Preparation and properties of Cp2Zr(μ-N=CAr2) 2PdCl(Me), new Zr/Pd heterobimetallic complexes with bridging alkylideneamido ligands

Article abstract of DOI:10.1021/om0495269

Zr/Pd heterobimetallic complexes with bridging alkylideneamido ligands, Cp₂Zr(μ-N=CAr₂)₂PdCl(Me) (Ar = Ph, C ₆H₄Me-4), were prepared from the reaction of Cp ₂Zr(N=CAr₂)₂ with PdCl(Me)(cod) (cod = 1,5-cyclooctadiene). Cp₂Zr(μ-N=CAr₂) ₂PdCl(Me) complexes have puckered ZrN₂Pd rings with Zr-Pd distances of 2.8135(5) A (Ar = Ph) and 2.8416(4) A (Ar = C ₆H₄Me-4), respectively. The complexes reacted with HCl to afford trans-PdCl(Me)(NH=CAr₂)₂ and Cp ₂ZrCl₂. Exposure of a CH₂Cl₂ solution of trans-PdCl(Me){NH= C(C₆H₄Me-4) ₂}₂ to light results in the formation of a mixture of cis- and trans-PdCl(CHCl₂){NH=C(C₆H₄Me-4) ₂}₂.

Full text of DOI:10.1021/om0495269

5092
Organometallics 2004, 23, 5092-5095
P r ep a r a tion a n d P r op er ties of
Cp 2Zr (µ-NdCAr 2)2P d Cl(Me), New Zr /P d Heter obim eta llic
Com p lexes w ith Br id gin g Alk ylid en ea m id o Liga n d s
J unpei Kuwabara, Daisuke Takeuchi, and Kohtaro Osakada*
Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta,
Midori-ku, Yokohama 226-8503, J apan
Received J une 30, 2004
Summary: Zr/ Pd heterobimetallic complexes with bridg-
ing alkylideneamido ligands, Cp2Zr(µ-NdCAr2)2PdCl-
(Me) (Ar ) Ph, C6H4Me-4), were prepared from the
reaction of Cp2Zr(NdCAr2)2 with PdCl(Me)(cod) (cod )
1,5-cyclooctadiene). Cp2Zr(µ-NdCAr2)2PdCl(Me) com-
plexes have puckered ZrN2Pd rings with Zr-Pd dis-
tances of 2.8135(5) Å (Ar ) Ph) and 2.8416(4) Å (Ar )
C6H4Me-4), respectively. The complexes reacted with HCl
to afford trans-PdCl(Me)(NHdCAr2)2 and Cp2ZrCl2.
Exposure of a CH2Cl2 solution of trans-PdCl(Me){NHd
C(C6H4Me-4)2}2 to light results in the formation of a
mixture of cis- and trans-PdCl(CHCl2){NHdC(C6H4Me-
4)2}2.
early-late heterobimetallic complexes because they
show high basicity and coordinate to both early and late
transition metals. There have been only a few reports
on such complexes with bridging alkylideneamido
ligands.6 (Cp2Ti)2(µ-η2:η2-2:3,6:7-PhHCdNNCHPhCH-
PhNNdCHPh) reacts with Cp2Co(C2H4)2 to produce
Cp2Ti(µ-NdCHPh)2CoCp via cleavage of the N-N bond
of the ligand.6a In this paper we report the formation of
new Zr/Pd heterobimetallic complexes and conversion
of them into mononuclear alkylpalladium complexes
with imine ligands.
