Synthesis, molecular structure, and reactivity of iridium(I) and iridium(III) complexes formed by coordination and C-H activation of the substituted arenes C6H5CH2CH2 PiPr2 and C6H5</s

Article abstract of DOI:10.1021/om0210457

The dimer [Ir(μ-Cl)(C₈H₁₄)₂]₂ (1) reacts with AgPF₆ in acetone to give the bis(acetone) adduct cis-[Ir(acetone)₂(C₈H₁₄)₂] PF₆ (2), which upon tre

Full text of DOI:10.1021/om0210457

Organometallics 2003, 22, 2151-2160
2151
Syn th esis, Molecu la r Str u ctu r e, a n d Rea ctivity of
Ir id iu m (I) a n d Ir id iu m (III) Com p lexes F or m ed by
Coor d in a tion a n d C-H Activa tion of th e Su bstitu ted
Ar en es C6H5CH2CH2P iP r 2 a n d C6H5OCH2CH2P tBu 2
Giuseppe Canepa,†,‡ Eduardo Sola,† Marta Mart´ın,† Fernando J . Lahoz,†
Luis A. Oro,*,† and Helmut Werner*,‡
Departamento de Quı´mica Inorga´nica, Instituto de Ciencia de Materiales de Arago´n,
Universidad de Zaragoza-CSIC, E-50009 Zaragoza, Spain, and Institut fu¨r Anorganische
Chemie der Universta¨t Wu¨rzburg, Am Hubland, D-97074 Wu¨rzburg, Germany
Received December 27, 2002
The dimer [Ir(µ-Cl)(C8H14)2]2 (1) reacts with AgPF6 in acetone to give the bis(acetone) adduct
cis-[Ir(acetone)2(C8H14)2]PF6 (2), which upon treatment with iPr2PCH2CH2C6H5 (L1) affords
the half-sandwich-type complex [(η6-L1-κ-P)Ir(C8H14)]PF6 (3). The methoxy-bridged dimer
[Ir(µ-OMe)(C8H12)]2 (4) gives upon treatment with the phosphonium salt L1‚HBF4 the
compound [Ir(C8H12)(acetone)(L1-κ-P)]BF4 (5), whereas with L2‚HBF4 (L2 ) tBu2PCH2CH2-
OC6H5) the bis(chelate) complex [Ir(C8H12)(L2-κ2-O,P)]BF4 (6) is generated. Both 5 and 6
react with hydrogen in acetone to yield the dihydridoiridium(III) derivatives [(η6-L1-κ-P)-
IrH2]BF4 (7) and [(η6-L2-κ-P)IrH2]BF4 (8), respectively. Compounds 7 and 8 react with excess
ethene or propene to give the iridium(I) olefin complexes [(η6-L1-κ-P)Ir(CH2dCHR)]BF4 [R
) H (9), Me (11)] and [(η6-L2-κ-P)Ir(CH2dCHR)]BF4 [R ) H (10), Me (12)], which in the
presence of H2 regenerate the dihydrido precursors. The reaction of 7 with 2 equiv of PhCt
CPh affords the π-alkyne complex [(η6-L1-κ-P)Ir(PhCtCPh]BF4 (14) via the stilbene derivative
[(η6-L1-κ-P)Ir(Z-PhCHdCHPh)]BF4 (13) as an intermediate. Compound 13 can be isolated
upon treatment of 11 with Z-stilbene and has been characterized crystallographically. The
reactions of 7 and 11 with acetonitrile lead to the cleavage of the arene-metal bond and
afford the octahedral iridium(III) complexes [IrH2(NCCH3)3(L1-κ-P)]BF4 (15) and [IrH(C6H4-
CH2CH2PiPr2-κ2-C,P)(NCCH3)3]BF4 (16), respectively. Treatment of the C-H activation
product 16 with H2 yields 15. The X-ray crystal structure analysis of 16 reveals that the
Ir(NCCH3)3 fragment possesses the fac configuration.
In tr od u ction
of various unsaturated substrates, including imines,4 we
were prompted to find out whether also iridium deriva-
tives of the functionalized phosphines are accessible and
what their reactivity is. With regard to catalysis, the
challenging aspect seemed to be whether the phosphine
chelate effect would lead to more robust compounds
while maintaining the desirable lability of the arene
moiety.
This work describes the preparation and character-
ization of a series of iridium(I) and iridium(III) com-
pounds in which the chosen phosphines iPr2PCH2-
CH2C6H5 (L1) and tBu2PCH2CH2OC6H5 (L2) are coordi-
nated either as two-electron donors or, more frequently,
as chelating (6+2)-electron donor ligands. Moreover, it
illustrates that in contrast to rhodium chemistry also
half-sandwich-type iridium complexes with L1 as the
functionalized arene react by ring metalation and that
this process is strictly reversible.
Recently, we reported the preparation of bulky func-
tionalized phosphine ligands of the general composition
R2P(CH2)nXC6H5 (R ) iPr, tBu; X ) CH2, O) which not
only are able to coordinate to rhodium(I) in a chelating
fashion but, in the coordination sphere of rhodium, also
undergo a C-H activation of the six-membered ring
under unusually mild conditions.1,2 In contrast, the
structurally related half-sandwich-type compounds [(η6-
arene)Rh(C8H14)(PiPr3)]PF6, in which the arene and the
phosphine are not linked by a (CH2)n unit, do not react
by ring metalation and, in the presence of PiPr3 or H2,
smoothly decompose.1,3
Since some of us showed, however, that η6-arene-
(hydrido) complexes of iridium such as [(η6-arene)IrH2-
(PiPr3)]BF4 are stable and catalyze the hydrogenation
* To whom correspondence should be addressed. E-mail
(for L.A.O.): oro@posta.unizar.es. E-mail (for H.W.): helmut.werner@
mail.uni-wuerzburg.de.
Resu lts a n d Discu ssion
1. P r ep a r a tion of Olefin ic Ir id iu m (I) a n d Dih y-
d r id oir id iu m (III) Com p lexes w ith L1 a n d L2 a s
† Universidad de Zaragoza-CSIC.
‡ Universta¨t Wu¨rzburg.
(1) Werner, H.; Canepa, G.; Ilg, K.; Wolf, J . Organometallics 2000,
19, 4756-4766.
(4) (a) Torres, F.; Sola, E.; Mart´ın, M.; Lo´pez, J . A.; Lahoz, F. J .;
Oro, L. A. J . Am. Chem. Soc. 1999, 121, 10632-10633. (b) Torres, F.;
Sola, E.; Mart´ın, M.; Ochs, C.; Picazo, G.; Lo´pez, J . A.; Lahoz, F. J .;
Oro, L. A. Organometallics 2001, 20, 2716-2724.
(2) Canepa, G.; Brandt, C. D.; Werner, H. Organometallics 2001,
20, 604-606.
(3) Canepa, G. Unpublished results.
10.1021/om0210457 CCC: $25.00 © 2003 American Chemical Society
Publication on Web 04/04/2003

2152 Organometallics, Vol. 22, No. 10, 2003
Canepa et al.
of 4 with the phosphonium salt L1‚HBF4 in acetone gives
the acetone-containing cation 5 (Scheme 2), the analo-
gous reaction of 4 with L2‚HBF4 furnishes the chelate
complex 6 in 92% yield. Compound 5 is isolated as an
orange oil containing small amounts of impurities,
which could not be separated by various techniques.
Therefore, the cationic species was characterized by
spectroscopic means and by a FAB mass spectrum. The
IR spectrum of 5 displays a ν(CdO) stretching mode at
1652 cm-1, whereas the 13C{1H} NMR spectrum shows
the resonances for the carbon atoms of the coordinated
ketone at δ 204.4 (CdO) and 30.2 (CH3).
Sch em e 1
The chelate complex 6 was isolated in analytically
pure form as an orange solid that is air-stable and
readily soluble in polar organic solvents. The value for
the conductivity in acetone is practically the same as
for the half-sandwich-type compound 3. Regarding the
spectroscopic data of 6, it is interesting to note that
while the room temperature 31P{1H} NMR spectrum in
CDCl3 shows a sharp singlet at δ 58.9, the spectrum in
acetone-d6 displays a significantly broadened signal,
suggesting the facile opening of the O,P-bonded chelate
ring in this solvent. The broadened resonance becomes
sharp at 323 K, but it is also quite broad at lower
temperatures. Moreover, the spectrum at 173 K exhib-
its, besides the broadened singlet at δ 59.4, two other
resonances at δ 32.0 and 30.8, which could be tentatively
attributed to the stabilization of acetone adducts [Ir-
(C8H12)(acetone)n(L2-κ-P)]BF4 (n ) 1 and 2) at low
temperature.
Liga n d s. In two recent papers we reported that the
highly reactive bis(acetone)rhodium(I) compound cis-
[Rh(acetone)2(C8H14)2]PF6 is an appropriate starting
material not only for the synthesis of (η6-arene)rhodium-
(I) complexes with chelating diphosphines such as iPr2-
5
PCH2CH2PCy2 but also for that of cyclooctene deriva-
tives with L1 and L2 as supporting ligand.1 A related
methodology has now been applied for the preparation
of the new cationic iridium(I) complex 3 (Scheme 1). The
first step consists of the reaction of the dimer 1 with
AgPF6 in acetone at room temperature, which affords,
after separation of AgCl, the bis(acetone) adduct 2 as
an orange air-sensitive solid in 89% isolated yield. In
the second step, a solution of L1 in acetone is added to
a solution of 2 in the same solvent, which leads to a
smooth change of color from orange-red to yellow. After
concentrating the solution to about 2 mL, subsequent
addition of diethyl ether led to the precipitation of a light
yellow solid, the elemental analysis and the spectro-
scopic data of which correspond to the half-sandwich-
type complex 3. Conductivity measurements confirm the
presence of a 1:1 electrolyte. As in the case of the
analogous rhodium compound [Rh(C8H14)(η6-L1-κ-P)]-
Both compounds 5 and 6 react at room temperature
in acetone under H2 atmosphere quite smoothly to give
the dihydridoiridium(III) complexes 7 and 8 in 79-87%
yield. The reactions have to be stopped if the solutions
(which are initially orange-red) become brownish-yellow,
since if stirring is continued, decomposition products are
formed. After repeated recrystallization from acetone/
diethyl ether, white solids are isolated that are air-
stable and readily soluble in acetone and dichlo-
romethane. Typical spectroscopic features of 7 and 8 are
the two metal-hydride stretching modes at 2241 and
2200 cm-1 (for 7) and 2244 and 2201 cm-1 (for 8) in the
IR as well as the high-field signal at δ -14.99 (7) and
1
PF6,1 in both the H and 13C{1H} NMR spectra of 3 the
signals for the protons and carbon atoms of the six-
membered ring are significantly shifted to higher field
compared to the free arene.
