Syntheses, characterization and crystal structures of copper(I) o-(diphenylphosphino)benzaldehyde complexes

Article abstract of DOI:10.1016/j.ica.2004.12.049

The complexes [Cu(PCHO)₂(NCMe)][BF₄] (1) and [Cu(PCHO)₃][BF₄] (2) have been prepared by treating [Cu(NCMe)₄][BF₄] with two and three equivalents of Ph ₂P(o-C₆H₄)C(O)H (abbreviated as PCHO) at room temperature, respectively. The reaction of 1 and (Ph₂PC ₅H₄)₂Fe (abbreviated as DPPF) affords [Cu(PCHO)(DPPF)][BF₄] (3). The molecular structures of 1-3 have been determined by an X-ray diffraction study. The aldehyde groups in 1 are pendant, while one of the formyl groups in 2 is weakly coordinated to the copper ion through the oxygen atom. On the other hand, the copper atom in 3 is strongly chelated by both DPPF and PCHO ligands.

Full text of DOI:10.1016/j.ica.2004.12.049

Inorganica Chimica Acta 358 (2005) 1987–1992
www.elsevier.com/locate/ica
Syntheses, characterization and crystal structures of copper(I)
o-(diphenylphosphino)benzaldehyde complexes
a,
a
b
b
Wen-Yann Yeh *, Yu-Chiao Liu , Shie-Ming Peng , Gene-Hsiang Lee
a
Department of Chemistry, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
b
Department of Chemistry, National Taiwan University, Taipei 106, Taiwan
Received 8 November 2004; accepted 30 December 2004
Abstract
The complexes [Cu(PCHO)2(NCMe)][BF4] (1) and [Cu(PCHO)3][BF4] (2) have been prepared by treating [Cu(NCMe)4][BF4] with
two and three equivalents of Ph2P(o-C6H4)C(@O)H (abbreviated as PCHO) at room temperature, respectively. The reaction of 1 and
(Ph2PC5H4)2Fe (abbreviated as DPPF) affords [Cu(PCHO)(DPPF)][BF4] (3). The molecular structures of 1–3 have been determined
by an X-ray diffraction study. The aldehyde groups in 1 are pendant, while one of the formyl groups in 2 is weakly coordinated to the
copper ion through the oxygen atom. On the other hand, the copper atom in 3 is strongly chelated by both DPPF and PCHO ligands.
Ó 2005 Elsevier B.V. All rights reserved.
Keywords: Cu(I) complex; P–O chelation; PCHO ligand
1. Introduction
g1-P donor in W(CO)5(PCHO) [4] and RhCl(CO)(P-
CHO)2 [5]. Subsequent oxidative addition of the alde-
hyde C–H bond on a Rh(I) [6], Ir(I) [7], Pt(0) [8],
Co(I) [9], Pd(II) [10] or Ru(II) [11] center can generate
a phosphine-acyl hydrido complex. On the other hand,
the PCHO ligand can act as chelating phosphine-alde-
hyde with the aldehyde moiety bonded to a metal in a
r-fashion through the oxygen atom in Re(CO)3Cl(P-
CHO) [12] and RuCl2(PCHO)2 [13], or in a p-fashion
The coordination chemistry of copper(I) and cop-
per(II) ions is well established. While copper(II) is gen-
erally considered a borderline hard acid, copper(I)
clearly behaves as a soft acid. For instance, with O, S,
N and P ligands, the O and N ligands dominate the
chemistry of copper(II), while the S and P ligands are
more frequent in copper(I) chemistry [1]. Recently, func-
tionalized tertiary phosphines have attracted consider-
able interest for their unusual coordination chemistry
and their increasing importance in catalysis [2]. The o-
(diphenylphosphino)benzaldehyde molecule (abbrevi-
ated as PCHO), which contains a ‘‘soft’’ phosphorus
and a ‘‘hard’’ oxygen donor atoms, is one of the simplest
bidendate P,O-chelating agents [3]. Usually, the phos-
phine center is coordinated to a metal in advance of
the aldehyde group and can serve as a monodentate
through the carbon–oxygen double bond in Cp Co(P-
*
CHO) [14], W(CO)3(PCHO)2 and W(CO)2(PCHO)2
[15]. In this paper, we explore the coordination chemis-
try of PCHO ligand with Cu(I) ion to give complexes
with/without the chelation of the aldehyde groups.
