Flexible building blocks for transition metal early-late chemistry. Synthesis of eterobimetallic tetranuclear metallomacrocycles

Article abstract of DOI:10.1021/om050644l

The reaction of LiOCH₂PPh₂ with the metallocene compounds [Cp₂MCl₂] yields the metallodiphosphines [Cp₂M(OCH₂PPh₂)₂] (M = Ti (1), Zr (2)). Compound 2 has also been pre

Full text of DOI:10.1021/om050644l

Organometallics 2005, 24, 5929-5936
5929
Flexible Building Blocks for Transition Metal
Early-Late Chemistry. Synthesis of Heterobimetallic
Tetranuclear Metallomacrocycles
M. Carmen AÄ lvarez-Vergara, Miguel A. Casado, M. Luisa Mart´ın,
Fernando J. Lahoz, Luis A. Oro,* and Jesu´s J. Pe´rez-Torrente*
Departamento de Quı´mica Inorga´nica, Instituto Universitario de Cata´lisis Homoge´nea,
Instituto de Ciencia de Materiales de Arago´n, Universidad de Zaragoza-CSIC,
50009-Zaragoza, Spain
Received July 28, 2005
The reaction of LiOCH2PPh2 with the metallocene compounds [Cp2MCl2] yields the
metallodiphosphines [Cp2M(OCH2PPh2)2] (M ) Ti (1), Zr (2)). Compound 2 has also been
prepared by reaction of HOCH2PPh2 with [Cp2ZrMe2], although the reaction with [Cptt -
2
ZrMe2] (Cptt ) η5-1,3-di-tert-butylcyclopentadienyl) stops at the complex [Cptt ZrMe(OCH2-
2
PPh2)] (3). The mononuclear late transition metal complexes containing (diphenylphosphanyl)-
methanol ligands, cis-[M(cod)(Ph2PCH2OH)2]BF4 (M ) Rh (4), Ir (5)) and cis-[Pt(p-
tolyl)2(Ph2PCH2OH)2] (6), have been prepared by reaction of [M(cod)(NCCH3)2]BF4 and [Pt(µ-
SEt2)(p-tolyl)2]2 with HOCH2PPh2. The reaction of the metallodiphosphines 1 and 2 with
the compounds [M(diolef)(NCCH3)2]BF4 (M ) Rh, Ir) afforded the tetranuclear d0-d8 early-
late heterobimetallic (ELHB) metallomacrocycles [Cp2M(OCH2PPh2)2Ir(cod)]22+ (M ) Zr (7),
Ti (8)) and [Cp2Zr(µ-OCH2PPh2)2Rh(nbd)]22+ (9). The crystal structures of the 16-membered
metallomacrocycles 7 and 9 have been determined by X-ray diffraction and show a rhomboidal
arrangement of the metal centers with a conformation that is largely determined on steric
grounds.
Introduction
in cis position and rigid or semirigid aromatic bifunc-
tional ligands as connectors.3 However, this methodol-
ogy is not applicable to the synthesis of heterometallic
metallocycles for which the modular self-assembly
strategy is more convenient. In this context, mono-
nuclear complexes with strong covalently bound ligands
and accessible donor sites have been used as building
blocks for the synthesis of mixed Pd/Pt,4 Pd/Re,5 Pd/
Ru,6 and Ni/Pd7 heterobimetallic squares using the
modular approach.
Coordination-driven self-assembly has shown remark-
able potential in the construction of solid-state archi-
tectures with interesting physicochemical properties.1
The application of the directional bonding approach to
supramolecular synthesis has produced a great variety
of discrete geometrically shaped molecular architectures
known as metallacyclic polygons and polyhedra with
predesigned geometries.2 For example, molecular squares,
one of the simplest members of the polygon family, have
been typically assembled using square-planar Pd(II) or
Pt(II) complexes having two accessible coordination sites
(2) (a) Fujita, M. In Comprehensive Supramolecular Chemistry;
Lehn, J.-M., Ed.; Elsevier Science: New York, 1996; Vol. 9, p 253. (b)
Stang, P. J.; Olenyuk, B. Acc. Chem. Res. 1997, 30, 502. (c) Stang, P.
J. Chem. Eur. J. 1998, 4, 19. (d) Fujita, M. Chem. Soc. Rev. 1998, 27,
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T.; Biradha, K. Chem. Commun. 2001, 509. (i) Liu, X.; Stern, C. L.;
Mirkin, C. A. Organometallics 2002, 21, 1017. (j) Eisenberg, A. H.;
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Chem. Soc. 1998, 120, 9398. (i) Onitsuka, K.; Yamamoto, S.; Takahashi,
S. Angew. Chem., Int. Ed. 1999, 38, 174. (j) Wu¨rthner, F.; Sautter, A.
Chem. Commun. 2000, 445. (k) Ferrer, M.; Rodr´ıguez, L.; Rossell, O.
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* To whom correspondence should be addressed. E-mail:
oro@unizar.es; perez@unizar.es. Fax: 34 976761143.
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10.1021/om050644l CCC: $30.25 © 2005 American Chemical Society
Publication on Web 10/28/2005

5930 Organometallics, Vol. 24, No. 24, 2005
AÄ lvarez-Vergara et al.
The self-assembly of mixed-metallic molecular squares
requires predesigned angular modules with turning
angles close to 90°. However, early transition metal
metallocenes have also been successfully assembled into
homometallic molecular squares because of their usually
distorted tetrahedral geometry.8 On the other hand, it
has been shown that highly flexible ligands are required
to bring about square-planar and tetrahedral metal
centers into a molecular square, as was evidenced by
the synthesis of a Rh/Zn heterobimetallic molecular
square with a polydentate ligand containing salicyla-
ldiminato and hemilabile thioether-phosphine moieties.9
Very few heterobimetallic macrocycles containing met-
allocenes and late transition metals have been de-
scribed. The pre-eminent examples are the tetranuclear
Ti/Pt metallomacrocycles,10 which were assembled using
the flexible bis(pyridine-4-carboxylate)titanocene entity
as building block, although titanocene or zirconocene
dihalide complexes containing phophinoalkylcyclopen-
tadienyl ligands have also been assembled into tetra-
nuclear M/Rh (M ) Ti, Zr) metallomacrocycles.11
In view of that, we envisage the preparation of
angular flexible metalloligands based on the (alkoxym-
ethy)diphenylphosphine (µ-OCH2PPh2) ligand for the
modular self-assembly of heterobimetallic d0-d8 early-
late metallomacrocycles. This bridging ligand should be
compatible with both electron-rich and electron-poor
metals because of their ambivalent hard-soft character.