The reaction of 3 with ethene does not lead to a
complete replacement of cyclooctene. Even at 333 K
under an atmosphere of C2H4, the corresponding ethene
complex 9 (Scheme 3, see below) is generated only to a
maximum amount of ca. 30%. This is in contrast to the
related rhodium system where the ethene derivative
[Rh(C2H4)(η6-L1-κ-P)]PF6 could be isolated as a yellow
solid in 92% yield.1 In the presence of H2, compound 3
is inert. At room temperature, no reaction takes place,
while at 323 K after 20 h only traces of the dihydride 7
(Scheme 2, see below) are formed. The general conclu-
sion is that the cyclooctene ligand of 3 is somewhat more
firmly bond to the metal center than in the rhodium
counterpart.
The preparation of square-planar iridium(I) com-
plexes with L1 and L2 as ligands is possible by using
the methoxy-bridged compound 4 as the precursor. The
same starting material has already been employed for
the synthesis of dihydridoiridium(III) derivatives with
benzene as the arene ring.4 However, while treatment
1
-15.31 (8) in the H NMR spectra. The hydride reso-
1
nance is split into a doublet due to H-31P coupling.
2. Rea ction s of th e Dih yd r id oir id iu m (III) Com -
p lexes 7 a n d 8 w ith Olefin s a n d Dip h en yla cety-
len e. Since we anticipated that the dihydrido com-
pounds 7 and 8 might be good hydrogenation catalysts,
we first had to find out what the reactivity of 7 and 8
toward simple olefins is. When solutions of 7 and 8 in
acetone-d6 were stirred under an ethene or propene
1
atmosphere and the reactions monitored by H NMR
spectroscopy, the formation of the corresponding alkanes
and the olefin complexes 9-12 was observed (Scheme
3). Compared with 7 the rate for the reactions of 8 is
rather low at room temperature, and for quantitative
hydrogenation, a temperature of ca. 323 K has to be
employed. The iridium(I) complexes 9-12 are then
formed almost quantitatively and can be isolated as
light yellow or yellow, only moderately air-sensitive
solids in good to excellent yields. The NMR spectra of
9-12 are similar to those of their rhodium counterparts1
and thus deserve no further comment. It should be
(5) Wolf, J .; Manger, M.; Schmidt, U.; Fries, G.; Barth, D.; Webern-
do¨rfer, B.; Vicic, D. A.; J ones, W. D.; Werner, H. J . Chem. Soc., Dalton
Trans. 1999, 1867-1875.

Iridium(I) and Iridium(III) Complexes
Organometallics, Vol. 22, No. 10, 2003 2153
Sch em e 2
Sch em e 3
F igu r e 1. Molecular representation of the cationic complex
of 13.
mixture is treated with an excess of PhCtCPh, the
signal at higher field disappears, and from the orange
solution, after removal of the solvent and recrystalliza-
tion from acetone/diethyl ether, a yellow solid can be
isolated. The spectroscopic data suggest that it is the
π-alkyne complex 14 (see Scheme 3). Typical features
are the ν(CtC) stretch at 1824 cm-1 in the IR and the
signal for the carbon atoms of the CtC triple bond at δ
93.8. The latter is split into a doublet due to 13C-31P
coupling. Compound 14 can also be prepared from the
propene analogue, 11, by replacing the olefin for the
alkyne; in this case the time for the reaction is 12 h
instead of 10 min. However, on both routes, the yield of
14 is excellent.
The second product formed in the reaction of 7 with
an equimolar amount of diphenylacetylene is the Z-
stilbene complex 13. While it cannot be conveniently
prepared from 7 and Z-PhCHdCHPh, it is obtained in
80% yield by ligand substitution from 11 and an excess
of the Z-stilbene. Even on prolonged heating, no isomer-
ization of the Z to the E isomer of the stilbene occurs.
The molecular structure of 13 is shown in Figure 1.
Similarly to the cyclooctenerhodium compound [Rh-
(C8H14)(η6-L1-κ-P)]PF6, the arene ring possesses a slightly
inverse boat conformation, the characteristic feature
being that the ipso-carbon atom C(3) and, to a smaller
extent, the carbon atom C(6) in para position are bent
toward the metal center. The consequence is that the
distance Ir-C(3) (Table 1) is ca. 0.09 Å shorter than the
distances Ir-C(4) and Ir-C(8). The bond lengths Ir-
noted, however, that the 31P NMR resonances of 9-12
are shifted by 22-38 ppm to higher fields compared
with 7 and 8, which indicates a higher electron density
at the metal center of the olefin complexes than of the
iridium dihydrides.
The feasibility of a reconversion of the olefin to the
dihydrido complexes was proven by the reaction of 9
with H2. At room temperature in acetone-d6 the dihy-
dride 7 was formed after 20 h in more than 90% yield.
Small quantities of byproducts, also containing hydrido
ligands, were equally generated, but all attempts to
characterize them more precisely failed.
The reaction of 7 with diphenylacetylene in the molar
ratio of 1:1 in acetone leads to a mixture of two products,
that with a signal at δ 60.2 in the 31P{1H} NMR
spectrum dominating. Part of the starting material is
still present. The second product resonates in the
31P{1H} NMR spectrum at δ 47.9. If the reaction

2154 Organometallics, Vol. 22, No. 10, 2003
Canepa et al.
Ta ble 1. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 13
Ta ble 2. Dep en d en ce of kobs on th e Con cen tr a tion
of CD3CN for th e Rea ction of 7 w ith CD3CN in
Aceton e a t 298 K
Ir-P
2.2594(9)
2.216(3)
2.296(3)
2.339(3)
2.326(4)
2.342(3)
2.309(3)
1.8195(15)
2.139(3)
2.118(3)
Ir-M(1)a
P-C(1)
2.000(2)
1.850(3)
1.852(3)
1.845(3)
1.540(5)
1.510(5)
1.452(5)
1.482(5)
1.496(4)
Ir-C(3)
Ir-C(4)
Ir-C(5)
Ir-C(6)
Ir-C(7)
Ir-C(8)
Ir-G(1)a
Ir-C(15)
Ir-C(16)
[CD3CN] (mol/L)
P-C(9)
6.38
30.2
3.09
11.4
1.03
5.45
0.28
1.00
P-C(12)
104‚kobs (s-1
)
C(1)-C(2)
C(2)-C(3)
C(15)-C(16)
C(15)-C(17)
C(16)-C(23)
P-Ir-G(1)a
P-Ir-C(15)
P-Ir-C(16)
P-Ir-M(1)a
122.26(5)
Ir-P-C(12)
117.51(11)
112.8(2)
111.2(3)
69.28(18)
119.6(2)
91.57(10) P-C(1)-C(2)
92.50(9)
92.17(7)
C(1)-C(2)-C(3)
Ir-C(15)-C(16)
G(1)-Ir-C(15)a 142.06(10) Ir-C(15)-C(17)
G(1)-Ir-C(16)a 139.58(10) C(16)-C(15)-C(17) 127.6(3)
G(1)-Ir-M(1)a
Ir-P-C(1)
145.54(8)
Ir-C(16)-C(15)
70.82(18)
120.9(2)
104.29(12) Ir-C(16)-C(23)
119.68(12) C(15)-C(16)-C(23) 126.7(3)
Ir-P-C(9)
a
G(1) represents the centroid of the arene ring C(3)-C(8). M(1)
represents the midpoint of the olefinic bond C(15)-C(16).
F igu r e 2. Plot of log(kobs) vs log([CD3CN]) for the reaction
of 7 with CD3CN in acetone at 253 K.
C(15), Ir-C(16), and C(15)-C(16) lie in the expected
range and are quite similar to those found in other (η6-
arene)iridium complexes containing olefinic ligands.4,6
The bond angles P-Ir-C(15) and P-Ir-C(16) deviate
only slightly from the 90° value and are in good
agreement with the proposed piano-stool configuration
of the molecule.
195 K with different amounts of CD3CN (30- to 250-
fold excess), and, after warming to 253 K, the decrease
in intensity of the hydride signal of 7 was measured.
Under these conditions, the rate law was of pseudo-first-
order, -d[7]/dt ) kobs[Ir], with the observed rate con-
stant corresponding to kobs ) k[CD3CN]n. Owing to this
equation, the values of kobs depend on the concentration
of CD3CN and are listed in Table 2. The corresponding
plot (see Figure 2) of log(kobs) versus log([CD3CN]) with
a slope of 1.05 illustrates that there is a first-order
dependence on the concentration of CD3CN, which
means that the reaction of 7 with acetonitrile-d3 follows
second-order kinetics.
