hz and J P-H
)
15.8 Hz);8 4, -26.0 ppm (d of two dec, J P-H ) 189.9
Hz, J P-H ) 11.0 Hz)).
1
3
For 6 and 7, molecular ion peaks were observed in
the mass spectra, confirming their composition.
EP R Sp ectr a of [{(η-C5H4)CMe2P HR}2TiCl] (R )
t
P h (9), Bu (10)). For both Ti(III) complexes 9 and 10
intense EPR signals were observed. The room-temper-
ature EPR spectrum of 10 is shown in Figure 2 together
with its simulation. It consists of an intense doublet due
to the interaction of the unpaired electron with one 31P
nucleus (nuclear spin I ) 1/2). Each of the doublet lines
is symmetrically flanked by a hyperfine sextet resulting
from the 47Ti nucleus (I ) 5/2, natural abundance 7.4%)
and a hyperfine octet caused by the 49Ti nucleus (I )
7/2, natural abundance 5.4%). Because of the similarity
of the nuclear properties of the two Ti isotopes,16 for
each “31P hyperfine line” an octet with the intensity ratio
0.7:1.9:1.9:1.9:1.9:1.9:1.9:0.7 was expected and observed.
However, the intense “31P doublet” prevents the obser-
vation of the “inner” lines (Figure 2) of the 47,49Ti
hyperfine pattern.
Figure 3 shows the EPR spectrum of 10 in a frozen
solution (T ) 130 K) together with its simulation. The
spectrum is rhombic-symmetric, like that recorded for
studied by 1H NMR spectroscopy. The paramagnetic
complexes 9 and 10 were also characterized by mass
spectrometry and studied by EPR spectroscopy (vide
infra). 6, 7, 9, and 10 exhibit a doublet in the 31P NMR
(16) BRUKER Almanac; Bruker Analytic GmbH: Rheinstetten/
Karlsruhe, Germany, 1999.

Unexpected P-Si or P-C Bond Cleavage
Organometallics, Vol. 19, No. 13, 2000 2559
Ta ble 1. EP R P a r a m eter sa for
[{(η-C5H4)CMe2P HP h }2TiCl] (9)b a n d
[{(η-C5H4)CMe2P HtBu }2TiCl] (10)c
4), where R2P is the overall spin density on the P atom
and amounts to R2P ) 1.4%.
(cPs )2 ) R2P(1 - n2)
(cPp )2 ) R2Pn2
(4)
tensor
component
tensor
component
9
10
9
10
A1P
A2P
A3P
For the degree of hybridization n2 a value of 0.71 was
obtained, which is close to that expected for a distorted
tetrahedrally coordinated P atom. This corresponds to
the structure proposed for the Ti(III) complex under
study.
g1
g2
g3
2.006 2.007
1.990 1.992
1.975 1.975
1.990 1.991
1.989 1.990
14.5 14.8
15.2 15.4
18.4 18.9
16.0 16.4
16.3 16.9
P
d
d
gav
Aav
a0P
solvent
g0
aT0 i
a
To our knowledge, up to now, 31P hfs interactions were
only observed for the Ti(III) complex [Cp2TiMe(PPh3)].20
The observed isotropic 31P hfs coupling constant of
aP0 ) 17.6 × 10-4 cm-1 is close to those obtained by us.
Unfortunately, no anisotropic 31P hfs data were re-
ported,20 so that no conclusions can be drawn about the
overall spin density and the degree of hybridization n2
on the P atom.
9.8
9.6
thf
toluene
Hyperfine coupling constants are given in 10-4 cm-1
.
gi
b
(0.004; ATi i,P (1.0. c gi (0.002; ATi,P (0.5. gav ) (g1 + g2 + g3)/3;
d
i
APav ) (A1P + AP2 + A3P)/3.
9. All spectra can be described with the spin Hamilto-
nian (2), with S ) 1/2; all other symbols have their usual
meaning.
Similar properties were observed by Xin et al. for
[(Cp2Ti)2(µ-H)(µ-PCy2)].21 This Ti(III) complex exhibits
no EPR signal at 253 K; this indicates the presence of
diamagnetic species. At room temperature, the EPR
Hsp ) g‚µB‚S‚B0 + S‚AP‚IP + S‚ATi‚ITi
(2)
spectrum shows an intense singlet (g0 ) 1.9808, aTi
)
In Table 1 the principal values obtained for the g
tensor and the 31P and 47,49Ti hyperfine structure ()hfs)
tensors AP and ATi are listed. Anisotropic 47,49Ti hfs
couplings were observed in the frozen-solution spectra,
but unfortunately they could not be analyzed in detail
because (i) the line widths of the frozen-solution spectra
are 2.5 times larger than those observed in liquid
solution, (ii) the intensity of the Ti satellite lines is low
(<2% of the major signals), and (iii) the small g tensor
anisotropy results in excessive line overlap, which
prevents an unambiguous analysis of the observed
47,49Ti satellites. In addition, 47,49Ti hfs coupling param-
eters so far observed17 are small and lie only in the
range of (10-20) × 10-4 cm-1. In our case (compound
10) a maximum Ti hfs coupling constant of about 18 ×
10-4 cm-1 can be estimated, which we ascribe to ATz i.
