Reaction of Rosenthal's zirconacyclocumulenes with chlorophosphines

Article abstract of DOI:10.1021/om050336n

The zirconacyclocumulenes 1a (R = CH₃) and 1b (R = Ph) were prepared by isomerization of bis(propynyl)ZrCp₂ or bis(phenylethynyl)ZrCp₂, respectively, catalyzed by B(C ₆F₅)₃ (6 mol %). The c

Full text of DOI:10.1021/om050336n

4742
Organometallics 2005, 24, 4742-4746
Reaction of Rosenthal’s Zirconacyclocumulenes with
Chlorophosphines
Patrick Spies, Gerald Kehr, Roland Fro¨hlich,† Gerhard Erker,*
Stefan Grimme,‡ and Christian Mu¨ck-Lichtenfeld‡
Organisch-Chemisches Institut der Universita¨t Mu¨nster, Corrensstrasse 40,
48149 Mu¨nster, Germany
Received April 29, 2005
The zirconacyclocumulenes 1a (R ) CH3) and 1b (R ) Ph) were prepared by isomerization
of bis(propynyl)ZrCp2 or bis(phenylethynyl)ZrCp2, respectively, catalyzed by B(C6F5)3 (6 mol
%). The compounds 1 added PCl3, PhPCl2, or Ph2PCl with cleavage of only one zirconium-
carbon single bond. Chloride was added to zirconium and the remaining -PCl2, -P(Ph)Cl,
or -PPh2 moiety attached at the distal â-carbon atom of the strained ZrC4R2 metallacycle
to yield the respective ring-opened Zr/P-substituted enyne systems (5-7). The complexes
7a and 7b (both with -PPh2) and 6b (with -P(Ph)Cl) were characterized by X-ray diffraction.
Scheme 1
Introduction
The reaction of titanocene or zirconocene derivatives
“RCp2M” derived from a variety of sources with substi-
tuted butadiynes leads to the formation of the unique
five-membered group 4 metallacyclocumulenes 1.1
Rosenthal et al. have characterized several examples
of this type of complexes by X-ray diffraction and have
largely developed the chemistry of such compounds.1,2
We had subsequently shown that such compounds can
be prepared by catalytic isomerization of bis(alkynyl)-
zirconocenes (4) under the influence of B(C6F5)3. We
had demonstrated that the zwitterion 2 is an inter-
mediate in this catalytic conversion that can be ob-
tained by treatment of either 1 or 4 with B(C6F5)3 (see
Scheme 1).3
Formally, complex 1 has a hetaryne-type composition,
but it is enormously stabilized by internal σ-interaction
of the central CdC multiple bond with the electron-
deficient group 4 metallocene.4 The metallacyclocumu-
lenes exhibit a remarkable stability. Surprisingly few
specific reactions of these uniquely structured metalla-
cycles have been observed so far.1 We will here describe
a series of reactions of two derivatives of 1, namely, the
zirconacyclocumulenes 1a (R ) CH3) and 1b (R ) Ph),
with the reagents PCl3, PhPCl2, or Ph2PCl. These
reactions gave a surprising result.
Results and Discussion
The zirconacyclocumulenes (1a, 1b) used in this study
were both synthesized by isomerization of the respective
bis(alkynyl)zirconocenes (4a, 4b) catalyzed by B(C6F5)3
(6 mol %) at room temperature in toluene. Complex 1a
reacted readily with 1 molar equiv of PCl3 in THF to
yield 5a. The product features a single 1H NMR Cp
resonance (in d6-benzene) at δ 5.87 (10H) and two CH3
signals at δ 2.33 (3H) and 1.63 (3H), quite different from
the starting material 1a [δ 5.08 (s, 10H), 2.83 (s, 6H)].
Complex 5a features typical 13C NMR Zr-alkenyl signals
* To whom correspondence should be addressed. E-mail: erker@
uni-muenster.de.
† X-ray crystal structure analyses.
‡ Quantum chemical calculations.
(1) Rosenthal, U.; Burlakov, V. V.; Arndt, P.; Baumann, W.; Span-
nenberg, A. Organometallics 2005, 24, 456-471, and references
therein.