Thus, the hard alkoxide end will link preferably to early
metals and the softer phosphine end to late metals
(HSAB principle). In addition, the strong alkoxy-early
metal linkage should avoid ligand transfer reactions
between the electronically disparate metal centers, an
undesirable reaction in the synthesis of heterobimetallic
complexes.12 In fact, the ability of (oxyalkyl)phosphine
bridging ligands to stabilize dinuclear Zr/Rh, Zr/Pt, and
Zr/Ni heterobimallic complexes that mimic the interface
of heterogeneous catalysts has been demonstrated by
Wolczanski et al.13
ethy)diphenylphosphine and (diphenylphosphanyl)-
methanol ligands, respectively, and their successful
application in the construction of tetranuclear hetero-
bimatallic d0-d8 early-late metallomacrocycles.
Results and Discussion
Synthesis of Early Transition Metal Metallo-
phosphine Ligands. The synthesis of early metallo-
ligands containing the (alkoxymethy)diphenylphosphine
ligand was readily accomplished from the lithium salt
LiOCH2PPh2, which was obtained in situ by reaction of
HOCH2PPh2 with n-BuLi in tetrahydrofuran. The reac-
tion of LiOCH2PPh2 with the dichloro compounds [Cp2-
MCl2] in a 2:1 molar ratio led to the formation of the
metallocene complexes [Cp2M(OCH2PPh2)2] (M ) Ti (1),
Zr (2)), which were isolated as highly moisture-sensitive
yellow oils in good yield. An alternative synthesis for
compound 2 involves an alcoholysis procedure. Thus, the
reaction of [Cp2ZrMe2] with HOCH2PPh2 (1:2 molar
ratio) resulted in the immediate evolution of CH4 and
the formation of [Cp2Zr(OCH2PPh2)2] (2) in comparable
yield. The metallodiphosphines 1 and 2 were character-
ized by microanalysis, mass spectra, and NMR spec-
troscopy. The 31P{1H} NMR spectra of both complexes
showed a single resonance at δ -6.50 (1) and -9.68 ppm
(2) indicative of an uncoordinated phosphine moiety by
comparison with that of HOCH2PPh2 (δ -11.84 ppm).14
In addition, the methylene fragments of the alcoxy
groups for compounds 1 and 2 were observed as char-
1
acteristic doublets, at δ 4.98 and 4.78 ppm in the H
NMR spectra and at δ 78.9 and 75.1 ppm in the 13C-
{1H} NMR spectra, respectively, due to the coupling to
phosphorus.
The synthesis of related metallodiphosphines with a
more protected early metal center prompted us to utilize
the compound [Cptt2ZrMe2] that contains the bulky η5-
1,3-di-tert-butylcyclopentadienyl ligand. The reaction of
[Cptt2ZrMe2] with HOCH2PPh2 in toluene at 60 °C gave
the compound [Cptt2ZrMe(OCH2PPh2)] (3) indepen-
dently of the molar ratio used. Thus, the steric shield
at the metal center after the introduction of 1 molar
equiv of HOCH2PPh2 prevents the alcoholysis of the
second Zr-Me bond even after prolonged heating with
an excess of ligand at reflux in toluene. Compound 3
was obtained as a moderately stable white solid in high
yield. The 31P{1H} NMR spectrum of 3 exhibited a single
resonance at δ -15.9 ppm, and it is consistent with an
uncoordinated phosphine fragment. The 1H NMR spec-
trum of 3 showed three triplets for the C-H protons
and two single resonances for the tBu protons of the two
equivalent Cptt rings, in agreement with the Cs sym-
metry of the molecule. It is noticeable that no rotamers
were observed in solution due the relative disposition
of the tert-butyl substituents, indicating free rotation
of the Cptt groups.15 The equivalent methylene protons
of the alkoxy-phosphine moiety were observed as a
We report herein the synthesis of complementary
early and late metalloligands containing the (alkoxym-
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Organometallics 1999, 18, 3502.
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1
doublet at δ 5.14 ppm in the H NMR spectrum. The
(14) Ferguson, G. S.; Wolczanski, P. T.; Pa´rkaa´nyi, L.; Zonnevylle,
M. C. Organometallics 1988, 7, 1967.
(15) (a) Hernandez-Gruel, M. A. F.; Pe´rez-Torrente, J. J.; Ciriano,
M. A.; Rivas, A. B.; Lahoz, F. J.; Dobrinovitch, I. T.; Oro, L. A.
Organometallics 2003, 22, 1237. (b) Hernandez-Gruel, M. A. F.; Pe´rez-
Torrente, J. J.; Ciriano, M. A.; Lo´pez, J. A.; Lahoz, F. J.; Oro, L. A.
Eur. J. Inorg. Chem. 1999, 2047.

Heterobimetallic Tetranuclear Metallomacrocycles
Organometallics, Vol. 24, No. 24, 2005 5931
Zr-Me fragment was observed at δ 0.59 ppm in the 1H
NMR spectrum and at δ 23.6 ppm in the 13C{1H} NMR
spectrum.
Scheme 1
Synthesis of (Diphenylphosphanyl)methanol
Late Transition Metal Complexes. The cationic d8
mononuclear square-planar [M(cod)(NCCH3)2]BF4 (M )
Rh, Ir) complexes with two cis-coordinated labile aceto-
nitrile ligands are convenient precursors for the syn-
thesis of late metalloligands containing two (diphe-
nylphosphanyl)methanol ligands in cis disposition. The
reaction of [M(cod)(NCCH3)2]BF4 with 2 molar equiv of
HOCH2PPh2 afforded the bisphosphine derivatives cis-
[M(cod)(Ph2PCH2OH)2]BF4 (M ) Rh (4), Ir (5)), which
were isolated as yellow and red microcrystalline solids,
respectively, in high yield. Both compounds behaved as
1:1 electrolytes in acetone and displayed the molecular
ion in the FAB+ mass spectra. The spectroscopic data
for both complexes are very similar. In particular, the
1H NMR spectra showed the expected 2:1 ratio for the
HOCH2PPh2:cod ligands. The 31P{1H} NMR spectra
consisted of a doublet at δ 21.6 ppm (JP-Rh ) 141.9 Hz)
for 4 and a single resonance at δ 12.3 ppm for compound
5, which are indicative of a P-coordination of the
(diphenylphosphanyl)methanol ligands. The -OH reso-
nance was observed as a broad resonance at 3.3 ppm in
both complexes. In addition, the CH2P fragment in
compound 4 was observed a doublet of doublets in the
13C{1H} NMR spectrum by additional coupling to rhod-
ium.
The dinuclear compound [Pt(µ-SEt2)(p-tolyl)2]2 con-
taining the labile diethyl sulfide ligands behaves as a
source of unsaturated cis-PtR2 fragments.16 Thus, the
reaction with 4 molar equiv of HOCH2PPh2 gave the
compound cis-[Pt(p-tolyl)2(Ph2PCH2OH)2] (6), which was
isolated as a white solid in excellent yield. The spec-
troscopic data for compound 6 are in agreement with a
mononuclear formulation having equivalent (diphe-
nylphosphanyl)methanol and p-tolyl ligands. The P-
coordination of the Ph2PCH2OH ligands is supported by
the 31P{1H} NMR spectrum that consisted of a singlet
at δ 8.06 ppm exhibiting the characteristic 195Pt satel-
lites (JPt-P ) 1804 Hz).