2. Results and dissusion
Reaction of [Cu(NCMe)4][BF4] with two equivalents
of PCHO in dichloromethane solvent at ambient tem-
perature afforded a yellow solution, from which yellow
crystals of [Cu(PCHO)2(NCMe)][BF4] (1) were obtained
*
Corresponding author. Tel.: +88 675 252 000 3927; fax: +88 675
253 908.
E-mail address: wenyann@mail.nsysu.edu.tw (W.-Y. Yeh).
0020-1693/$ - see front matter Ó 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2004.12.049

1988
W.-Y. Yeh et al. / Inorganica Chimica Acta 358 (2005) 1987–1992
in 89% yield after crystallization from n-hexane/dichlo-
romethane. Further reaction of 1 with equimolar
amount of PCHO in dichloromethane solvent at ambi-
ent temperature produced orange-yellow crystals of
[Cu(PCHO)3][BF4] (2) in 92% yield after crystallization
from n-hexane/dichloromethane. It was thought that
elimination of the acetonitrile ligand from 1 might gen-
erate the species, [Cu(PCHO)2]+, with both PCHO li-
gands in a P,O-chelating mode. However, heating
compound 1 in THF underwent a disproportion reac-
tion to give 2 as the only isolable product. On the other
hand, reaction of 1 with the diphosphine molecule
(Ph2PC5H4)2Fe (abbreviated as DPPF) led to dissocia-
tion of a PCHO ligand to afford orange crystals of
[Cu(PCHO)(DPPF)][BF4] (3) in 56%, in which both
DPPF and PCHO act as a chelating ligand. The reac-
tions are summarized in Scheme 1. Previously, the
importance of steric constraints in [Cu(PR3)3]+ com-
plexes was well established [16], so that the PCHO li-
gand forming the trigonal complexes 1 and 2 is likely
for steric reasons. Nevertheless, the steric properties of
the neutral ligands are not the sole determinations and
the electronic properties of the ligands can also affect
cation stoichiometry. This is well illustrated by Cu(I)
complexes formed by pyridine, 2-methylpyridine and
4-methylpyridine [17].
Single crystals of 1–3 were grown by diffusion of
diethyl ether (for 1) or n-hexane (for 2 and 3) into a
dichloromethane solution of the compound at ambient
temperature. The structure of 1 consists of discrete cat-
ions [Cu(PCHO)2(NCMe)]+ and tetrafluoroborate
counter anions. The ORTEP drawing for the complex
is depicted in Fig. 1. In contrast to the tetrahedron
geometry in [Cu(NCMe)4]+ [18], the copper atom of 1
is nominally three-coordinate with ligation by an aceto-
nitrile and two PCHO ligands. With the N1, P1 and P2
atoms forming the basal trigonal plane, the interligand
bond angles surrounding the Cu atom are within 7° of
the trigonal expectation of 120° ; the three angles sum
to 360°, consistent with the small displacement of the
˚
Cu atom from the basal trigonal plane (0.01 A). The for-
myl groups are on opposite sides of the CuP2N plane,
with the oxygen atoms oriented toward the copper
atom. The two benzaldehyde units are planar, indicating
conjugation of C@O p bond with the aromatic system.