(2) Rosenthal, U.; Ohff, A.; Baumann, W.; Kempe, R.; Tillack, A.;
Burlakov, V. V. Angew. Chem. 1994, 106, 1678-1680; Angew. Chem.,
Int. Ed. Engl. 1994, 33, 1605-1607. Burlakov, V. V.; Ohff, A.; Lefeber,
C.; Tillack A.; Baumann, W.; Kempe, R.; Rosenthal, U. Chem. Ber.
1995, 128, 967-971.
(3) Temme, B.; Erker, G.; Fro¨hlich, R.; Grehl, M. Angew. Chem.
1994, 106, 1570-1572; Angew. Chem., Int. Ed. Engl. 1994, 33, 1480-
1482. Ahlers, W.; Temme B.; Erker, G.; Fro¨hlich, R.; Fox, T. J.
Organomet. Chem. 1997, 527, 191-201. Erker, G.; Venne-Dunker, S.;
Kehr, G.; Kleigrewe, N.; Fro¨hlich, R.; Mu¨ck-Lichtenfeld, C.; Grimme,
S. Organometallics 2004, 23, 4391-4395.
(4) Jemmis, E. D.; Phukan, A. K.; Jiao, H.; Rosenthal, U. Organo-
metallics 2003, 22, 4958-4965. Lam, K. C.; Lin, Z. Organometallics
2003, 22, 3466-3470.
for 5 at δ 223.6 (2JPC ) 23 Hz, C2) and 133.2 (1JPC
)
70.0 Hz, C3), alkynyl resonances at δ 79.0 (C4) and 90.1
(C5), and a 31P NMR feature at δ 154.3. The reaction of
1b with PCl3 proceeds analogously to give the addition
product 5b (isolated in a yield of 66%; see Scheme 2 and
Table 1). In this case the attachment of a -PCl2 group
at C3 of the σ-ligand framework is illustrated by the
observation of three separated signals of the respective
isotopomers in close to statistical experimental intensity
10.1021/om050336n CCC: $30.25 © 2005 American Chemical Society
Publication on Web 08/24/2005

Reaction of Rosenthal’s Zirconacyclocumulenes
Organometallics, Vol. 24, No. 20, 2005 4743
Scheme 2
Table 1. Selected NMR Data of the Complexes
5-7a
[Zr]-Cd
dC-[P]
Figure 2. Molecular structure of complex 7a. Selected
structural parameters: C1-C2 1.504(3) Å, C2-C3 1.347-
(3) Å, C3-C4 1.432(3) Å, C4-C5 1.188(3) Å, C5-C6 1.460-
(3) Å, C3-P 1.844(2) Å, Zr-C2-C3 130.6(2)°.
b
b
compd
5ac,d Me
5bc
6ad,e Me
R
n
1H (Cp) 31P
(2JPC
)
(1JPC
)
CtCR
0
5.87
154.3 223.6 (23) 133.2 (70) 79.0
90.1
Ph
0
1
1
2
2
6.04
151.4 223.9 (27) 129.1 (59) 87.8
85.8
6.50
6.30
6.47
6.35
6.37
68.1 222.0 (20) 130.7 (47) 81.3
89.8
6b
7a
7b
Ph
Me
Ph
70.4 224.5 (23) 132.6 (50) 91.0
95.4
-12.3 217.3 (15) 127.4 (39) 84.7
89.1
-7.8 223.1 (19) 129.1 (28) 94.4
94.4
6.43
a 1H NMR (599.8 MHz), 31P (81.0 MHz), 13C (150.8 MHz) in d8-
b
THF, 300 K, if not noted otherwise. JPC coupling constants in
c
Hz. In d6-benzene. d 13C NMR at 125.7 MHz. e 1H NMR at 499.8
MHz.
Figure 3. Molecular structure of complex 7b. Selected
structural parameters: C1-C2 1.482(4) Å, C2-C3 1.352-
(5) Å, C3-C4 1.426(6) Å, C4-C5 1.192(6) Å, C5-C6 1.444-
(6) Å, C3-P 1.849(4) Å, Zr-C2-C3 135.9(3)°, C3-C4-C5
173.1(4)°, Cl-Zr-C2-C3 178.1(4)°, Cl-Zr-C2-C1 -2.9-
(3)°, Zr-C2-C3-C4 -1.6(7)°, Zr-C2-C3-P 179.1(2)°.