Resu lts a n d Discu ssion
Erker et al. reported the preparation of the zirconium
alkylideneamido complex Cp2Zr(NdCPh2)2 (1).7 Cp2Zr-
{NdC(C6H4Me-4)2}2 (2) is prepared similarly in this
study. Complexes 1 and 2 react with PdCl(Me)(cod) at
3 °C to form the Zr/Pd heterobimetallic complexes
Cp2Zr(µ-NdCAr2)2PdCl(Me) (3, Ar ) Ph, 32%; 4, Ar )
C6H4Me-4, 50%) (eq 1). Figure 1 shows the molecular
In tr od u ction
Heterobimetallic complexes1 containing early and late
transition metals exhibit unique characters such as
donor-acceptor bonding between the two different
metal centers2 and cooperative activation of the organic
bridging ligand by the metal centers.3 Transmetalation
of an organic ligand between the early- and late-
transition-metal complexes involves these dinuclear
complexes as the intermediate.4 There have been a
number of reports of heterobimetallic complexes having
metallocenes of group 4 transition metals with two
anionic ligands such as amido, thiolate, and phosphido,
Cp2M(ERn)2 (M ) Ti, Zr, Hf; E ) N (n ) 2), S(n ) 1), P
(n ) 2)), as the metalloligands of late transition metals
(Co, Rh, Fe, Ni, Pd, Pt).2-5 Alkylideneamido (imido)
groups would be suited as the bridging ligand of the
structures of 3 and 4 determined by X-ray crystal-
lography. The molecules have a crystallographic mirror
plane containing Zr and Pd, which causes the disorder
of positions of the methyl and chloro groups in equal
probability. The Pd center has a slightly distorted
square-planar coordination with Pd-N bond distances
of 2.130(3) Å (3) and 2.127(2) Å (4), while Zr is bonded
to the nitrogen atoms with bond distances of 2.152(3) Å
(3) and 2.150(2) Å (4). Short Zr-Pd distances (2.8235(5)
and 2.8416(4) Å) and the puckered structure of the ZrN2-
Pd four-membered ring (tilt angles of 42.6° (3) and
(1) For the reviews on early-late heterobimetallic complexes: (a)
Stephan, D. W. Coord. Chem. Rev. 1989, 95, 41. (b) Chetcuti, M. J . In
Comprehensive Coordination Chemistry II; Abel, E. W., Stone, F. G.
A., Wilkinson, G. W., Eds.; Pergamon: New York, 1994; Vol. 10, pp
23-84. (c) Wheatley, N.; Kalck, P. Chem. Rev. 1999, 99, 3379. (d) Gade,
L. H. Angew. Chem., Int. Ed. 2000, 39, 2658.
(2) (a) Powell, J .; Coutoure, C.; Gregg, M. R. J . Chem. Soc., Chem.
Commun. 1988, 1208. (b) Ferguson, G. S.; Wolczanski, P. T.; Pa´rka´nyi,
L.; Zonnevylle, M. C. Organometallics 1988, 7, 1967. (c) J ansen, G.;
Schubart, M.; Findeis, B.; Gade, L. H.; Scowen, I. J .; McPartlin, M. J .
Am. Chem. Soc. 1998, 120, 7239. (d) Braunstein, P.; Morise, X.; Be´nard,
M.; Rohmer, M.; Welter, R. Chem. Commun. 2003, 610.
(3) (a) Ozawa, F.; Park, J . W.; Mackenzie, P. B.; Schaefer, W. P.;
Henling, L. M.; Grubbs, R. H. J . Am. Chem. Soc. 1989, 111, 1319. (b)
Baranger, A. M.; Hollander, F. J .; Bergman, R. G. J . Am. Chem. Soc.
1993, 115, 7890. (c) Fulton, J . R.; Hanna, T. A.; Bergman, R. G.
Organometallics 2000, 19, 602. (d) Gade, L. H.; Memmler, H.; Kauper,
U.; Schneider, A.; Fabre, S.; Bezougli, I.; Lutz, M.; Galka, C.; Scowen,
I. J .; McPartlin, M. Chem. Eur. J . 2000, 6, 692. (e) Takeuchi, D.;
Kuwabara, J .; Osakada, K. Organometallics 2003, 22, 2305. (f)
Tsutsuminai, S.; Komine, N.; Hirano, M.; Komiya, S. Organometallics
2004, 23, 44.
(5) (a) Sato, M.; Yoshida, T. J . Organomet. Chem. 1975, 94, 403. (b)
Gelmini, L.; Stephan, D. W. Inorg. Chem. 1986, 25, 1222. (c) Baker,
R. T.; Fults, W. C. Marder, T. B.; Williams, I. D. Organometallics 1990,
9, 2357. (d) Amador, U.; Delgado, E.; Fornie´s, J .; Herna´ndez, E.;
Lalinde, E.; Moreno, M. T. Inorg. Chem. 1995, 34, 5279.
