Substitution and migratory insertion reactions of square-planar allenylidene iridium complexes

Article abstract of DOI:10.1021/om010353m

A series of (allenylidene)iridium(I) complexes of general composition trans-[IrX{=C=C=C(Ph)R}(PiPr₃)₂] [X = Br (5), I (6), NCO (7, 8), NCS (9, 10), OH (11, 12), N₃ (13, 14)] was prepared from the corresponding chloro derivatives trans-[IrCl{=C=C=C(Ph)R}(PiPr₃)₂] (3, 4) by salt metathesis. An X-ray crystal structure analysis of 4 (R = Ph) confirmed the almost linear arrangement of the Ir-C-C-C chain. The azido compounds 13 (R = Ph) and 14 (R = tBu) react with CO by migratory insertion of the allenylidene ligand into the Ir-N₃ bond. While the product trans-[Ir{C≡C-CR(Ph)N₃}(CO)(PiPr₃)₂] with R = tBu (16) is thermally stable, the related complex with R = Ph (15) rearranges slowly in benzene to the metalated acrylonitrile derivative trans-[Ir{C(CN)=CPh₂}(CO)(PiPr₃)₂] (17) by elimination of N₂. Treatment of the phenolato compound trans-[Ir(OPh){=C=C=C(Ph)tBu}(PiPr₃)₂] (19), obtained from the analogous hydroxo derivative 12 and phenol, with CO also proceeds by migratory insertion and affords the functionalized (alkynyl)iridium(I) complex trans-[Ir{C≡C-CtBu(Ph)OPh}(CO)(PiPr₃)₂] (20) in excellent yield. The Lewis basicity of the hydroxo compounds 11 and 12 was also illustrated by the reactions with CF₃CO₂H, NEt₃·3HF, and [pyH]BF₄, which gave the substitution products trans-[Ir(κ¹-O₂CCF₃){=C=C=C(Ph)tBu}-(PiPr ₃)₂] (21), trans-[IrF(=C=C=CPh₂)(PiPr₃)₂] (22), and trans-[Ir{=C=C=C(Ph)tBu}(py)-(PiPr₃)₂]BF₄ (23), respectively. In methanol solution, both 11 and 12 react by complete fragmentation of 1 equiv of CH₃OH to afford the octahedral (allenyl)dihydridoiridium(III) complexes [IrH₂{CH=C=C(Ph)R}(CO)(PiPr₃)₂] (24, 25). An unprecedented type of insertion reaction occurs by treating the hydroxo derivatives 11 and 12 with an excess of 1-alkynes R′C≡CH (R′ = Ph, CO₂Me), which leads to the formation of the novel five-coordinate iridium(III) compounds [Ir(C≡CR′)₂{η¹-(E)-CH=CR′-CH=C=C(Ph) R}(PiPr₃)₂] (26-29). From 26, 27 (R′ = Ph), and CO, the octahedral 1:1 adducts 30 and 31 are formed. The molecular structures of 22 and 26 have been determined by X-ray crystallography.

Full text of DOI:10.1021/om010353m

3782
Organometallics 2001, 20, 3782-3794
Su bstitu tion a n d Migr a tor y In ser tion Rea ction s of
Squ a r e-P la n a r Allen ylid en e Ir id iu m Com p lexes†
Kerstin Ilg and Helmut Werner*
Institut fu¨r Anorganische Chemie der Universita¨t Wu¨rzburg, Am Hubland,
D-97074 Wu¨rzburg, Germany
Received April 30, 2001
A series of (allenylidene)iridium(I) complexes of general composition trans-[IrX{dCdCd
C(Ph)R}(PiPr3)2] [X ) Br (5), I (6), NCO (7, 8), NCS (9, 10), OH (11, 12), N3 (13, 14)] was
prepared from the corresponding chloro derivatives trans-[IrCl{dCdCdC(Ph)R}(PiPr3)2] (3,
4) by salt metathesis. An X-ray crystal structure analysis of 4 (R ) Ph) confirmed the almost
linear arrangement of the Ir-C-C-C chain. The azido compounds 13 (R ) Ph) and 14 (R
) tBu) react with CO by migratory insertion of the allenylidene ligand into the Ir-N3 bond.
While the product trans-[Ir{C≡C-CR(Ph)N3}(CO)(PiPr3)2] with R ) tBu (16) is thermally
stable, the related complex with R ) Ph (15) rearranges slowly in benzene to the metalated
acrylonitrile derivative trans-[Ir{C(CN)dCPh2}(CO)(PiPr3)2] (17) by elimination of N2.
Treatment of the phenolato compound trans-[Ir(OPh){dCdCdC(Ph)tBu}(PiPr3)2] (19),
obtained from the analogous hydroxo derivative 12 and phenol, with CO also proceeds by
migratory insertion and affords the functionalized (alkynyl)iridium(I) complex trans-[Ir{Ct
C-CtBu(Ph)OPh}(CO)(PiPr3)2] (20) in excellent yield. The Lewis basicity of the hydroxo
compounds 11 and 12 was also illustrated by the reactions with CF3CO2H, NEt3‚3HF, and
[pyH]BF4, which gave the substitution products trans-[Ir(κ1-O2CCF3){dCdCdC(Ph)tBu}-
(PiPr3)2] (21), trans-[IrF(dCdCdCPh2)(PiPr3)2] (22), and trans-[Ir{dCdCdC(Ph)tBu}(py)-
(PiPr3)2]BF4 (23), respectively. In methanol solution, both 11 and 12 react by complete
fragmentation of 1 equiv of CH3OH to afford the octahedral (allenyl)dihydridoiridium(III)
complexes [IrH2{CHdCdC(Ph)R}(CO)(PiPr3)2] (24, 25). An unprecedented type of insertion
reaction occurs by treating the hydroxo derivatives 11 and 12 with an excess of 1-alkynes
R′CtCH (R′ ) Ph, CO2Me), which leads to the formation of the novel five-coordinate iridium-
(III) compounds [Ir(CtCR′)2{η1-(E)-CHdCR′-CHdCdC(Ph)R}(PiPr3)2] (26-29). From 26,
27 (R′ ) Ph), and CO, the octahedral 1:1 adducts 30 and 31 are formed. The molecular
structures of 22 and 26 have been determined by X-ray crystallography.
In tr od u ction
trans-[IrCl(dCdCdCRR′)(PiPr3)2] the C3RR′ unit would
exert a strong influence on the ligand in the trans
position. Hence, we started to study the substitution
reactions of the chloro derivatives with the particular
aim to replace the chloride not only by other halides but
In the search for analogues of the square-planar
rhodium complexes trans-[RhCl(dCdCdCRR′)(PiPr3)2],1
we recently reported that the iridium counterpart trans-
[IrCl(dCdCdCPh2)(PiPr3)2] can be obtained from the
dihydrido compound [IrH2Cl(PiPr3)2] and HCtCCPh2-
OH via [IrHCl(CtCCPh2OH)(PiPr3)2] or the isomer
trans-[IrCl(dCdCHCPh2OH)(PiPr3)2] as the intermedi-
ate.2 Since allenylidenes such as vinylidenes and the
more carbon-rich cumulenylidenes C(dC)ndCRR′ (n )
2, 3)3 are predicted to be good π-acceptor ligands,4 it
could be anticipated that in square-planar (allenylide-
ne)iridium(I) complexes of the general composition
-
also by pseudohalides such as OCN- or N3 and by
hydroxide. It was only recently that we observed that
the vinylidene iridium(I) compounds trans-[IrX(dCd
CRR′)(PiPr3)2] with X ) OH and N3 are useful starting
materials for the synthesis of a variety of iridium(I)
complexes which are not (or hardly) accessible on other
routes.5
In this paper we describe our investigations on the
reactivity of iridium allenylidenes trans-[IrCl{dCdCd
C(Ph)R}(PiPr3)2] toward various anionic nucleophiles.
Moreover, we illustrate that in the presence of CO the
C3RR′ unit undergoes migratory insertion reactions into
both Ir-N and Ir-O bonds, thus generating new func-
tionalized alkynyl groups coordinated to iridium(I). A
rather unusual insertion process takes place upon
treatment of the hydroxo complexes trans-[Ir(OH){dCd
CdC(Ph)R}(PiPr3)2] with terminal alkynes, which leads
† Dedicated to Professor R. G. Bergman on the occasion of his 60th
birthday.
(1) (a) Werner, H.; Rappert, T. Chem. Ber. 1993, 126, 669-678. (b)
Werner, H.; Rappert, T.; Wiedemann, R.; Wolf, J .; Mahr, N. Organo-
metallics 1994, 13, 2721-2727.
(2) Werner, H.; Lass, R. W.; Gevert, O.; Wolf, J . Organometallics
1997, 16, 4077-4088.
(3) For iridium complexes with carbon-rich cumulenylidenes as
ligands see: (a) Lass, R. W.; Steinert, P.; Wolf, J .; Werner, H. Chem.
Eur. J . 1996, 2, 19-23. (b) Ilg, K.; Werner, H. Angew. Chem. 2000,
112, 1691-1693; Angew. Chem., Int. Ed. 2000, 39, 1632-1634.
(4) Schilling, B. E. R.; Hoffmann, R.; Lichtenberger, D. L. J . Am.
Chem. Soc. 1979, 101, 585-591.
(5) Werner, H.; Ilg, K.; Weberndo¨rfer, B. Organometallics 2000, 19,
3145-3153.