The hfs parameters can be used to estimate the spin
density on the nuclei and, therefore, allow conclusions
to be made about the nature of the M-L bonds, in
particular the hybridization of the orbitals.18,19 For this,
0
9.43 G). No 31P hfs interaction was observed.
Because of the lack of a complete parameter set for
the 47,49Ti hyperfine tensor ATi, only a rough estimate
of the spin density on the metal atom can be made. From
the isotropic Ti hfs coupling and by using eq 3a and
Ti
av,theor
a
) 260.8 × 10-4 cm-1 19
,
a Ti 4s contribution of
3.7% can be calculated. To estimate the Ti 3d contribu-
tion, we assume the observed maximum Ti hfs coupling
constant of about 18 × 10-4 cm-1 as being the axial
component ATz i of the Ti hfs tensor. Then, from ATz i
-
aT0 i ) 2b, a b value of 4.2 × 10-4 cm-1 was obtained.
With bXtheor ) 7 × 10-4 cm-1 19
,
eq 3 yields a Ti 3d
contribution of about 60%. Therefore, roughly 65% of
the unpaired spin density is located on the metal. Since
the spin density determined for the coordinating P atom
is small, the residual spin density is expected to be
located on the Cl and Cp ligands.
Molecu la r St r u ct u r es of [{(η-C5Me4)2SiMe2}-
Zr Cl2] (5) a n d [{(η-C5H4)2CMe2}MCl2] (M ) Zr (8),
Ti (11)). Compound 5 was obtained as pale green
crystals from thf and crystallizes in the monoclinic space
group C2/c (Figure 4). Complex 8 was obtained as yellow
crystals on recrystallizing 6 or 7 from thf after several
days. Accordingly, 11 is obtained on recrystallizing 9
or 10 from thf after several days as dark red crystals. 8
(Figure 5) and 11 (Figure 6) are isotypic and isostruc-
tural and crystallize in the monoclinic space group
P21/m.
In 5, the Zr atom and the Si atom of the SiMe2 bridge
are located on a crystallographic C2 axis which gener-
ates the atoms “a”. In 8 and 11, the metal atom (Zr or
Ti) as well as Cl(1), Cl(2), and the C atoms of the CMe2
bridge (C(1), C(2), C(3)) are located on a crystallographic
mirror plane, by which the atoms “a” are generated. A
comparison of 5, 8, and 11 with related ansa-metal-
locenes is given in Tables 2 and 3, respectively. The Zr-
Cl and Si-C bond lengths of 5 are in the range observed
for related complexes (Table 2). The Zr-CEN distance
the complete parameters of the hfs tensors are needed.
The spin densities (csX,p,d
)
can then be obtained by
2
using eqs 3a,b, where s, p, and d represent atomic
(csX)2 ) aXav,exptl/aXav,theor
(cXp,d)2 ) bXexptl/btXheor
(3a)
(3b)
orbitals, X is the nucleus under discussion, aXav is the
isotropic hyperfine coupling constant, and bX is the
dipolar part of the hyperfine tensors. For the 31P nucleus
the complete tensor has been obtained. Using the values
for the parameters aXav,theor and btXheor calculated by
Morton and Preston19 and eqs 3a,b gave the following
spin densities for the 31P 3s and 3p orbitals: (cPs )2 )
0.004 and (cPp )2 ) 0.010. The latter values can be used
to estimate the 3s/3p hybridization of the P atom (eq
(17) Bajgur, C. S.; Tikkanen, W. R.; Petersen, J . L. Inorg. Chem.
1985, 24, 2539.
(18) Kirmse, R.; Stach, J . ESR-Spektroskopie-Anwendungen in der
Chemie; Akademie-Verlag: Berlin, 1985; pp 86-95.
(19) Morton, J . R.; Preston, K. F. J . Magn. Reson. 1978, 30, 577.
(20) Klei, E.; Teuben, J . H. J . Organomet. Chem. 1980, 188, 97.
(21) Xin, S.; Woo, H. G.; Harrod, J . F.; Samuel, E.; Lebuis, A. J .
Am. Chem. Soc. 1997, 119, 5307.

2560 Organometallics, Vol. 19, No. 13, 2000
Koch et al.