(6) (a) Zippel, T.; Arndt, P.; Ohff, A.; Spannenberg, A.; Kempe, R.;
Rosenthal, U. Organometallics 1998, 17, 4429. For imine-bridged
early-late heterobimetallics, see: (b) Uflyand, I. E.; Kurbatov, V. P.;
Pomogailo, A. D. Transition Met. Chem. 1992, 17, 501.
(4) (a) Berenguer, J . R.; Fornie´s, J .; Lalinde, E.; Mart´ın, A. Angew.
Chem., Int. Ed. Engl. 1994, 33, 2083. (b) Osakada, K.; Kawaguchi, Y.;
Yamamoto, T. Organometallics 1995, 14, 4542.
(7) Erker, G.; Fro¨mberg, W.; Kru¨ger, C.; Raabe, E. J . Am. Chem.
Soc. 1988, 110, 2400.
10.1021/om0495269 CCC: $27.50 © 2004 American Chemical Society
Publication on Web 09/15/2004

Notes
Organometallics, Vol. 23, No. 21, 2004 5093
F igu r e 2. UV/vis spectra of 2 and 4 (solvent THF).
490 nm (ꢀ ) 480), while the Zr/Pd heterobimetallic
complex 4 shows no absorption in that region. These
crystallographic and spectroscopic results indicate that
the Zr-N bond of the bridging alkylideneamido ligands
do not have double-bond character.
The 1H NMR spectrum of 4 shows two signals as-
signed to Cp hydrogens at δ 5.24 and 6.58, indicating
that the puckered ZrN2Pd ring is kept in solution. The
resonances of methyl hydrogens of the imido ligands are
observed as four magnetically unequivalent peaks at δ
2.42, 2.43, 2.46, and 2.67. This can be contrasted with
the 1H NMR spectra of mononuclear 1 and 2, which
show a set of signals due to the methyl and phenyl
hydrogens.7 Complexes 1 and 2 undergo exchange of the
two aryl groups on the NMR time scale, probably via
rotation of the Zr-N bond, although the rigid structure
of 3 and 4 prevents such bond rotation.
F igu r e 1. ORTEP drawing of (a) 3 and (b) 4 at the 30%
ellipsoidal level. Each molecule has a crystallographic
mirror plane. Atoms with asterisks are crystallographically
equivalent to those having the same number without
asterisks. Selected bond distances (Å) and angles (deg) are
as follows. 3: Zr-Pd, 2.8235(5); Zr-N, 2.152(3); Pd-N,
2.130(3); Pd-C1, 2.253(1); N-C8, 1.278(4); N-Zr1-N*,
89.34(7); N-Pd-N*, 90.45(7); Zr-N-Pd, 82.5(1); Zr-N-
C8, 148.0(2); Pd-N-C8, 127.5(2). 4: Zr-Pd, 2.8416(4); Zr-
N, 2.150(2); Pd-N, 2.127(2); Pd-C1, 2.2926(7); N-C8,
1.275(4); N-Zr1-N*, 89.66(9); N-Pd-N*, 90.88(8); Zr-
N-Pd, 83.27(8); Zr-N-C8, 145.7(2); Pd-N-C8, 128.4(2).
The Zr/Pd heterobimetallic complexes are treated
with HCl to afford Cp2ZrCl2 and trans-PdCl(Me)(NHd
CAr2)2 (Ar ) Ph (5), C6H4Me-4 (6)) in 83 and 93% yields,
respectively (eq 2). Addition of PhOH to a solution of 4
Ta ble 1. Meta l-Meta l Dista n ces a n d Dih ed r a l
An gles of th e Cen tr a l ME2M′ Rin g (E ) N, P , S)
dihedral metal-
angle
(deg)
metal
dist (Å)
ref
10
produces 6 and Cp2Zr(OPh)2 quantitatively. Figure 3
3
4
42.6
48.3
0.0
24.5
19.3
2.8235(5) this work
2.8416(4) this work
2.569(3) 6a
2.896(1) 5c
3.140(3) 5d
depicts the molecular structure of 5 obtained by X-ray
crystallography. The molecule has a slightly distorted
square-planar coordination around the Pd center. Two
alkylideneamine ligands are located at trans positions.