Synthesis of Early-Late Heterobimetallic Met-
allomacrocycles. Molecular models indicate that the
compounds [Cp2M(OCH2PPh2)2] are capable of behaving
as both chelating and/or bridging metallodiphosphines
due to their adequate flexibility. However, we have
found a preference for the bridging coordination mode
that allowed us to prepare early-late heterobimetallic
tetranuclear complexes.
The reaction of [Cp2Zr(OCH2PPh2)2] (2) with [Ir(cod)-
(NCCH3)2]BF4 in a 1:1 molar ratio in dichloromethane
gave an insoluble pink microcrystalline solid, isolated
in moderate yield, which was characterized as the
tetranuclear compound [Cp2Zr(µ-OCH2PPh2)2Ir(cod)]2-
(BF4)2 (7). Noteworthy, this compound can also be
prepared from [Ir(cod)(Ph2PCH2OH)2]BF4 (5). Thus, the
reaction of 5 with [Cp2ZrMe2] in a 1:1 molar ratio gave
7 in similar yield upon evolution of methane (Scheme
1). In the same way, the compound [Cp2Ti(µ-OCH2-
PPh2)2Ir(cod)]2(BF4)2 (8) was obtained from the reaction
of [Cp2Ti(OCH2PPh2)2] (1) with [Ir(cod)(NCCH3)2]BF4
under similar conditions.
To get precise insight into the macrocycle conforma-
tion and details of molecular parameters of [Cp2Zr(µ-
OCH2PPh2)2Ir(cod)]2(BF4)2 (7), suitable crystals for X-
ray diffraction were obtained by slow diffusion of a
dichloromethane solution of 5 into a solution of com-
pound [Cp2ZrMe2] in toluene at 4 °C. A molecular
2+
diagram of the cation [Cp2Zr(µ-OCH2PPh2)2Ir(cod)]2
is shown in Figure 1 and confirms the formation of a
Zr/Ir tetranuclear heterobimetallic metallomacrocycle.
The crystallographic study has shown that only half the
tetranuclear molecule is independent, as the whole
dication is positioned around an inversion center of
symmetry; selected bond lengths and angles are given
in Table 1. The heterobimetallic macrocycle contains
alternating zirconium and iridium metal atoms and
displays a rhomboidal arrangement of the metal centers.
The longest intermetallic separation has been detected
between iridium centers (10.4134(4) Å), whereas the Zr‚
‚‚Zr distance is significantly shorter, 8.5502(8) Å. The
Zr‚‚‚Ir separations are too long, 6.7353 and 6.7385(6)
Å, to display any intermetallic cooperativity. The ligand
arrangement around the zirconium center is distorted
tetrahedral by coordination of two η5-cyclopentadienyl
rings and two oxygen atoms of the (alkoxymethyl)-
diphenylphosphine ligands. The geometry around the
iridium atoms is square-planar by coordination of two
phosphorus atoms of the two bridging phosphines and
two olefinic bonds of a η4-1,5-cyclooctadiene ligand. The
interatomic bond distances and angles in the 16-
membered metallomacrocycle ring show values in the
usual ranges for these types of atoms and hybridiza-
tions;17 this is indicative of an unstrained conformation
and of a facile assembly process. In particular, the P(1)-
(16) (a) Casado, M. A.; Canty, A. J.; Lutz, M., Patel, J.; Speck, A.
L.; Sun, H.; Van Koten, G. Inorg. Chim. Acta 2002, 327, 15. (b) Lindner,
E.; Veigel, R.; Ortner, K.; Nachtigal, C.; Steimann, M. Eur. J. Inorg.
Chem. 2000, 959.

5932 Organometallics, Vol. 24, No. 24, 2005
AÄ lvarez-Vergara et al.
process in solution involving a conformational change
of the flexible 16-membered metallomacrocycle. This
dynamic process makes the four Cp ligands equivalent,
and as a consequence, a single resonance was observed
for the cyclopentadienyl protons in the 1H NMR spectra
of both compounds. Similarly, the cyclooctadiene ligands
in both complexes displayed a broad resonance for the
equivalent dCH protons. The 31P{1H} NMR spectra of
7 and 8 consisted of a single resonance, at δ 23.45 and
27.0 ppm, respectively, in agreement with the chemical
equivalence of the four (alkoxymethy)diphenylphosphine
ligands.
On the other hand, the FAB+ spectra of both com-
plexes showed the heterodinuclear ions [Cp2M(OCH2-
PPh2)2Ir(cod)]+ (M ) Ti, Zr) at m/z 951 and 909,
respectively, but not the tetranuclear molecular ions.
However, the tetranuclear ion [Cp2Ti(OCH2PPh2)2Ir-
(cod)]2(BF4)+ was detected in the FAB+ spectrum of
compound 8, and the molecular ion was observed in the
MALDI-TOF spectrum of compound 7. These data
strongly support that the heterobimetallic tetranuclear
structures are sustained in solution and rule out any
fragmentation into dinuclear species.
The related heterobimetallic tetranuclear macrocycles
Ti/Rh and Zr/Rh have been prepared following the same
synthetic protocols used in the preparation of the
iridium metallomacrocycles. The compounds were ob-
tained directly as yellow solids in moderate yields.
Despite that the FAB+ showed the heterodinuclear ions
[Cp2M(OCH2PPh2)2Rh(cod)]+ (M ) Ti, Zr), at m/z 819
and 863, respectively, their characterization in solution
became difficult because of their low solubility in a wide
range of solvents, where they gradually decomposed to
give an unidentified mixture of many different species,
as confirmed by the 31P{1H} and 1H NMR spectra.
Additionally, these compounds were too air-sensitive to
give satisfactory elemental analysis.
Figure 1. Molecular diagrams showing the structure of
the cation of [Cp2Zr(µ-OCH2-PPh2)2Ir(cod)]2(BF4)2 (7): (a)
ellipsoid representation together with labeling scheme
used; (b) schematic view of the 16-membered metallacycle
conformation (olefins and phenyl groups have been omit-
ted).