F igu r e 6. Molecular structure of [{(η-C5H4)2CMe2}TiCl2]
(11) showing the atom-numbering scheme employed (ORTEP
plot, 50% probability, SHELXTL PLUS; XP32). Hydrogen
atoms are omitted for clarity.
F igu r e 4. Molecular structure of [{(η-C5Me4)2SiMe2}ZrCl2]
(5) showing the atom-numbering scheme employed (ORTEP
plot, 50% probability, SHELXTL PLUS; XP32). Hydrogen
atoms are omitted for clarity.
solvent (benzene); external standard, TMS. 13C NMR: external
standard, TMS; internal standard, solvent. 31P NMR: external
standard, 85% H3PO4. The IR spectra were recorded on a FT-
IR spectrometer Perkin-Elmer System 2000 in the range 350-
4000 cm-1. GC-MS: Hewlett-Packard HP 6890 GC, HP 5973
MSD (mass selective detector). EPR spectra were recorded in
the X-band (ν ≈ 9.5 GHz) with a Bruker ESP 300E spectrom-
eter in the temperature range 295 K g T g 130 K by using
about 10-3 M solutions of 9 (thf) and 10 (toluene). The EPR
parameters were obtained by using the computer program
Win-EPR-SimFonia.28 The melting points were determined in
sealed capillaries under argon and are uncorrected. Li2[(C5-
Me4)SiMe2PCy] (1),8 Li[(C5H4)CMe2PHPh] (3),8 [TiCl3(thf)3],29
and 1-SiMe2Cl-2,3,4,5-Me4C5H30 were prepared according to
the literature procedures. ZrCl4 is commercially available.
Syn th esis of 1-SiMe2P HMes-2,3,4,5-Me4C5H (2a ). LiPH-
Mes (3.50 g, 22.2 mmol) was suspended in a mixture of
n-hexane (50 mL) and Et2O (5 mL) and cooled to -80 °C.
(Dimethylchlorosilyl)tetramethylcyclopentadiene (4.83 g, 22.5
mmol) was added, and the reaction mixture was warmed to
ambient temperature. The mixture was stirred for 3 days, after
which the yellow color of the lithium phosphanide had disap-
peared completely. The mixture was filtered, the solvent
evaporated in vacuo, and the resulting yellow oil distilled
under reduced pressure (100-115 °C, 2‚10-3 Torr), giving 2.2
F igu r e 5. Molecular structure of [{(η-C5H4)2CMe2}ZrCl2]
(8) showing the atom-numbering scheme employed (ORTEP
plot, 50% probability, SHELXTL PLUS; XP32). Hydrogen
atoms are omitted for clarity.
1
g (30%) of 2a as a yellow oil. H NMR (C6D6): δ 6.76 (s, 2H,
1
m-H in Mes), 3.30 (d, 1H, PH, J P-H ) 211.4 Hz), 2.86 (s, 1H,
C5HMe4), 2.33 (s, 6H, o-CH3 in Mes), 2.10 (s, 3H, p-CH3 in
(22) Herrmann, W. A.; Rohrmann, J .; Herdtweck, E.; Spaleck, W.;
Winter, A. Angew. Chem. 1989, 101, 1536; Angew. Chem., Int. Ed. Engl.
1989, 28, 1511.
(23) Spaleck, W.; Antberg, M.; Rohrmann, J .; Winter, A.; Bachmann,
B.; Kiprof, P.; Behm, J .; Herrmann, W. A. Angew. Chem. 1992, 104,
1371; Angew. Chem., Int. Ed. Engl. 1992, 31, 1345.
(24) Razavi, A.; Atwood, J . L. J . Organomet. Chem. 1995, 497, 105.
(25) Willoughby, C. A.; Davis, W. M.; Buchwald, S. L. J . Organomet.
Chem. 1995, 497, 11.
is about 0.1 Å larger. As no data for the CMe2-C(Cp)
bond lengths are given in the literature, the bond
lengths of C(1)-C(4) and C(1)-C(4A) of 1.532(3) Å in 8
and 11 cannot be compared with known values (Table
3). Of the reported complexes, 8 has the smallest CEN-
Zr-CEN bite angle (116.7°).
(26) Smith, J . A.; von Seyerl, J .; Huttner, G.; Brintzinger, H. H. J .
Organomet. Chem. 1979, 173, 175.
(27) Nifant’ev, I. E.; Churakov, A. V.; Urazowski, I. F.; Mkoyan, Sh.
G.; Atovmyan, L. O. J . Organomet. Chem. 1992, 435, 37.
(28) Weber, R. T. WIN-EPR-SimFonia, Version 1.2; EPR Division,
Bruker Instruments Inc., 1995.
Exp er im en ta l Section
All experiments were carried out under purified dry argon.