The mechanistic scheme derived from the kinetic data
is depicted in Scheme 5. Although the rate law suggests
that the primary and rate-determining step probably
consists of the attack of the nitrile ligand to the metal
center, the possibility of an equilibrium between 7 and
the coordinatively unsaturated intermediate A cannot
be excluded. If this equilibrium is fast and the subse-
quent addition of acetonitrile to the free coordination
site is slow, a second-order rate law would equally
result. We note that a η6-to-η4 ring slippage has been
discussed for the ligand exchange reactions of (η6-arene)-
chromiumtricarbonyls with different arenes8 and has
been proved for the formation of [(η5-C5Me5)Ir(η4-C6-
Me6)] from [(η5-C5Me5)Ir(η6-C6Me6)]2+ as the precursor.9
In contrast to 7, the half-sandwich-type iridium(I)
complex 11 reacts with acetonitrile not only by displace-
ment of the arene ring but also by insertion of the metal
into one of the C-H bonds of the C6H5 unit. Treating a
solution of 11 in acetone with an excess of CH3CN leads
to a stepwise change of color from light yellow to orange-
red and then again to light yellow. After removal of the
solvent, a solid is isolated, the analytical composition
of which corresponds to that of [Ir(L1)(NCCH3)3]BF4.
Although the existence of a compound like this is
3. Dih ydr ido- an d Mon oh ydr idoir idiu m (III) Com -
p lexes F or m ed by Ar en e Dissocia tion a n d C-H
Meta la tion . Treatment of 7 with excess CH3CN leads
to a partial opening of the chelate bond and, even if the
ratio of acetone to acetonitrile is 8:1, affords the six-
coordinate iridium(III) complex 15 in 87% isolated yield
(Scheme 4). Both the elemental analysis and the mass
spectrum (FAB) are consistent with the expected com-
position. The resonance of the hydrido ligands is ob-
1
served in the H NMR spectrum of 15 at δ -22.64 as a
doublet, the chemical shift being in agreement with the
data of [IrH2(NCCH3)3(PiPr3)]BF4.7 Due to the stereo-
chemical inequivalence of the acetonitriles, two signals
for the CH3 protons appear at δ 2.42 and 2.32 with an
intensity ratio of 2:1. Only the resonance of the CH3CN
ligand trans to the phosphine is split into a doublet with
an 1H-31P coupling constant of 0.9 Hz. The splitting
pattern for the signals of the acetonitrile carbon atoms
in the 13C{1H} NMR spectrum of 15 is quite similar to
1
that for the protons. Although neither the H nor the
13C NMR data of 15 reveal whether the fac or the mer
isomer is formed, we assume that in analogy with [IrH2-
(NCCH3)3(PiPr3)]BF47 the fac configuration is preferred.
To get some more insight into the mechanism of the
ring displacement leading to 15, a kinetic study of the
reaction of 7 with acetonitrile-d3 was carried out. For
this purpose, solutions of 7 in CD2Cl2 were treated at
(6) (a) Uso´n, R.; Oro, L. A.; Carmona, D.; Esteruelas, M. A.; Foces-
Foces, C.; Cano, F. H.; Garc´ıa-Blanco, S. J . Organomet. Chem. 1983,
254, 249-260. (b) Uso´n, R.; Oro, L. A.; Carmona, D.; Esteruelas, M.
A.; Foces-Foces, C.; Cano, F. H.; Garcı´a-Blanco, S.; Va´zquez de Miguel,
A. J . Organomet. Chem. 1984, 273, 111-128. (c) Cano, F. H.; Foces-
Foces, C. J . Organomet. Chem. 1985, 291, 363-369. (d) Mu¨ller, J .; Qiao,
K.; Schubert, R.; Tschampel, M. Z. Naturforsch. B 1993, 48, 1558-
1564.
(8) Traylor, T. G.; Stewart, K. J . J . Am. Chem. Soc. 1986, 108, 6977-
(7) Sola, E.; Bakhmutov, V. I.; Torres, F.; Elduque, A.; Lo´pez, J . A.;
Lahoz, F. J .; Werner, H.; Oro, L. A. Organometallics 1998, 17, 3534-
3546.
6985.
(9) Bowyer, W. J .; Geiger, W. E. J . Am. Chem. Soc. 1985, 107, 5657-
5663.

Iridium(I) and Iridium(III) Complexes
Organometallics, Vol. 22, No. 10, 2003 2155
Sch em e 4
Sch em e 5
F igu r e 3. Molecular view of the metal complex of 16.
conceivable (it possibly is the short-lived orange-red
Ta ble 3. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 16
1
intermediate), the H and 13C{1H} NMR spectra reveal
that the isolated product does not contain an intact
ligand L1; the arylhydrido complex 16 is formed instead
(see Scheme 4). Typical spectroscopic features are the
high-field signal at δ -22.33 (with J (PH) ) 19.8 Hz)
Ir-P
2.2302(10)
2.090(3)
2.150(3)
2.098(3)
2.038(4)
1.51(4)
P-C(9)
1.840(4)
1.843(4)
1.134(5)
1.129(5)
1.134(5)
1.515(5)
1.512(5)
Ir-N(1)
Ir-N(2)
Ir-N(3)
Ir-C(4)
Ir-H(1)
P-C(1)
P-C(12)
N(1)-C(17)
N(2)-C(19)
N(3)-C(15)
C(1)-C(2)
C(2)-C(3)
1
for the hydride in the H NMR and the doublet reso-
nance at δ 125.5 (with J (PC) ) 8.3 Hz) for the metalated
1.837(4)
carbon atom of the six-membered ring in the 13C{1H}
P-Ir-N(1)
173.76(9)
100.38(9)
95.16(9)
88.27(10) Ir-P-C(9)
89.0(15) Ir-P-C(12)
85.81(12) P-C(1)-C(2)
84.34(12) C(1)-C(2)-C(3)
91.96(13) Ir-N(1)-C(17)
84.8(15)
86.57(12) Ir-N(3)-C(15)
N(3)-Ir-H(1)
C(4)-Ir-H(1)
Ir-P-C(1)
91.5(15)
85.9(15)
112.19(14)
117.05(14)
114.07(14)
114.3(3)
112.5(3)
170.6(3)
172.2(3)
176.2(3)
1
NMR spectrum. Moreover, in both the H and 13C{1H}
P-Ir-N(2)
NMR spectra three sets of signals for the protons and
carbon atoms of the acetonitriles are observed, indicat-
ing that they are stereochemically different and thus
arranged in a fac configuration.
P-Ir-N(3)
P-Ir-C(4)
P-Ir-H(1)
N(1)-Ir-N(2)
N(1)-Ir-N(3)
N(1)-Ir-C(4)
N(1)-Ir-H(1)
N(2)-Ir-N(3)
N(2)-Ir-C(4)
The result of the X-ray crystal structure analysis of
16 is shown in Figure 3. It confirms that an intramo-
lecular C-H metalation has taken place and an isomer
of the above-mentioned species [Ir(L1)(NCCH3)3]BF4 has
been generated. The coordination geometry around the
iridium center corresponds to a distorted octahedron,
the cis bond angles C(4)-Ir-P, C(4)-Ir-N, P-Ir-N,
and N-Ir-N lying between 84.34(12)° and 100.38(9)°,
respectively. The Ir-N-C axes are not exactly linear
and deviate by ca. 4-10° from the ideal 180° value. The
bond lengths Ir-N(1) and Ir-N(3) are nearly identical
(see Table 3), while compared with Ir-N(1) and Ir-N(3)
the distance Ir-N(2) is somewhat elongated. This could
Ir-N(2)-C(19)
95.44(13) N(1)-C(17)-C(18) 178.0(5)
N(2)-C(19-C(20) 178.8(5)
175.66(13) N(3)-C(15)-C(16) 179.0(5)
N(2)-Ir-H(1) 170.5(15)
N(3)-Ir-C(4)
reflect the strong trans influence of the hydrido ligand,
which in a difference Fourier analysis has been located.
The distance Ir-H of 1.51(4) Å corresponds to that of
other hydridoiridium complexes.10 Analogously to the
(10) Typical Ir-H bond lengths are 1.48-1.63 Å. See: Allen, F. H.;
Kennard, O. Chem. Des. Automat. News 1993, 8, 31.

2156 Organometallics, Vol. 22, No. 10, 2003
Canepa et al.
five-coordinate cyclometalated rhodium(III) compound
[RhHCl(C6H5CH2CH2PtBu2-κ-P)(C6H4CH2CH2PtBu2-κ-
C,P)] (17),2 the six-membered chelate ring of 16 built
up by Ir, P, and C(1)-C(4) possesses a boat conformation
with the atoms Ir and C(2) representing the top and the
end of the boat. The Ir-C(4) bond length of 2.038(4) Å
is slightly shorter than in the phenyl(hydrido) derivative
[IrH(C6H5)Cl(PiPr3)2] (2.010(5) Å), the latter being
prepared from trans-[IrCl(C8H14)(PiPr3)2] and benzene
by C-H activation.11
The cyclometalated complex 16 is formed not only
from 11 but also from 14 upon treatment with excess
acetonitrile in acetone. If this reaction is monitored by
31P{1H} NMR spectroscopy, the yield of 16 is practically
100%. However, if the solvent and other volatile sub-
strates are removed in vacuo, a change of color from
light yellow to orange occurs and the π-alkyne com-
pound 14 is partly regenerated. Addition of a 10-fold
excess of diphenylacetylene to the solution of the oily
residue in acetone affords the half-sandwich-type com-
plex 14 quantitatively.