Figure 1. 31P NMR spectrum (in d6-benzene, 242.8 MHz,
300 K) of complex 5b, showing the features of the three
isotopomers in a close to statistical intensity ratio.
ratio of (31P35Cl35Cl:31P37Cl35Cl:31P37Cl37Cl of 55:37:8;
calcd 58:36:6; see Figure 1).
The addition of PhPCl2 to 1a and 1b gave the products
6a and 6b, respectively. The replacement of a chloride
at phosphorus by C3 of the σ-ligand chain has made the
P center of the -P(Ph)Cl substituent chiral, and con-
sequently the cyclopentadienyl ligands in 6a and 6b
have become diastereotopic (see Table 1). The reaction
of 1a and 1b with Ph2PCl gave the products 7a and 7b,
respectively. Both were characterized by X-ray diffrac-
tion (see Figures 2 and 3).
The structure of 7a, which is depicted in Figure 2,
shows that the five-membered metallacycle of the start-
ing material (1a) was opened by the addition of a
chloride ligand to zirconium. The remaining Ph2P-
moiety was attached at C3 of the σ-ligand chain to form
an E-configured substituted σ-enyne ligand, which has
remained attached to the metal via the Zr-C2 σ-bond
(2.299(2) Å). The organic σ-ligand is planar and oriented
in the metallocene σ-ligand plane (angle Cl-Zr-C2
102.76(6)°). The large enyne σ-ligand is oriented toward
a lateral sector of the bent metallocene wedge (dihedral
angles Cl-Zr-C2-C3 -179.9(2)°, Zr-C2-C3-P -177.6-
Figure 4. View of the molecular structure of complex rac-
6b (only one enatiomer is depicted). Selected bond lengths
and angles: Zr-C2 2.320(3) Å C1-C2 1.493(4) Å, C2-C3
1.353(4) Å, C3-P1 1.851(3) Å, C3-C4 1.426(4) Å, C4-C5
1.200(4) Å, C5-C6 1.444(5) Å, Zr-C2-C1 111.1(2)°,
Zr-C2-C3 128.2(2)°, C1-C2-C3 120.5(3)°, C2-C3-P1
118.7(2)°, C4-C3-P1 116.7(2)°, C2-C3-C4 124.3(3)°,
C3-C4-C5 175.1(3)°, C4-C5-C6 177.8(4)°.
(1)°). Complex 7b features a similar molecular structure
in the crystal (Figure 3). In this case the presence of
the bulky phenyl substituents has resulted in a few
minor distortions. Complex 6b was also characterized
by X-ray diffraction (see Figure 4). In this case the
product contains a stereogenic phosphorus center, fea-
turing three different substituents. Single crystals were

4744 Organometallics, Vol. 24, No. 20, 2005
Spies et al.
Figure 5. View of the DFT-calculated (B-LYP/TZVP, Zr: def-TZVPP) structures of E-7a (left, calcd Zr-C2 2.350 Å,
C1-C2 1.524 Å, C2-C3 1.369 Å, C3-P 1.922 Å, C3-C4 1.423 Å, C4-C5 1.221 Å, C5-C6 1.462 Å, Cl-Zr-C2 101.8°,
Zr-C2-C3 129.8°) and Z-7a (right, calcd Zr-C2 2.357 Å, C1-C2 1.532 Å, C2-C3 1.372 Å, C3-C4 1.427 Å, C3-P 1.891
Å, C4-C5 1.220 Å, C5C6 1.461 Å, Cl-Zr-C2 101.3°, Zr-C2-C3 134.9°).
ring “phosphacyclocumulene” product.9 Ring opening
with formation of a phosphorus-substituted conjugated
enyne system,10 remotely related to the pathway in-
volved in the catalytic formation of 1 from 4 (see Scheme
1), seems to provide a favored alternative. This study,
thus, provides evidence for the special chemical features
that are derived from the unusual electronic structure
of the zirconacyclocumulenes 1.