Solvents were dried and freshly distilled under argon. The
NMR spectra were recorded at 25 °C in C6D6 with an AVANCE
DRX 400 spectrometer (Bruker), 1H NMR: internal standard,
(29) Manzer, L. F. Inorg. Synth. 1982, 21, 135.
(30) Plenio, H. Chem. Ber. 1991, 124, 2185.

Unexpected P-Si or P-C Bond Cleavage
Organometallics, Vol. 19, No. 13, 2000 2561
Ta ble 2. Com p a r ison of Selected Bon d Len gth s (Å) a n d An gles (d eg) of 5 w ith Th ose of Rela ted
Silylen e-Br id ged Zir con ocen e Dich lor id e Com p lexes
CEN-Zr- C(Cp)-Si-
compd
Zr-C
Si-C(Cp)
Zr-CEN Cl-Zr-Cl
2.238 97.35(4)
CENa
128.1
C(Cp)
ref
rac-[{(2-methyltetrahydrobenz[e]indenyl)2-
SiMe2}ZrCl2]
2.4100(7)
1.876(3)
95.6(2)
2
rac-[({bis(4,5,6,7-tetrahydroindenyl)}SiMe2)ZrCl2] 2.444, 2.440
b
b
2.226, 2.225 97.3
2.236, 2.236 97.2
2.233, 2.233 97.6(3)
126.3
129.5
126.7
b
b
3
3
4
[({bis(2,4,7-trimethylindenyl)}SiMe2)ZrCl2]
2.414, 2.414
2.435(1),
2.422(1)
2.435(1)
2.431(1)
2.419
rac-[{(2-SiMe3-4-But-C5H2)2SiMe2}ZrCl2]
1.872(3),
1.879(3)
1.866(4)
1.871(1)
b
94.0(1)
[{(η-C5H4)2SiMe2}ZrCl2]
2.197
2.293
2.244
2.329
97.98(4)
98.76(1)
99.06
125.4
119.0
128.1
128.6
93.2(2)
94.57(6) 22
94.3(1)
95.7(1)
17
rac-[({bis(indenyl)}SiMe2)ZrCl2]
rac-[({bis(2-methylindenyl)SiMe2})ZrCl2]
[{(η-C5Me4)2SiMe2}ZrCl2] (5)
23
this work
2.4334(7)
1.887(2)
99.28(3)
a
b
CEN ) center of the cyclopentadienyl ring. No value given.
Ta ble 3. Com p a r ison of Selected Bon d Len gth s (Å) a n d An gles (d eg) of 8 a n d 11 w ith Th ose of Rela ted
Meth ylen e-Br id ged Tita n ocen e a n d Zir con ocen e Dich lor id e (a n d Dim eth yl) Com p lexes
CEN-M- C(Cp)-C-
compd
M-Cl
Cbr-C(Cp)
M-CEN
Cl-M-Cl
CENa
C(Cp)
ref
[Me2C{(3-But-C5H3)-9-fluorenyl}ZrCl2]
[Me2C{(3-Me-C5H3)-9-fluorenyl}ZrCl2] 2.425(3), 2.403(3)
[cyclo-C6H10(η-C5H4)(4,5,6,7-tetrahydro- 2.346(2), 2.338(2)
indenyl)})TiCl2]
2.420, 2.420
b
b
b
2.184, 2.245
2.16, 2.26
2.07, 2.08
96.2
99.1
97.6(1)
118.5
118.6
121.8
b
98.4
96.3(4)
3
24
25
[{(η-C5H4)2CH2}TiCl2]
2.33(1), 2.34(1)
1.53(5)
1.465(6)
1.441(6)
2.05, 206
b
b
97.2(3)
121
99(2)
b
b
99.5(2)
96.6(2)
26
27
27
[{(η-C5H4)2CMe2}TiMe2]
[{(η-C5H4)2CMe2}ZrMe2]
[{(η-C5H4)2CMe2}ZrCl2] (8)
[{(η-C5H4)2CMe2}TiCl2] (11)
120.9
115.9
116.7
121.6
2.4321(8), 2.4406(8) 1.532(3) 2.213
2.333(1), 2.352(1)
100.25(3)
98.04(4)
this work
this work
1.532(3) 2.193
a
b
CEN ) center of the cyclopentadienyl ring. No value given.
Mes), 1.97 (s, 6H, CH3 in C5Me4), 1.84 (s, 6H, CH3 in C5Me4),
perature for 12 h. Then the solvent was removed in vacuo and
the residue washed with 20 mL of pentane. The resulting
yellow powder was recrystallized from thf, yielding 0.72 g of
5 (82% relative to 1) as pale green crystals. The product
0.17 (d, 6H, SiMe2, 3J P-H ) 5.0 Hz). 31P NMR (C6D6): δ -168.6
1
(d, J P-H ) 212.0 Hz). EI-MS: m/z 328 (25) [M+], 179 (100)
[(CH3)4C5Si(CH3)2+], 151 (85) [PHMes+], and fragmentation
thereof. Anal. Calcd for C20H31SiP (328.51): C, 72.7; H, 9.4;
P, 9.4. Found: C, 67.3 (lower due to silicon carbide formation);
H, 9.0; P, 9.2.