This result convincingly illustrates that the insertion
of the metal into one of the arene C-H bonds is
completely reversible. It is in good agreement with the
recent observations that, after passing a slow stream
of CO or H2 through a solution of the cyclometalated
rhodium complex 17, the compounds trans-[RhCl(CO)-
(C6H5CH2CH2PtBu2-κ-P)2] and [RhH2Cl(C6H5CH2CH2-
PtBu2-κ-P)2], respectively, are formed.2 Quite similarly,
the reaction of 16 with hydrogen in acetone gives after
12 h at room temperature the dihydridoiridium(III)
derivative 15. In this case, the isolated yield of the
product is 72%. If instead of H2 deuterium D2 is used,
owing to the 1H NMR spectrum the bis(deuteride) [IrD2-
(NCCH3)3(L1)]BF4 (15-d 2) is generated up to at least
95%. Only traces of deuterium might be incorporated
into the arene ligand. A plausible interpretation of these
observations suggests that not only the reaction of 16
with PhCtCPh but also the hydrogenation could take
place via the postulated 16-electron species [Ir(L1)-
(NCCH3)3]+, which would be not the thermodynamically
but the kinetically favored isomer of 16.
isolation of the six-coordinate complex 16, the metal can
easily insert into one of the C-H bonds of the phenyl
group of L1 to give a new six-membered chelate ring
system. This orthometalation reaction not only has a
low energy of activation but is also reversible, which is
illustrated by the formation of 15-d 2 from 16 and D2
and of 14 from 16 and diphenylacetylene. It could well
be that compound 16 represents the resting state for
hydride transfer reactions of the dihydrido complex 15
with unsaturated substrates, but this has to be proved
by further investigations.
Exp er im en ta l Section
All experiments were carried out under an atmosphere of
argon by Schlenk techniques. Solvents were dried by known
procedures and distilled before used. The starting materials
1,12 4,13 and the phosphines L1 and L2 were prepared as
described in the literature.1 D2 was a product from Aldrich.
IR spectra were recorded on a Nicolet 550 spectrometer; NMR
spectra (at room temperature or at the temperature mentioned
in the appropriate procedure), on a Varian Gemini 2000
instrument. Abbreviations used: s, singlet; d, doublet; t,
triplet; sept, septet; m, multiplet; br, broadened signal. The
conductivity Λ(M) was measured in acetone with a Philips PW
9501/01 conductometer. Mass spectra were recorded on a VG
Autospec instrument.
P r ep a r a tion of [HP iP r 2(CH2CH2C6H5)]BF 4 (L1‚HBF 4).
To a solution of L1 (1.37 g, 6.16 mmol) in 20 mL of diethyl
ether was added dropwise a 1.6 M solution of HBF4 (850 µL,
6.17 mmol) in diethyl ether at room temperature. A white solid
precipitated. After the suspension was stirred for 12 h, the
mother liquor was decanted, and the remaining solid was
washed twice with 15 mL portions of diethyl ether and dried.
1
Yield: 1.76 g (92%). Mp: 329 K. H NMR (300 MHz, CDCl3):
δ 7.24 (m, 5 H, C6H5), 5.81 (br d, J (PH) ) 472.9 Hz, 1 H, PH),
3.01 (m, 2 H, PCH2CH2), 2.70 (m, 2 H, PCHCH3), 2.50 (m, 2
H, PCH2), 1.32 (dd, J (PH) ) 18.6, J (HH) ) 6.9 Hz, 12 H,
PCHCH3). 13C{1H} NMR (75.5 MHz, CDCl3): δ 138.5 (d, J (PC)
) 11.6 Hz, ipso-C of C6H5), 129.1, 128.4, 127.4 (all s, C6H5),
29.4 (d, J (PC) ) 4.6 Hz, PCH2CH2), 19.2 (d, J (PC) ) 42.3 Hz,
PCHCH3), 17.1 (d, J (PC) ) 2.3 Hz, PCHCH3), 16.5 (d, J (PC)
) 2.7 Hz, PCHCH3), 15.5 (d, J (PC) ) 41.9 Hz, PCH2). 31P{1H}
NMR (121.5 MHz, CDCl3): δ 32.7 (s). Anal. Calcd for C14H24
-
BF4P (310.1): C, 54.22; H, 7.80. Found: C, 53.94; H, 7.72.
P r ep a r a tion of [HP tBu 2(CH2CH2OC6H5)]BF4 (L2‚HBF4).
The preparation was analogous with that described for L1‚
HBF4, from L2 (3.78 g, 14.2 mmol) and a 1.6 M solution of HBF4
(1.95 mL, 14.2 mmol) in diethyl ether. White solid: yield 4.60
Con clu sion s
The results presented in this paper illustrate that the
phosphines L1 and L2, having a phenyl group in the
alkyl side chain, coordinate not only to rhodium but also
to iridium in both the oxidation state +I and +III as
2-electron or (6+2)-electron donor ligands. The chelating
bonding mode allows the isolation of dihydrido com-
plexes of the formal composition [IrH2(L1)]BF4 and
[IrH2(L2)]BF4, which are suitable precursors for the
preparation of various olefin and alkyne iridium(I)
compounds of the half-sandwich-type. In the presence
of hydrogen, these complexes regenerate the dihydri-
doiridium(III) derivatives. This behavior is probably
important for catalytic purposes, which we are currently
studying in our laboratories.
1
g (91%); mp 367 K. H NMR (300 MHz, CDCl3): δ 7.26, 6.97,
6.91 (all m, 5 H, C6H5), 5.89 (br d, J (PH) ) 468.7 Hz, 1 H,
PH), 4.37 (dt, J (PH ) 17.1, J (HH) ) 6.9 Hz, 2 H, PCH2CH2),
2.82 (dt, J (PH) ) 14.7, J (HH) ) 6.9 Hz, 2 H, PCH2), 1.50 (d,
J (PH) ) 16.8 Hz, 18 H, PCCH3). 13C{1H} NMR (75.5 MHz,
CDCl3): δ 157.2 (s, ipso-C of C6H5), 129.8, 122.1, 114.6 (all s,
C6H5), 62.2 (d, J (PC) ) 6.9 Hz, PCH2CH2), 32.8 (d, J (PC) )
34.9 Hz, PCCH3), 27.1 (s, PCCH3), 16.0 (d, J (PC) ) 42.9 Hz,
PCH2). 31P{1H} NMR (121.5 MHz, CDCl3): δ 40.3 (s). Anal.
Calcd for C16H28BF4OP (354.2): C, 54.26; H, 7.97. Found: C,
54.00; H, 7.94.
P r ep a r a tion of cis-[Ir (a ceton e)2(C8H14)2]P F 6 (2). A sus-
pension of 1 (1.05 g, 1.17 mmol) in 15 mL of acetone was
treated dropwise with a solution of AgPF6 (593 mg, 2.34 mmol)
in 5 mL of acetone at room temperature. A white solid rapidly
precipitated and was filtered. The filtrate was concentrated
However, the capabilities of the functionalized phos-
phines used in these studies go beyond the η6-Ln-κ-P and
Ln-κ-P coordination modes. As it has been shown by the
(12) van der Ent, A.; Onderdelinden, A. L. Inorg. Synth. 1973, 14,
92-95.
(11) Werner, H.; Ho¨hn, A.; Dziallas, M. Angew. Chem. 1986, 98,
1112-1114; Angew. Chem., Int. Ed. Engl. 1986, 25, 1090-1092.
(13) Uso´n, R.; Oro, L. A.; Cabeza, J . A. Inorg. Synth. 1986, 23, 126-
130.

Iridium(I) and Iridium(III) Complexes
Organometallics, Vol. 22, No. 10, 2003 2157
to ca. 3 mL in vacuo, and 40 mL of diethyl ether was added.
An orange precipitate was formed, which was filtered, washed
three times with 10 mL portions of diethyl ether, and dried.
ing orange solid was washed twice with 5 mL portions of
diethyl ether and dried. Yield: 562 mg (92%). Λ(M) ) 97 cm2
Ω-1 mol-1 1H NMR (300 MHz, CDCl3, 293 K): δ 7.41, 7.25
.
1
Yield: 1.41 g (89%). H NMR (300 MHz, acetone-d6): δ 2.75
(both m, 5 H, C6H5), 4.63 (dt, J (PH) ) 13.8, J (HH) ) 6.9 Hz,
2 H, PCH2CH2), 4.24, 4.13 (both m, 2 H each, dCH of C8H12),
2.21 (dt, J (PH) ) 8.7, J (HH) ) 6.9 Hz, 2 H, PCH2), 2.20, 2.06,
1.64, 1.51 (all m, 2 H each, CH2 of C8H12), 1.43 (d, J (PH) )
13.8 Hz, 18 H, PCCH3). 13C{1H} NMR (75.5 MHz, CDCl3): δ
157.5 (s, ipso-C of C6H5), 130.5, 128.0, 121.3 (all m, C6H5), 92.2
(d, J (PC) ) 10.6 Hz, dCH of C8H12), 88.1 (br s, PCH2CH2),
51.4 (s, dCH of C8H12), 37.1 (d, J (PC) ) 19.9 Hz, PCCH3), 33.4
(d, J (PC) ) 2.7 Hz, CH2 of C8H12), 29.9 (d, J (PC) ) 3.6 Hz,
PCCH3), 27.1 (s, CH2 of C8H12), 21.3 (d, J (PC) ) 22.6 Hz,
PCH2). 31P{1H} NMR (121.5 MHz, CDCl3, 293 K): δ 58.9 (s).
31P{1H} NMR (121.5 MHz, acetone-d6, 293 K): δ 58.1 (br s).
31P{1H} NMR (121.5 MHz, acetone-d6, 323 K): δ 58.6 (s). 31P-
{1H} NMR (121.5 MHz, acetone-d6, 173 K): δ 59.4 (br s). Anal.
Calcd for C24H39BF4OPIr (653.6): C, 44.11; H, 6.01. Found:
C, 44.09; H, 5.86.
P r ep a r a tion of [(η6-C6H5CH2CH2P iP r 2-K-P )Ir H2]BF 4 (7).