The benzaldehyde rings are about parallel with a dihe-
dral angle of 4.8° and the mean separation of the planes
˚
˚
is 3.41 A. This value may be compared with 3.35 A for
-
[Cu(NCMe)4]+ BF4
+
PCHO
2
3NCMe
H
H
H
O
O
O
+
Cu
P
P
+
Cu
+ PCHO
NCMe
P
P
-
Ph2
Ph2
-
BF4
P
MeCN
BF4
Ph2
Ph2
Ph2
O
O
H
H
2
1
NCMe
PCHO
+ DPPF
H
+
O
H
P
P
Ph2
-
Cu
BF4
O
Ph2
O
+
P
P
Ph2
-
Cu
BF4
H
Ph2 P
Ph2
Fe
3
Scheme 1.

W.-Y. Yeh et al. / Inorganica Chimica Acta 358 (2005) 1987–1992
1989
˚
3.14 A, respectively. The O1–Cu–P1 angle is very acute,
being 68.1(7)°.
The structure of 3 consists of discrete cations [Cu(P-
CHO)(DPPF)]+ and tetrafluoroborate counter anions.
The ORTEP drawing for the cation is illustrated in
Fig. 3. The coordination about the Cu+ ion can be de-
scribed as an irregular tetrahedron. The angles around
the copper atom range from 82.90(5)° for P1–Cu–O1
to 127.86(2)° for P1–Cu–P2. Distortion of the CuP3 con-
figuration is noted with the further displacement of the
˚
copper atom to a distance of 0.27 A above the plane
of the three phosphorous atoms. Accompanying the dis-
placement of the copper toward O1 is the decrease of the
mean P–Cu–P bond angles from a value of 119.9° in 2 to
a value of 118.6° in 3. The DPPF and PCHO ligands are
bidentate, showing a bite angle of 109.31(2)° and
82.90(5)°, respectively. The two Cp rings of DPPF li-
gand are about parallel, with a dihedral angle of 2.63°
ꢁ
Fig. 1. Molecular structure of 1. The BF4 anion has been artificially
omitted. Only the ipso carbons of the C6H5 groups are shown for
˚
clarity. Selected bond distances (A) and angles (°): Cu–P1 2.231(1),
Cu–P2 2.239(1), Cu–N1 1.954(5), C7–O1 1.218(6), C26–O2 1.217(7),
Cuꢀ ꢀ ꢀO1 2.74, Cuꢀ ꢀ ꢀO2 3.23; P1–Cu–P2 127.12(5), P1–Cu–N1
118.7(1), P2–Cu–N1 114.1(1), Cu–N1–C39 178.2(5), N1–C39–C40
178.5(6), C25–C26–O2 125.7(5), C6–C7–O1 124.1(5).
˚
and a mean interplane distance of 3.30 A. The formyl
group is coordinated to the copper atom through the
˚
oxygen atom with the Cu–O1 length of 2.276(2) A,
˚
which is 0.41 A shorter than the Cu–O3 length in 2.
the interplane distance in graphite and can be described
in terms of a van der Waals type interaction [19].
The structure of 2 consists of discrete cations [Cu(P-
CHO)3]+, tetrafluoroborate counter anions and solvent
molecules. The ORTEP drawing for the cation is de-
picted in Fig. 2. The Cu+ ion is in a mildly distorted tri-
gonal pyramidal environment with the copper atom
The benzaldehyde group is not planar, where the C7–
O1 vector is tilted 7.60° away from the ring plane. The
˚
Cuꢀ ꢀ ꢀFe distance is 4.12 A, too large a value to support
a significant metal–metal interaction.
Compounds 1–3 form stable crystals. The 31{1H}
1
˚
lying 0.08 A above the plane (toward the O3 atom) of
the three phosphorous atoms. The Cu–P distances range
NMR of 1 shows one broad signal at d 0.47. The H
NNR spectrum of 1 at 25 °C displays a 2H singlet
at d 9.74 for the formyl protons, a multiplet in the range
d 7.98–7.07 for the phenyl protons, and a 3H singlet at d
˚
from 2.297(2) to 2.345(2) A, with a mean value of
˚
2.324 A. The mean P–Cu–P bond angle is 119.9°, which
1
2.12 for the methyl protons. The H and 31P resonance
is close to the ideal value of 120°. The benzaldehyde
groups connected to the P1 and P2 atoms are about par-
patterns essentially remain unchanged down to ꢁ90 °C,
in agreement with the structure with a time-averaged
C2 symmetry in solution.