Scheme 3
obtained from the racemate. Figure 4 shows one of the
enantiomeric forms.
So far we have identified only the E-configured
products that were formed from the reaction of the
zirconacyclocumulenes 1 with these P-Cl-containing
reagents. The structures (see Figure 5) and relative
energies of both the E-7a and Z-7a isomers were
calculated by DFT. The E-7a isomer was found to be
favored by only 0.8 kcal mol-1 over the Z-7a isomer.
This indicated that the observed reaction of 1 with the
R2P-Cl reagents was kinetically controlled E-selective.
The direct addition of X-Y molecules either to the
starting materials 1 or to their η2-butadiyne metallocene
isomers would be expected to be cis-additions, as was
shown for many examples by Rosenthal and others.7 The
fact that we have here observed a trans-selective addi-
tion/ring-opening reaction points to an intermolecular
addition pathway, e.g., as schematically depicted in
Scheme 3, although any detailed mechanistic interpre-
tation at this time must await further specific experi-
mental evidence.
Experimental Section
General Procedures. Reactions with organometallic com-
pounds were carried out under argon using Schlenk-type
glassware or in a glovebox. Solvents were dried and distilled
under argon prior to use. For additional general information
see, for example, ref 3. The bis(alkynyl)zirconocenes (1) were
prepared analogously as described in the literature.3,5
X-ray Crystal Structure Analyses. Data sets were col-
lected with a Nonius KappaCCD diffractometer, equipped with
a rotating anode generator. Programs used: data collection
COLLECT (Nonius B.V., 1998), data reduction Denzo-SMN
(Z. Otwinowski, W. Minor, Methods Enzymol. 1997, 276, 307-
326), absorption correction Denzo (Z. Otwinowski, D. Borek,
W. Majewski, W. Minor, Acta Crystallogr. 2003, A59, 228-
234), structure solution SHELXS-97 (G. M. Sheldrick, Acta
Crystallogr. 1990, A46, 467-473), structure refinement
SHELXL-97 (G. M. Sheldrick, Universita¨t Go¨ttingen, 1997),
graphics XP (BrukerAXS, 2000).
Quantum Chemical Calculations. Quantum chemical
calculations have been performed with the TURBOMOLE 5.6
suite of programs (Universita¨t Karlsruhe, 2003). The struc-
tures have been fully optimized at the density functional (DFT)
level employing the B-LYP functional (A. D. Becke, Phys. Rev.
A 1988, 38, 3098-3100. C. Lee, W. Yang, R. G. Parr, Phys.
Rev. B 1988, 37, 785-789). A Gaussian AO basis of valence-
triple-ú quality including polarization functions (TZVP) (A.
Scha¨fer, C. Huber, R. Ahlrichs, J. Chem. Phys. 1994, 100,
5829-5835) was used for all heavy atoms. One additional
f-polarization function (R ) 0.988993) and a relativistic
pseudopotential (small core) were employed for Zr (D. Andrae,
U. Haeussermann, M. Dolg, H. Stoll, H. Preuss, Theor. Chim.
Acta 1990, 77, 123-141). The RI approximation was used for
the two-electron integrals (K. Eichkorn, O. Treutler, H. O¨ hm,
M. Ha¨ser, R. Ahlrichs, Chem. Phys. Lett. 1995, 240, 283-290).
Conventional zirconacyclopentadienes often react with
RPCl2 reagents to yield the corresponding phospholes.8
This reaction pathway is apparently not favored for the
systems 1 due to the high endothermicity that would
be associated with the formation of a hypothetical five-
(5) Erker, G.; Fro¨mberg, W.; Angermund, K.; Schlund, R.; Kru¨ger,
C. Chem. Commun. 1986, 372-374. Erker, G.; Dorf, U.; Rheingold, A.
L. Organometallics 1988, 7, 138-143. Erker, G.; Schlund, R.; Kru¨ger,
C. Organometallics 1989, 8, 2349-2355. Hyla-Kryspin, I.; Gleiter, R.;
Kru¨ger, C.; Zwettler, R.; Erker, G. Organometallics 1990, 9, 517-523.