(PCy)4 (31P NMR (C6D6): δ -68.4 s) was detected by H and
13
1
31P NMR spectroscopy.
(b) F r om Zr Cl4 a n d Li2[(C5Me4)SiMe2P Mes] (2). Alter-
natively, 5 was obtained from ZrCl4 (1.00 g, 4.4 mmol) in 30
mL of toluene and Li2[(C5Me4)SiMe2PMes] (2; 1.50 g, 4.4 mmol)
in 25 mL of thf at -30 °C. Yield: 1.41 g (70% relative to 2).
Syn th esis of Li2[(C5Me4)SiMe2P Mes] (2). 2a (2.2 g, 6.7
mmol) was dissolved in thf (50 mL), and at -50 °C an MeLi
solution (8.9 mL of a 1.5 M solution in Et2O) was added slowly.
The mixture was then brought to ambient temperature and
refluxed for 5 h. The compound was used without further
purification. 31P NMR (thf/ C6D6): δ -181.2 br, s.
The product (PHMes)2 (31P NMR (C6D6): δ -111.1, meso
14
isomer; -118.5, d and l isomer) was detected by 1H and 31P
NMR spectroscopy.
1H and 13C NMR (in CDCl3) are in agreement with the
literature values.11 In C6D6, the signals are shifted slightly:
1H NMR δ 2.07 (s, 12H, C5Me4), 1.79 (s, 12H, C5Me4), 0.61 (s,
6H, SiMe2).
Syn th esis of Li[(C5H4)CMe2P HtBu ] (4). 6,6-Dimethylful-
vene (1.34 g, 12.6 mmol) was added to a suspension of LiPHtBu
(1.21 g, 12.6 mmol) in Et2O (30 mL), and the reaction mixture
was stirred for 12 h. The resulting solid was isolated by
filtration and washed twice with n-hexane to yield 4 as a pale
yellow powder (1.5 g, 58%). Mp: 120 °C dec. 1H NMR (thf-d8):
δ 6.06 (s, 2H, CH in C5H4), 6.00 (s, 2H, CH in C5H4), 3.57 (d,
Syn th esis of a n sa -{Dim eth ylm eth a n ylbis(cyclop en ta -
d ien yl)}zir con iu m Dich lor id e (8). (a ) F r om Zr Cl4 a n d Li-
[(C5H4)CMe2P HP h ] (3). A 1.30 g (5.6 mmol) amount of ZrCl4
was suspended in 50 mL of toluene, and a solution of 1.24 g
(5.6 mmol) of Li[(C5H4)CMe2PHPh] (3) in 20 mL of thf was
added dropwise at -50 °C. The solution turned dark red
immediately. The reaction mixture was stirred at room tem-
perature for 12 h. Then the solvent was removed in vacuo and
the residue washed with 50 mL of pentane. The resulting pale
yellow powder exhibits a doublet in the 31P NMR spectrum
(C6D6) at 17.1 ppm (1J P-H ) 206.0 Hz), which is consistent with
the presence of the complex [{(η-C5H4)CMe2PHPh}2ZrCl2] (6).
On recrystallization from thf, 6 decomposed over several days
with formation of 8. Yield: 1.17 g of 8 (61% relative to 3) as
1
3
1H, P-H, J P-H ) 199.2 Hz), 1.82 (d, 3H, C(CH3)2, J P-H
)
3
14.2 Hz), 1.80 (d, 3H, C(CH3)2, J P-H ) 14.3 Hz), 1.16 (d, 9H,
C(CH3)3, J P-H ) 10.6 Hz). 13C NMR (thf-d8): δ 132.23 (d,
3
ipso-C in C5H4, 2J P-C ) 8.5 Hz), 103.39 (C3, C4 in C5H4), 102.46
3
2
(d, C2, C5 in C5H4, J P-C ) 3.3 Hz), 39.53 (d, C-CH3, J P-C
)
10.3 Hz), 35.33 (d, C(CH3)2, 1J P-C ) 15.6 Hz), 34.08 (d, C(CH3)3,
1J P-C ) 15.1 Hz), 33.52 (d, C-CH3, 2J P-C ) 11.7 Hz), 31.89 (d,
C(CH3)3, J P-C ) 12.7 Hz). 31P NMR (thf, C6D6): δ 26.0 (d of
2
two dec, J P-H ) 189.9 Hz, J P-H ) 11.0 Hz). 7Li NMR (thf-
d8): δ -4.6, s. IR (KBr): ν (cm-1): 2282 m (ν(PH)), 1606 br, m
(Cp, ν(CdC)). Anal. Calcd for C12H20PLi (202.20): C, 71.3; H,
10.0; P, 15.3. Found: C, 70.9; H, 9.8; P, 15.9. Recrystallization
from Et2O gave colorless crystals.