˚
allel, with a mean interplane distance of 3.41 A. An unu-
sual feature of the copper center is the long, off-normal
˚
bond to the apical O3 atom (2.68(7) A), while the non-
bonded Cuꢀ ꢀ ꢀO1 and Cuꢀ ꢀ ꢀO2 distances are 2.97 and
ꢁ
ꢁ
Fig. 2. Molecular structure of 2. The BF4 anion has been artificially
omitted. Only the ipso carbons of the C6H5 groups are shown for
Fig. 3. Molecular structure of 3. The BF4 anion has been artificially
omitted. Only the ipso carbons of the C6H5 groups are shown for
˚
˚
clarity. Selected bond distances (A) and angles (°): Cu–P1 2.330(2),
clarity. Selected bond distances (A) and angles (°): Cu–P1 2.2452(6),
Cu–P2 2.297(2), Cu–P3 2.345(2), C7–O1 1.204(8), C26–O2 1.210(8),
C45–O3 1.202(8), Cu–O3 2.69, Cuꢀ ꢀ ꢀO1 2.97, Cuꢀ ꢀ ꢀO2 3.14; P1–Cu–
P2 123.56(7), P1–Cu–P3 120.47(7), P2–Cu–P3 115.62(7), C25–C26–O2
125.3(6), C6–C7–O1 126.1(6), C44–C45–O3 125.5(6).
Cu–P2 2.2484(6), Cu–P3 2.2586(6), Cu–O1 2.276(2), C7–O1 1.216(3);
P1–Cu–P2 127.86(2), P1–Cu–P3 118.52(2), P2–Cu–P3 109.31(2), P1–
Cu–O1 82.90(5), P2–Cu–O1 112.04(4), P3–Cu–O1 96.44(5), C6–C7–O1
127.8(2), C7–O1–Cu 126.0(2).

1990
W.-Y. Yeh et al. / Inorganica Chimica Acta 358 (2005) 1987–1992
1
The H NNR spectrum of 2 at 25 °C presents a 3H
singlet at d 9.17 for the formyl protons, and a multiplet
between d 7.74 and 6.82 for the phenyl protons. The for-
myl signal collapses at ꢁ30 °C, and at ꢁ80 °C splits into
three 1H signals at d 9.18, 8.98, and 8.88 (Fig. 4). The
slow-exchange spectrum obtained at ꢁ80 °C is consis-
tent with the solid-state structure, where the three alde-
hyde groups are inequivalent. A dynamic process by
exchange of the Cu–aldehyde interaction may account
for the spectra observed. The existence of a Cuꢀ ꢀ ꢀO
interaction in solution is supported by the IR spectrum
in CH2Cl2, which displays two C@O stretching bands at
1698 and 1675 cmꢁ1 in an approximate 1:2 ratio. On the
other hand, the 31P{1H} NMR spectrum at 25 °C shows
one broad signal at d5.06, while at ꢁ80 °C it becomes a
complicate multiplet in the range d 6.36–3.01, likely due
to superimposed coupling between the inequivalent
phosphorus nuclei and coupling to the 63Cu (I = 3/2,
69%) and 65Cu (I = 3/2, 31%) nuclei.
d 1.90 and a doublet signal at d ꢁ6.14 (2JP–P = 81 Hz) in
an approximate 1:2 ratio for the PCHO and the DPPF
ligands, respectively. The coordinated C@O stretching
frequency is recorded at 1663 cmꢁ1 in CH2Cl2 solvent.
In conclusion, we have prepared three Cu(I)–PCHO
complexes with/without the chelation of formyl groups.