This is the first example of an alkylpalladium complex
with a monodentate imine ligand. The Pd-N bonds of
5 (2.007(6) and 2.013(5) Å) are shorter than those of 4
Cp2Ti(µ-NdCHPh)2CoCp
Cp2Hf(µ-PPh2)2PdPPh3
(C5H4SiMe3)2Ti(µ-SPh)2Pd(C6F5)2
48.3° (4) between the ZrN2 and N2Pd planes) are
observed in the crystal structures. Table 1 compares the
angles of the coordination planes with those of analo-
gous early-late heterobimetallic complexes. Cp2Hf(µ-
PPh2)2PdPPh3 has a longer metal-metal distance (2.896
(1) Å) and a smaller dihedral angle (24.5°) than those
of 3 and 4.5c,8
Complex 1 has large Zr-N-C angles of 173.7 and
164.1° and short Zr-N bonds (2.058(2) and 2.063(2) Å).7
They were attributed to a heteroallene-type coordination
of the alkylideneamido group. The heterobimetallic
complexes 3 and 4 contain smaller Zr-N-C(8) angles
(3, 148.0°; 4, 145.7°) and longer Zr-N bond lengths (3,
2.152(3) Å; 4, 2.150(2) Å) than 1. The bond distances
are similar to those of Cp2Zr(NC4H4)2 (2.171(2) and
2.169(2) Å).9 Figure 2 compares the absorption spectra
of 2 and 4 in THF. Complex 2 exhibits absorption at
and trans-PdCl(Me)(NNHC(t-Bu)CHC-t-Bu)2, having
(8) The puckered ZrN2Pd ring, observed in the crystal structures of
3 and 4, may be related to the existence of a Zr/Pd interaction. An
EHMO calculation of the model compound Cp2Zr(µ-NdCMe2)2PdCl-
(Me) shows a Zr/Pd reduced overlapped population (ROP) of 5.4%,
which is much smaller than the average value of ROP between Pd
and N (20.0%). These results are not sufficient to discuss the presence
or absence of interaction between the metals. The calculations were
conducted on the basis of the method in the following reports: (a)
Hoffmann, R. J . Chem. Phys. 1963, 39, 1397. (b) Hoffmann, R.;
Lipscomb, W. N. J . Chem. Phys. 1962, 36, 2179. (c) Hoffmann, R.;
Lipscomb, W. N. J . Chem. Phys. 1962, 36, 3489. (d) Ammeter, J . H.;
Burgi, H.-B.; Thibeault, J . C.; Hoffmann, R. J . Am. Chem. Soc. 1978,
100, 3686. (e) Mealli, C.; Prosterpio, D. J . Chem. Educ. 1990, 67, 399.
(9) Bynum, R. V.; Hunter, W. E.; Rogers, R. D.; Atwood, J . L. Inorg.
Chem. 1980, 19, 2368.
(10) (a) Andra¨, K.; Hille, E. Z. Chem. 1968, 8, 65. (b) Howard, W.
A.; Trnka, T. M.; Parkin, G. Inorg. Chem. 1995, 34, 5900.

5094 Organometallics, Vol. 23, No. 21, 2004
Notes
accompanied by its conversion into the imine ligand is
observed.
Exp er im en ta l Section
Gen er a l P r oced u r e, Ma ter ia ls, a n d Mea su r em en t. All
the manipulations of the air-unstable complexes were carried
out under nitrogen or argon using standard Schlenk tech-
niques. Benzene and THF were distilled from sodium benzo-
phenone ketyl and stored under nitrogen. CDCl3 was distilled
from CaH2 and stored under nitrogen. C6D6 was distilled from
Na and stored under nitrogen. Benzophenoneimine and other
chemicals were used as received from commercial suppliers.
Cp2Zr(NdCPh2)2 (1)7 and PdCl(Me)(cod)13 were prepared ac-
cording to the literature. The NMR spectra (1H and 13C) were
recorded on Varian Mercury 300 and J EOL J NM LA-500
spectrometers. UV/vis spectra were measured with a J ASCO
V-530 UV/vis spectrometer. Elemental analysis was carried
out on a Yanaco MT-5 CHN autocorder.
F igu r e 3. ORTEP drawing of 5 at the 30% ellipsoidal
level. The hydrogen atoms are omitted for simplicity.