1
3
13
yellow crystals. The products (PPh)n (n ) 4-6) and PH2Ph
were detected by 31P NMR spectroscopy (C6D6: δ -4.0 (m,
(PPh)5), -26.4 (s, (PPh)6), -47.7 (s, (PPh)4), -123.8 (t, PH2-
Syn th esis of a n sa -{Dim eth ylsilylbis(tetr a m eth ylcyclo-
p en ta d ien yl)}zir con iu m Dich lor id e (5). (a ) F r om Zr Cl4
a n d Li2[(C5Me4)SiMe2P Cy] (1). A 0.76 g (3.3 mmol) amount
of ZrCl4 was suspended in 30 mL of toluene, and a solution of
1.00 g (3.3 mmol) of Li2[(C5Me4)SiMe2PCy] (1) in 25 mL of thf
was added dropwise at -30 °C. The solution turned dark red
immediately. The reaction mixture was stirred at room tem-
1
Ph, J P-H ) 197 Hz)).
(b) F r om Zr Cl4 a n d Li[(C5H4)CMe2P HtBu ] (4). Alterna-
tively, 8 was obtained from ZrCl4 (1.10 g, 4.7 mmol) in 50 mL
of toluene and Li[(C5H4)CMe2PHtBu] (4; 0.95 g, 4.7 mmol) in
20 mL of Et2O at -50 °C. The solution turned dark red
immediately. The reaction mixture was stirred at room tem-

2562 Organometallics, Vol. 19, No. 13, 2000
Koch et al.
Ta ble 4. Cr ysta l Da ta a n d Str u ctu r e Refin em en t
Deta ils for 5, 8, a n d 11
perature for 24 h. Then the solvent was removed in vacuo and
the residue washed with 25 mL of pentane. The resulting pale
yellow powder exhibits a doublet in the 31P NMR spectrum
(C6D6) at 42.3 ppm (1J P-H ) 193.8 Hz), consistent with the
presence of the complex [{(η-C5H4)CMe2PHtBu}2ZrCl2] (7). On
recrystallization from thf, 7 slowly decomposed over several
days with formation of 8. Yield: 1.2 g of 8 (75% relative to 4)
5
8
11
formula
Mr
C
20H30Cl2SiZr C13H14Cl2Zr
C13H14Cl2Ti
289.04
460.65
332.38
temp (K)
cryst syst
space group
a (Å)
b (Å)
c (Å)
220(2)
monoclinic
213(2)
monoclinic
220(2)
monoclinic
as yellow crystals. The products (PtBu)4 and PH2 Bu were
13
t
C2/c (No. 15) P21/m (No. 11) P21/m (No. 11)
detected by 31P NMR spectroscopy (C6D6: δ -32.4 (s, ?), -59.0
15.454(3)
12.219(2)
11.135(2)
105.05(3)
2030.5(6)
2
7.118(1)
8.831(1)
10.163(1)
90.49(1)
638.84(3)
2
7.102(2)
8.604(4)
9.967(3)
90.67(2)
609.0(3)
2
t
1
(s, (PtBu)4), -80.1 (t, PH2 Bu, J P-H ) 174 Hz)).
[{(η-C5H4)CMe2P HP h }2Zr Cl2] (6). 1H NMR (thf-d8): δ 7.36
(m, 2H, Ph), 7.28 (m, 2H, Ph), 7.10-6.93 (m, 6H, Ph), 6.03 (m,
â (deg)
V (Å3)
3
1H, CH in C5H4), 5.99 (t, 1H, CH in C5H4, J H-H ) 2.7 Hz),
Z
3
Fcalcd (Mg m-3
F(000)
)
1.507
952
1.790
344
1.576
296
5.95 (t, 1H, CH in C5H4, J H-H ) 2.7 Hz), 5.88 (t, 1H, CH in
3
3
C5H4, J H-H ) 2.7 Hz), 5.85 (m, 1H, CH in C5H4, J H-H ) 3.5
Hz), 5.79 (m, 1H, CH in C5H4), 5.77 (m, 1H, CH in C5H4), 5.73
cryst size (mm) 0.5 × 0.4 × 0.3 0.5 × 0.4 × 0.3 0.4 × 0.2 × 0.1
abs coeff (mm-1
2θmax (deg)
no. of rflns
collected
)
0.864
4.3-56.1
10942
1.251
4.0-55.5
3565
1.108
4.1-54.7
2666
1
(m, 1H, CH in C5H4), 4.00 (d, 2H, P-H, J P-H ) 207.3 Hz),
3
3
1.11 (d, 6H, CH3, J H-H ) 9.8 Hz), 1.10 (d, 6H, CH3, J H-H
)
9.8 Hz). 31P NMR (C6D6): δ 17.1 (d, J P-H ) 206.0 Hz). IR
1
(KBr): ν (cm-1): 2292 m (ν(PH)).