10.1021/om010353m CCC: $20.00 © 2001 American Chemical Society
Publication on Web 07/27/2001

Square-Planar Allenylidene Ir Complexes
Organometallics, Vol. 20, No. 17, 2001 3783
Ta ble 1. Cr ysta llogr a p h ic Da ta for 4, 22, a n d 26
formula
C33H52ClIrP2
738.34
C33H52FIrP2
721.89
C57H69IrP2
1008.26
fw
cryst size, mm3
0.19 × 0.16 × 0.15
0.19 × 0.14 × 0.11
0.21 × 0.18 × 0.16
cryst syst
monoclinic
monoclinic
triclinic
space group
cell dimens determn
a, Å
b, Å
P21 (No. 5)
25 reflns, 10° < θ < 15°
11.9916(10)
11.1053(10)
12.7777(10)
P21/n (No. 14)
24 reflns,5° < θ < 15°
8.6057(13)
34.735(3)
10.8860(15)
P1h (No. 2)
24 reflns,5° < θ < 15°
13.600(4)
13.634(4)
14.994(4)
83.92(2)
66.63(3)
87.23(2)
2537.8(13)
2
1.319
193(2)
2.728
ω/θ
45
6946
c, Å
R, deg
â, deg
γ, deg
V, Å3
Z
98.658(10)
95.737
1682.2(2)
2
1.458
193(2)
4.162
ω/θ
46
3237.7(7)
4
1.481
173(2)
4.248
ω/θ
47
d
calc, g‚cm-3
temp, K
µ, mm-1
scan method
2θ(max), deg
tot. no. of reflns
no. of unique reflns
no. of obsd reflns
[I > 2σ(I)]
3704
5131
3534 [R(int) ) 0.0404]
3338
4604 [R(int) ) 0.0657]
2743
6598 [R(int) ) 0.0483]
5794
no. of reflns used for refinement
no. of params refined
final R indices
[I > 2σ(I)]
3534
347
4597
346
R1 ) 0.0661,
wR2 ) 0.1386a
R1 ) 0.1363,
wR2 ) 0.1702a
6598
598
R1 ) 0.0370
wR2 ) 0.0672a
R1 ) 0.0464,
wR2 ) 0.0718a
R1 ) 0.0332,
wR2 ) 0.0833a
R1 ) 0.0368,
wR2 ) 0.0866a
0.317(14)
R indices (all data)
absolute structure param
resid electron density, e Å-3
0.624/-0.712
1.173/-1.682
0.620/-1.097
a
2
2
2
w-1 ) 1/[σ2Fo + (0.0636P)2 + 0.0000P] (4), 1/[σ2Fo + (0.0750P)2 + 0.0000P] (22), 1/[σ2Fo + (0.0160P)2 + 5.7281P] (26), where P )
2
[Fo + 2Fc2]/3.
Sch em e 1
yield. Typical features of 2 are the hydride resonance
at δ -42.44 (i.e., at remarkably high field) in the 1H
NMR spectrum and the OH, Ir-H, and C≡C stretching
modes at, respectively, 3481, 2300, and 2092 cm-1 in
the IR spectrum. Similar data have been observed for
related five-coordinate hydrido(alkynyl)- and hydrido-
(diyndiyl)iridium(III) complexes.2 Since only one signal
appears in the 31P NMR spectrum of 2, we conclude that
the two phosphine ligands are trans disposed in the
basal plane of a square pyramid.
If a solution of 2 in ether is stirred for 3 h at room
temperature in the presence of small amounts of tri-
fluoroacetic acid, a quantitative conversion to the alle-
nylidene compound 3 occurs by elimination of water.
The IR and NMR spectroscopic data of 3 (which is a red-
violet, only moderately air-sensitive solid) are similar
to those of 4 and of the analogous rhodium(I) complex
trans-[RhCl{dCdCdC(Ph)tBu}(PiPr3)2].7 Since in each
to the formation of a highly unsaturated C5 ligand. A
few of these results have already been communicated.6
1
of the H, 13C, and 31P NMR spectra of 4 only one set of
signals for the phosphorus, hydrogen, and carbon atoms
of the PiPr3 ligands has been observed, we assume that
the barrier for rotation around the Ir-C bond is quite
small on the NMR time scale.
Resu lts a n d Discu ssion
P r ep a r a tion of Allen ylid en e Ir id iu m Com p lexes
by Sa lt Meta th esis. In addition to the previously
described chloro compound trans-[IrCl(dCdCdCPh2)-
(PiPr3)2] (4),2 the structurally related complex 3, con-
taining one phenyl and one tert-butyl group as substit-
uents at the γ-carbon atom of the IrC3 chain, was also
prepared (Scheme 1). The procedure to obtain 3 followed
the methodology that we had developed for the diphenyl
analogue 4. Treatment of the dihydrido complex 1 with
the propargylic alcohol HCtCCPh(tBu)OH in hexane
at -20 °C led to the formation of the iridium(III)
derivative 2, which was isolated as a red solid in 84%
Attempts to replace the chloro ligand of 3 or 4 by
methyl, vinyl, or phenyl using the corresponding organo
lithium compound as a substrate failed. If instead of
RLi the analogous Grignard reagent RMgX (X ) Br or
I) reacted with the chloro derivative, a mixture of
products was formed, among which the bromo or iodo
complexes trans-[IrX{dCdCdC(Ph)R}(PiPr3)2] (X ) Br,
I) were the major components. These compounds (il-
lustrated by using 4 as the starting material) are more
conveniently prepared by salt metathesis from the
(6) Ilg, K.; Werner, H. Organometallics 1999, 18, 5426-5428.
(7) Laubender, M.; Werner, H. Chem. Eur. J . 1999, 5, 2937-2946.

3784 Organometallics, Vol. 20, No. 17, 2001
Ilg and Werner
Sch em e 2
chloro complex and NaBr or KI, respectively. Both 5 and
6 (see Scheme 2) are deeply colored solids which have
been characterized by elemental analyses and IR and
NMR spectroscopy. In solution, 5 and even more 6 are
less stable than 4, which is probably due to the weaken-
ing of the allenylidene-metal bond by reducing the
π-donor capability of the ligand X in trans disposition.
Compounds 3 and 4 react not only with alkalimetal
halides but also with excess NaOCN and KSCN in
acetone at room temperature to give the isocyanato and
isothiocyanato complexes 7-10 as red or dark red,
almost air-stable solids in 86-95% isolated yield. The
IR spectra of 7 and 8 display two strong absorptions at
around 2230 and 1450 cm-1, which are assigned to the
asymmetrical and symmetrical NCO stretching modes.
Since it has been established that the symmetrical
stretch for O-bonded isocyanates appears below 1200
cm-1 and that for N-bonded NCO ligands in the region
between 1300 and 1500 cm-1,8 we conclude that in 7
and 8 an Ir-NCO linkage exists. A similar criterion can
be applied regarding the coordination of the NCS ligand
in compounds 9 and 10. Since for S-bonded isothiocy-
anates the asymmetrical NCS stretching mode should
be observed at around 2120 cm-1 and for the N-bonded
analogues at around 2070 cm-1,9 the appearance of an
infrared band at 2077 cm-1 for 9 and at 2080 cm-1 for
10 indicates that in both cases the isothiocyanate is
linked via the nitrogen atom to iridium(I). In this
context we note that the IR spectrum of the Vaska-type
complex trans-[Ir(NCS)(CO)(PPh3)2] also indicates an
N-coordination of the NCS unit.10
pared by treatment of the corresponding chloro deriva-
tives with KOtBu in a mixture of benzene and tert-butyl
alcohol,11 the iridium(I) counterparts 11 and 12 (Scheme
2) were obtained from 3 or 4 and excess KOH in acetone
as orange and green microcrystalline solids. The pres-
ence of the hydroxo ligand is indicated both by the
strong absorption at 3643 cm-1 (11) or 3648 cm-1 (12)
in the IR and by the broadened singlet at δ 4.25 (11) or
1
3.80 (12) in the H NMR spectrum. The chemical shifts
for the resonances of the allenylidene carbon atoms in
the 13C NMR spectrum of 12 are quite similar to those
of 3, which supports the assumption that the trans
influence of the chloro and the hydroxo ligands is of
comparable magnitude.
The synthesis of the azido complexes 13 and 14
follows the route that we have used to obtain the
isocyanato and isothiocyanato analogues 7-10. This
procedure is equally similar to that for the preparation
of the rhodium(I) compounds trans-[RhN3(dCdCdCRR′)-
(PiPr3)2],7 trans-[RhN3(CO)(PR3)2] (R ) Ph, Cy),12 and
[RhN3(PPh3)3].13 The most typical spectroscopic data of
13 and 14 are the two low-field signals (both triplets)
in the 13C NMR spectra between δ 250 and 205 for the
R- and â-carbon atoms of the IrC3 chain and the intense
ν(N3) mode in the IR spectra at 2066 cm-1 (13) and 2078
cm-1 (14), respectively.
Migr a tor y In ser tion s of Allen ylid en e Un its in to
Ir -N a n d Ir -O Bon d s. In acetone, the azido com-
plexes 13 and 14 react quite rapidly with carbon
monoxide to afford yellow microcrystalline solids 15 and
16 in 83% and 90% isolated yield. The analytical
composition of both 15 and 16 corresponds to that of
1:1 adducts between the corresponding starting material
and CO. While in the IR spectra of the products two
In contrast to the hydroxorhodium(I) compounds
trans-[Rh(OH)(dCdCdCRR′)(PiPr3)2], which were pre-
(8) (a) Burmeister, J . L.; Deardorff, E. A.; J ensen, A.; Christiansen,
V. H. Inorg. Chem. 1970, 9, 58-63. (b) Mu¨ller, U. Z. Anorg. Allg. Chem.
1973, 396, 187-198.
(9) (a) J urisson, S.; Halihan, M. M.; Lydon, J . D.; Barnes, C. L.;
Nowotnik, D. P.; Nunn, A. D. Inorg. Chem. 1998, 37, 1922-1928. (b)
Nakamoto, K. Infrared and Raman Spectra of Inorganic and Coordi-
nation Compounds, Part B; Wiley: New York, 1997.
(10) DeStefano, N. J .; Burmeister, J . L. Inorg. Chem. 1971, 10, 998-
1003.
(11) Werner, H.; Wiedemann, R.; Laubender, M.; Windmu¨ller, B.;
Wolf, J . Chem. Eur. J . 2001, 7, 1959-1967.
(12) (a) Vaska, L.; Peone, J . Chem. Commun. 1971, 418-419. (b)
van Gaal, H. L. M.; van den Bekerom, F. L. A. J . Organomet. Chem.
1977, 134, 237-248.
(13) Beck, W.; Fehlhammer, W. P.; Po¨llmann, P.; Scha¨chl, H. Chem.
Ber. 1969, 102, 1976-1987.