A suspension of 4 (756 mg, 1.14 mmol) in 12 mL of acetone
was treated with a solution of L1‚HBF4 (707 mg, 2.28 mmol)
in 40 mL of acetone at room temperature. After stirring for 5
min, an orange solution was formed, which was brought to
dryness in vacuo. The oily residue was dissolved in 40 mL of
acetone, and the solution was stirred for 50-60 min under a
H2 atmosphere. As soon as the solution began to darken, the
solvent was evaporated. The brownish-yellow residue was
dissolved in 7 mL of acetone, and 30 mL of diethyl ether was
added to the solution. A yellow solid precipitated, which was
separated from the mother liquor, washed with 10 mL of
diethyl ether, and dried. After repeated recrystallization from
acetone/diethyl ether (1:7) a white solid was obtained. Yield:
901 mg (79%). Λ(M) ) 112 cm2 Ω-1 mol-1. IR (KBr): ν(IrH)
2241 and 2200 cm-1. 1H NMR (300 MHz, CDCl3): δ 6.86, 6.80,
6.23 (all m, 5 H, C6H5), 3.24 (dt, J (PH) ) 9.0, J (HH) ) 7.5 Hz,
2 H, PCH2), 2.76 (dt, J (PH) ) 19.2, J (HH) ) 7.5 Hz, 2 H,
PCH2CH2), 2.01 (m, 2 H, PCHCH3), 1.10 (dd, J (PH) ) 16.8,
J (HH) ) 6.6 Hz, 6 H, PCHCH3), 1.07 (dd, J (PH) ) 18.0, J (HH)
) 7.5 Hz, 6 H, PCHCH3), -14.99 (d, J (PH) ) 22.8 Hz, 2 H,
IrH). 13C{1H} NMR (75.5 MHz, CDCl3): δ 124.5 (d, J (PC) )
7.8 Hz, ipso-C of C6H5), 98.0 (d, J (PC) ) 2.9 Hz, C6H5), 90.86
(s, C6H5), 81.49 (d, J (PC) ) 7.5 Hz, para-C of C6H5), 38.84 (d,
J (PC) ) 32.9 Hz, PCH2), 25.86 (d, J (PC) ) 2.0 Hz, PCH2CH2),
21.5 (d, J (PC) ) 35.8 Hz, PCHCH3), 14.2 (s, PCHCH3), 13.4
(d, J (PC) ) 1.7 Hz, PCHCH3). 31P{1H} NMR (121.5 MHz,
CDCl3): δ 71.7 (s). Anal. Calcd for C14H25BF4PIr (503.4): C,
33.41; H, 5.01. Found: C, 33.27; H, 4.74.
(m, 4 H, dCH of C8H14), 2.21 (s, 12 H, OdC(CH3)2), 1.75, 1.58,
1.38 (all m, 24 H, CH2 of C8H14). 13C{1H} NMR (75.5 MHz,
acetone-d6): δ 28.1 (s, dCH of C8H14), 27.3, 26.1, 24.3 (all s,
CH2 of C8H14). The signals for coordinated acetone could not
be detected. Even though the NMR data did not reveal the
presence of impurities, a correct elemental analysis could not
be obtained, probably as a consequence of the high air-
sensitivity of the compound.
P r ep a r a tion of [(η6-C6H5CH2CH2P iP r 2-K-P )Ir (C8H14)]-
P F 6 (3). A solution of 2 (124 mg, 0.18 mmol) in 3 mL of acetone
was treated dropwise over 5 min with a solution of L1 (41 mg,
0.18 mmol) in 5 mL of acetone at room temperature. A smooth
change of color from orange-red to yellow occurred. After the
solution was concentrated to ca. 2 mL in vacuo, 10 mL of
diethyl ether was added. A light yellow solid precipitated,
which was filtered, washed twice with 3 mL portions of diethyl
ether, and dried. Yield: 109 mg (90%). Λ(M) ) 100 cm2 Ω-1
1
mol-1. H NMR (300 MHz, acetone-d6): δ 7.15, 6.99, 6.10 (all
m, 5 H, C6H5), 3.06 (m, 2 H, dCH of C8H14), 3.04 (dt, J (PH) )
9.3, J (HH) ) 7.5 Hz, 2 H, PCH2), 2.55 (dt, J (PH) ) 18.6, J (HH)
) 7.5 Hz, 2 H, PCH2CH2), 2.42-2.24 (br m, 4 H, CH2 of C8H14
and PCHCH3), 1.71-1.26 (br m, 10 H, CH2 of C8H14), 1.24 (dd,
J (PH) ) 15.6, J (HH) ) 6.9 Hz, 6 H, PCHCH3), 1.23 (dd, J (PH)
) 16.5, J (HH) ) 7.2 Hz, 6 H, PCHCH3). 13C{1H} NMR (75.5
MHz, acetone-d6): δ 114.9 (d, J (PC) ) 6.4 Hz, ipso-C of C6H5),
104.3, 93.9 (both s, C6H5), 87.3 (d, J (PC) ) 10.1 Hz, para-C of
C6H5), 46.8 (s, dCH of C8H14), 41.8 (d, J (PC) ) 35.9 Hz, PCH2),
34.3, 33.3, 26.1 (all s, CH2 of C8H14), 29.8 (s, PCH2CH2), 23.6
(d, J (PC) ) 32.2 Hz, PCHCH3), 18.6, 17.3 (both s, PCHCH3).
31P{1H} NMR (121.5 MHz, acetone-d6): δ 52.6 (s, PiPr2),
-139.7 (sept, J (FP) ) 712.1 Hz, PF6). Anal. Calcd for
C
22H37F6P2Ir (669.7): C, 39.46; H, 5.57. Found: C, 39.45; H,
5.48.
P r ep a r a tion of [Ir (C8H12)(OdCMe2)(C6H5CH2CH2P iP r 2-
K-P )]BF 4 (5). A suspension of 4 (121 mg, 0.18 mmol) in 2 mL
of acetone was treated with a solution of L1‚HBF4 (113 mg,
0.37 mmol) in 6 mL of acetone at room temperature. A light
orange-colored solution was formed, which after removal of
the solvent afforded an oily orange-yellow residue. The residue
was dissolved in 5 mL of acetone, and the solution was
evaporated in vacuo. The NMR spectra of the remaining
orange oil indicated that besides 5 some impurities were still
present. Repeated recrystallization from acetone could not
completely remove the impurities. Data for 5. IR (CH2Cl2):
1
ν(CdO) 1652 cm-1. H NMR (300 MHz, acetone-d6): δ 7.35-
P r ep a r a tion of [(η6-C6H5OCH2CH2P tBu 2-K-P )Ir H2]BF 4
(8). The preparation was analogous with that described for 7,
from 6 (137 mg, 0.21 mmol) and H2. The product already
precipitated upon concentrating the solution in vacuo. After
recrystallization from acetone/diethyl ether (1:6) a white solid
7.17 (m, 5 H, C6H5), 4.63 (br m, 2 H, dCH of C8H12), 3.79 (br
s, 2 H, dCH of C8H12), 2.94 (dt, J (PH) ) 9.0, J (HH) ) 4.5 Hz,
2 H, PCH2CH2), 2.42 (m, 2 H, PCHCH3), 2.29 (m, 4 H, CH2 of
C8H12), 2.08 (s, 6 H, OdC(CH3)2), 2.05 (m, 2 H, PCH2), 1.78
(m, 4 H, CH2 of C8H12), 1.41 (dd, J (PH) ) 13.8, J (HH) ) 6.9
Hz, 6 H, PCHCH3), 1.38 (dd, J (PH) ) 15.6, J (HH) ) 7.2 Hz, 6
H, PCHCH3). 13C{1H} NMR (75.5 MHz, acetone-d6): δ 204.4
(s, CdO), 142.4 (d, J (PC) ) 11.6 Hz, ipso-C of C6H5), 129.2,
128.6, 127.0 (all s, C6H5), 92.4 (d, J (PC) ) 11.6 Hz, dCH of
C8H12), 54.1 (s, dCH of C8H12), 33.7 (d, J (PC) ) 3.2 Hz, CH2
of C8H12), 30.7 (d, J (PC) ) 4.2 Hz, PCH2CH2), 30.2 (s,
OdC(CH3)2), 28.1 (s, CH2 of C8H12), 23.9 (d, J (PC) ) 27.6 Hz,
PCHCH3), 18.9 (d, J (PC) ) 1.8 Hz, PCHCH3), 18.8 (s, PCHCH3),
18.5 (d, J (PC) ) 22.6 Hz, PCH2). 31P{1H} NMR (121.5 MHz,
was obtained. Yield: 100 mg (87%). Λ(M) ) 110 cm2 Ω-1 mol-1
.
IR (KBr): ν(IrH) 2244 and 2201 cm-1 1H NMR (300 MHz,
.
CDCl3): δ 6.85, 6.61, 6.15 (all m, 5 H, C6H5), 4.58 (m, 2 H,
PCH2CH2), 1.69 (m, 2 H, PCH2), 1.26 (d, J (PH) ) 15.0 Hz, 18
H, PCCH3), -15.31 (d, J (PH) ) 23.7 Hz, 2 H, IrH). 13C{1H}
NMR (75.5 MHz, CD2Cl2): δ 134.6 (s, ipso-C of C6H5), 103.8
(d, J (PC) ) 2.1 Hz, C6H5), 89.8 (s, C6H5), 82.3 (d, J (PC) ) 7.8
Hz, para-C of C6H5), 74.9 (d, J (PC) ) 2.9 Hz, PCH2CH2), 36.1
(d, J (PC) ) 31.6 Hz, PCCH3), 28.5 (d, J (PC) ) 2.4 Hz, PCCH3),
9.9 (d, J (PC) ) 30.7 Hz, PCH2). 31P{1H} NMR (121.5 MHz,
CDCl3): δ 43.6 (s). Anal. Calcd for C16H29BF4OPIr (547.4): C,
35.11; H, 5.34. Found: C, 35.00; H, 5.31.
acetone-d6): δ 25.4 (s). MS (FAB): m/z 651 [M+], 564 [M+
BF4].