no. of indep rflns 2306
1466
1313
[{(η-C5H4)CMe2P HtBu }2Zr Cl2] (7). 1H NMR (C6D6): δ 6.26
(t, 4H, CH in C5H4, 3J H-H ) 2.8 Hz), 6.01 (m, 4H, CH in C5H4),
Rint
0.0286
170
0.0247
0.0626
-0.374
0.330
0.0264
112
0.0227
0.0609
-0.396
0.367
0.0173
112
0.0282
0.0836
-0.328
0.436
no. of params
R (I > 2σ(I))
wR2 (all data)
1
3.57 (d, 2H, P-H, J P-H ) 189.0 Hz), 1.75 (m, 6H, CH3 in
t
CMe2) 1.71 (m, 6H, CH3 in CMe2), 0.86 (d, 18H, CH3 in Bu,
(∆/F)min (e Å-3
(∆/F)max (e Å-3
)
)
1
3J P-H ) 11.4 Hz). 31P NMR (C6D6): δ 42.3 (d, J P-H ) 193.8
Hz). IR (KBr): ν (cm-1): 2379 m (ν(PH)).
[{(η-C5H4)2CMe2}Zr Cl2] (8). 1H NMR (C6D6): δ 6.38 (t, 4H,
NMR spectroscopy (C6D6: δ -32.4 (s, ?), -59.0 (s, (PtBu)4),
CH in C5H4, 3J H-H ) 2.7 Hz), 5.15 (t, 4H, CH in C5H4, 3J H-H
)
t
1
-80.1 (t, PH2 Bu, J P-H ) 174 Hz)).
2.7 Hz), 1.07 (s, 6H, CH3). 13C NMR (C6D6): δ 123.23 (s, 4C,
C5H4), 123.05 (s, 2C, ipso-C in C5H4), 107.17 (s, 4C, C5H4), 37.92
(s, 1C, C-CH3), 24.10 (s, 2C, CH3). EI-MS: 332 (100) [M+],
296 (25) [M+ - Cl], 281 (25) [M+ - Cl - Me]. Anal. Calcd for
C13H14ZrCl2 (332.38): C, 47.0; H, 4.2. Found: C, 46.7; H, 4.1.
[{(η-C5H4)CMe2P HP h }2TiCl] (9). 31P NMR (C6D6): δ 18.4
1
(d, J P-H ) 212.0 Hz). EI-MS: m/z 513 (7) [M+], 297 (20)
[M+ - C5H4Me2PHPh], 260 (75) [M+ - 2 Ph], 216 (25) [C5H4-
CMe2PHPh+], and fragmentation thereof. IR (KBr): ν (cm-1):
2287 m (ν(PH)), 1579 m (ν(CdC)), 1569 m (ν(CdC)). EPR: see
Table 1.
Syn th esis of a n sa -{Dim eth ylm eth a n ylbis(cyclop en ta -
d ien yl)}tita n iu m Dich lor id e (11). (a ) F r om [TiCl3(th f)3]
a n d Li[(C5H4)CMe2P HP h ] (3). A 1.25 g (3.4 mmol) amount
of [TiCl3(thf)3] was dissolved in 25 mL of thf, and a solution of
0.75 g (3.4 mmol) of Li[(C5H4)CMe2PHPh] (3) in 30 mL of thf
was added at -20 °C. The solution turned dark green im-
mediately. The reaction mixture was stirred at room temper-
ature for 12 h. Then the solvent was removed in vacuo and
the residue washed with 20 mL of hexane. The resulting green
powder (complex 9) was recrystallized from thf. The EPR
spectrum of this highly air-sensitive solution showed the
presence of a paramagnetic Ti(III) species ([{(η-C5H4)CMe2-
PHPh}2TiCl] (9)) which exhibits Ti-P interaction. The 31P
[{(η-C5H4)CMe2P HtBu }2TiCl] (10). 31P NMR (C6D6):
δ
1
38.6 (d, J P-H ) 195.0 Hz). EI-MS: m/z 473 (2) [M+], 385 (10)
[M+ - PtBu], 296 (12) [M+ - 2 PtBu], 260 (12) [(C5H4)2CMe2-
Ti+], and fragmentation thereof. IR (KBr): ν (cm-1): 2282 m
(ν(PH)), 1471 s (ν(CdC)), 1261 s (ν(CdC)). EPR: see Table 1.