(6) The E/Z-isomerization of alkenylzirconocene complexes can be
achieved photochemically: Czisch, P.; Erker, G. J. Organomet. Chem.
1983, 253, C9-C11.
(7) Burlakov, V. V.; Peulecke, N.; Baumann, W.; Spannenberg, A.;
Kempe, R.; Rosenthal, U. J. Organomet. Chem. 1997, 293-297. Miyayi,
T.; Xi, Z.; Nakajima, K.; Takahashi, T. Organometallics 2001, 20,
2859-2863.
(8) Fagan, P.; Nugent, W. A. J. Am. Chem. Soc. 1988, 110, 2310-
2312. Fagan, P.; Nugent, W. A.; Calabrese, J. C. J. Am. Chem. Soc.
1994, 116, 1880-1889. Takahashi, T.; Hara, R.; Nishihara, Y., Kotora,
M. J. Am. Chem. Soc. 1996, 118, 5154-5155. Ura, Y.; Li, Y.; Xi, Z.;
Takahashi, T. Tetrahedron Lett. 1998, 39, 2787-2790.
(9) For related hetarynes see, for example: Wittig, G.; Wahl, V.
Angew. Chem. 1961, 73, 492-493; Angew. Chem., Int. Ed. Engl. 1962,
1, 415-416. Ye, X.-S.; Wong, H. N. C., J. Org. Chem. 1997, 62, 1940-
1954. Liu, J.-H.; Chan, H.-W.; Xue, F.; Wang, Q.-G.; Mak, T. C.; Wong,
H. N. C. J. Org. Chem. 1999, 64, 1630-1634.
(10) See for comparison: Kawatkar, S., P.; Schreiner, P. R. Org. Lett.
2002, 4, 3643-3646.

Reaction of Rosenthal’s Zirconacyclocumulenes
Organometallics, Vol. 24, No. 20, 2005 4745
General Procedure for the Preparation of 5a, 6a, and
7a. Zirconacyclocumulene 1a was dissolved in 50 mL of THF.
The respective chlorophosphine was added, and the reaction
mixture was stirred for 3 h at ambient temperature. The
solvent was removed in vacuo, and the residue was washed
with pentane (3 × 10 mL) and dried in vacuo. For 5b and 6b,
the same procedure was used as for the preparation of 5a-7a
except that the solvent was changed to toluene.
(C3). 31P NMR (d6-benzene, 242.8 MHz, 300 K): δ 151.37,
151.35, 151.32 (Cl isotopomeres: 57%:35%:8% ≡ 31P(35Cl,
35Cl):31P(35Cl, 37Cl):31P(37Cl, 37Cl).
Preparation of Complex 6b. A sample of 1.20 g (2.8
mmol) of 1b was treated with 0.39 mL (0.51 g, 2.8 mmol) of
dichlorophenylphosphine to yield 0.50 g (29%) of 6b, mp 154.0
°C (DSC, dec). Anal. Calcd for C32H25Cl2PZr (602.64): C, 63.78;
H, 4.18. Found: C, 63.51; H, 3.83. 1H NMR (d8-THF, 599.8
MHz, 300 K): δ 7.72 (m, 2H, o-PhP), 7.43 (m, 2H, m-PhP),
7.40 (m, 1H, p-PhCt), 7.38 (m, 1H, p-PhP), 7.34 (m, 2H,
o-PhCt), 7.33 (m, 2H, m-PhCt), 7.23, 7.16 (each m, each 1H,
m-PhCd), 7.14 (m, 1H, p-PhCd), 7.12, 6.92 (each m, each 1H,
o-PhCd), 6.47, 6.35 (each s, each 5H, Cp). 13C{1H} NMR