Selected bond distances (Å) and angles (deg): Pd-C1,
2.039(7); Pd-Cl, 2.447(2); Pd-N1, 2.007(6); Pd-N2, 2.013(5);
N1-C2, 1.298(8); N2-C15, 1.267(8); C1-Pd-N1, 90.7(3);
C1-Pd-N2, 86.4(3); Cl-Pd-N1, 89.6(2); Cl-Pd-N2,
93.0(2); Pd-N1-C2, 139.7(4); Pd-N2-C15, 131.5(4).
P r ep a r a tion of Cp 2Zr {NdC(C6H4Me-4)2}2 (2). The reac-
tion of LiNdC(C6H4Me-4)2 with Cp2ZrCl2 was conducted in a
7
manner similar to the preparation of Cp2Zr(NdCPh2)2 to
1
produce 2 in 30% yield. H NMR (300 MHz, C6D6): δ 7.25 (d,
J ) 8 Hz, 8H, C6H4), 7.09 (d, J ) 8 Hz, 8H, C6H4), 5.86 (s,
10H, Cp), 2.20 (s, 12H, Ar-Me). 13C{1H} NMR (75 MHz, C6D6):
δ 170.1 (NdC), 139.4 (C6H4 ipso), 138.0 (C6H4 ipso), 128.9 (C6H4
ortho and meta), 108.8 (C5H5), 21.3 (C6H4-Me).
P r ep a r a tion of Cp 2Zr (µ-NdCP h 2)2P d Cl(Me) (3). Com-
plex 1 (130 mg, 0.21 mol) and PdCl(Me)(cod) (51.7 mg, 0.20
mmol) were dissolved in benzene (2.6 mL). The reaction
mixture was left for 12 h at 3 °C. The yellow powder that
formed was collected by filtration, washed with benzene (1 mL
× 2) and hexane (1 mL × 2), and dried under reduced pressure
to give 3 (51.3 mg, 32%). Anal. Calcd for C37H33ClN2PdZr: C,
60.15; H, 4.50; N, 3.79; Cl, 4.80. Found: C, 60.21; H, 4.71; N,
3.45; Cl, 4.56. 1H NMR (300 MHz, CDCl3): δ 8,21 (d, J ) 8 Hz,
2H, C6H5), 7.75 (d, J ) 8 Hz, 2H, C6H5), 7.32-7.62 (m, 16H,
C6H5), 6.60 (br, 5H, C5H5), 6.25 (br, 5H, C5H5), 0.28 (s, 3H,
Pd-Me).
F igu r e 4. ORTEP drawing of 7 at the 30% ellipsoidal
level. The hydrogen atoms are omitted for simplicity.
Selected bond distances (Å) and angles (deg): Pd-C1,
1.995(4); Pd-Cl, 2.3100(9); Pd-N1, 2.039(3); Pd-N2,
2.107(4); N1-C2, 1.289(5); N2-C3, 1.312(6); C1-Cl2,
1.805(4); C1-Cl3, 1.795(4); C1-Pd-N1, 88.4(1); C1-Pd-
N2, 175.9(1); Cl-Pd-N1, 176.8(1); Cl-Pd-N2, 87.22(8);
Pd-N1-C2, 133.7(3); Pd-N2-C3, 136.5(3); Pd-C1-Cl2,
111.3(2); Pd-C1-Cl3, 112.0(2).
P r ep a r a tion of Cp 2Zr {µ-NdC(C6H4Me-4)2}2P d Cl(Me)
(4). Complex 2 (38.3 g, 60 µmol) and PdCl(Me)(cod) (15.8 mg,
60 µmol) were dissolved in benzene (3 mL). The reaction
mixture was left for 36 h at 3 °C to form yellow crystals, which
were collected by filtration, washed with benzene (1 mL × 2)
and hexane (1 mL × 2), and dried under reduced pressure to
give 4‚C6H6 (23.9 mg, 50%). Anal. Calcd for C41H41ClN2PdZr‚
C6H6: C, 64.66; H, 5.43; N, 3.21; Cl, 4.06. Found: C, 65.20; H,
two pyrazole ligands at trans positions (2.035(3) and
2.041(2) Å).11 Complex 5 is prepared also by the reaction
of benzophenoneimine with PdCl(Me)(cod).