Square-Planar Allenylidene Ir Complexes
Organometallics, Vol. 20, No. 17, 2001 3785
Sch em e 3
Sch em e 4
strong absorptions at, respectively, 2098 and 1933 cm-1
for 15 and 2104 and 1932 cm-1 for 16 are observed,
assigned to N3 and CO stretching modes, the 13C NMR
spectra exhibit a triplet resonance at around δ 125-
127 and a singlet resonance at around δ 115 for the
carbon atoms of an alkynyl group. From these data we
conclude (see Scheme 3) that treatment of the azido
the disappearance of the IR bands of the intermediate
and, after evaporation of the solvent and recrystalliza-
tion from acetone at -78 °C, to the isolation of a yellow
solid with the analytical composition of 17 in 90% yield.
The IR spectrum of 17 displays instead of three (as for
the intermediate) two strong absorptions at 2159 and
1937 cm-1, which we assign to CN and CO stretching
modes. Since the 13C NMR spectrum exhibits three
resonances in the region between δ 161 and 126, which
all show P,C couplings, we assume that the new product
is a four-coordinate carbonyl(vinyl)iridium(I) derivative.
We note that a related rhodium(I) complex (with p-
anisyl instead of phenyl substituents at the â-carbon
atom of the vinylic ligand) is known and has been
characterized by X-ray crystallography.7
In the presence of CO, the phenolato compound 19
behaves similarly to the azido analogue 14. For the
preparation of both 18 and 19, instead of a salt meta-
thesis of the chloro derivatives 3, 4, and NaOR14 the
more convenient method consists in the acid-base
reaction of 11 and 12 with phenol (Scheme 4). The
reactions are carried out in benzene at room tempera-
ture and afford the phenolates 18 and 19 as dark red
or brown solids in excellent yield. Under the conditions
used for the synthesis, there is no attack of PhOH at
the allenylidene unit. The reaction of 1915 with CO takes
-
complexes with CO results in a migration of the N3
ligand to the allenylidene unit and that the intact azido
group is linked to the γ-carbon atom of the C3 chain.
The thermal stability of compounds 15 and 16 is
remarkably different. While solutions of 16 in benzene
can be stirred for 24 h at room temperature without any
decomposition or rearrangement, the corresponding
diphenyl derivative 15 is more labile and, under the
same conditions, slowly reacts to give first an (noniso-
lated) intermediate and then a new product. According
to the IR spectra, taken after 4-6 h, the intermediate
contains besides the carbonyl ligand [ν(CO) ) 1909
cm-1] an azido group [ν(N3) ) 2076 cm-1] and a
cumulene fragment [ν(CdCdC) ) 1862 cm-1]. We
therefore assume that in the first step of the thermal
reaction of 15 the allenyl complex trans-[Ir{C(N3)dCd
CPh2}(CO)(PiPr3)2] is generated by migration of the N3
unit from the γ-carbon to the R-carbon atom of the C3
chain. Stirring the benzene solution for 24 h leads to

3786 Organometallics, Vol. 20, No. 17, 2001
Ilg and Werner
Sch em e 5
place in pentane and gives the insertion product 20 as
a yellow, moderately air-sensitive solid in 83% yield. The
presence of the functionalized alkynyl ligand is indicated
in the 13C NMR spectrum by the appearance of two
signals at δ 125.4 (triplet for CR) and 115.2 (singlet for
Câ). Moreover, the elemental analysis and the mass
spectrum confirm the supposed composition. The (tri-
fluoroacetato)iridium(I) complex 21, prepared from the
hydroxo compound 12 and CF3CO2H in benzene, also
reacts with CO, but, in contrast to the analogous
reaction of 12 with phenol, in this case no analytically
pure product could be isolated.
Rea ction s of th e (Allen ylid en e)h yd r oxo Ir id iu m
Com p lexes w ith Oth er Acid ic Su bstr a tes. The abil-
ity of the hydroxo compounds 11 and 12 to behave as
organometallic Bro¨nsted bases is illustrated not only by
the reactions with PhOH and CF3CO2H but also by
those with NEt3‚3HF and [pyH]BF4 (see Scheme 5). We
have recently shown that triethylamine-tris(hydrogen
fluoride), which has been used for the first time by
Grushin et al. as a versatile fluorinating agent in the
chemistry of late transition metals,16 can be successfully
applied for the preparation of rhodium(I) as well as
iridium(I) complexes with metal-fluorine bonds.5,17
Treatment of 11 with NEt3‚3HF in benzene affords,
after recrystallization from acetone, the fluoro com-
pound 22 as a red solid in 88% yield. The single
F igu r e 1. Molecular diagram of compound 4. Selected
bond distances (Å) and angles (deg): Ir-Cl ) 2.3649(19),
Ir-P1 ) 2.344(3), Ir-P2 ) 2.340(3), Ir-C1 ) 1.862(7), C1-
C2 ) 1.247(11), C2-C3 ) 1.360(11); Cl-Ir-P1 ) 89.55-
(15), Cl-Ir-P2 ) 89.27(15), Cl-Ir-C1 ) 178.1(5), P1-Ir-
P2 ) 178.42(9), P1-Ir-C1 ) 90.6(6), P2-Ir-C1 ) 90.5(6),
Ir-C1-C2 ) 178.5(14), C1-C2-C3 ) 176.7(14).
resonances in the 19F and 31P NMR spectra of 22 are
split into a triplet and a doublet, both due to P,F
couplings.
(14) Formation of alkoxo and aroxo metal compounds from chloro
derivatives by salt metathesis is known; see: (a) Gregorio, G.;
Pregaglia, G.; Ugo, R. Inorg. Chim. Acta 1969, 3, 89-93. (b) Vaska,
L.; Peone, J . J . Chem. Soc. D 1971, 418-421. (c) Rees, W. M.; Atwood,
J . D. Organometallics 1985, 4, 402-404. (d) Rees, W. M.; Churchill,
M. R.; Fettinger, J . C.; Atwood, J . D. Organometallics 1985, 4, 2179-
2185. (e) Churchill, M. R.; Fettinger, J . C.; Rees, W. M.; Atwood, J . D.
J . Organomet. Chem. 1986, 308, 361-371.
The molecular structure of 22 and, for comparison,
also that of the chloro analogue 4 has been determined
by X-ray crystallography. The molecular diagrams in
Figures 1 and 2 reveal that in both cases the iridium is
coordinated in an almost perfect square-planar fashion.
The two phosphine ligands are trans to each other with
an eclipsed conformation along the P-Ir-P axis. The
Ir-C1 distance of 1.85(2) Å for 4 and 1.862(7) Å for 22
is slightly shorter than in the carbene complex trans-
[IrCl(dCPh2)(PiPr3)2] (1.887(5) Å)18 but somewhat longer
than in the corresponding vinylidene derivative trans-
(15) Compound 18 behaves similarly toward CO, but this reaction
has not been studied in detail.
(16) (a) Fraser, S. L.; Antipin, M. Y.; Khroustalyov, V. N.; Grushin,
V. V. J . Am. Chem. Soc. 1997, 119, 4769-4770. (b) Pilon, M. C.;
Grushin, V. V. Organometallics 1998, 17, 1774-1781.
(17) Gil-Rubio, J .; Weberndo¨rfer, B.; Werner, H. J . Chem. Soc.,
Dalton Trans. 1999, 1437-1444.

Square-Planar Allenylidene Ir Complexes
Organometallics, Vol. 20, No. 17, 2001 3787
CdCdC a second zwitterionic resonance structure has
to be taken into consideration.20 The IrC3 chain is nearly
linear with only a slight bending at C2 in the case of
22. We note that the ipso-carbon atoms C30 and C40 of
the two phenyl groups do not lie in the same plane as
the ligand atoms around iridium, the dihedral angle
between the best planes [X-Ir-C1-P1-P2] and [C3-
C30-C40] being 14(1)° for 4 and 19(2)° for 22, respec-
tively. There is a small difference in the Ir-P bond
distances in 4 and 22, which we explain by the different
electronic influence of the chloro and fluoro ligands.
Under acidic conditions, the OH group of the Bro¨nsted
bases trans-[Ir(OH){dCdCdC(Ph)R}(PiPr3)2] can also
be replaced by neutral ligands. This is exemplified by
the preparation of the cationic complex 23 from 12 and
[pyH]BF4 (see Scheme 5). The composition of 23, which
was isolated as a red-violet, thermally rather labile
solid, was substantiated not only by elemental analysis
but also by conductivity measurements and spectro-
scopic data. The 13C NMR spectrum of 23 exhibits, in
contrast to the spectra 4 and 22, the resonance of
the R-carbon atom of the IrC3 unit at significantly
lower field than that of the â-carbon atom. The ace-
tone derivative trans-[Ir(OdCMe2){dCdCdC(Ph)tBu}
(PiPr3)2]BF4 seems to be more labile than the pyridine
compound 23 since we observed that upon treatment
of 12 with HBF4 in acetone, even at -78 °C, only
decomposition of the starting material occurs.
F igu r e 2. Molecular diagram of compound 22. Selected
bond distances (Å) and angles (deg): Ir-F ) 2.015(10), Ir-
P1 ) 2.317(4), Ir-P2 ) 2.326(4), Ir-C1 ) 1.85(2), C1-C2
) 1.22(2), C2-C3 ) 1.37(2); F-Ir-P1 ) 88.5(3), F-Ir-P2
) 89.0(3), F-Ir-C1 ) 179.3(6), P1-Ir-P2 ) 177.51(16),
P1-Ir-C1 ) 91.0(5), P2-Ir-C1 ) 91.5(5), Ir-C1-C2 )
177.1(17), C1-C2-C3 ) 173(2).