The Cu–aldehyde interaction presented in 2 is appar-
ently arising from overlap of the carbonyl lone pair with
the empty Cu pz-orbital (see below). One would expect
some distortion of the trigonal-planar (sp2) arrangement
of the complex toward a trigonal-pyramidal (sp3)
arrangement in response to this donor–acceptor interac-
tion, as observed for 2, whereas repulsions between the
bulky phosphine groups prevent further distortion to-
ward a tetrahedral arrangement. On the other hand, in
1 the copper atom is essentially lying on the basal trigo-
˚
nal plane, so its short Cuꢀ ꢀ ꢀO contact (2.74 A) is better
described as a consequence of packing constraints in-
stead of bonding. Although complex 3 contains three
phosphine ligands as 2, the confined P–Cu–P bite angle
of DPPF ligand (109.3°) likely facilitates chelation of the
formyl group to lead to a tetrahedral geometry. Finally,
we note that the arrangement of formyl groups in 1 and
1
The H NNR spectrum of 3 at 25 °C displays a 1H
singlet at d 9.65 for the formyl proton, a multiplet be-
tween d 7.70 and 6.99 for the phenyl protons, and two
4H broad signals at d 4.44 and 4.22 for the Cp protons.
The 31P{1H} NMR spectrum presents a triplet signal at
ꢁ
2 effectively blocks the access of the BF4 counterion to
the Cu+ ion, whereas the structures of [Cu(PPh3)3][BF4]
[20] and [Cu(PPh3)3][FeCl4] [21] reveal a weak coordina-
tion of the anion to the copper atom through one of its
terminal halogen atoms.
H
O
z
C
y
x
Cu
P
3. Experimental
3.1. General methods
All manipulations were carried out under an atmo-
sphere of dinitrogen with standard Schlenk techniques.
[Cu(NCMe)4][BF4] [22], Ph2P(o-C6H4)C(@O)H (abbre-
viated as PCHO) [3b], and (Ph2PC5H4)2Fe (abbreviated
as DPPF) [23] were prepared by the literature methods.
2,20-bipyridine and 4,40-bipyridine were purchased from
Aldrich and used as received. Solvents were dried over
appropriate reagents under dinitrogen and distilled
Fig. 4. Variable-temperature 500 MHz 1H NMR spectra of 2 in
CD2Cl2.

W.-Y. Yeh et al. / Inorganica Chimica Acta 358 (2005) 1987–1992
1991
1
immediately before use. H and 31P NMR spectra were
solvent (5 ml) was then introduced into the flask and
the mixture was stirred at room temperature for 12 h,
yielding an orange-yellow solution. The solution was fil-
trated under dinitrogen and then carefully layered with
n-hexane (20 ml). [Cu(PCHO)3] [BF4] (2) (185 mg,
0.187 mmol, 92%) was precipitated as an air-stable, or-
ange-yellow crystalline solid. Anal. Calc. for
obtained on a Varian Unity INOVA-500 spectrometer.
Infrared spectra were recorded with a 0.1 mm path
CaF2 solution cell on a Hitachi I-2001 IR spectrometer.
Fast-atom-bombardment (FAB) mass spectra were re-
corded on a JEOL JMS-SX102A mass spectrometer.
Elemental analyses were performed at the National Sci-
ence Council Regional Instrumentation Center at Na-
tional Chen-Kung University, Tainan, Taiwan.