Dissolution of 6 in CH2Cl2 leads to formation of a
mixture of cis- and trans-PdCl(CHCl2){NHdC(C6H4Me-
4)2}2. The reaction does not take place in the dark and
is induced by exposure of the solution to light. Figure 4
shows the crystallographic structure of 7 having CHCl2
and Cl ligands at cis positions around the square-planar
Pd center. J ordan et al. reported the photoassisted
conversion of PdCl(Me){(hexyl)HC(N-methylimidazol-
2-yl)2} into PdCl(CHCl2){(hexyl)HC(N-methylimidazol-
2-yl)2} via a radical pathway.12 The above reactions also
involve a radical intermediate, formed via cleavage of
the C-Pd bond caused by photoirradiation.
In summary, this study revealed that an alkylidene-
amido group coordinates to Zr and Pd as a bridging
ligand to form a heterobimetallic complex and that the
complexes react with HCl or HOPh easily to produce a
monometallic Zr complex and alkylideneamine com-
plexes of Pd. Transfer of the imido ligand from Zr to Pd
1
5.39; N, 3.05; Cl, 3.89. H NMR (300 MHz, CDCl3): δ 7.67 (d,
J ) 8 Hz, 2H, C6H4), 7.36 (s, 6H, benzene), 7.35 (d, J ) 8 Hz,
2H, C6H4), 7.20-7.36 (m, 12H, C6H4), 6.58 (br, 5H, C5H5), 6.24
(br, 5H, C5H5), 2.47 (s, 3H, C6H4-Me), 2.46 (s, 3H, C6H4-Me),
2.43 (s, 3H, C6H4-Me), 2.42 (s, 3H, C6H4-Me), 0.25 (s, 3H,
Pd-Me).
P r ep a r a tion of tr a n s-P d Cl(Me)(NHdCP h 2)2 (5). To a
suspension of 3 (7.3 mg, 9.0 µmol) in CDCl3 (0.9 mL) was added
a Et2O solution of HCl (20 µL, 20 µmol) and mesitylene (1.0
µL, 7.2 µmol). After 15 min of stirring, the reaction mixture
became a clear yellow solution. The quantitative formation of
Cp2ZrCl2 and 5 was confirmed by 1H NMR measurement using
mesitylene as an internal standard. Complex 5 was prepared
also from the reaction of PdCl(Me)(cod) with NHdCPh2.
To a solution of PdCl(Me)(cod) (52.6 mg, 0.20 mmol) in
toluene (5 mL) was added NHdCPh2 (6.72 × 10-4 mL, 0.40
mmol). After it was stirred at room temperature for 5 h, the
solution was evaporated to dryness at reduced pressure. The
residue was extracted with toluene/THF (8/92). After the
solvent was reduced under vacuum, Et2O was added to the
solution to cause the separation of 5‚0.5C7H8 as a pale yellow
(11) Li, K.; Darkwa, J .; Guzei, I. A.; Mapolie, S. F. J . Organomet.
Chem. 2002, 660, 108.
(12) Burns, C. T.; Shen, H.; J ordan, R. F. J . Organomet. Chem. 2003,
683, 240.
(13) Ru¨lke, R. E.; Ernsting, J . M.; Spek, A. L.; Elsevier, C. J .; van
Leeuwen, P. W. N. M.; Vrieze, K. Inorg. Chem. 1993, 32, 5769.