Nevertheless, more conclusive results were obtained
when shifting to another diolefin such as norborna-2,5-
diene (nbd). The reaction of [Cp2Zr(OCH2PPh2)2] (2)
with [Rh(nbd)(NCCH3)2]BF4 in a 1:1 molar ratio in
dichloromethane gave an orange solution, from which
an orange solid could be isolated in moderate yield. The
spectroscopic analysis by NMR of this solid showed the
presence of two compounds. However, the crystallization
of this mixture from dichloromethane/hexane resulted
in red crystals of the tetranuclear heterobimetallic
metallomacrocycle [Cp2Zr(µ-OCH2PPh2)2Rh(nbd)]2(BF4)2
(9), as was confirmed by an X-ray diffraction study. The
NMR data for compound 9 compare well with those for
Ir-P(2) bond angle, 95.16(4)°, is very close to the ideal
value expected for a square-planar coordination, bearing
also in mind the presence of a chelate diolefinic ligand;
in the zirconium environment the O(1)-Zr-O(2′) bond
angle (95.74(15)°) clearly reflects the high space re-
quirement of the two coordinated Cp ligands (G(3)-Zr-
G(4), 127.73(10)°). The conformational geometry of the
metallomacrocycle seems to be dictated by the steric
repulsions of the bulky diphenylphosphino groups that,
in this way (see torsional angles in Table 1), are placed
further apart from the Cp and cod ligands. Figure 1b
displays a schematic view of the metallocycle along the
coplanar iridium coordination environments and shows
both “Cp2ZrOCH2-” fragments located up and down of
this plane, resembling an analogue of a classical chair
conformer. It is worth mentioning that the accessibility
of the metallomacrocyclic cavity is significantly reduced
by the steric influence of both Cp and phenyl rings of
the phosphine groups. In fact, neither the solvent
dichloromethane molecules nor the tetrafluoroborate
counteranions are found to be into this cavity.
1
the metallomacrocycles 7 and 8. In particular, the H
NMR spectrum showed a single resonance for the
equivalent cyclopentadienyl rings at δ 6.37 ppm and the
expected 2:1 ratio for the OCH2PPh2:nbd ligands. The
31P{1H} NMR spectrum displayed a sole doublet at δ
19.3 ppm (JP-Rh ) 153.9 Hz) for the equivalent alkoxy-
phosphine ligands. Additionally, the FAB+ mass spec-
trum showed the heterodinuclear ion [Cp2Zr(OCH2-
PPh2)2Rh(nbd)]+ at m/z 847, and the MALDI-TOF an
ion at m/z 1991 that resulted from the interaction of
the heterotetranuclear ion with the matrix (ditranol).
On the other hand, the second minority species, which
could not be isolated and characterized, displayed a
doublet at 32.54 ppm (JP-Rh ) 145.3 Hz) in the 31P{1H}
The spectroscopic data for complexes 7 and 8 evi-
denced a higher symmetry than that observed for the
molecular framework in the solid state (C2h). This fact
is straightforwardly explained assuming a dynamic
(17) Allen, F. H. Acta Crystallogr. 2002, B58, 380.

Heterobimetallic Tetranuclear Metallomacrocycles
Organometallics, Vol. 24, No. 24, 2005 5933
9 (M ) Rh) b
Table 1. Selected Bond Lengths (Å) and Bond and Torsion Angles (deg) for 7 and 9a
7 (M ) Ir)
M-P(1)
2.3285(13)
2.3408(13)
2.218(5)
2.312(3)
2.294(3)
2.322(3)
2.194(10)
2.190(10)
2.202(10)
2.188(10)
1.372(15)
1.370(15)
1.853(11)
1.853(11)
1.392(12)
1.388(12)
1.960(7)
2.008(7)
2.474-2.562(13)
2.535-2.546(11)
2.225(8)
2.245(5)
97.12(10)
97.5(2)
M-P(2)
2.314(3)
2.209(11)
2.208(10)
2.208(10)
2.192(11)
1.396(15)
1.365(16)
1.830(10)
1.871(10)
1.391(11)
1.388(12)
1.997(7)
1.984(7)
2.502-2.558(11)
2.506-2.586(11)
2.219(6)
2.242(5)
97.38(10)
96.9(2)
M-C(1)
M-C(2)
2.197(5)
M-C(5)
2.219(5)
M-C(6)
2.203(5)
C(1)-C(2)
1.390(8)
C(5)-C(6)
1.372(7)
P(1)-C(9)
1.846(5)
P(2)-C(44)
1.858(5)
O(1)-C(9)
1.398(6)
O(2)-C(44)
1.387(6)
Zr-O(1)
1.973(3)
Zr-O(2′)
2.007(3)
Zr-C(Cp1)c
2.533-2.566(5)
2.516-2.545(6)
2.254(2)
Zr-C(Cp2)c
Zr-G(3) d
Zr-G(4) d
2.231(3)
95.16(4)
P(1)-M-P(2)
P(1)-M-G(1)d
P(1)-M-G(2)d
P(2)-M-G(1)d
P(2)-M-G(2)d
G(1)-M-G(2)d
O(1)-Zr-O(2′)
O(1)-Zr-G(3)d
O(1)-Zr-G(4)d
O(2′)-Zr-G(3)d
O(2′)-Zr-G(4)d
G(3)-Zr-G(4)d
M-P(1)-C(9)
P(1)-C(9)-O(1)
C(9)-O(1)-Zr
M-P(2)-C(44)
P(2)-C(44)-O(2)
C(44)-O(2)-Zr(1′)
O(2′)-Zr(1)-O(1)-C(9)
Zr(1)-O(1)-C(9)-P(1)
O(1)-C(9)-P(1)-M
C(9)-P(1)-M-P(2)
P(1)-M-P(2)-C(44)
M-P(2)-C(44)-O(2)
P(2)-C(44)-O(2)-Zr(1′)
C(44)-O(2)-Zr(1′)-O(1′)
91.05(12)
173.22(10)
173.73(13)
89.36(10)
84.54(15)
95.74(15)
106.64(12)
106.24(12)
104.24(12)
111.56(13)
127.73(10)
116.10(17)
110.7(3)
162.9(2)
165.7(2)
96.4(2)
69.8(3)
96.7(3)
166.5(2)
165.3(2)
95.5(2)
70.1(3)
97.5(3)
106.1(3)
105.0(3)
110.6(3)
105.9(3)
128.1(2)
120.9(3)
112.2(7)
139.0(6)
116.4(3)
114.9(7)
146.7(6)
-75.7(10)
164.8(6)
174.7(5)
52.8(4)
105.3(3)
105.9(3)
110.8(3)
104.4(2)
128.6(2)
115.0(3)
111.3(7)
151.6(6)
118.4(3)
114.2(7)
141.1(6)
-92.5(14)
177.3(9)
173.8(6)
62.9(4)
147.8(3)
116.87(16)
114.3(3)
145.6(3)
-85.4(6)
172.9(4)
172.9(3)
58.4(2)
34.0(2)
36.0(4)
33.0(4)
167.7(3)
166.9(6)
-143.3(8)
-92.1(12)
172.1(6)
-162.8(6)
-70.2(11)
-155.3(4)
-77.6(6)
a Primed atoms are related to the unprimed ones by the symmetry transformation -x, 2-y, 2-z (7), 1-x, 2-y, -z and 1-x, 2-y, 1-z
(9). b Complex 9 presents two independent half-molecules. c Range values for the Zr-C bond distances of the C(34)-C(38) (Cp1) and
C(39)-C(43) (Cp2) cyclopentadienyl rings. d G(1) and G(2) represent the midpoints of the C(1)-C(2) and C(5)-C(6) olefinic double bonds;
G(3) and G(4), the centroids of the two Cp rings.