C57H45BCuF4O3P3: C, 67.04; H, 4.44. Found: C,
þ
66.65; H, 4.49%. Mass (FAB): m/z 933 (CuðPCHOÞ
;
3
63Cu). 1H NMR (CD2Cl2, 25 °C): d 9.17 (s, 3H,
CHO), 7.74–7.56 (m, 6H), 7.42–7.25(m, 9H), 7.11–6.82
3.2. Preparation of 1
1
(m, 27H, Ph). H NMR (CD2Cl2, ꢁ80 °C): d 9.18 (s,
[Cu(NCMe)4][BF4] (102 mg, 0.325 mmol), acetoni-
trile (1 ml) and dichloromethane (10 ml) were placed in
an oven-dried 50 ml Schlenk flask, equipped with a mag-
netic stir bar and a rubber serum stopper. PCHO
(190 mg, 0.65 mmol) in dichloromethane solvent (5 ml)
was then introduced into the flask and the mixture was
stirred at room temperature for 16 h, yielding a yellow
solution. The solution was filtrated under dinitrogen
and carefully layered with n-hexane (20 ml). The air-
stable, yellow crystals of [Cu(PCHO)2(NCMe)] [BF4]
(1) (214 mg, 0.289 mmol) were obtained in 89% yield.
Anal. Calc. for C40H33BCuF4NO2P2: C, 62.23; H,
4.31, N, 1.81. Found: C, 62.70; Hþ, 4.51; N, 1.72%. Mass
1H), 8.98 (s, 1H), 8.88 (s, 1H, CHO), 8.33 (m, 1H),
8.05 (m, 2H), 7.65–6.66 (m, 32H), 6.45 (m, 1H), 6.35
(m, 3H), 6.19 (m, 1H), 5.85 (m, 1H), 5.21 (m, 1H, Ph).
31P{1H} NMR: (CD2Cl2, 25 °C) d 5.07 (s); (CD2Cl2,
ꢁ80 °C) d 6.36–3.01 (m). IR (CH2Cl2, cmꢁ1): 1698w,
1675m (C@O).
3.4. Direct synthesis of 2 from [Cu(NCMe)4][BF4] and
PCHO
[Cu(NCMe)4][BF4] (105 mg, 0.335 mmol), PCHO
(310 mg, 1.07 mmol) and THF (5 ml) were placed in
an oven-dried 25 ml Schlenk tube. The solution was re-
fluxed for 40 min to afford an orange-yellow precipitate,
characterized as compound 2 (298 mg, 90%).
(FAB): m/z 643 (CuðPCHOÞ
;
63Cu). 1H NMR
2
(CD2Cl2, 25 °C): d 9.74 (s, 2H, CHO), 7.97–7.03 (m,
28H, Ph), 2.12 (s, 3H, Me). 31P{1H} NMR (CD2Cl2,
25 °C): d 0.47 (s). IR (CH2Cl2, cmꢁ1): 2284 (C„N),
1670 (C@O).
3.5. Preparation of 3
Compound 1 (37 mg, 0.05 mmol), DPPF (28 mg,
0.05 mmol) and THF (5 ml) were placed in an oven-
dried 25 ml Schlenk tube. The solution was refluxed
for 40 min, cooled to ambient temperature, and care-
fully layered with n-hexane. [Cu(PCHO)(DPPF)][BF4]
(3) (28 mg, 0.028 mmol, 56%) was obtained as air-stable,
3.3. Preparation of 2 from 1
Compound 1 (150 mg, 0.203 mmol) and dichlorome-
thane (5 ml) were placed in an oven-dried 50 ml Schlenk
flask. PCHO (59 mg, 0.203 mmol) in dichloromethane
Table 1
Crystallographic data for 1–3
1
2
3
Formula
C
40H33BCuF4NO2P2
C57H45BCuF4O3P3
2 CH2Cl2
triclinic
C53H43BCuF4FeOP3
Crystal solvent
Crystal system
Formula weight
T (K)
0.5 Et2O
monoclinic
809.02
150
triclinic
994.98
150
1191.04
150
ꢀ
ꢀ
Space group
˚
P21/c
P1
P1
A (A)
˚
8.3108(4)
25.293(1)
18.4483(9)
90
12.496(1)
15.454(1)
15.693(1)
69.724(2)
88.827(2)
76.487(2)
2754.5(4)
2
10.4768(7)
14.0088(9)
15.949(1)
93.405(1)
93.115(1)
108.539(1)
2208.8(2)
2
b (A)
˚
c (A)
a (°)
b (°)
c (°)
93.634(1)
90
3
˚
V (A )
3870.1(3)
4
1.389
Z
Dcalc (Mg/m3)
1.436
0.736
1.496
0.976
l (mmꢁ1
)
0.705
0.0746/0.1650
1.176
Final R indices (I > 2r(I))
Goodness-of-fit on F2
0.0879/0.1997
1.020
0.0390/0.0977
1.057

1992
W.-Y. Yeh et al. / Inorganica Chimica Acta 358 (2005) 1987–1992
(d) M.A. Carvajal, J.J. Novoa, S. Alvarez, J. Am. Chem. Soc. 126
(2004) 1465.