Notes
Organometallics, Vol. 23, No. 21, 2004 5095
Ta ble 2. Cr ysta llogr a p h ic Da ta a n d Deta ils of Refin em en t of 3-5 a n d 7
3
4
5
7
empirical formula
C
37H33ClN2PdZrC6H6
C
41H41ClN2PdZrC6H6
C
27H25ClN2Pd
C31H31Cl3N2Pd
644.36
formula wt
cryst syst
space group
a, Å
b, Å
c, Å
816.87
872.97
519.36
orthorhombic
Pnma (No. 62)
17.262(6)
18.244(6)
11.419(4)
orthorhombic
Pnma (No. 62)
18.641(5)
18.013(5)
11.793(3)
monoclinic
P21/n (No. 14)
12.602(8)
13.727(8)
13.601(8)
104.43(1)
2279(2)
4
monoclinic
P21/n (No. 14)
16.97(1)
9.739(6)
18.54(1)
109.313(8)
2893(3)
4
â, deg
V, Å3
3596(2)
4
8.97
1656.00
1.509
3960(2)
4
8.20
1784.00
1.464
Z
µ, cm-1
F(000)
9.49
1056.00
1.514
9.42
1312.00
1.479
D
calcd, g cm-3
cryst size, mm
exposure rate s/deg
no. of obsd data (I > 3σ(I))
no. of variables
R(Fo) (Rw(F0))
0.3 × 0.2 × 0.2
0.3 × 0.2 × 0.2
0.3 × 0.3 × 0.2
0.8 × 0.5 × 0.5
40.0
20.0
60.0
10.0
12 303
254
0.049 (0.054)
3.18
4202
270
0.038 (0.052)
1.09
3627
305
0.061 (0.070)
0.95
15 166
365
0.085 (0.096)
8.12
GOF
solid (82.6 mg, 74%). Anal. Calcd for C27H25ClN2Pd‚C3.5H4: C,
equilibrated via isomerization in solution. 1H NMR (300 MHz,
at 25 °C in CDCl3, obtained as a mixture of the cis and trans
isomers): δ 8.82 (br, NH), 8.38 (br, NH), 8.15 (d, J ) 8 Hz,
C6H4), 8.03 (d, J ) 8 Hz, C6H4), 7.95 (d, J ) 8 Hz, C6H4), 7.37
(d, J ) 8 Hz, C6H4), 7.34 (d, J ) 8 Hz, C6H4), 7.32 (d, J ) 8
Hz, C6H4), 7.28 (d, J ) 8 Hz, C6H4), 7.25 (d, J ) 8 Hz, C6H4),
7.05 (d, J ) 8 Hz, C6H4), 6.99 (d, J ) 8 Hz, C6H4), 6.58 (d, J )
8 Hz, C6H4), 6.46 (d, J ) 8 Hz, C6H4), 6.34 (s, cis, CHCl2), 4.81
(s, trans, CHCl2), 2.57 (s, Ar-Me), 2.56 (s, Ar-Me), 2.47 (s,
Ar-Me), 2.41 (s, Ar-Me), 2.35 (s, Ar-Me), 2.32 (s, Ar-Me).
Molecu la r Or bita l Ca lcu la tion s. Extended Hu¨ckel mo-
lecular orbital calculations were carried out by using param-
eters of the Coulomb integrals and the orbital exponents taken
from ref 8. The calculation was performed by using the
program CACAO.8 The geometrical assumption was derived
from simplification of the crystal structure of 4.
Cr ysta l Str u ctu r e Deter m in a tion . Crystals of 3 and 4
suitable for an X-ray diffraction study were obtained by
recrystallization from benzene at 3 °C and mounted in glass
capillary tubes under Ar. The data for 3 were collected at a
temperature of -160 ( 1 °C to a maximum 2θ value of 55.0°
on a Rigaku Saturn CCD area detector. Calculations were
carried out by using the program package CrystalStructure
for Windows. The structure was solved by direct methods and
expanded using Fourier techniques. A full-matrix least-squares
refinement was used for non-hydrogen atoms with anisotoropic
thermal parameters. Atomic scattering factors were obtained
from the literature.14 Crystals of 5 suitable for X-ray diffraction
study were obtained by crystallization from THF/Et2O.
Data for 4, 5, and 7 were collected under conditions similar
to those for 3. Crystallographic data and details of refinement
of the complexes are summarized in Table 2.
64.79; H, 5.17; N, 4.92; Cl, 6.27. Found: C, 64.72; H, 5.07; N,
1
4.95; Cl, 6.19. H NMR (300 MHz, at 25 °C in CDCl3): δ 9.22
(br, 2H, NH), 8.21 (d, 4H, J ) 8 Hz, C6H5 ortho), 7.58 (t, 2H,
J ) 8 Hz, C6H5 para), 7.52 (t, 2H, J ) 8 Hz, C6H5 para), 7.45
(t, 4H, J ) 8 Hz, C6H5 meta), 7.41 (t, 4H, J ) 8 Hz, C6H5 meta),
7.34 (d, 4H, J ) 8 Hz, C6H5 ortho), 7.25 (t, J ) 7 Hz, toluene,
meta), 7.17 (m, toluene, ortho and para), 2.36 (s, toluene),
-1.80 (s, 3H, Pd-Me). 13C{1H} NMR (75 MHz, at 25 °C in
CDCl3): δ 180.2 (NdC), 138.7 (C6H5 ipso), 137.2 (C6H5 ipso),
131.8 (C6H5 para), 131.4 (C6H5 para), 130.8, 128.7, 128.4, 127.7
(C6H5 ortho and meta), -4.1 (Pd-Me).