-
P r ep a r a tion of [Ir (C8H12)(C6H5OCH2CH2P tBu 2-K2-O,P )]-
BF 4 (6). A suspension of 4 (307 mg, 0.46 mmol) in 2 mL of
acetone was treated with a solution of L2‚HBF4 (328 mg, 0.93
mmol) in 8 mL of acetone at room temperature. After the
reaction mixture was stirred for 5 min, a clear orange solution
was formed. The solvent was evaporated in vacuo, the remain-
P r ep a r a tion of [(η6-C6H5CH2CH2P iP r 2-K-P )Ir (C2H4)]-
BF 4 (9). A solution of 7 (125 mg, 0.25 mmol) in 10 mL of
acetone was stirred under an ethene atmosphere for 2 h at
room temperature. After the solution was concentrated to ca.
2 mL in vacuo, 12 mL of diethyl ether was added. This led to
the precipitation of a light yellow solid, which was filtered,

2158 Organometallics, Vol. 22, No. 10, 2003
Canepa et al.
washed twice with 5 mL portions of diethyl ether, and dried.
P r ep a r a tion of [(η6-C6H5OCH2CH2P tBu 2-K-P )Ir (CH2d
CHCH3)]BF 4 (12). The preparation was analogous to that
described for 11, from 8 (190 mg, 0.35 mmol) and propene.
However, the reaction time was 4 days and the reaction
temperature 323 K. Yellow solid: yield 145 mg (71%). Λ(M)
) 103 cm2 Ω-1 mol-1. 1H NMR (300 MHz, acetone-d6): δ 7.26,
7.21, 7.18, 7.05, 5.69 (all m, 1 H each, C6H5), 4.62-4.47 (m, 2
H, PCH2CH2), 3.43 (dddq, J (PH) ) 5.7, J (HH) ) 11.1, 8.1, 6.0
Hz, 1 H, dCHCH3), 2.95 (dd, J (HH) ) 11.1, 1.8 Hz, 1 H, d
CH2), 2.74 (ddd, J (PH) ) 3.3, J (HH) ) 8.1, 1.8 Hz, 1 H, d
CH2,), 2.02, 1.74 (both m, 1 H each, PCH2), 1.92 (d, J (HH) )
6.0 Hz, 3 H, dCHCH3), 1.43, 1.26 (both d, J (PH) ) 13.8 Hz, 9
H each, PCCH3). 13C{1H} NMR (75.5 MHz, acetone-d6): δ 126.1
(s, ipso-C of C6H5), 105.6 (d, J (PC) ) 1.4 Hz, C6H5), 101.7 (d,
J (PC) ) 3.2 Hz, C6H5), 91.1, 90.6 (both s, C6H5), 84.2 (d, J (PC)
) 9.7 Hz, para-C of C6H5), 71.5 (d, J (PC) ) 2.3 Hz, PCH2CH2),
37.8 (d, J (PC) ) 24.9 Hz, PCCH3), 37.3 (s, dCHCH3), 37.2 (d,
J (PC) ) 23.9 Hz, PCCH3), 31.6, 29.9 (both d, J (PC) ) 2.8 Hz,
PCCH3), 25.0 (s, dCHCH3), 24.7 (s, dCH2), 13.5 (d, J (PC) )
31.3 Hz, PCH2). 31P{1H} NMR (121.5 MHz, acetone-d6): δ 11.1
(s). Anal. Calcd for C19H33BF4OPIr (587.5): C, 38.85; H, 5.66.
Found: C, 38.54; H, 5.62.
Yield: 123 mg (93%). Λ(M) ) 101 cm2 Ω-1 mol-1 1H NMR
.
(300 MHz, acetone-d6): δ 7.37-7.18 (m, 4 H, C6H5), 5.68 (m,
1 H, C6H5), 3.06 (dt, J (PH) ) 9.0, J (HH) ) 7.5 Hz, 2 H, PCH2),
2.91 (m, 2 H, exo-H of C2H4), 2.63 (dt, J (PH) ) 18.9, J (HH) )
7.5 Hz, 2 H, PCH2CH2), 2.25 (m, 2 H, PCHCH3), 2.07 (m, 2 H,
endo-H of C2H4), 1.21 (dd, J (PH) ) 15.9, J (HH) ) 7.2 Hz, 6 H,
PCHCH3), 1.16 (dd, J (PH) ) 16.2, J (HH) ) 7.2 Hz, 6 H,
PCHCH3). 13C{1H} NMR (75.5 MHz, acetone-d6): δ 116.9 (d,
J (PC) ) 6.5 Hz, ipso-C of C6H5), 101.7 (d, J (PC) ) 3.7 Hz,
C6H5), 95.1 (d, J (PC) ) 1.4 Hz, C6H5), 86.5 (d, J (PC) ) 10.2
Hz, para-C of C6H5), 42.1 (d, J (PC) ) 35.5 Hz, PCH2), 30.0 (s,
PCH2CH2), 23.4 (d, J (PC) ) 32.2 Hz, PCHCH3), 18.4, 17.2 (both
d, J (PC) ) 1.8 Hz, PCHCH3), 18.3 (s, C2H4). 31P{1H} NMR
(121.5 MHz, acetone-d6): δ 53.4 (s). Anal. Calcd for C16H27
-
BF4PIr (529.4): C, 36.30; H, 5.14. Found: C, 36.27; H, 5.01.
Rea ction of Com p ou n d 9 w ith H 2. A solution of 9 (23
mg, 0.04 mmol) in 0.4 mL of acetone-d6 was stirred under a
hydrogen atmosphere at room temperature. The reaction was
1
monitored by H NMR spectroscopy. After 20 h, the signals of
9 had disappeared, while those of 7 dominated. In addition,
some signals of low intensity were observed in the high-field
region which could not be assigned.
P r ep a r a tion of [(η6-C6H5CH2CH2P iP r 2-K-P )Ir (Z-P h CHd
CHP h )]BF 4 (13). A solution of 11 (100 mg, 0.18 mmol) in 6
mL of acetone was treated with Z-stilbene (103 µL, 0.55 mmol)
and stirred for 2 h under reflux. After the solution was cooled
to room temperature, the solvent was evaporated in vacuo, and
the residue was dissolved in 2 mL of CH2Cl2. Dropwise addition
of 10 mL of diethyl ether led to the precipitation of a yellow
solid, which was filtered, washed with 10 mL of diethyl ether,
P r ep a r a tion of [(η6-C6H5OCH2CH2P tBu 2-K-P )Ir (C2H4)]-
BF 4 (10). A solution of 8 (152 mg, 0.28 mmol) in 5 mL of
acetone was stirred under an ethene atmosphere for 12 h at
323 K. After cooling to room temperature, the solvent was
evaporated in vacuo, the residue was dissolved in 3 mL of
acetone, and the solution was filtered. Addition of 10 mL of
diethyl ether to the filtrate led to the precipitation of a light
yellow solid, which was filtered, washed twice with 4 mL
portions of diethyl ether, and dried. Yield: 116 mg (72%). Λ(M)
) 99 cm2 Ω-1 mol-1. 1H NMR (300 MHz, acetone-d6): δ 7.29-
7.17 (m, 4 H, C6H5), 5.32 (m, 1 H, C6H5), 4.57 (m, 2 H,
PCH2CH2), 3.16 (m, 2 H, exo-H of C2H4), 2.49 (m, 2 H, endo-H
of C2H4), 1.83 (m, 2 H, PCH2), 1.32 (d, J (PH) ) 14.1 Hz, 18 H,
PCCH3). 13C NMR (75.5 MHz, acetone-d6): δ 126.6 (s, ipso-C
of C6H5), 102.3 (d, J (PC) ) 2.7 Hz, C6H5), 92.2 (s, C6H5), 84.4
(d, J (PC) ) 9.7 Hz, para-C of C6H5), 71.9 (d, J (PC) ) 2.8 Hz,
PCH2CH2), 37.2 (d, J (PC) ) 24.8 Hz, PCCH3), 30.5 (d, J (PC)
) 2.8 Hz, PCCH3), 18.3 (d, J (PC) ) 2.3 Hz, C2H4), 12.9 (d,
J (PC) ) 31.3 Hz, PCH2). 31P{1H} NMR (121.5 MHz, acetone-
d6): δ 12.1 (s). Anal. Calcd for C18H31BF4OPIr (573.4): C,
37.70; H, 5.45. Found: C, 37.36; H, 5.40.
and dried. Yield: 100 mg (80%). IR (KBr): ν(CdC) 1598 cm-1
.
1H NMR (300 MHz, CDCl3): δ 7.16 (m, 12 H, CH2C6H5 and
dCHC6H5), 6.18 (m, 2 H, dCHC6H5), 5.05 (m, 1 H, CH2C6H5),
4.45 (d, J (PH) ) 4.9 Hz, 2 H, dCHC6H5), 3.08 (dt, J (PH) )
9.0, J (HH) ) 7.6 Hz, 2 H, PCH2), 2.61 (dt, J (PH) ) 19.5, J (HH)
) 7.6 Hz, 2 H, PCH2CH2), 2.24 (m, 2 H, PCHCH3), 1.34 (dd,
J (PH) ) 16.2, J (HH) ) 7.1 Hz, 12 H, PCHCH3). 13C{1H} NMR
(75.5 MHz, CDCl3): δ 143.0 (s, ipso-C of dCHC6H5), 129.9,
128.2, 126.6 (all s, dCHC6H5), 115.7 (d, J (PC) ) 6.9 Hz, ipso-C
of CH2C6H5), 108.1 (d, J (PC) ) 2.9 Hz, CH2C6H5), 93.4 (s,
CH2C6H5), 91.8 (d, J (PC) ) 9.8 Hz, CH2C6H5), 43.0 (d, J (PC)
) 1.5 Hz, dCHC6H5), 41.5 (d, J (PC) ) 36.3 Hz, PCH2), 30.2
(s, PCH2CH2), 23.6 (d, J (PC) ) 31.2 Hz, PCHCH3), 19.1, 17.7
(both s, PCHCH3). 31P{1H} NMR (121.5 MHz, CDCl3): δ 47.9
(s). Anal. Calcd for C28H35BF4PIr (681.6): C, 49.34; H, 5.18.