orange crystals. Anal. Calc. for C53H43BF4FeOP3Cu: C,
63.97; H, 4.36. Found: C, 63.50; H, 4.45%. Mass (FAB):
m/z 907 (Cu(PCHO)(DPPF)+; 63Cu). 1H NMR (CDCl3,
25 °C): d 9.65 (s, 1H, CHO), 7.70–6.99 (m, Ph), 4.44 (br,
4H), 4.22 (br, 4H, C5H4). 31P{1H} NMR (CDCl3, 25
[2] (a) H.-F. Klein, A. Bickelhaupt, T. Jung, G. Cordier, Organo-
metallics 13 (1994) 2557;
(b) J.-C. Hierso, R. Amardeil, E. Bentabet, R. Broussier, B.
Gautheron, P. Meunier, P. Kalck, Coord. Chem. Rev. 236 (2003)
143;
2
°C): d 1.90 (t, PCHO, JP–P = 81 Hz), ꢁ6.14 (d, DPPF).
IR (CH2Cl2, cmꢁ1): 1663 (C@O).
3.6. Structure determination for 1–3
(c) P. Braunstein, J. Durand, M. Knorr, C. Strohmann, Chem.
Commun. (2001) 211;
(d) G.R. Newkome, Chem. Rev. 93 (1993) 2067;
(e) V.J. Catelano, B.L. Bennett, S. Muratidis, B.C. Noll, J. Am.
Chem. Soc. 123 (2001) 173.
[3] (a) G.P. Schiemenz, H. Kaack, Justus Liebigs Ann. Chem. (1973)
1480;
The crystals of 1, 2 and 3 found suitable for X-ray
analysis were each mounted in a thin-walled glass capil-
lary and aligned on the Bruker Smart ApexCCD diffrac-
tometer, with graphite-monochromated Mo Ka
(b) J.E. Hoots, T.B. Rauchfuss, D.A. Wrobleski, Inorg. Synth. 21
(1982) 175.
[4] E.W. Ainscough, A.M. Brodie, S.L. Ingham, J.M. Waters, Inorg.
Chim. Acta 234 (1995) 163.
˚
radiation (k = 0.71073 A). The h range for data collec-
[5] R. El Mail, M.A. Garralda, R. Herna´ndez, L. Ibarlucea, J.
Organomet. Chem. 648 (2002) 149.
tion is 1.37–25.00° for 1, 1.39–25.00° for 2, and 1.28–
27.50° for 3. Of the 30852, 29598 and 28408 reflections
collected for 1, 2 and 3, 6805, 9704, and 10104 reflec-
tions were independent, respectively. All data were cor-
rected for Lorentz and polarization effects and for the
effects of absorption. The structure was solved by the di-
rect method and refined by least-square cycles. The non-
hydrogen atoms were refined anisotropically. Hydrogen
atoms were included but not refined. All calculations
were performed using the SHELXTL-97 package [24].
The data collection and refinement parameters are pre-
sented in Table 1.