NMR spectrum and a single resonance for the Cp
1
ligands at 5.59 ppm in the H NMR spectrum in CD2-
Cl2.
The molecular structure of the cation of [Cp2Zr(µ-
OCH2PPh2)2Rh(nbd)]2(BF4)2 (9) is shown in Figure 2,
and selected bond distances and angles are collected in
Table 1. The crystal structure shows the existence of
two independent dinuclear moieties that generate two
slightly different tetranuclear complexes through sym-
metry-related atoms (inversion centers). The molecular
structures of both molecules show the expected 16-
membered Zr/Rh tetranuclear heterobimetallic macro-
cycle with an alternated rhomboidal disposition of the
metal centers analogous to that observed in 7. The
structural parameters of the metallomacrocycles 7 and
9 are comparable, and actually both cycles roughly
exhibit the same conformation (see Table 1). This
conformation seems to be the more adequate to accom-
Figure 2. Molecular diagram showing the structure of the
modate the bulky tetrahedral zirconium centers and the
cation of [Cp2Zr(µ-OCH2PPh2)2Rh(nbd)]2(BF4)2 (9). Only one
square-planar rhodium fragments. The distance be-
of the two independent molecules is shown.
tween the zirconium atoms (8.6385 and 8.5019(14) Å)
is slightly longer than that found in compound 7, and
the separation between the rhodium atoms (10.2954 and
10.3717(16) Å) is also somewhat longer than the separa-
tion between the iridium atoms in compound 7. The Zr-

5934 Organometallics, Vol. 24, No. 24, 2005
AÄ lvarez-Vergara et al.
carried out in a drybox. The compounds [Pt(µ-SEt2)(p-tolyl)2]2,20
[Cp2ZrMe2],21 [Cptt2ZrMe2],22 and (hidroxymethyl)diphenylphos-
phine23 were prepared as described previously. [M(diolef)-
(NCCH3)2]BF4 (diolef ) cod, M ) Rh, Ir; diolef ) nbd, M )
Rh) were obtained following a slight modification of the
literature procedure.24 The compounds [Cp2MCl2] (M ) Ti, Zr)
were purchased from Aldrich and used as received.
Physical Measurements. Elemental C, H, and N analyses
were performed in a 240-C Perkin-Elmer microanalyzer.
Conductivities were measured in ca. 5 × 10-4 M acetone
solutions using a Phillips PW 9501/01 conductimeter. Mass
spectra were recorded in a VG Autospec double-focusing mass
spectrometer operating in the FAB+ or EI+ mode. MALDI-TOF
spectra were recorded in a REFLEX MALDI spectrometer
operating in the linear and reflector modes using dithranol
as matrix. 1H, 13C{1H}, and 31P{1H} NMR spectra were
recorded on a Varian Gemini 300 spectrometer operating at
300.08, 75.46, and 121.47 MHz, respectively. Chemical shifts
are reported in ppm and referenced to SiMe4 using the signal
of the deuterated solvent (1H and 13C) and 85% H3PO4 (31P) as
external reference, respectively.
Rh distances lie in the range 6.6529-6.7577(15) Å. It
is also interesting to mention that the average Zr-O
distances in 7 (1.990(2) Å) and in 9 (1.987(4) Å) are short
enough to propose a weak zirconium-oxygen π inter-
action,12e,18 which is corroborated by the large Zr-O-C
bond angles observed in both compounds (mean val-
ues: 146.7(2)° in 7 and 144.6(3)° in 9).
Ligand Transfer Reactions. The synthesis of Ti/
Pt or Zr/Pt heterobimetallic compounds following a
similar synthetic strategy has been unsuccessful. First,
the compound [Pt(p-tolyl)2(Ph2PCH2OH)2] (6) is less
reactive than the related rhodium and iridium coun-
terparts, and second, ligand transfer or exchange reac-
tions between the divergent metals have been observed.
It is interesting that these undesirable reactions are
believed to proceed through heterobimetallic intermedi-
ates where the ligand redistribution takes place.12b
The compound cis-[Pt(p-tolyl)2(Ph2PCH2OH)2] (6) was
unreactive toward [Cptt2ZrMe2] and [Cp2ZrMe2] at room
temperature. However, the reaction took place gradually
at higher temperature to give a complex mixture of
species as deduced from the 31P{1H} NMR spectra. On
the other hand, monitoring of the reaction between the
compounds [Cp2M(OCH2PPh2)2] (1, 2) and 0.5 molar
equiv of [Pt(µ-SEt2)(p-tolyl)2]2 in benzene-d6 evidenced
the immediate formation of cis-[Pt(p-tolyl)2(Ph2PCH2-
OH)2] (6) along with other unidentified titanium- or
zirconium-containing species. As the driving force for
the ligand transfer could not be attributed to the hard/
soft mismatching between the donor atoms of the
alkoxy-phosphine bridging ligands in the heterobime-
tallic intermediates, we suggest that the formation of 6
is a consequence of the extreme sensitivity to the
adventitious water in the reaction media of these
intermediate compounds.
Synthesis of the Complexes. [Cp2Ti(OCH2PPh2)2] (1).
To a solution of HOCH2PPh2 (1.0 g, 4.625 mmol) in THF (20
mL) was added a solution of n-BuLi 1.6 M in hexanes (2.9 mL,
4.640 mmol) to give a pale orange solution of LiOCH2PPh2.
The addition of solid [Cp2TiCl2] (0.548 g, 2.202 mmol) gave a
yellow-greenish solution, which was stirred for 10 min. The
solvent was removed under vacuum and the residue extracted
with toluene (20 mL) and filtered through a short pad of
kiesselghur under argon to give a yellow solution. The solution
was brought to dryness to give the compound as a yellow oil,
which was dried in vacuo. Yield: 1.165 g (87%). 1H NMR (C6D6,
293 K): δ 7.31 (m, 8H), 7.22 (m, 12H) (Ph), 5.72 (s, 10H, Cp),
2
4.98 (d, 4H, JH-P ) 8.4 Hz, CH2P). 31P{1H} NMR (C6D6, 293
K): δ - 6.50 (s). 13C{1H} NMR (C6D6, 293 K): δ 137.7 (d, 1JC-P
2
) 14.3 Hz, Ci Ph), 133.9 (d, JC-P ) 17.9 Hz, Co Ph), 128.7-
128.4 (set of m, Ph), 114.5 (s, Cp), 78.9 (d, JC-P ) 12.4 Hz,
CH2P). Anal. Calcd for C36H34O2P2Ti: C, 71.06; H, 5.63.
Found: C, 70.89; H, 5.45. MS (EI+, CH2Cl2, m/z): 543 (M+
-
Cp, 13%), 328 (M+ - Cp - OCH2PPh2, 10%), 263 (M+ - 2Cp
- OCH2PPh2, 28%).