Found: C, 49.23; H, 4.88.
P r ep a r a t ion of [(η6-C6H 5CH 2CH 2P iP r 2-K-P )Ir (CH 2d
CHCH3)]BF 4 (11). A solution of 7 (134 mg, 0.27 mmol) in 10
mL of acetone was stirred under a propene atmosphere for 15
min at room temperature. A gradual change of color from off-
white to light yellow occurred. After the solution was concen-
trated to ca. 2 mL in vacuo, 10 mL of diethyl ether were added.
A light yellow solid precipitated, which was filtered, washed
twice with 4 mL portions of diethyl ether, and dried. Yield:
P r ep a r a t ion of [(η6-C6H 5CH 2CH 2P iP r 2-K-P )Ir (P h Ct
CP h )]BF 4 (14). (a) A solution of 7 (109 mg, 0.22 mmol) in 8
mL of acetone was treated with a 10-fold excess of diphenyl-
acetylene (392 mg, 2.20 mmol) and stirred for 5 min at room
temperature. A change of color from off-white to orange-red
occurred. After the solvent and volatile materials were re-
moved in vacuo, the residue was washed with diethyl ether
and then dissolved in 3 mL of acetone. Addition of 12 mL of
diethyl ether led to the precipitation of a brownish-yellow solid,
which was filtered, washed twice with 5 mL portions of diethyl
ether, and dried. Yield: 132 mg (90%). (b) A solution of 9 (75
mg, 0.14 mmol) in 6 mL of acetone was treated with a 10-fold
excess of diphenylacetylene and stirred for 12 h at room
temperature. The reaction mixture was then worked up as
described for procedure a). Yield: 80 mg (84%). Λ(M) ) 110
1
132 mg (91%). ΛM ) 112 cm2 Ω-1 mol-1. H NMR (300 MHz,
acetone-d6): δ 7.31, 7.26, 7.19, 6.95, 5.95 (all m, 1 H each,
C6H5), 3.19-2.85 (br m, PCH2, and dCHCH3), 2.72 (dd, J (HH)
) 10.2, 1.5 Hz, 1 H, dCH2], 2.61 (m, 2 H, PCH2CH2), 2.41-
2.18 (br m, 3 H, dCH2 and PCHCH3), 1.89 (d, J (HH) ) 6.0
Hz, 3 H, dCHCH3), 1.29 (dd, J (PH) ) 16.8, J (HH) ) 7.2 Hz,
3 H, PCHCH3), 1.25 (dd, J (PH) ) 15.6, J (HH) ) 6.9 Hz, 3 H,
PCHCH3), 1.20 (dd, J (PH) ) 16.2, J (HH) ) 6.9 Hz, 3 H,
PCHCH3), 1.11 (dd, J (PH) ) 16.2, J (HH) ) 7.2 Hz, 3 H,
PCHCH3). 13C{1H} NMR (75.5 MHz, acetone-d6): δ 115.7 (d,
J (PC) ) 6.9 Hz, ipso-C of C6H5), 105.5. 101.2 (both d, J (PC) )
3.2 Hz, C6H5), 94.6 (s, C6H5), 86.8 (d, J (PC) ) 9.7 Hz, C6H5),
41.9 (d, J (PC) ) 36.4 Hz, PCH2), 39.1 (d, J (PC) ) 1.9 Hz, d
CHCH3), 29.9 (s, PCH2CH2), 26.1 (s, dCHCH3), 23.9 (br s, d
CH2), 23.7 (d, J (PC) ) 32.3 Hz, PCHCH3), 23.2 (d, J (PC) )
32.2 Hz, PCHCH3), 19.0, 17.8, 17.7 (all s, PCHCH3), 16.7 (d,
J (PC) ) 2.3 Hz, PCHCH3). 31P{1H} NMR (121.5 MHz, acetone-
d6): δ 47.7 (s). Anal. Calcd for C17H29BF4PIr (543.4): C, 37.58;
H, 5.38. Found: C, 37.54; H, 5.28.
cm2 Ω-1 mol-1. IR (KBr): ν(CtC) 1824 cm-1
.
1H NMR (300
MHz, acetone-d6): δ 7.95 (m, 2 H, CH2C6H5), 7.86 (m, 4 H,
tCC6H5), 7.51 (m, 2 H, CH2C6H5), 7.47 (m, 4 H, tCC6H5), 7.34
(m, 2 H, tCC6H5), 6.08 (m, 1 H, CH2C6H5), 3.14 (dt, J (PH) )
9.0, J (HH) ) 7.5 Hz, 2 H, PCH2), 2.90 (dt, J (PH) ) 18.0, J (HH)
) 7.5 Hz, 2 H, PCH2CH2), 1.92 (m, 2 H, PCHCH3), 1.07, (dd,
J (PH) ) 16.1, J (HH) ) 7.1 Hz, 6 H, PCHCH3), 0.91 (dd, J (PH)
) 16.7, J (HH) ) 7.1 Hz, 6 H, PCHCH3). 13C{1H} NMR (75.5
MHz, acetone-d6): δ 131.2, 129.2, 128.3, 128.1 (all s, tC6H5),
119.6 (d, J (PC) ) 6.4 Hz, ipso-C of CH2C6H5), 105.6 (d, J (PC)

Iridium(I) and Iridium(III) Complexes
Organometallics, Vol. 22, No. 10, 2003 2159
Ta ble 4. Cr ysta l Da ta a n d Da ta Collection a n d
Refin em en t for Com p lexes 13 a n d 16
) 4.2 Hz, CH2C6H5), 93.8 (d, J (PC) ) 12.0 Hz, CtC), 93.2 (s,
CH2C6H5), 82.5 (d, J (PC) ) 4.6 Hz, para-C of CH2C6H5), 40.9
(d, J (PC) ) 35.9 Hz, PCH2), 30.7 (s, PCH2CH2), 24.1 (d, J (PC)
) 32.7 Hz, PCHCH3), 17.2 (s, PCHCH3), 16.8 (d, J (PC) ) 1.8
Hz, PCHCH3). 31P{1H} NMR (121.5 MHz, acetone-d6): δ 60.2
(s). Anal. Calcd for C28H33BF4PIr (679.6): C, 49.49; H, 4.89.
Found: C, 49.70; H, 5.13.
13
16
chem formula
fw
C
28H35BF4IrP
C20H32BF4IrN3P
624.47
681.54
cryst size,mm
cryst syst
space group
a, Å
b, Å
c, Å
0.28 × 0.27 × 0.17 0.237 × 0.171 × 0.136
monoclinic
P21/c
triclinic
P1h
P r ep a r a tion of [Ir H2(NCCH3)3(C6H5CH2CH2P iP r 2-η-P )]-
BF 4 (15). (a) A solution of 7 (95 mg, 0.19 mmol) in 4 mL of
acetone was treated with excess acetonitrile (0.5 mL, 9.53
mmol) and stirred for 3 h at room temperature. The solution
was concentrated to ca. 0.5 mL in vacuo, and 6 mL of diethyl
ether was added. A yellow oily product precipitated. After it
was washed six times with 10 mL portions of diethyl ether
(273 K), a white solid was obtained and dried. Yield: 104 mg
(87%). (b) Analogously as described for (a) from 16 (62 mg,
0.10 mmol) and H2 as starting materials. The reaction time
was 12 h. White solid: yield 45 mg (72%). Λ(M) ) 97 cm2 Ω-1
8.4249(5)
19.1858(11)
15.9442(9)
90.0(0)
93.0220(10)
90.0(0)
11.3293(7)
11.3608(7)
11.8529(8)
113.8270(10)
117.5450(10)
91.5830(10)
1193.34(13)
2
R, deg
â, deg
γ, deg
V, Å3
2573.6(3)
4
Z
D
calcd, gcm-3
1.759
1.738
µ, mm-1
5.295
5.704
no. of measd reflns 16 658
14 641
1
mol-1. IR (KBr): ν(IrH) 2227 cm-1. H NMR (300 MHz, CD2-
no. of unique reflns 5976 (Rint ) 0.0294) 5550 (Rint ) 0.0326)
min., max. transm 0.265, 0.407
factor
0.321, 0.460
5550/0/399
Cl2): δ 7.31 (m, 2 H, C6H5), 7.21 (m, 3 H, C6H5), 2.79 (dt, J (PH)
) 12.6, J (HH) ) 5.1 Hz, 2 H, PCH2CH2), 2.42 (d, J (PH) ) 0.9
Hz, 3 H, CH3CN), 2.32 (s, 6 H, CH3CN), 2.12-1.84 (m, 4 H,
PCH2 and PCHCH3), 1.12 (dd, J (PH) ) 15.0, J (HH) ) 6.9 Hz,
6 H, PCHCH3), 1.10 (dd, J (PH) ) 14.4, J (HH) ) 6.9 Hz, 6 H,
PCHCH3), -22.64 (d, J (PH) ) 21.6 Hz, 2 H, IrH). 13C{1H}
NMR (75.5 MHz, CD2Cl2): δ 142.4 (d, J (PC) ) 13.4 Hz, ipso-C
of C6H5), 129.0, 128.1, 126.6 (all s, C6H5), 119.4 (d, J (PC) )
7.8 Hz, CH3CN), 119.3 (s, CH3CN), 31.3 (s, PCH2CH2), 26.8
(d, J (PC) ) 32.2 Hz, PCH2), 25.2 (d, J (PC) ) 37.8 Hz,
PCHCH3), 18.2, 18.0 (both s, PCHCH3), 3.4 (d, J (PC) ) 1.4
Hz, CH3CN), 3.2 (s, CH3CN). 31P{1H} NMR (121.5 MHz, CD2-
Cl2): δ 22.2 (s). MS (FAB): m/z 538 [M+ - H - BF4], 417 [M+
+ H - (3‚CH3CN) - BF4]. Anal. Calcd for C20H34BF4N3PIr
(626.5): C, 38.34; H, 5.47; N, 6.71. Found: C, 37.70; H, 5.27;
N, 6.46.
no. of data/
restraints/
params
5976/0/454
R(F) (F2 g 2σ(F2))a 0.0255
0.0274
0.0502
wR(F2) (all data)b
0.0554
a
R(F) ) ∑||Fo| - |Fc||/∑||Fo| for 5348(13) and 4951(16) observed
reflections. wR(F2) ) (∑[w(Fo - Fc2)2]/∑[w(Fo2)2])1/2
.
b
2
change of color from light yellow to orange-red took place. The
NMR spectra of the oily residue confirmed that compound 14
was partly regenerated. If the residue was dissolved in 2 mL
of acetone and an excess of diphenylacetylene was added, the
reaction afforded the alkyne complex 14 quantitatively.