Attempts to perform substitution reactions of the
hydroxo complexes 11 and 12 in methanol as the solvent
led to a noteworthy result. After dissolving 11 or 12 in
CH3OH at room temperature, in a relatively short
period of time a change of color from orange or green to
pale brown took place, and, after removal of the solvent
and crystallization of the residue from pentane, the
carbonyl(dihydro)iridium(III) compounds 24 and 25 (see
Scheme 5) were isolated in, respectively, 88% and 91%
yield. Apart from the strong ν(CO) stretching mode at
1978 cm-1 (24) and 1972 cm-1 (25) in the IR spectra,
the most typical spectroscopic features of the octahedral
complexes are both the hydride resonance at δ -9.27
(24) and -9.47 (25) and the signal for the CHdCdC
proton at δ 6.53 (24) and 6.31 (25) in the 1H NMR
spectra. The chemical shift of the latter is in good
agreement with that of other allenyl transition-metal
complexes.21 Since the NMR spectra display only one
single resonance for the Ir-H protons, which is split
into a sharp doublet of triplets due to P,H and H,H
couplings, and only one signal for the two phosphorus
atoms, there is no doubt that the two hydrides as well
as the two PiPr3 ligands are in trans disposition.
If the reaction of 11 is carried out in CD3OD instead
of CH3OH, the tris(deuterio) compound [IrD2(CDdCd
CPh2)(CO)(PiPr3)2] (24-d3) is formed, the 1H NMR
spectrum of which does not exhibit a signal around δ
F igu r e 3. Molecular diagram of compound 26. Selected
bond distances (Å) and angles (deg): Ir-C1 ) 1.998(6), Ir-
C40 ) 2.020(6), Ir-C50 ) 2.018(6), Ir-P1 ) 2.359(2), Ir-
P2 ) 2.371(2), C1-C2 ) 1.35(1), C2-C3 ) 1.46(1), C3-
C4 ) 1.32(1), C4-C5 ) 1.31(1); C1-Ir-C40 ) 98.0(2), C1-
Ir-C50 ) 89.5(2), C1-Ir-P1 ) 95.1(2), C1-Ir-P2 )
96.7(2), C40-Ir-C50 ) 172.4(3), C40-Ir-P1 ) 92.2(2),
C40-Ir-P2 ) 89.3(2), C50-Ir-P1 ) 87.7(2), C50-Ir-P2
) 89.3(2), P1-Ir-P2 ) 167.77(6), Ir-C1-C2 ) 135.8(5),
C1-C2-C3 ) 125.0(6), C2-C3-C4 ) 127.9(6), C3-C4-
C5 ) 175.1(6), Ir-C40-C41 ) 176.9(5), Ir-C50-C51 )
177.9(6).
[IrCl(dCdCHCO2Me)(PiPr3)2] (1.764(6) Å).19 This order
of bond lengths is in agreement with that found in the
chloro rhodium counterparts. The two carbon-carbon
distances in the IrC3 chain differ by 0.12-0.15 Å, which
indicates that besides the usual bonding description Ird
(20) (a) Selegue, J . P. Organometallics 1982, 1, 217-218. (b) Bruce,
M. I. Chem. Rev. 1991, 91, 197-257. (c) Le Bozec, H.; Dixneuf, P. H.
Russ. Chem. Bull. 1995, 44, 801-812. (d) Werner, H. Chem. Commun.
1997, 903-910. (e) Bruce, M. I. Chem. Rev. 1998, 98, 2797-2858. (f)
Cadierno, V.; Gamasa, M. P.; Gimeno, J . Eur. J . Inorg. Chem. 2001,
571-591.
(21) (a) Elsevier: C. J .; Kleijn, H.; Boersma, J .; Vermeer, P.
Organometallics 1986, 5, 716-720. (b) Keng, R.-S.; Lin, Y.-C. Orga-
nometallics 1990, 9, 289-291. (c) Shuchart, C. E.; Willis, R. R.;
Wojcicki, A. J . Organomet. Chem. 1992, 424, 185-198. (d) Werner,
H.; Flu¨gel, R.; Windmu¨ller, B.; Michenfelder, A.; Wolf, J . Organome-
tallics 1995, 14, 612-618.
(18) Ortmann, D. A.; Weberndo¨rfer, B.; Scho¨neboom, J .; Werner, H.
Organometallics 1999, 18, 952-954.
(19) Werner, H.; Ho¨hn, A.; Schulz, M. J . Chem. Soc., Dalton Trans.
1991, 777-781.

3788 Organometallics, Vol. 20, No. 17, 2001
Ilg and Werner
F igu r e 4. VT 31P NMR spectrum of compound 27 (in toluene-d8).
Sch em e 6
6.5 or in the high-field region. It should be mentioned
that there is ample precedence for the generation of a
(carbonyl)hydrido complex from a chloro, bromo, or iodo
metal precursor and a primary alcohol (or its anion) and
that it is generally assumed that (aldehyde)(hydrido)-
metal intermediates are involved in this fragmentation
process.22,23 The nearest analogy to the formation of 24
and 25 from 11 and 12, we are aware of, is the
preparation of [IrH2(CO)(CHdCHPh)(PiPr3)2] from
trans-[IrCl(dCdCHPh)(PiPr3)2] and NaOCH3, which
affords the vinyl compound in excellent yield.24
A New Typ e of Alk yn e In ser tion in to a Ca r bon -
Ir id iu m Bon d . The observation that the (hydroxo)-
vinylidene complex trans-[Ir(OH)(dCdCHPh)(PiPr3)2]
reacts with phenylacetylene and methylpropiolate by
elimination of water to give the alkynyl derivatives
trans-[Ir(CtCR)(dCdCHPh)(PiPr3)2]5 prompted us to
study also the reactivity of 11 and 12 toward terminal
alkynes. Stirring a solution of 11 or 12 in benzene with
a 10-fold excess of the alkyne for 30 min at room
temperature leads to a change of color from orange to
violet or red and, after chromatographic workup and
(22) (a) Vaska, L.; Diluzio, J . W. J . Am. Chem. Soc. 1961, 83, 1262-
1263. (b) Vaska, L. J . Am. Chem. Soc. 1964, 86, 1943-1950. (c) Gill,
D. F.; Shaw, B. L. Inorg. Chim. Acta 1979, 32, 19-23.
(23) (a) Esteruelas, M. A.; Werner, H. J . Organomet. Chem. 1986,
303, 221-231. (b) Werner, H.; Esteruelas, M. A.; Meyer, U.; Wrack-
meyer, B. Chem. Ber. 1987, 120, 11-15. (c) Stahl, S.; Werner, H. J .
Am. Chem. Soc. 1991, 113, 2944-2947.
(24) Ho¨hn A.; Werner, H. J . Organomet. Chem. 1990, 382, 255-
272.

Square-Planar Allenylidene Ir Complexes
Organometallics, Vol. 20, No. 17, 2001 3789
recrystallization from pentane, affords the novel irid-
ium(III) complexes 26-29 in 87-92% isolated yield
(Scheme 6). The elemental analyses as well as the
spectroscopic data of the compounds indicated that not
only a substitution of the OH group for a CtCR unit
but also the coordination of a second alkynyl ligand plus
the generation of a highly unsaturated C5 moiety had
taken place.
insertion reaction is preceded first by the substitution
of OH for CtCR′ followed by the generation of the
(hydrido)iridium(III) intermediate [IrH(CtCR′)2{dCd
CdC(Ph)R}(PiPr3)2], which then rearranges to an alle-
nyl unit that undergoes the C-C coupling process. It
should be mentioned that in contrast to 11 the related
compound trans-[RhCl(dCdCdCPh2)(PiPr3)2] reacts with
phenylacetylene to give, via coupling of the C3 moiety
with the alkyne and one of the phosphines, a rhodium-
(I) complex containing the unusual Wittig-type ylide
iPr3PdCH-C(Ph)dCdCdCPh2 as a neutral π-bonded
ligand.26 The reaction of 11 with PhCtCD affords the
The supposed stereochemistry of the products formed
by alkyne insertion has been substantiated by the X-ray
crystal structure analysis of 26 (Figure 3). The coordi-
nation geometry around the metal center is square-
pyramidal with two trans-disposed alkynyls and two
trans-disposed phosphines in the basal plane and the
σ-bonded allenylvinyl unit in the apical position. The
bond angles of the two axes, P1-Ir-P2 (167.77(6)°) and
C40-Ir-C50 (172.4(3)°), deviate somewhat from the
ideal value of 180°, which is possibly due to the steric
requirements of the C5 ligand. The Ir-C1 bond lies not
exactly perpendicular to the basal plane of the pyramide
but is slightly bent toward the carbon atom C50. The
distance Ir-C1 (1.998(6) Å) is marginally shorter than
the Ir-C40 and Ir-C50 bond lengths (2.020(6) and
2.018(6) Å) but virtually identical to the Ir-C distance
in the six-coordinate (vinyl)iridium(III) complex [IrHCl-
(CHdCH2)(NCMe)(PiPr3)2] (1.99(2) Å).25 The carbon-
carbon bond lengths C1-C2, C3-C4, and C4-C5 (1.35-
(1), 1.32(1), and 1.31(1) Å) are significantly shorter than
the distance C2-C3 (1.46(1) Å), which confirms the
presence of an allenylvinyl ligand.
The 31P NMR data of compounds 26-29 deserve some
comment. While the spectra of 26, 28, and 29 display
at room temperature the expected single resonance,
indicating the equivalence of the two phosphine ligands,
the spectrum of 27 shows two slightly broadened sin-
glets in close proximity. They probably represent the
two central lines of an AB system. At lower tempera-
tures, the two signals sharpen (Figure 4), whereas by
increasing the temperature from 293 to 313 K (when
decomposition begins to occur) the lines broaden and
would presumably coalesce at around 320-330 K.
Although we have not done a reliable VT NMR study
for 29 (and therefore cannot make any conclusion about
the nonrigidity of this compound), we assume that the
observed temperature dependence of the 31P NMR
spectrum of 27 is due to the linkage of two different
substituents at the terminal carbon atom of the C5
chain. Provided that the rotation around the C-C single
bond of the allenylvinyl ligand is slow on the NMR time
scale, the two phosphines are stereochemically non-
equivalent and thus two separate signals should appear.
In contrast to 26, the 1H and 13C NMR spectra of 27
also display two resonances for the PCH and the PCH
nuclei of the isopropyl groups, which supports our
assumption about the different environment at the sites
of the PiPr3 ligands.
1
bis(deuterio) derivative 26-d2, the H NMR spectrum of
which does not exhibit a signal for the IrCH or the CHd
CdCPh2 proton. From this we conclude that the OH unit
(or the eliminated water molecule) is not involved in the
formation of the allenylvinyl ligand.