Concluding Remarks
[Cp2Zr(OCH2PPh2)2] (2). Method A. To a solution of
LiOCH2PPh2 (2.312 mmol), prepared as described previously,
in THF (20 mL) was added solid [Cp2ZrCl2] (0.338 g, 1.156
mmol) to give a pale yellow solution, which was stirred for 20
min. Workup as described above gave the compound as a pale
yellow oil, which was dried in vacuo. Yield: 0.700 g (93%).
Method B. A Schlenk tube was charged with [Cp2ZrMe2] (0.087
g, 0.347 mmol) and PPh2CH2OH (0.150 g, 0.694 mmol) and
the solid mixture dissolved in toluene (10 mL) to give a
colorless solution with evolution of methane. The solution was
stirred for 1.5 h and the solvent removed under vacuum to
give a pale yellow oil, which was dried in vacuo. Yield: 0.190
g (84%). 1H NMR (C6D6, 293 K): δ 7.58 (m, 8H), 7.16 (m, 12H)
We have applied the HSAB principle for the design
of flexible early transition metal metallodiphosphines
containing (alkoxymethy)diphenylphosphine ligands.
These complexes behave as metalloligands for late
2d
transition metals and are useful for the A22aA2 as-
sembly19 of d0-d8 early-late heterobimetallic (ELHB)
macrocycles of composition Ti/Ir, Zr/Rh, and Zr/Ir. This
modular synthetic strategy overcomes the ligand redis-
tribution reactions frequently observed in the synthesis
of ELHB complexes. Interestingly, the zirconium met-
allomacrocycles can also be assembled using an alterna-
tive covalent strategy using rhodium and iridium com-
plexes containing (diphenylphosphanyl)methanol ligands.
2
(Ph), 5.82 (s, 10H, Cp), 4.78 (d, 4H, JH-P ) 8.1 Hz, CH2P).
31P{1H} (C6D6, 293 K): δ -9.68 (s). 13C{1H} NMR (C6D6, 293
2
K): δ 138.4 (d, JC-P ) 15.2 Hz, Ci Ph), 134.0 (d, JC-P ) 17.5
Hz, Co Ph), 128.7 (s, Cm Ph), 128.6 (s, Cp Ph), 112.2 (s, Cp),
75.1 (d, JC-P ) 8.3 Hz, CH2P). Anal. Calcd for C36H34O2P2Zr:
C, 66.33; H, 5.26. Found: C, 66.25; H, 5.21. MS (FAB+, CH2-
Cl2, m/z): 585 (M+ - Cp, 10%), 435 (M+ - OCH2PPh2, 57%),
370 (M+ - Cp - OCH2PPh2, 10%), 220 (M+ - 2 OCH2PPh2,
80%).
Experimental Section
General Methods. All manipulations were performed
under a dry argon atmosphere using Schlenk-tube techniques.
Solvents were dried by standard methods and distilled under
argon immediately prior to use. The reactions involving the
metallodiphosphines [Cp2M(OCH2PPh2)2] (M ) Ti, Zr) were
(20) Kauffman, G. B.; Cowan, D. O. Inorg. Synth. 1960, 6, 211.
(21) Samuel, E.; Rausch, M. D. J. Am. Chem. Soc. 1973, 95, 6263.
(22) Hernandez-Gruel, M. A. F.; Pe´rez-Torrente, J. J.; Ciriano, M.
A.; Lo´pez, J. A.; Lahoz, F. J.; Oro, L. A. Eur. J. Inorg. Chem. 1999,
2047.
(23) Hellmann, von H.; Bader, J.; Brikner, H.; Schumacher, O.
Liebigs Ann. Chem. 1962, 659, 49.
(24) Green, M.; Kuc, T. A.; Taylor, S. H. J. Chem. Soc. (A) 1971,
2334.
(18) (a) Spaether, W.; Klass, K.; Erker, G.; Zippel, F.; Froehlich, R.
Chem. Eur. J. 1998, 4, 1411. (b) Howard, W. A.; Trnka, T. M.; Waters,
M.; Parkin, G. J. Orgonomet. Chem. 1997, 528, 95. (c) Siedle, A. R.;
Newmark, R. A.; Kamanna, W. M.; Huffman, J. C. Organometallics
1993, 12, 1491.
(19) (a) Swiegers, G. F.; Malefetse, T. J. Chem. Eur. J. 2000, 7, 3637.
(b) Swiegers, G. F.; Malefetse, T. J. Coord. Chem. Rev. 2002, 225, 91.

Heterobimetallic Tetranuclear Metallomacrocycles
Organometallics, Vol. 24, No. 24, 2005 5935
[Cptt2ZrMe(OCH2PPh2)] (3). A Kontes tube was charged
with [Cptt2ZrMe2] (0.200 g, 0.420 mmol) and PPh2CH2OH
(0.909 g, 0. 420 mmol) and the solid mixture dissolved in
toluene (10 mL) to give a colorless solution, which was stirred
for 6 h at 60 °C. The solution was cooled to room temperature
and the solvent removed under vacuum to give a colorless oil,
which solidified after 2 days at 4 °C. Yield: 0.126 g (93%). 1H
NMR (C6D6, 293 K): δ 7.65 (m, 4H), 7.23 (m, 6H) (Ph), 6.51 (t,
2H, JH-H ) 2 Hz), 5.87 (t, 2H, JH-H ) 2.7 Hz), 5.65 (t, 2H,
JH-H ) 2.5 Hz) (Cptt), 5.14 (d, 2H, 3JH-P ) 3.7 Hz, CH2P), 1.39
(s, 18H, tBu), 1.36 (s, 18H, tBu), 0.59 (s, 3H, Me). 31P{1H} NMR
(C6D6, 293 K): δ -15.9 (s). 13C{1H} NMR (C6D6, 293 K): δ
138.3-128.6 (set of m, Ph), 139.5, 137.9 (s, CCMe), 112.0,
102.8, 102.1 (s, CH, Cptt), 78.0 (d, JC-P ) 5.0 Hz, CH2P), 33.6,
32.9 (s, CMe3), 31.5, 31.3 (s, CH3), 23.6 (s, Zr-CH3). Anal.
Calcd for C40H57OPZr: C, 71.06; H, 8.40. Found: C, 70.38; H,
8.22. MS (FAB+, toluene, m/z): 676 (M+, 24%), 660 (M+ - CH3,
100%), 445 (M+ - CH3 - OCH2PPh2, 72%).
[Ir(cod)(NCCH3)2]BF4 (0.106 g, 0.227 mmol) in dichloromethane
(20 mL) to give a pink suspension within 5 min. The suspen-
sion was stirred for 2 h and the pink solid filtered, washed
with dichloromethane, and dried under vacuum. Yield: 0.120
g (51%). Method B. To a solution of [Ir(cod)(Ph2PCH2OH)2]BF4
(5) (0.100 g, 0.122 mmol) in dichloromethane (7 mL) was added
solid [Cp2ZrMe2] (0.031 g, 0.122 mmol) to give a pink suspen-
sion within 5 min upon evolution of methane, which was
stirred for 1 h. Workup as described above gave the compound
as a reddish pink microcrystalline solid. Yield: 0.072 g (59%).