P r ep a r a tion of tr a n s-P d Cl(Me){NdC(C6H4Me-4)2}2 (6).
To a suspension of 4 (103 mg, 0.12 mmol) in THF (5 mL) was
added an Et2O solution of HCl (0.26 mmol; 1 M, 0.26 mL) at
room temperature. After 15 min of stirring, H2O was added
to the pale yellow solution. The organic layer was extracted
with Et2O and washed with H2O. The extracts were evaporated
and extracted with toluene. After filtration, the volatiles were
removed at reduced pressure to give 6 (55.8 mg, 83%).
Analytically pure complex was obtained by recrystallization
from toluene/hexane. Anal. Calcd for C31H33ClN2Pd‚C3.5H4: C,
66.67; H, 6.00; N, 4.51; Cl, 5.70. Found: C, 66.96; H, 6.17; N,
1
4.62; Cl, 6.10. H NMR (300 MHz, at 25 °C in CDCl3): δ 8.96
(br, 2H, NH), 8.10 (d, 4H, J ) 8 Hz, C6H4), 7.24 (d, 4H, J ) 8
Hz, C6H4), 7.23 (d, 4H, J ) 9 Hz, C6H4), 7.18 (d, 4H, J ) 9 Hz,
C6H4), 2.46 (s, Ar-Me), 2.38 (s, Ar-Me), -0.19 (s, 3H, Pd-
Me). 13C{1H} NMR (75 MHz, at 25 °C in CDCl3): δ 179.8 (Nd
C), 142.1 (C6H4 ipso), 141.6 (C6H4 ipso), 136.2 (C6H4 ipso), 134.5
(C6H4 ipso), 130.9, 129.3, 128.5, 128.3 (C6H4 ortho and meta),
21.7 (Ar-Me), 21.4 (Ar-Me), -4.1 (Pd-Me).
Rea ction of Cp 2Zr {µ-NdC(C6H4Me-4)2}2P d Cl(Me) (4)
w ith P h OH. A CDCl3 solution of 4 (8.1 mg, 9.3 µmol) and
PhOH (1.9 mg, 21 µmol) was stirred for 15 min. The quantita-
tive formation of 6 and Cp2Zr(OPh)2 was confirmed by 1H
10
Ack n ow led gm en t. This work was supported by a
Grant-in-Aid for Scientific Research from the Ministry
of Education, Science, Sports, and Culture of J apan and
partially supported by the 21st Century COE program.
We thank Prof. Tomoaki Tanase and Dr. Eri Goto for
useful discussion and encouragement.
NMR measurement.
P r ep a r a tion of cis- a n d tr a n s-P d Cl(CHCl2){NHdC-
(C6H4Me-4)2}2 (7). Complex 6 (55.1 mg, 0.096 mmol) was
dissolved in CH2Cl2 (7.7 mL). After it was stirred for 19 h
under light, the yellow solution was filtered and evaporated
to dryness. The residue was washed with hexane (10 mL × 1,
3 mL × 2) and dried under reduced pressure to give 7 (50.5
mg, 82%). Recrystallization of the product from CH2Cl2/hexane
afforded a complex with CH2Cl2 solvate as crystals. Anal. Calcd
for C31H31Cl3N2Pd‚C0.25H0.5Cl0.5: C, 56.39; H, 4.77; N, 4.21; Cl,
18.64. Found: C, 56.97; H, 4.70; N, 4.17; Cl, 18.76. It may be
assigned to cis-7, which was confirmed by X-ray crystal-
lography. A solution of the crystals showed the 1H NMR signals
of a mixture of the cis and trans isomers (1:2 ratio) which were
Su p p or tin g In for m a tion Ava ila ble: Crystallographic
data for 3-5 and 7. This material is available free of charge
via the Internet at http://pubs.acs.org.
OM0495269
(14) International Tables for X-ray Crystallography; Kynoch: Bir-
mingham, England, 1974; Vol. 4.