(d8-THF, 150.8 MHz, 300 K): δ 224.5 (d, 2JPC ) 22.6 Hz, C1),
Preparation of Complex 5a. A sample of 1.58 g (5.3 mmol)
of 1a was treated with 0.50 mL (0.76 g, 5.5 mmol) of
phosphorus trichloride to yield 0.80 g (35%) of 5a, mp 120 °C
(DSC, dec). Anal. Calcd for C16H16Cl3PZr (436.9): C, 43.99; H,
3.69. Found: C, 44.63; H, 3.60. 1H NMR (d6-benzene, 599.8
MHz, 300 K): δ 5.87 (s, 10H, Cp), 2.33 (s, 3H, Me-Cd), 1.63
(s, 3H, Me-Ct). 13C{1H} NMR (d6-benzene, 150.7 MHz, 300
K): δ 223.6 (d, 2JPC ) 23 Hz, C1), 133.2 (d, 1JPC ) 70 Hz, C2),
3
1
144.0 (d, JPC ) 22.0 Hz, i-PhCd), 140.9 (d, JPC ) 38.5 Hz,
1
i-PhP), 132.6 (d, JPC ) 49.9 Hz, C2), 132.1 (p-PhCt), 131.5
(d, JPC ) 24.8 Hz, o-PhP), 130.1 (p-PhP), 129.4 (o-PhCd),
129.0, 129.0 (m-PhP), 128.9 (m-PhCt), 128.8 (d, JPC ) 2.3
Hz, o′-PhCd), 128.6 (m-PhCd), 127.8 (d, JPC ) 3.1 Hz
3
2
113.5 (Cp), 90.1 (d, JPC ) 2.9 Hz, C4), 79.0 (d, JPC ) 2.9 Hz
1
C3), 25.5 (d, JPC ) 62 Hz, Me-Cd), 4.2 (Me-Ct). 31P NMR
4
3
(d6-benzene, 202.4 MHz, 300 K): δ 154.3 (ν1/2 ) 5 Hz).
Preparation of Complex 6a. A sample of 1.14 g (3.8 mmol)
of 1a was treated with 0.53 mL (0.68 g, 3.8 mmol) of
dichlorophenylphosphine to yield 0.83 g (46%) of 6a, mp 120
°C (DSC, dec). Anal. Calcd for C22H21Cl2PZr (478.5): C, 55.22;
H, 4.42. Found: C, 53.80; H, 4.08. 1H NMR (d8-THF, 499.8
MHz, 300 K): δ 7.64 (m, 2H, o-Ph), 7.41 (m, 2H, m-Ph), 7.35
(m, 1H, p-Ph), 6.50, 6.30 (each s, each 5H, Cp), 2.39 (s, 3H,
Me-Cd), 1.89 (s, 3H, Me-Ct). 13C{1H} NMR (d8-THF, 125.7
6
p-PhCd), 127.1 (p-PhCt), 124.7 (i-PhCt), 114.0, 113.8 (Cp),
95.4 (C4), 91.0 (C3). 31P NMR (d6-benzene, 242.8 MHz, 300
K): δ 70.4 (ν1/2 ) 8 Hz).
X-ray crystal structure analysis of 6b: formula
C32H25Cl2PZr, M ) 602.61, yellow crystal 0.25 × 0.06 × 0.03
mm, a ) 9.259(1) Å, b ) 20.346(1) Å, c ) 14.921(1) Å, â )
99.86(1)°, V ) 2769.4(4) Å3, Fcalc ) 1.445 g cm-3, µ ) 6.67 cm-1
,
empirical absorption correction (0.851 e T e 0.980), Z ) 4,
monoclinic, space group P21/c (No. 14), λ ) 0.71073 Å, T )
198 K, ω and æ scans, 18 363 reflections collected ((h, (k,
(l), [(sin θ)/λ] ) 0.66 Å-1, 6554 independent (Rint ) 0.075) and
4471 observed reflections [I g 2σ(I)], 325 refined parameters,
R ) 0.060, wR2 ) 0.089, max. residual electron density 0.53
(-0.48) e Å-3, hydrogen atoms calculated and refined as riding
atoms.
Preparation of Complex 7b. The zirconacyclocumulene
1b (1.60 g, 3.8 mmol) was dissolved in 50 mL of toluene.