1H NMR (CD3CN, 293 K): δ 7.9-7.4 (m, 40H, Ph), 5.52 (s,
2
20H, Cp), 4.41 (d, JH-P ) 3.9 Hz, 8H, CH2P), 4.16 (m, 8H,
dCH), 2.19 (m, 8H, CH2), 2.03 (m, 4H, CH2) (cod). 31P{1H}
NMR (CD3CN, 293 K): δ 23.45 (s). 13C{1H} NMR (CD3CN, 293
K): δ 134.4-128.5 (set of m, Ph), 112.6 (s, Cp), 86.3 (s, CdC
cod), 62.5 (m, CH2P), 31.4 (s, CH2 cod). Anal. Calcd for
C88H92B2F8Ir2O4P4Zr2: C, 50.86; H, 4.46. Found: C, 50.79; H,
4.28. MS (FAB+, CH3CN, m/z): 951 (M/2+, 12%). MALDI-TOF
(CH3CN, m/z): 1991 [M2+ + BF4-]+.
[Rh(cod)(Ph2PCH2OH)2]BF4 (4). Solid [Rh(cod)(NCCH3)2]-
BF4 (0.100 g, 0.263 mmol) was added to a solution of HOCH2-
PPh2 (0.114 g, 0.527 mmol) in CH2Cl2 (10 mL) to give an orange
solution. This solution was stirred for 30 min and then
concentrated under vacuum to ca. 2-3 mL. Slow addition of
diethyl ether (20 mL) gave a yellow oily solid. The solution
was decanted and the residue stirred with diethyl ether (20
mL). The resulting yellow solid was filtered, washed with
diethyl ether, and dried under vacuum. Yield: 0.159 g (83%).
1H NMR (CDCl3, 293 K): δ 7.60-7.25 (set of m, 20H, Ph), 4.69
(br m, 4H, dCH, cod), 4.29 (br s, 4H, CH2P), 3.35 (m, 2H, OH),
2.38 (m, 4H), 2.19 (m, 4H) (CH2 cod). 31P{1H} NMR (CDCl3,
293 K): δ 21.6 (d, JP-Rh ) 141.9 Hz). 13C{1H} NMR (CDCl3,
293 K): δ 134-128 (set of m, Ph), 98.6 (m, dCH, cod), 61.7
[Cp2Ti(µ-OCH2PPh2)2Ir(cod)]2(BF4)2 (8). A solution of [Ir-
(cod)(NCCH3)2]BF4 (0.125 g, 0.266 mmol) in dichloromethane
(10 mL) was added to a solution of [Cp2Ti(OCH2PPh2)2] (1)
(0.162 g, 0.266 mmol) in toluene (10 mL) to give a pink
suspension. The suspension was stirred for 30 min and the
pink solid filtered, washed with acetone, and dried under
vacuum. Yield: 0.127 g (48%). 1H NMR (CD3CN, 293 K): δ
8.00-7.20 (set of m, 40H, Ph), 6.36 (s, 20H, Cp), 4.67 (d, 8H,
2JH-P ) 4.35 Hz, CH2P), 4.18 (m, 8H, dCH cod), 2.23 (m, 8H,
CH2), 1.98 (m, 8H, CH2) (cod). 31P{1H} NMR (CD3CN, 293 K):
δ 27.0 (s). Anal. Calcd for C88H92B2F8Ir2O4P4Ti2: C, 53.08; H,
4.66. Found: C, 52.00; H, 4.62. MS (FAB+, acetone, m/z): 1903
([M2+ + BF4-]+, 35), 909 ([M/2]+, 93%), 801 ([M/2 - cod]+, 39%).
[Cp2Zr(µ-OCH2PPh2)2Rh(nbd)]2(BF4)2 (9). A solution of
[Rh(nbd)(NCCH3)2]BF4 (0.111 g, 0.304 mmol) in dichlo-
romethane (10 mL) was added to a solution of [Cp2Zr(OCH2-
PPh2)2] (2) (0.198 g, 0.304 mmol) in dichloromethane (10 mL)
to give an orange solution, which was stirred for 30 min.
Concentration of the volume to ca. 2 mL under vacuum and
slow addition of diethyl ether gave an orange solid, which was
isolated by filtration, washed with diethyl ether, and then
dried under vacuum. The crude solid was dissolved in CH2Cl2
(3 mL) and layered with hexanes (30 mL). The mixture was
allowed to stand at 4 °C for 3 days, affording the compound
2
(dd, JC-P ) 17 Hz, JC-Rh ) 17 Hz, CH2P), 30.6 (s, CH2, cod).
Anal. Calcd for C34H38BF4O2P2Rh: C, 55.92; H, 5.24. Found:
C, 55.89; H, 5.17. MS (FAB+, CH2Cl2, m/z): 643 (M+, 5%), 535
(M+ - cod, 11%), 427 (M+ - HOCH2PPh2, 62%). ΛM (Ω-1 cm2
mol-1): 99.1 (acetone, 5.38 × 10-4 M).
[Ir(cod)(Ph2PCH2OH)2]BF4 (5). Solid HOCH2PPh2 (0.092
g, 0.426 mmol) was added to a solution of [Ir(cod)(NCCH3)2]-
BF4 (0.100 g, 0.213 mmol) in CH2Cl2 (10 mL) to give a red
solution. This solution was stirred for 30 min and then
concentrated under vaccum to ca. 2-3 mL. Workup as
described above gave the compound as a red microcrystalline
solid, which was filtered, washed with diethyl ether, and dried
under vacuum. Yield: 0.145 g (83%). 1H NMR (CDCl3, 293
K): δ 8.0-6.8 (set of m, 20H, Ph), 4.39 (br s, 4H, CH2P), 4.28
(m, 4H, dCH, cod), 3.30 (br s, 2H, OH), 2.20 (m, 4H), 1.44 (m,
4H) (CH2 cod). 31P{1H} NMR (CDCl3, 293 K): δ 12.3 (s). 13C-
{1H} NMR (CDCl3, 293 K): δ 133.7-128.6 (set of m, Ph), 86.5
(m, dCH, cod), 61.7 (m, CH2P), 30.8 (s, CH2, cod). Anal. Calcd
for C34H38BF4IrO2P2: C, 49.82; H, 4.67. Found: C, 49.19; H,
5.08. MS (FAB+, acetone, m/z): 733 (M+, 100%). ΛM (Ω-1 cm2
mol-1): 91.7 (acetone, 5.27 × 10-4 M).