In the presence of carbon monoxide, compounds 26
and 27 do not react by insertion of CO into the Ir-CH
bond. Instead, addition of CO to the metal center occurs,
and the octahedral (carbonyl)iridium(III) complexes 30
and 31 are formed in excellent yields. Both compounds
are significantly more stable in solution than the
coordinatively unsaturated precursors 26 and 27. In
complete analogy with 27, the 31P NMR spectrum of 31
(but not that of 30) displays two signals at δ -4.0 and
-4.2, which confirms that the two phosphine ligands
are stereochemically not exactly equivalent. Moreover,
the 13C NMR spectrum of 31 exhibits two resonances
for the Ir-CtC carbon atoms at δ 86.5 and 80.9,
indicating that in contrast to 27 also the two alkynyl
groups are different. We assume that due to the increase
of the coordination number from five to six the rotation
around the metal-vinyl bond is somewhat hindered,
and thus a different stereochemical environment of the
ligands lying in the basal plane of the octahedron
results.
Con clu sion s
The work presented in this paper illustrates that the
(allenylidene)iridium(I) complexes of general composi-
tion trans-[IrCl{dCdCdC(Ph)R}(PiPr3)2] (3, 4) offer a
rich chemistry indeed. The chloro ligand can be substi-
tuted not only by other halides but also by relatives
thereof such as OCN-, SCN-, or N3- and even by OH-.
The noteworthy message is that besides 3 and 4 the
corresponding hydroxo compounds trans-[Ir(OH){dCd
CdC(Ph)R}(PiPr3)2] (11, 12) can equally be used as
starting materials to incorporate anionic O-donor, N-
donor, and C-donor ligands into the coordination sphere
of iridium. The azido (13, 14) and phenolato (19)
complexes react with carbon monoxide by migratory
insertion of the allenylidene unit into the Ir-N and
Ir-O bonds, thus generating functionalized alkynyl
ligands. While the insertion product trans-[Ir{CtCCPh-
(N3)R}(CO)(PiPr3)2] with R ) tBu (16) is quite inert, the
analogous compound with R ) Ph (15) reacts under mild
conditions by elimination of N2 to afford the cyano-
substituted (vinyl)iridium(I) complex 17. The hydroxo
derivatives 11 and 12 not only undergo acid-base
reactions with PhOH, CF3CO2H, NEt3‚3HF, and [pyH]-
With regard to the mechanism of formation of the
complexes 26-29, the most remarkable feature is that
despite the strength of the metal-carbon double bond
in the starting materials 11 and 12 a coupling of an
alkyne molecule with the C3 fragment occurs under
exceedingly mild conditions. It is conceivable that the
(25) Werner, H.; Ortmann, D. A.; Ilg, K. Z. Anorg. Allg. Chem. 2000,
626, 2457-2462.
(26) Wiedemann, R.; Steinert, P.; Gevert, O.; Werner, H. J . Am.
Chem. Soc. 1996, 118, 2495-2496.

3790 Organometallics, Vol. 20, No. 17, 2001
Ilg and Werner
Found: C, 51.99; H, 7.73. MS (70 eV): m/z 718 (M+ for 193Ir).
BF4 but also react with methanol by complete fragmen-
tation of the OCH3 moiety to give the six-coordinate
(allenyl)(carbonyl)dihydridoiridium(III) compounds 24
and 25. An unusual insertion process, for which to the
best of our knowledge there is no precedence, takes place
upon treatment of the hydroxo complexes 11 and 12
with phenylacetylene and methylpropiolate leading via
C-C coupling to a novel σ-bonded C5 unit. Although
some mechanistic details of the reactions of 11 and 12
with various substrates are still unresolved, the results
summarized in Schemes 4, 5, and 6 supplement recent
discoveries by Milstein27 and Bergman,28 which showed
that both (hydroxo)- and (alkoxo)iridium(III)snot iridium-
(I)scompounds are valuable starting materials for car-
rying out substitution, elimination, and insertion reac-
tion.
1
IR (C6H6): ν(CdCdC) 1890 cm-1. H NMR (C6D6, 200 MHz):
δ 7.16, 7.04, 6.83 (all m, 5 H, C6H5), 2.88 (m, 6 H, PCHCH3),
1.27 [dvt, N ) 13.5, J (H,H) ) 7.3 Hz, 36 H, PCHCH3], 1.06 [s,
9 H, C(CH3)3]. 13C NMR (C6D6, 100.6 MHz): δ 237.8 [t, J (P,C)
) 3.7 Hz, IrdCdCdC], 215.6 [t, J (P,C) ) 13.4 Hz, IrdCdCd
C], 162.7 (s, ipso-C of C6H5), 152.8 (s, IrdCdCdC), 126.5,
126.2, 115.6 (all s, C6H5), 57.2 [s, C(CH3)3], 22.9 (vt, N ) 26.9
Hz, PCHCH3), 22.5 [s, C(CH3)3], 20.0 (s, PCHCH3). 31P NMR
(C6D6, 162.0 MHz): δ 22.4 (s).
P r ep a r a tion of tr a n s-[Ir Br (dCdCdCP h 2)P iP r 3)2] (5).
A solution of 4 (52 mg, 0.07 mmol) in 15 mL of acetone was
treated with NaBr (35 mg, 0.35 mmol) and stirred for 6 h at
room temperature. The solvent was evaporated, the residue
was extracted with 30 mL of benzene/pentane (1:5), and the
extract was brought to dryness in vacuo. The residue was
dissolved in 3 mL of acetone, and the solution was stored for
12 h at -78 °C. Dark red crystals precipitated, which were
separated from the mother liquor, washed twice with 1 mL of
pentane (0 °C), and dried: yield 46 mg (83%); mp 152 °C dec.
Anal. Calcd for C33H52BrIrP2: C, 50.63; H, 6.70. Found: C,
Exp er im en ta l Section
50.51; H, 6.71. IR (C6H6): ν(CdCdC) 1866 cm-1 1H NMR
.
All reactions were carried out under an atmosphere of argon
by Schlenk techniques. The starting materials 1,29 4,2 and
HCtCCPh(tBu)OH30 were prepared as described in the lit-
erature. NMR spectra were recorded on Bruker AC 200 and
Bruker AMX 400 instruments at room temperature. IR spectra
were recorded on a Bruker IFS 25 FT-IR and mass spectra on
a Finnigan MAT 90 (70 eV) or on a Hewlett-Packard G 1800
GCD instrument. Melting points were measured by DTA. The
term vt indicates a virtual triplet, and N ) 3J (P,H) + 5J (P,H)
(C6D6, 200 MHz): δ 7.99, 7.59, 6.71 (all s, 10 H, C6H5), 3.13
(m, 6 H, PCHCH3), 1.33 [dvt, N ) 13.4, J (H,H) ) 7.3 Hz, 36
H, PCHCH3]. 13C NMR (C6D6, 50.3 MHz): δ 249.8 [t, J (P,C) )
3.8 Hz, IrdCdCdC], 193.9 [t, J (P,C) ) 14.0 Hz, IrdCdCdC],
162.8 [t, J (P,C) ) 1.9 Hz, ipso-C of C6H5], 140.0 [t, J (P,C) )
1.9 Hz, IrdCdCdC], 130.0, 126.6, 121.1 (all s, C6H5), 23.7 (vt,
N ) 26.8 Hz, PCHCH3), 20.3 (s, PCHCH3). 31P NMR (C6D6,
81.0 MHz): δ 16.4 (s).
P r ep a r a t ion of tr a n s-[Ir I(dCdCdCP h 2)(P iP r 3)2] (6).
A solution of 4 (65 mg, 0.09 mmol) in 15 mL of acetone was
treated with KI (150 mg, 0.90 mmol) and stirred for 3 h at
room temperature. The solvent was evaporated, the residue
was extracted with 50 mL of pentane, and the extract was
brought to dryness in vacuo. The residue was dissolved in 2
mL of acetone, and the solution was stored for 12 h at -78
°C. Violet crystals precipitated, which were separated from the
mother liquor, washed twice with 1 mL of pentane (0 °C), and
3
or 1J (P,C) + J (P,C).
P r ep a r a tion of [Ir HCl{CtCCP h (tBu )OH}(P iP r 3)2] (2).
A solution of 1 (170 mg, 0.31 mmol) in 20 mL of hexane was
treated at -20 °C with HCtCCPh(tBu)OH (58 mg, 0.31 mmol),
which led to a rapid evolution of gas (H2) and to a change of
color from orange-yellow to red. After the reaction mixture was
warmed to room temperature, it was stirred for 10 min and
then concentrated to ca. 5 mL in vacuo. A red solid precipi-
tated, the crystallization of which was completed by storing
the solution at -78 °C. The solid was separated from the
mother liquor, washed with small amounts of pentane (0 °C),
and dried in vacuo: yield 192 mg (84%); mp 42 °C. Anal. Calcd
for C31H58ClIrOP2: C, 50.56; H, 7.94. Found: C, 50.10; H, 7.81.
dried: yield 64 mg (88%); mp 78 °C dec. Anal. Calcd for C33H52
-
IIrP2: C, 47.77; H, 6.32. Found: C, 47.42; H, 6.21. IR (KBr):
ν(CdCdC) 1879 cm-1. 1H NMR (C6D6, 200 MHz): δ 8.02, 7.59,
6.70 (all s, 10 H, C6H5), 3.27 (m, 6 H, PCHCH3), 1.33 [dvt, N
) 13.5, J (H,H) ) 6.7 Hz, 36 H, PCHCH3]. 13C NMR (C6D6,
50.3 MHz): δ 248.1 [t, J (P,C) ) 4.2 Hz, IrdCdCdC], 186.2 [t,
J (P,C) ) 14.0 Hz, IrdCdCdC], 163.3 (s, ipso-C of C6H5), 141.4
[t, J (P,C) ) 2.4 Hz, IrdCdCdC], 130.1, 126.6, 120.7 (all s,
IR (C6H6): ν(OH) 3481, ν(IrH) 2300, ν(CtC) 2092 cm-1 1H
.