Chlorodiphenylphosphine (0.43 mL, 0.84 g, 3.8 mmol) was
added and the reaction mixture stirred for 3 h at ambient
temperature. The product precipitated as a white solid. It was
collected by filtration, washed with pentane (3 × 10 mL), and
dried in vacuo to yield 1.52 g (62%) of 7b, mp 250.4 °C
(DSC, dec). Anal. Calcd for C38H30ClPZr (602.6): C, 70.84; H,
4.69. Found: C, 70.28; H, 4.47. 1H NMR (d8-THF, 499.8
MHz, 300 K): δ 7.46 (m, 4H, o-PhP), 7.33 (m, 4H, m-PhP),
7.30 (m, 2H, p-PhP), 7.23 (m, 2H, m-PhCt), 7.22 (m, 2H,
o-PhCt), 7.09 (m, 2H, m-PhCd), 7.08 (m, 1H, p-PhCt), 7.07
(m, 1H, p-PhCd), 6.87 (m, 2H, o-PhCd), 6.43 (s, 10H, Cp).
MHz, 300 K): δ 222.0 (d, 2JPC ) 19.6 Hz, C1), 140.6 (d, 1JPC
)
2
1
34.0 Hz, i-Ph), 131.2 (d, JPC ) 23.7 Hz, o-Ph), 130.7 (d, JPC
3
) 65.0 Hz, C2), 129.7 (p-Ph), 128.6 (d, JPC ) 6.2 Hz, m-Ph),
114.3, 114.2 (Cp), 89.8 (C4), 81.3 (C3), 26.5 (Me-Cd), 3.9
(Me-Ct). 31P NMR (d6-benzene, 81.0 MHz, 300 K): δ 68.1 (ν1/2
) 3 Hz).
Preparation of Complex 7a. A sample of 1.14 g (3.8 mmol)
of 1a was treated with 0.44 mL (0.885 g, 3.8 mmol) of
chlorodiphenylphosphine to yield 1.07 g (54%) of 7a, mp 171
°C (DSC, dec). Anal. Calcd for C28H26ClPZr (520.2): C, 64.65;
H, 5.04. Found: C, 64.66; H, 5.22. 1H NMR (d8-THF, 599.8
MHz, 300 K): δ 7.43 (m, 2H, o-Ph), 7.31 (m, 2H, m-Ph), 7.27
(m, 1H, p-Ph), 6.37 (s, 10H, Cp), 2.20 (s, 3H, Me-Cd), 1.66 (s,
3H, Me-Ct). 13C{1H} NMR (d8-THF, 150.8 MHz, 300 K): δ
2
1
217.3 (d, JPC ) 14.9 Hz, C1), 140.3 (d, JPC ) 14.3 Hz, i-Ph),
134.3 (d, 2JPC ) 19.5 Hz, o-Ph), 128.5 (d, 3JPC ) 6.5 Hz, m-Ph),
1
128.5 (p-Ph), 127.4 (d, JPC ) 39.0 Hz, C2), 117.1 (Cp), 89.1
(C4), 84.7 (C3), 26.3 (d, 3JPC ) 45.4 Hz, Me-Cd), 4.0 (Me-Ct).
31P NMR (d6-benzene, 81.0 MHz, 300 K): δ -12.3 (ν1/2 ) 10
Hz).
X-ray Crystal Structure Analysis of 7a: formula
C28H26ClPZr, M ) 520.13, yellow crystal 0.35 × 0.20 × 0.10
mm, a ) 7.732(1) Å, b ) 18.380(1) Å, c ) 33.917(1) Å, V )
4820.1(7) Å3, Fcalc ) 1.433 g cm-3, µ ) 6.47 cm-1, empirical
absorption correction (0.805 e T e 0.938), Z ) 8, orthorhombic,
space group Pbca (No. 61), λ ) 0.71073 Å, T ) 198 K, ω and
æ scans, 36 846 reflections collected ((h, (k, (l), [(sin θ)/λ] )
0.66 Å-1, 5745 independent (Rint ) 0.058) and 4315 observed
reflections [I g 2σ(I)], 282 refined parameters, R ) 0.035, wR2
13C{1H} NMR (d8-THF, 125.7 MHz, 300 K): δ 223.1 (d, 2JPC
)
)
18.9 Hz, C1), 143.9 (d, 3JPC ) 18 Hz, i-PhCd), 140.8 (d, 1JPC
2
17.7 Hz, i-PhP), 134.1 (d, JPC ) 19.9 Hz, o-PhP), 131.8
(p-PhCt), 129.1 (m-PhCt), 129.1 (d, 1JPC ) 28.3 Hz, C2), 128.8
2
3
(d, JPC ) 5.8 Hz, m-PhP), 128.8 (o-PhPd), 128.7 (d, JPC
)
5
2.0 Hz, p-PhP), 128.6 (d, JPC ) 1.8 Hz, m-PhCd), 128.5
(o-PhCt), 126.7 (p-PhCd), 125.0 (i-PhCt), 113.6 (Cp), 94.4
(C4), 94.4 (C3). 31P NMR (d6-benzene, 81.0 MHz, 300 K): δ
-7.8 (ν1/2 ) 6 Hz).