1
[{(η-C5H4)2CMe2}TiCl2] (11). H NMR (CDCl3): δ 6.90 (t,
3
4H, CH in C5H4, J H-H ) 2.5 Hz), 5.55 (t, 4H, CH in C5H4,
3J H-H ) 2.5 Hz), 1.74 (s, 6H, CH3). 13C NMR (CDCl3): δ 132.08
(s, 4C, C5H4), 116.42 (s, 2C, ipso-C in C5H4), 111.86 (s, 4C,
C5H4), 37.77 (s, 1C, C-CH3), 24.11 (s, 2C, C-CH3). EI-MS:
m/z 288 (28) [M+], 252 (30) [M+ - Cl], 237 (10) [M+ - Cl -
Me]. Anal. Calcd for C13H14TiCl2 (289.04): C, 54.0; H, 4.8.
Found: C, 53.8; H, 4.7.
NMR spectrum (C6D6) showed a doublet at 18.4 ppm (1J P-H
)
212.0 Hz). The dark green solution decomposes slowly over
several days with formation of a red solution from which dark
red crystals of 11 can be obtained. Yield: 0.54 g (55% relative
X-r a y Cr ysta l Str u ctu r e Deter m in a tion of 5, 8, a n d 11.
Data (λ(Mo KR) ) 0.710 73 Å) were collected with a Siemens
CCD (SMART) diffractometer. All observed reflections were
used for refinement (SAINT) of the unit cell parameters.
Empirical absorption correction was carried out with SAD-
ABS.31 The structures were solved by direct methods (SHELX-
TL PLUS).32 Zr, Ti, Si, Cl, and C atoms were refined aniso-
tropically; H atoms were located by difference maps and
refined isotropically. Table 4 lists crystallographic details.
Crystallographic data (excluding structure factors) for the
structures reported in this paper have been deposited with the
Cambridge Crystallographic Data Centre (5, CCDC-133344;
8, CCDC-133345; 11, CCDC-133346). Copies of the data can
be obtained free of charge on application to The Director,
CCDC, 12 Union Road, Cambridge, CB2 1EZ, U.K. (fax, int.
code +(1223)336-033; e-mail, deposit@ccdc.cam.ac.uk).
13
to 3). The products (PPh)n (n ) 4-6) and PH2Ph were
detected by 31P NMR spectroscopy (C6D6: δ -4.0 (m, (PPh)5),
-26.4 (s, (PPh)6), -47.7 (s, (PPh)4), -123.8 (t, PH2Ph, 1J P-H
)
197 Hz)).
(b) F r om [TiCl3(th f)3] a n d Li[(C5H4)CMe2P Ht Bu ] (4).
Alternatively, 11 was obtained from 1.00 g (2.7 mmol) of [TiCl3-
(thf)3], dissolved in 25 mL of thf and a solution of 0.60 g (2.7
mmol) of Li[(C5H4)CMe2PHtBu] (4) in 30 mL of thf at -20 °C.
The solution turned dark green immediately. The reaction
mixture was stirred at room temperature for 12 h. Then the
solvent was removed in vacuo and the residue washed with
20 mL of hexane.The resulting green powder (complex 10) was
recrystallized from toluene. An EPR spectrum of this highly
air-sensitive solution showed the presence of a paramagnetic
Ti(III) species ([{(η-C5H4)CMe2PHtBu}2TiCl] (10)) which ex-
hibits Ti-P interaction. The dark green solution decomposes
slowly with formation of a red solution, from which dark red
crystals of 11 can be obtained. Yield: 0.48 g (62% relative to
(31) Sheldrick, G. M. SADABSsA Program for Empirical Absorption
Correction; University of Go¨ttingen, Go¨ttingen, Germany, 1998.
(32) SHELXTL PLUS, Siemens Analytical X-ray Instruments Inc.,
1990: XS, Program for Crystal Structure Solution; XL, Program for
Crystal Structure Determination; XP, Interactive Molecular Graphics.
4). The products (PtBu)4 and PH2 Bu were detected by 31P
13
t

Unexpected P-Si or P-C Bond Cleavage
Organometallics, Vol. 19, No. 13, 2000 2563
Su p p or tin g In for m a tion Ava ila ble: Tables giving X-ray
crystal structure data for 5, 8, and 11. This material is
available free of charge via the Internet at http://pubs.acs.org.
Ack n ow led gm en t. We gratefully acknowledge fi-
nancial support from the Fonds der chemischen Indus-
trie, the Alexander von Humboldt-Foundation (F.B.S.),
the Landesgraduiertenfo¨rderung Sachsen (S.B.) and the
German-Israeli Foundation (Grant No. I-142/95).
OM990763Z