Rea ction of Com p ou n d 16 w ith D2. A solution of 16 (25
mg, 0.14 mmol) in 0.5 mL of acetone-d6 was stirred under a
D2 atmosphere for 3 days at room temperature. The NMR
spectra revealed that almost exclusively (>95%) the complex
[IrD2(NCCH3)3(C6H5CH2CH2PiPr2-κ-P)]BF4 (15-d2) was formed.
1H NMR (300 MHz, acetone-d6): δ 7.37-7.18 (m, 5 H, C6H5),
2.86 (dt, J (PH) ) 12.3, J (HH) ) 5.3 Hz, 2 H, PCH2CH2), 2.56
(s, 3 H, CH3CN), 2.49 (s, 6 H, CH3CN), 2.20-2.03 (m, 4 H,
PCH2 and PCHCH3), 1.16 (dd, J (PH) ) 15.0, J (HH) ) 7.2 Hz,
6 H, PCHCH3), 1.13 (dd, J (PH) ) 14.7, J (HH) ) 6.8 Hz, 6 H,
PCHCH3). 13C{1H} NMR (75.5 MHz, acetone-d6): δ 142.8 (d,
J (PC) ) 12.9 Hz, ipso-C of C6H5), 129.0, 128.4, 126.5 (all s,
C6H5), 120.2 (br s, CH3CN), 31.4 (s, PCH2CH2), 26.4 (d, J (PC)
) 31.3 Hz, PCH2), 25.1 (d, J (PC) ) 38.3 Hz, PCHCH3), 18.1,
17.9 (both s, PCHCH3), 2.2 (d, J (PC) ) 0.9 Hz, CH3CN), 2.1
(s, CH3CN). 31P{1H} NMR (121.5 MHz, acetone-d6): δ 27.2 (s).
P r ep a r a t ion of [Ir (H )(C6H 4CH 2CH 2P iP r 2-K2-C,P )(NC-
CH3)3]BF 4 (16). A solution of 11 (103 mg, 0.19 mmol) in 5
mL of acetone was treated with excess acetonitrile (0.5 mL,
9.53 mmol) and stirred for 12 h at room temperature. A
stepwise change of color from light yellow to orange-red and
again to light yellow occurred. The solvent and other volatile
substances were removed in vacuo, and the oily residue was
washed six times with 10 mL portions of diethyl ether (273
K). A light yellow solid was obtained and dried. Yield: 99 mg
(83%). Λ(M) ) 116 cm2 Ω-1 mol-1. IR (KBr): ν(IrH) 2242 cm-1
.
1H NMR (300 MHz, CD2Cl2): δ 7.55 (m, 1 H, C6H4), 6.82-
6.55 (m, 3 H, C6H4), 2.83-2.57 (m, 2 H, PCH2CH2), 2.46, 2.45,
2.41 (all s, 3 H each, CH3CN), 2.16, 1.98 (both m, 1 H each,
PCHCH3), 1.60, 1.25 (both m, 1 H each, PCH2), 1.20 (dd, J (PH)
) 15.8, J (HH) ) 7.1 Hz, 3 H, PCHCH3), 1.06 (dd, J (PH) )
13.8, J (HH) ) 6.9 Hz, 3 H, PCHCH3), 0.96 (dd, J (PH) ) 15.6,
J (HH) ) 7.2 Hz, 3 H, PCHCH3), 0.66 (dd, J (PH) ) 14.7, J (HH)
) 7.2 Hz, 3 H, PCHCH3), -22.33 (d, J (PH) ) 19.8 Hz, 1 H,
IrH). 13C{1H} NMR (75.5 MHz, acetone-d6): δ 145.4 (d, J (PC)
) 6.0 Hz, ipso-C of C6H4), 139.7 (d, J (PC) ) 3.6 Hz, CH of
C6H4), 125.9, 124.9, 122.6 (all s, CH of C6H4), 125.5 (d, J (PC)
) 8.3 Hz, IrC), 121.1 (s, CH3CN), 120.2 (br s, CH3CN), 118.2
(d, J (PC) ) 15.7 Hz, CH3CN), 40.8 (s, PCH2CH2), 24.3 (d, J (PC)
) 38.6 Hz, PCHCH3), 23.8 (d, J (PC) ) 35.0 Hz, PCHCH3), 17.7,
16.2, 16.1, 16.0 (all s, PCHCH3), 15.3 (d, J (PC) ) 43.2 Hz,
PCH2), 2.3, 2.2, 2.1 (all s, CH3CN). 31P{1H} NMR (121.5 MHz,
CD2Cl2): δ 26.6 (s). MS (FAB): m/z 538 [M+ + H - BF4], 523
[M+ - CH3 - BF4]. Anal. Calcd for C20H32BF4N3PIr (624.5):
C, 38.47; H, 5.16; N, 6.73. Found: C, 37.78; H, 5.36; N, 6.50.
Rea ction of Com p ou n d 14 w ith Aceton itr ile. A solution
of 14 (20 mg, 0.03 mmol) in 2 mL of acetone was treated with
acetonitrile (15 µL, 0.30 mmol) and stirred for 12 h at room
temperature. A smooth change of color from orange-red to light
yellow occurred. The 31P NMR spectrum revealed that the
hydrido complex 16 was exclusively formed. When removing
the solvent and other volatile substances in vacuo, again a
Kin etic Da ta for th e Rea ction of 7 w ith CD3CN. The
1
kinetics of this reaction were studied by H NMR in samples
of 0.01-0.03 M solutions of 7 in CD2Cl2. The samples were
treated at 195 K with different quantities of CD3CN (30- to
250-fold excess) and, after warming to 253 K, the reaction was
followed by measuring the decrease of intensity of the hydride
signal of 7. The pseudo-first-order rate constants (kobs) were
obtained by fitting the data to an exponential decay function
with the routine programs of the spectrometer.
Cr ysta l Str u ctu r e Deter m in a tion of Com p lexes 13 a n d
16. A summary of crystal data collection and refinement
parameters for the two structural analyses is reported in Table
4. A yellow (13) or a pale yellow (16) crystals were glued to
glass fibers and mounted on a Bruker SMART APEX CCD
area detector diffractometer equipped with graphite-mono-
chromated Mo KR radiation (λ ) 0.71073 Å) and low-temper-
ature equipment (100(1) K). Cell constants were refined from
the observed setting angles and detector positions of strong
reflections (6655 ref, 4.84° e 2θ e 56.40° for 13, and 6125 ref,
4.36° e 2θ e 53.61° for 16). During data collection instrument
and crystal stability was evaluated from measurement of

2160 Organometallics, Vol. 22, No. 10, 2003
Canepa et al.
equivalent reflections at different measuring times; no impor-
tant variations were observed. Intensities were integrated from
several series of exposure frames covering almost a complete
sphere of reciprocal space.14 Data were corrected for Lorentz
and polarization effects, and a semiempiricial absorption
correction based on the repeated and symmetry-equivalent
reflections was also applied.15
the final difference map of both structures were about 1.0 e
Å-3 and were localized in the proximity of metal atoms. Atomic
scattering factors, corrected for anomalous dispersion, were
used as implemented in the refinement programs.16
Ack n ow led gm en t. The generous financial support
by MCYT (BQU2000-1170), the Deutsche Forschungs-
gemeinschaft, and the Fonds der Chemischen Industrie
(Ph.D. grant to G.C.) is gratefully acknowledged. This
research was supported through a European Com-
munity Marie Curie fellowship (to G.C., HTMP-CT-
2000-00200).
The structure was solved by the Patterson method and
completed by successive difference Fourier syntheses. Aniso-
tropic thermal parameters were included for all non-hydrogen
atoms, with the exception of the disordered fluorine atoms of
13. In this complex, a model for the disorder of the tetrafluo-
roborato anion (two moieties, 0.524 and 0.476(10) occupancies)
was necessary to be included. Hydrogen atoms were found in
the difference maps and were refined with free positional and
isotropic displacement parameters. Refinements were carried
out by full-matrix least-squares on F2 for all data.16 Final
agreement factors are collected in Table 4. Residual peaks in
Su p p or tin g In for m a tion Ava ila ble: Listings of atomic
coordinates, hydrogen positional parameters, isotropic and
anisotropic displacement parameters, and complete bond
distances and angles for compounds 1 and 2 (CIF format). This
material is available free of charge via the Internet at
http://pubs.acs.org.
(14) SMART and SAINT+ software for CCD diffractometers, Bruker
AXS, Madison, WI, 2000.
OM0210457
(15) Sheldrick, G. M. SADABS, Program for Corrections of Area
Detector Data v. 2.03; University of Go¨ttingen: Go¨ttiengen, Germany,
2001.
(16) Sheldrick, G. M. SHELXL-97 Program for Crystal Structure
Refinement; University of Go¨ttingen: Go¨ttiengen, Germanuy, 1997.