) 0.083, max. residual electron density 0.40 (-0.40) e Å-3
hydrogen atoms calculated and refined as riding atoms.
,
X-ray crystal structure analysis of 7b: formula
C38H30ClPZr‚1/2C4H8O), M ) 680.31, light yellow crystal 0.15
× 0.10 × 0.03 mm, a ) 8.557(1) Å, b ) 8.631(1) Å, c ) 2.404-
(1) Å, R ) 84.47(1)°, â ) 89.37(1)°, γ ) 64.53(1)°, V ) 1618.7-
(3) Å3, Fcalc ) 1.396 g cm-3, µ ) 5.01 cm-1, empirical absorp-
tion correction (0.929 e T e 0.985), Z ) 2, triclinic, space
group P1h (No. 2), λ ) 0.71073 Å, T ) 198 K, ω and æ scans,
Preparation of Complex 5b. A sample of 1.15 g (2.7
mmol) of 1b was treated with 0.25 mL (0.37 g, 2.7 mmol) of
phosphorus trichloride to yield 1.00 g (66%) of 5b, mp
181.0 °C (DSC, dec). Anal. Calcd for C26H20Cl3PZr (561.0): C,
55.67; H, 3.59. Found: C, 56.47; H, 3.69. 1H NMR (d6-benzene,
599.8 MHz, 300 K): δ 7.56 (m, 2H, o-PhCt), 7.07 (m, 2H,
m-PhCd), 7.05 (m, 2H, m-PhCt), 7.02 (m, 1H, p-PhCt), 7.01
(m, 1H, p-PhCd), 6.87 (m, 2H, o-PhCd), 6.04 (s, 10H, Cp).
13C{1H} NMR (d6-benzene, 150.8 MHz, 300 K): δ 223.9 (d,
18 330 reflections collected ((h, (k, (l), [(sin θ)/λ] ) 0.59 Å-1
,
5690 independent (Rint ) 0.070) and 4395 observed reflections
[I g 2σ(I)], 410 refined parameters, R ) 0.064, wR2 ) 0.101,
max. residual electron density 0.42 (-0.48) e Å-3, due to crystal
size and disordered solvent molecule (refined as half a molecule
of THF, split over two positions, geometrically fixed by
constraints, isotropic thermal displacement parameters are
2
2JCP ) 26.9 Hz, C1), 142.0 (d, JCP ) 26.7, i-PhCd), 131.5
(o-PhCt), 129.1 (d, 1JPC ) 59.0 Hz, C2), 128.6 (m-PhCt), 128.5
4
(p-PhCt), 128.4 (m-PhCd), 127.1 (p-PhCd), 126.7 (d, JCP
)
4.2 Hz, o-PhCd), 123.4 (i-PhCt), 112.9 (Cp), 95.8 (C4), 87.8

4746 Organometallics, Vol. 24, No. 20, 2005
Spies et al.
used) only limited accurancy, hydrogen atoms calculated and
refined as riding atoms.
Supporting Information Available: Details of the X-ray
crystal structure analyses and the DFT calculations and
additional spectroscopic data. This material is available free
of charge via the Internet at http://pubs.acs.org.
Acknowledgment. Financial support from the Deut-
sche Forschungsgemeinschaft and the Fonds der Che-
mischen Industrie is gratefully acknowledged.
OM050336N