NMR (C6D6, 200 MHz): δ 7.90, 7.24 (both m, 5 H, C6H5), 3.11
(m, 6 H, PCHCH3), 1.20 [br m, 45 H, PCHCH3 and C(CH3)3],
-42.44 [t, J (P,H) ) 11.6 Hz, 1 H, Ir-H]. 13C NMR (C6D6, 50.3
MHz): δ 146.2 (s, ipso-C of C6H5), 128.5, 128.3, 126.6, 126.4
(all s, C6H5), 115.6 (s, Ir-CtC), 80.7 [t, J (P,C) ) 16.3 Hz, Ir-
CtC], 74.0 (s, COH), 39.9 [s, C(CH3)3], 26.3 [s, C(CH3)3], 25.4
(vt, N ) 26.4 Hz, PCHCH3), 20.5 (s, PCHCH3). 31P NMR (C6D6,
162.0 MHz): δ 37.8 (s).
P r ep a r a tion of tr a n s-[Ir Cl{dCdCdC(P h )tBu }(P iP r 3)2]
(3). A solution of 2 (200 mg, 0.27 mmol) in 10 mL of ether was
treated with 4 µL of CF3CO2H and stirred for 3 h at room
temperature. The solvent was evaporated in vacuo, the residue
was dissolved in 3 mL of acetone, and the solution was stored
for 18 h at -78 °C. A red-violet solid precipitated, which was
separated from the mother liquor, washed with small amounts
of pentane (0 °C), and dried in vacuo: yield 178 mg (91%); mp
154 °C. Anal. Calcd for C31H56ClIrP2: C, 51.83; H, 7.86.
C6H5), 24.8 (vt, N ) 26.8 Hz, PCHCH3), 20.5 (s, PCHCH3). 31
NMR (C6D6, 81.0 MHz): δ 13.1 (s).
P
P r ep a r a tion of tr a n s-[Ir (NCO)(dCdCdCP h 2)(P iP r 3)2]
(7). This compound was prepared as described for 6 from 4
(60 mg, 0.08 mmol) and NaOCN (55 mg, 0.80 mmol) in 15 mL
of acetone. Dark red solid: yield 53 mg (88%); mp 147 °C dec.
Anal. Calcd for C34H52IrONP2: C, 54.82; H, 7.04; N, 1.88.
Found: 54.61; H, 6.93; N, 1.77. IR (KBr): ν(OCN)as 2228, ν(Cd
1
CdC) 1882, ν(OCN)sym 1448 cm-1. H NMR (C6D6, 400 MHz):
δ 7.96, 7.58, 6.71 (all s, 10 H, C6H5), 2.76 (m, 6 H, PCHCH3),
1.23 [dvt, N ) 13.8, J (H,H) ) 7.3 Hz, 36 H, PCHCH3]. 13C
NMR (C6D6, 100.6 MHz): δ 250.5 [t, J (P,C) ) 3.1 Hz, IrdCd
CdC], 212.5 [t, J (P,C) ) 14.1 Hz, IrdCdCdC], 162.1 (s, ipso-C
of C6H5), 147.0 (m, NCO), 137.8 [t, J (P,C) ) 2.0 Hz, IrdCd
CdC], 130.1, 130.0, 126.6 (all s, C6H5), 23.8 (vt, N ) 25.4 Hz,
PCHCH3), 20.0 (s, PCHCH3). 31P NMR (C6D6, 162.0 MHz): δ
20.7 (s).
(27) (a) Blum, O.; Milstein, D. Angew. Chem. 1995, 107, 210-212;
Angew. Chem., Int. Ed. Engl. 1995, 34, 229-231. (b) Blum, O.; Milstein,
D. J . Am. Chem. Soc. 1995, 117, 4582-4594.
P r ep a r a t ion of tr a n s-[Ir (NCO){dCdCdC(P h )tBu }-
(P iP r 3)2] (8). This compound was prepared as described for 6
from 3 (64 mg, 0.09 mmol) and NaOCN (59 mg, 0.09 mmol) in
15 mL of acetone. Dark red solid: yield 62 mg (95%); mp 147
°C dec. Anal. Calcd for C32H56IrNOP2: C, 53.02; H, 7.79; N,
1.93. Found: C, 53.32; H, 7.58; N, 1.81. IR (CH2Cl2): ν(OCN)as
(28) (a) Woerpel, K. A.; Bergman, R. G. J . Am. Chem. Soc. 1993,
115, 7888-7889. (b) Ritter, J . C. M.; Bergman, R. G. J . Am. Chem.
Soc. 1997, 119, 2580-2581. (c) Ritter, J . C. M.; Bergman, R. G. J . Am.
Chem. Soc. 1998, 120, 6826-6827.
(29) (a) Hietkamp, S.; Stufkens, D. J .; Vrieze, K. J . Organomet.
Chem. 1978, 152, 347-357. (b) Werner, H.; Wolf, J .; Ho¨hn, A. J .
Organomet. Chem. 1985, 287, 395-407.
1
(30) Strzelecki, L.; Maric, B. Bull. Soc. Chim. Fr. 1969, 12, 4413.
2229, ν(CdCdC) 1895, ν(OCN)sym 1458 cm-1. H NMR (C6D6,

Square-Planar Allenylidene Ir Complexes
Organometallics, Vol. 20, No. 17, 2001 3791
200 MHz): δ 7.11, 7.03, 6.81 (all m, 5 H, C6H5), 2.58 (m, 6 H,
PCHCH3), 1.18 [dvt, N ) 14.0 Hz, J (H,H) ) 7.0 Hz, 36 H,
PCHCH3], 1.03 [s, 9 H, C(CH3)]. 13C NMR (C6D6, 50.3 MHz):
δ 237.7 [t, J (P,C) ) 3.7 Hz, IrdCdCdC], 228.9 [t, J (P,C) )
14.0 Hz, IrdCdCdC], 162.4 (s, ipso-C of C6H5), 152.3 [t, J (P,C)
) 2.4 Hz, IrdCdCdC], 145.5 (m, NCO), 126.6, 126.2, 115.8
(all s, C6H5), 56.6 [s, C(CH3)3], 23.5 (vt, N ) 26.8 Hz, PCHCH3),
22.6 [s, C(CH3)3], 19.8 (s, PCHCH3). 31P NMR (C6D6, 81.0
MHz): δ 24.5 (s).
P r ep a r a tion of tr a n s-[Ir (NCS)(dCdCdCP h 2)(P iP r 3)2]
(9). This compound was prepared as described for 6 from 4
(74 mg, 0.10 mmol) and KSCN (97 mg, 1.00 mmol) in 15 mL
of acetone. Dark red solid: yield 65 mg (86%); mp 84 °C. Anal.
Calcd for C34H52IrNP2S: C, 53.66; H, 6.89; N, 1.85; S, 4.21.
Found: C, 53.40; H, 6.80; N, 1.76; S, 4.00. IR (CH2Cl2):
ν(SCN)as 2077, ν(CdCdC) 1886, ν(SCN)sym 1463 cm-1. 1H NMR
(C6D6, 400 MHz): δ 7.94, 7.57, 6.90 (all m, 10 H, C6H5), 2.74
(m, 6 H, PCHCH3), 1.23 [dvt, N ) 13.8, J (H,H) ) 7.0 Hz, 36
H, PCHCH3]. 13C NMR (C6D6, 100.6 MHz): δ 246.3 [t, J (P,C)
) 3.6 Hz, IrdCdCdC], 217.6 [t, J (P,C) ) 13.2 Hz, IrdCdCd
C], 163.2 (s, NCS), 163.1 (s, ipso-C of C6H5), 140.5 [t, J (P,C) )
2.5 Hz, IrdCdCdC], 130.1, 127.0, 122.0 (all s, C6H5), 24.1 (vt,
N ) 26.7 Hz, PCHCH3), 20.0 (s, PCHCH3). 31P NMR (C6D6,
162.0 MHz): δ 22.3 (s).
3.7 Hz, IrdCdCdC], 217.4 [t, J (P,C) ) 12.8 Hz, IrdCdCdC],
162.0 (s, ipso-C of C6H5), 138.7 [t, J (P,C) ) 2.4 Hz, IrdCd
C)C], 126.5, 125.6, 117.0 (all s, C6H5), 54.9 [s, C(CH3)3], 23.1
[s, C(CH3)3], 22.2 (vt, N ) 25.6 Hz, PCHCH3), 19.9 (s,
PCHCH3). 31P NMR (C6D6, 81.0 MHz): δ 27.1 (s).
P r epar ation of tr a n s-[Ir (N3)(dCdCdCP h 2)(P iP r 3)2] (13).
This compound was prepared as described for 6 from 4 (74
mg, 0.10 mmol) and NaN3 (33 mg, 0.50 mmol) in 15 mL of
acetone. Deep red solid: yield 68 mg (91%); mp 114 °C dec.
Anal. Calcd for C33H52IrN3P2: C, 53.21; H, 7.04; N, 5.64.
Found: C, 52.93; H, 6.71; N, 5.48. MS (70 eV): m/z 745 (M+
for 193Ir), 717 [M+ - N2], 703 [M+ - N3]. IR (hexane): ν(N3)
2066, ν(CdCdC) 1870 cm-1. 1H NMR (C6D6, 400 MHz): δ 7.97,
7.57, 6.72 (all m, 10 H, C6H5), 2.78 (m, 6 H, PCHCH3), 1.26
[dvt, N ) 13.5, J (H,H) ) 7.0 Hz, 36 H, PCHCH3]. 13C NMR
(C6D6, 100.6 MHz): δ 248.3 [t, J (P,C) ) 3.1 Hz, IrdCdCdC],
206.4 [t, J (P,C) ) 13.7 Hz, IrdCdCdC], 161.9 (br s, ipso-C of
C6H5), 136.0 (br s, IrdCdCdC), 130.0, 126.5, 121.7 (all s,
C6H5), 24.0 (vt, N ) 25.8 Hz, PCHCH3), 19.9 (s, PCHCH3). 31
NMR (C6D6, 162.0 MHz): δ 23.5 (s).