[6] (a) C. Bianchini, A. Meli, M. Peruzzini, J.A. Ramirez, A. Vacca,
F. Vizza, F. Zanobini, Organometallics 8 (1989) 337;
´
(b) R. El Mail, M.A. Garralda, R. Hernandez, L. Ibarlu-
cea, E. Pinilla, M.R. Torres, Organometallics 19 (2000)
5310;
´
(c) R. El Mail, M.A. Garralda, R. Hernandez, L. Ibarlucea,
E. Pinilla, M.R. Torres, Helv. Chim. Acta 85 (2002) 1485.
[7] (a) E.F. Landvatter, T.B. Rauchfuss, Organometallics 1 (1982)
506;
´
(b) M.A. Garralda, R. Hernandez, L. Ibarlucea, E. Pinilla, M.R.
Torres, Organometallics 22 (2003) 3600.
[8] (a) J.J. Koh, W.H. Lee, P.G. Williard, W.M. Risen, J. Organomet.
Chem. 284 (1985) 409;
(b) C.A. Ghilardi, S. Midollini, S. Moneti, A. Orlandini, J. Chem.
Soc., Dalton Trans. (1988) 1833.
[9] H.F. Klein, U. Lemke, M. Lemke, A. Brand, Organometallics 17
(1998) 4196.
Acknowledgment
[10] S.E. Watkins, D.C. Craig, S.B. Colbran, Inorg. Chim. Acta 307
(2000) 134.
We are grateful for support of this work by the Na-
tional Science Council of Taiwan.
´
[11] P. Crochet, M.A. Fernandez-Zumel, C. Beauquis, J. Gimeno,
Inorg. Chim. Acta 356 (2003) 114.
[12] X. Chen, F.J. Femia, J.W. Babich, J. Zubieta, Inorg. Chim. Acta
315 (2001) 147.
Appendix A. Supplementary material
[13] T.B. Rauchfuss, J. Am. Chem. Soc. 101 (1979) 1045.
[14] C.P. Lenges, M. Brookhart, P.S. White, Angew. Chem., Int. Ed.
38 (1999) 552.
Crystallographic data for 1–3 have been deposited
with the Cambridge Crystallographic Data Centre,
deposition numbers CCDC 249800–249802. Copies of
these data may be obtained free of charge from The
Director, CCDC, 12 Union Road, Cambridge CB2
1EZ, UK. Supplementary data associated with this arti-
cle can be found, in the online version at doi:10.1016/
j.ica.2004.12.049.
[15] W.-Y. Yeh, C.-S. Lin, S.-M. Peng, G.-H. Lee, Organometallics 23
(2004) 917.
[16] A. Baiada, F.H. Jardine, R.D. Willett, K. Emerson, Inorg. Chem.
30 (1991) 1365.
[17] A.H. Levin, R.J. Michl, P. Garis, U. Lepore, J. Chem. Soc.,
Chem. Commun. (1972) 661.
[18] I. Csoregh, P. Kierkegaard, R. Norrestam, Acta Crystallogr.,
Sect. B 31 (1975) 314.
[19] F.A. Cotton, G. Wilkinson, Advanced Inorganic Chemistry, fifth
ed., Wiley, New York, 1988.
References
[20] A.P. Gaughan, Z. Dori, J.A. Ibers, Inorg. Chem. 7 (1974) 1657.
[21] D.J. Saturnino, A.M. Arif, Inorg. Chem. 32 (1993) 4157.
[22] G.J. Kubas, Inorg. Synth. 19 (1979) 90.
[23] I.R. Butler, in: Inorganic Experiments, VCH, Weinheim, Ger-
many, 1994.
[1] (a) B.J. Hathaway, in: Comprehensive Coordination Chemistry,
vol. 5, Pergamon, Oxford, UK, 1987, p. 533;
(b) D.R. Smith, Coord. Chem. Rev. 172 (1998) 457;
(c) R. Mukherjee, in: Comprehensive Coordination Chemistry II,
vol. 6, Elsevier, Oxford, UK, 2004, p. 747;
[24] G.M. Sheldrick, SHELXTL-97, University of Go¨ttingen, Germany,
1997.