1
as red crystals. Yield: 0.127 g (45%). H NMR (CD2Cl2, 293
K): δ 7.63-7.38 (set of m, 40H, Ph), 6.37 (s, 20H, Cp), 4.58
(m, 4H, CH nbd), 4.39 (m, 8H, CH2P), 3.98 (m, 8H, dCH), 1.60
(s, 4H, CH2) (nbd). 31P{1H} NMR (CD3CN, 293 K): δ 19.3 (d,
JP-Rh ) 153.9 Hz). Anal. Calcd for C86H84B2F8O4P4Rh2Zr2: C,
55.31; H, 4.53. Found: C, 55.15; H, 4.14. MS (FAB+, CH2Cl2,
m/z): 847 ([M/2]+, 28%). MALDI-TOF (CH3CN, m/z): 1991
-
[M2+ + 2BF4 + dithranol]+.
Crystal Structure Determination of [Cp2Zr(µ-OCH2-
PPh2)2Ir(cod)]2(BF4)2‚4CH2Cl2 (7) and [Cp2Zr(µ-OCH2-
PPh2)2Rh(nbd)]2(BF4)2‚2CH2Cl2 (9). A summary of crystal
data and data collection and refinement parameters is given
in Table 2. Preliminary crystal quality checks revealed the
presence of twinned crystals in the case of 9; eventually a tiny
sample with no more than 10% twinned reflections was used
in the analysis. Intensity data were collected for both com-
pounds at low temperature (100(2) K) on a CCD Bruker
SMART APEX diffractometer with graphite-monochromated
Mo KR radiation (λ ) 0.71073 Å) by using ω rotations (0.3°).
Instrument and crystal stability were evaluated by measuring
equivalent reflections at different times; no significant decay
was observed. Data were corrected for Lorentz and polarization
effects, and a semiempirical absorption correction was ap-
plied.25 The structures were solved by Patterson and difference
Fourier methods.26 For 7, only half the tetranuclear complex
was observed as a crystallographic independent moiety (to-
cis-[Pt(p-tolyl)2(Ph2PCH2OH)2] (6). A Schlenk tube was
charged with [Pt(µ-SEt2)(p-tolyl)2]2 (0.100 g. 0.107 mmol) and
PPh2CH2OH (0.0925 g, 0.428 mmol) and the solid mixture
dissolved in CH2Cl2 (10 mL) to give a colorless solution. The
solution was stirred for 1 h and the solvent removed under
vacuum to give a white solid, which was washed with n-hexane
and dried in vacuo. Yield: 0.151 g (87%). 1H NMR (C6D6, 293
K): δ 7.86-6.96 (set of m, 28H, Ph and p-tolyl), 4.07 (d, 4H,
2JH-P ) 7.8 Hz, CH2P), 2.39 (t, 2H, 3JH-H ) 7.2 Hz, OH), 2.09
(s, 6H, CH3 p-tolyl). 31P{1H} NMR (C6D6, 293 K): δ 8.06 (s,
JPt-P ) 1804 Hz). 13C{1H} NMR (CDCl3, 293 K): δ 136.4-128.8
(set of m, Ph + p-tolyl), 63.9 (d, CH2P), 20.9 (s, CH3 p-tolyl).
Anal. Calcd for C40H40O2P2Pt: C, 59.33; H, 4.98. Found: C,
58.95; H, 4.84. MS (FAB+, CH2Cl2, m/z): 809 (M+, 13%), 627
(M+ - 2 p-tolyl, 53%), 502 (M+ - p-tolyl - HOCH2PPh2, 17%),
411 (M+ - 2 p-tolyl - HOCH2PPh2, 33%).
-
[Cp2Zr(µ-OCH2PPh2)2Ir(cod)]2(BF4)2 (7). Method A. [Cp2-
Zr(OCH2PPh2)2] (2) (0.148 g, 0.227 mmol) was reacted with
gether with one BF4 anion and two dichloromethane mol-
-
ecules). The BF4 anion and one of the two CH2Cl2 solvent

5936 Organometallics, Vol. 24, No. 24, 2005
AÄ lvarez-Vergara et al.
Table 2. Crystal Data, Data Collection, and Refinement Parameters for the X-ray Analysis of Complexes 7
and 9
7
9
formula
Mr
C
88H92B2F8Ir2O4P4Zr2‚4CH2Cl2
C
86H84B2F8O4P4Rh2Zr2‚2CH2Cl2
2417.66
2037.14
cryst size, mm
cryst syst
0.328 × 0.260 × 0.251
monoclinic
P21/n
15.4325(10)
15.4098(10)
19.5915(13)
97.8530(10)
2
0.090 × 0.085 × 0.070
monoclinic
P21/n
19.703(2)
17.9741(18)
25.627(3)
110.236(2)
4
8515.4(15)
1.589
0.888
2.3-52.2
49 707
16 821 (Rint ) 0.0806)
0.9244/0.9405
16 821/12/1022
0.0963
0.2220
1.147
space group
a, Å
b, Å
c, Å
â, deg
Z
V, Å3
4615.4(5)
1.740
Dcalc, g‚cm-3
µ, mm-1
3.461
θ range, deg
no. measd rflns
no. unique rflns
min./max. transm fact
no. rflns/restr/params
R1(F) (F2g 2σ(F2))
wR2(F2) (all data)
S (all data)
3.2-56.8
29 387
10 544 (Rint ) 0.0261)
0.3488/0.4197
10 544/16/533
0.0425
0.1178
1.055
molecules were observed as disordered and were modeled with
two moieties with complementary occupancy factors. In the
case of 9, two half tetranuclear complexes were observed in
were carried out by full-matrix least-squares on F2 (SHELXL-
97).26 The highest residuals were found close to the metal
centers or in proximity to disordered atoms; they have no
chemical sense.
-
the asymmetric unit, together with the corresponding BF4
counterions and two additional solvation dichloromethane
-
molecules; one of the BF4 anions and the two CH2Cl2
Acknowledgment. The generous financial support
from Direccio´n General de Ensen˜anza Superior e In-
vestigacio´n (DGES) (Project BQU2003-05412-C02-01) is
gratefully acknowledged.
molecules were found to be disordered and refined from two
moieties with complementary factors. Anisotropic displace-
ment parameters were applied for all non-hydrogen nondis-
ordered atoms. Hydrogen atoms were included in calculated
positions in the final cycles of refinement only for the cations;
they were refined with a typical riding model. Refinements
Supporting Information Available: An X-ray crystal-
lographic file in CIF format for the structure determination
of complexes 7 and 9. The molecular diagram of the structure
and schematic view showing the conformation of the second
independent cation of compound 9. This material is available
free of charge via the Internet at http://pubs.acs.org.
(25) SAINT+ Software for CCD difractometers; Bruker AXS: Madi-
son, WI, 2000. Sheldrick, G. M. SADABS Program for Correction of
Area Detector Data; University of Go¨ttingen: Go¨ttingen, Germany,
1999.
(26) SHELXTL Package v. 6.10; Bruker AXS: Madison, WI, 2000.
Sheldrick, G. M. SHELXS-86 and SHELXL-97; University of Go¨ttin-
gen: Go¨ttingen, Germany, 1997.
OM050644L