P
P r epar ation of tr a n s-[Ir (N3){dCdCdC(P h )tBu }(P iP r 3)2]
(14). This compound was prepared as described for 6 from 3
(45 mg, 0.06 mmol) and NaN3 (40 mg, 0.60 mmol) in 15 mL of
acetone; reaction time 1.5 h. Orange solid: yield 43 mg (95%);
mp 98 °C dec. Anal. Calcd for C31H56IrN3P2: C, 51.34; H, 7.79;
N, 5.80. Found: C, 51.71; H, 7.61; N, 5.93. IR (CH2Cl2): ν(N3)
2078, ν(CdCdC) 1895 cm-1. 1H NMR (C6D6, 200 MHz): δ 7.02,
6.82 (both m, 5 H, C6H5), 2.61 (m, 6 H, PCHCH3), 1.21 [dvt, N
) 13.5, J (H,H) ) 6.8 Hz, 36 H, PCHCH3], 1.05 [s, 9 H,
C(CH3)3]. 13C NMR (C6D6, 50.3 MHz): δ 235.8 [t, J (P,C) ) 4.9
Hz, IrdCdCdC], 222.8 [t, J (P,C) ) 14.0 Hz, IrdCdCdC],
162.1 (s, ipso-C of C6H5), 150.8 (s, IrdCdCdC), 126.6, 126.2,
116.0 (all s, C6H5), 52.6 [s, C(CH3)3], 23.7 (vt, N ) 25.6 Hz,
PCHCH3), 22.7 [s, C(CH3)3], 19.7 (s, PCHCH3). 31P NMR (C6D6,
81.0 MHz): δ 27.0 (s).
P r ep a r a tion of tr a n s-[Ir (NCS){dCdCdC(P h )tBu }-
(P iP r 3)2] (10). This compound was prepared as described for
6 from 3 (61 mg, 0.08 mmol) and KSCN (78 mg, 0.80 mmol) in
15 mL of acetone; reaction time 4 h. Red solid: yield 56 mg
(90%); mp 151 °C dec. Anal. Calcd for C32H56IrNP2S: C, 51.87;
H, 7.62; N, 1.89; S, 4.33. Found: C, 52.02; H, 7.48; N, 1.77; S,
4.43. IR (CH2Cl2): ν(SCN)as 2080, ν(CdCdC) 1901, ν(SCN)sym
1
1462 cm-1. H NMR (C6D6, 200 MHz): δ 7.06, 6.78 (both m, 5
H, C6H5), 2.54 (m, 6 H, PCHCH3), 1.17 [dvt, N ) 13.5, J (H,H)
) 6.8 Hz, 36 H, PCHCH3], 1.00 [s, 9 H, C(CH3)3]. 13C NMR
(C6D6, 100.6 MHz): δ 235.0 [t, J (P,C) ) 3.0 Hz, IrdCdCdC],
234.6 [t, J (P,C) ) 12.2 Hz, IrdCdCdC], 161.7 [t, J (P,C) ) 2.4
Hz, IrdCdCdC], 161.9 (s, ipso-C of C6H5), 156.0 (s, SCN),
126.7, 126.4, 115.9 (all s, C6H5), 56.5 [s, C(CH3)3], 23.9 (vt, N
) 25.6 Hz, PCHCH3), 22.7 [s, C(CH3)3], 19.8 (s, PCHCH3). 31P
NMR (C6D6, 81.0 MHz): δ 25.3 (s).
P r ep a r a tion of tr a n s-[Ir {C≡CC(N3)P h 2}(CO)(P iP r 3)2]
(15). A slow stream of CO was passed through a solution of
13 (72 mg, 0.10 mmol) in 10 mL of acetone for 15 s at -78 °C.
When the solution was warmed to room temperature, a change
of color from deep red to orange-yellow occurred. The solution
was stirred for 5 min at 20 °C, concentrated to ca. 2 mL in
vacuo, and then stored for 24 h at -78 °C. Yellow crystals
precipitated, which were separated from the mother liquor,
washed with small amounts of acetone (-20 °C), and dried:
yield 62 mg (83%); mp 86 °C dec. Anal. Calcd for C34H52IrN3-
OP2: C, 52.83; H, 6.78; N, 5.44. Found: C, 52.38; H, 7.00; N,
P r ep a r a t ion of tr a n s-[Ir (OH )(dCdCdCP h 2)(P iP r 3)2]
(11). A solution of 4 (70 mg, 0.09 mmol) in 20 mL of acetone
was treated with KOH (34 mg, 0.60 mmol) and stirred for 2 h
at room temperature. A change of color from red to orange
was observed. The solvent was evaporated in vacuo, the
residue was extracted with 50 mL of pentane, and the solution
was concentrated to ca. 3 mL in vacuo. After the solution was
stored for 12 h at -78 °C, orange crystals precipitated, which
were separated from the mother liquor, washed with small
amounts of pentane (0 °C), and dried: yield 54 mg (84%); mp
104 °C dec. Anal. Calcd for C33H53IrOP2: C, 55.05; H, 7.42.
Found: C, 55.53; H, 7.57. IR (C6H6): ν(OH) 3643 ν(CdCdC)
5.29. IR (hexane): ν(N3) 2098, ν(CO) 1933 cm-1 1H NMR
.
(C6D6, 400 MHz): δ 7.67, 7.16, 7.06 (all m, 10 H, C6H5), 2.59
(m, 6 H, PCHCH3), 1.24 [dvt, N ) 13.5, J (H,H) ) 7.0 Hz, 36
H, PCHCH3]. 13C NMR (C6D6, 100.6 MHz): δ 188.0 [t, J (P,C)
) 10.2 Hz, Ir-CO], 144.4 (s, ipso-C of C6H5), 130.8, 128.7, 127.8
(all s, C6H5), 127.4 [t, J (P,C) ) 4.1 Hz, Ir-CtC-C], 115.0 (br
s, Ir-CtC-C), 71.7 (s, Ir-CtC-C), 25.6 (vt, N ) 27.7 Hz,
PCHCH3), 19.8 (s, PCHCH3). 31P NMR (C6D6, 162.0 MHz): δ
42.4 (s).
1
1857 cm-1. H NMR (C6D6, 400 MHz): δ 8.10, 7.60, 6.79 (all
m, 10 H, C6H5), 4.25 (br s, 1 H, OH), 2.80 (m, 6 H, PCHCH3),
1.31 [dvt, N ) 13.5, J (H,H) ) 7.3 Hz, 36 H, PCHCH3]. 13C
NMR (C6D6, 100.6 MHz): δ 252.8 [t, J (P,C) ) 3.1 Hz, IrdCd
CdC], 202.7 [t, J (P,C) ) 12.7 Hz, IrdCdCdC], 161.9 [t, J (P,C)
) 2.5 Hz, ipso-C of C6H5], 129.8, 125.5, 121.8 (all s, C6H5), 22.6
(vt, N ) 24.4 Hz, PCHCH3), 20.0 (s, PCHCH3); signal of Ird
CdCdC not exactly located. 31P NMR (C6D6, 162.0 MHz): δ
23.5 (s).
P r epar ation of tr a n s-[Ir {CtCCP h (N3)tBu }(CO)(P iP r 3)2]
(16). This compound was prepared as described for 15 from
14 (40 mg, 0.06 mmol) and CO in 10 mL of acetone. Yellow
solid: yield 39 mg (90%); mp 76 °C dec. Anal. Calcd for C32H56
IrN3OP2: C, 51.04; H, 5.70; N, 5.58. Found: C, 50.78; H, 5.40;
N, 5.76. IR (C6H6): ν(N3) 2104, ν(CtC) 2050, ν(CO) 1932 cm-1
-
.
1H NMR (C6D6, 200 MHz): δ 7.72, 7.11 (both m, 5 H, C6H5),
2.70 (m, 6 H, PCHCH3), 1.29 [dvt, N ) 13.9, J (H,H) ) 7.3 Hz,
18 H, PCHCH3], 1.27 [dvt, N ) 13.2, J (H,H) ) 6.6 Hz, 18 H,
PCHCH3], 1.11 [s, 9 H, C(CH3)3]. 13C NMR (C6D6, 50.3 MHz):
δ 187.0 [t, J (P,C) ) 11.0 Hz, Ir-CO], 141.1 (s, ipso-C of C6H5),
129.0, 128.3, 127.1 (all s, C6H5), 124.4 [t, J (P,C) ) 15.8 Hz,
Ir-CtC], 114.9 (s, Ir-CtC), 77.5 (s, Ir-CtC-C), 41.0 [s,
C(CH3)3], 26.3 [s, C(CH3)3], 26.0 (vt, N ) 26.9 Hz, PCHCH3),
20.1, 20.0 (both s, PCHCH3). 31P NMR (C6D6, 81.0 MHz): δ
42.3 (s).
P r ep a r a tion
of tr a n s-[Ir (OH){dCdCdC(P h )tBu }-
(P iP r 3)2] (12). This compound was prepared as described for
11 from 3 (80 mg, 0.11 mmol) and KOH (34 mg, 0.60 mmol) in
20 mL of acetone; reaction time 3 h. Green solid: yield 58 mg
(75%); mp 63 °C dec. Anal. Calcd for C31H57IrOP2: C, 53.19;
H, 8.21. Found: C, 53.12; H, 8.27. IR (C6H6): ν(OH) 3480, ν(Cd
CdC) 1869 cm-1. 1H NMR (C6D6, 200 MHz): δ 7.25, 7.02, 6.88
(all m, 5 H, C6H5), 3.80 (br s, 1 H, OH), 2.62 (m, 6 H, PCHCH3),
1.26 [dvt, N ) 13.5, J (H,H) ) 6.8 Hz, 36 H, PCHCH3], 1.13 [s,
9 H, C(CH3)]. 13C NMR (C6D6, 50.3 MHz): δ 239.1 [t, J (P,C) )

3792 Organometallics, Vol. 20, No. 17, 2001
Ilg and Werner
P r ep a r a tion of tr a n s-[Ir {η1-C(CN)dCP h 2}(CO)(P iP r 3)2]
(17). A solution of 15 (50 mg, 0.06 mmol) in 1 mL of benzene
was stirred for 24 h at room temperature. The solvent was
evaporated in vacuo, the residue was dissolved in 2 mL of
acetone, and the solution was stored for 15 h at -78 °C. Yellow
crystals precipitated, which were separated from the mother
liquor, washed with small amounts of acetone (0 °C), and
dried: yield 43 mg (90%); mp 161 °C dec. Anal. Calcd for
dvt, N ) 13.8, J (H,H) ) 6.8 Hz, 18 H each, PCHCH3]. 13C NMR
(C6D6, 100.6 MHz): δ 186.8 [t, J (P,C) ) 11.2 Hz, Ir-CO], 157.1
(s, ipso-C of C6H5), 141.0 (s, ipso-C of OC6H5), 129.5, 128.6,
128.3, 126.9, 119.6, 118.6 (all s, C6H5), 125.4 [t, J (P,C) ) 15.7
Hz, Ir-CtC], 115.2 (s, Ir-CtC), 86.6 (s, Ir-CtC-C), 41.8
[s, C(CH3)3], 26.5 [s, C(CH3)3], 26.2 (vt, N ) 27.5 Hz, PCHCH3),
20.3, 20.2 (both s, PCHCH3). 31P NMR (C6D6, 162.0 MHz): δ
42.1 (s).
P r epar ation of tr a n s-[Ir (K1-O2CCF3){dCdCdC(P h )tBu }-
(P iP r 3)2] (21). A solution of 12 (60 mg, 0.08 mmol) in 10 mL
of benzene was treated dropwise with a solution of CF3CO2H
(6.6 µL, 0.08 mmol) in 1 mL of benzene at room temperature.
A rapid change of color from green to red-violet occurred. After
the solution was stirred for 5 min at 20 °C and then for 20
min at 40 °C, the solvent was evaporated in vacuo. The oily
residue was dissolved in 2 mL of acetone, and the solution was
stored for 12 h at -78 °C. Red-violet crystals precipitated,
which were separated from the mother liquor, washed with
small amounts of pentane (0 °C), and dried: yield 62 mg (91%);
mp 106 °C. Anal. Calcd for C33H56IrO3P2: C, 49.80; H, 7.09.
Found: C, 49.49; H, 6.90. IR (KBr): ν(CdCdC) 1902, ν(OCO)as
1709, ν(OCO)sym 1457 cm-1. 1H NMR (C6D6, 200 MHz): δ 7.04,
6.79 (both m, 5 H, C6H5), 2.45 (m, 6 H, PCHCH3), 1.21 [dvt, N
) 13.5, J (H,H) ) 6.8 Hz, 36 H, PCHCH3], 1.01 [s, 9 H,
C(CH3)3]. 13C NMR (C6D6, 50.3 MHz): δ 235.8 [t, J (P,C) ) 3.7
Hz, IrdCdCdC], 224.9 [t, J (P,C) ) 13.4 Hz, IrdCdCdC],
161.8 [t, J (P,C) ) 2.4 Hz, IrdCdCdC], 160.0 [q, J (P,C) ) 36.0
Hz, CO2CF3], 156.1 (br s, ipso-C of C6H5), 128.3, 126.6, 116.0
(all s, C6H5), 117.7 [q, J (F,C) ) 291.1 Hz, CO2CF3], 56.7 [s,
C(CH3)3], 23.7 (vt, N ) 25.6 Hz, PCHCH3), 22.8 [s, C(CH3)3],
19.9 (s, PCHCH3). 19F NMR (C6D6, 188.0 MHz): δ -74.5 (s).
31P NMR (C6D6, 81.0 MHz): δ 26.8 (s).
C
34H52IrNOP2: C,54.82; H, 7.04; N, 1.88. Found: C, 54.71; H,
7.14; N, 1.75. IR (C6H6): ν(CN) 2159, ν(CO) 1937 cm-1 1H
.
NMR (C6D6, 400 MHz): δ 8.64, 7.40, 7.35, 7.13 (all m, 10 H,
C6H5), 2.42 (m, 6 H, PCHCH3), 1.30 [dvt, N ) 14.2, J (H,H) )
7.3 Hz, 18 H, PCHCH3], 1.03 [dvt, N ) 13.5, J (H,H) ) 7.0 Hz,
18 H, PCHCH3]. 13C NMR (C6D6, 100 MHz): δ 186.0 [t, J (P,C)
) 11.1 Hz, Ir-CO], 161.3 [t, J (P,C) ) 5.1 Hz, Ir-C(CN)dC],
146.3, 143.4 (both s, ipso-C of C6H5), 142.4 [t, J (P,C) ) 12.7
Hz, Ir-C(CN)dC], 130.8, 129.3, 128.7, 128.3, 127.4, 127.1 (all
s, C6H5), 125.9 [t, J (P,C) ) 2.0 Hz, Ir-C(CN)dC], 26.5 (vt, N
) 27.5 Hz, PCHCH3), 20.5, 19.5 (both s, PCHCH3). 31P NMR
(C6D6, 162.0 MHz): δ 32.7 (s).
P r ep a r a tion of tr a n s-[Ir (OP h )(dCdCdCP h 2)(P iP r 3)2]
(18). A solution of 11 (57 mg, 0.08 mmol) in 10 mL of benzene
was treated with phenol (7.5 mg, 0.08 mmol) and stirred for 5
min at room temperature. A rapid change of color from orange
to red occurred. The solvent was evaporated in vacuo, and the
residue extracted with 25 mL of acetone. After the extract was
concentrated to ca. 2 mL and then stored for 20 h at -78 °C,
dark red crystals precipitated. They were separated from the
mother liquor, washed twice with small quantities of pentane
(-20 °C), and dried: yield 49 mg (82%); mp 86 °C dec. Anal.
Calcd for C39H57IrOP2: C, 58.84; H, 7.22. Found: C, 58.63; H,
1
7.45. IR (C6H6): ν(CdCdC) 1868 cm-1. H NMR (C6D6, 100.6
MHz): δ 7.98, 7.57, 7.28, 6.78, 6.65, 6.43 (all m, 15 H, C6H5),
2.60 (m, 6 H, PCHCH3), 1.25 [dvt, N ) 13.2, J (H,H) ) 7.0 Hz,
36 H, PCHCH3]. 13C NMR (C6D6, 100.6 MHz): δ 255.7 [t,
J (P,C) ) 3.6 Hz, IrdCdCdC], 203.6 [t, J (P,C) ) 13.7 Hz, Ird
CdCdC], 169.3 (s, ipso-C of OC6H5), 162.7 [t, J (P,C) ) 2.0 Hz,
ipso-C of C6H5), 131.8 [t, J (P,C) ) 3.1 Hz, IrdCdCdC], 129.7,
128.9, 126.2, 121.8, 121.7, 115.4 (all s, C6H5), 23.8 (vt, N )
25.8 Hz, PCHCH3), 20.2 (s, PCHCH3). 31P NMR (C6D6, 162.0
MHz): δ 23.3 (s).
P r ep a r a tion of tr a n s-[Ir F (dCdCdCP h 2)(P iP r 3)2] (22).
A solution of 11 (69 mg, 0.10 mmol) in 10 mL of benzene was
treated with NEt3‚3HF (5.2 µL, 0.10 mmol) and stirred for 3
min at room temperature. The solvent was evaporated in
vacuo, and the residue was extracted with 50 mL of pentane.
The extract was brought to dryness in vacuo, the residue was
dissolved in 3 mL of acetone, and the solution was stored for
24 h at -78 °C. Red crystals precipitated, which were
separated from the mother liquor, washed with small amounts
of pentane (0 °C), and dried: yield 61 mg (88%); mp 89 °C
dec. Anal. Calcd for C33H52FIrP2: C, 54.90; H, 7.26. Found:
C, 55.09; H, 7.11. IR (CH2Cl2): ν(CdCdC) 1872 cm-1. 1H NMR
(C6D6, 400 MHz): δ 8.03. 7.60, 6.76 (all m, 10 H, C6H5), 2.81
(m, 6 H, PCHCH3), 1.33 [dvt, N ) 13.5, J (H,H) ) 7.0 Hz, 36
H, PCHCH3]. 13C NMR (C6D6, 100.6 MHz): δ 259.1 (m, Ird
CdCdC), 210.0 (m, IrdCdCdC), 163.0 (s, ipso-C of C6H5),
129.9, 126.1, 122.0 (all s, C6H5), 127.3 (m, IrdCdCdC), 23.1
(vt, N ) 25.4 Hz, PCHCH3), 20.1 (s, PCHCH3). 19F NMR (C6D6,
188.0 MHz): δ -145.3 [t, J (P,F) ) 20.0 Hz]. 31P NMR (C6D6,
162.0 MHz): δ 26.2 [d, J (F,P) ) 20.3 Hz].
P r epar ation of tr a n s-[Ir (py){dCdCdC(P h )tBu }(P iP r 3)2]-
BF 4 (23). A solution of 12 (70 mg, 0.10 mmol) in 10 mL of
acetone was treated at -78 °C with [pyH]BF4 (17 mg, 0.10
mmol), which led to a change of color from green to red-violet.
After the solution was warmed to room temperature, the
solvent was evaporated in vacuo, and the residue was sus-
pended in 30 mL of pentane. The suspension was irradiated
in an ultrasonic bath for 10 min, which led to the formation of
a red-violet solid. This was separated from the mother liquor
and dried: yield 79 mg (93%); mp 38 °C dec. Anal. Calcd for
C36H61BF4IrNP2: C, 50.94; H, 7.24; N, 1.65. Found: C, 51.21;
H, 7.01; N, 1.58. Λ(CH3NO2): 64 cm2 Ω-1 mol-1. IR (CH2Cl2):
ν(CdCdC) 1909 cm-1. 1H NMR (acetone-d6, 200 MHz): δ 8.21,
8.04, 7.88 (all m, 5 H, NC5H5), 7.44-7.23 (m, 5 H, C6H5), 2.18
(m, 6 H, PCHCH3), 1.20 [dvt, N ) 14.6, J (H,H) ) 7.3 Hz, 36
H, PCHCH3]. 13C NMR (acetone-d6, 100.6 MHz): δ 248.4 [t,
J (P,C) ) 14.0 Hz, IrdCdCdC], 228.6 [t, J (P,C) ) 3.7 Hz, Ird
CdCdC], 159.5 (s, ipso-C of C6H5), 127.8, 127.1, 126.9, 117.0,
116.7 (all s, C6H5 and NC5H5), 116.8 [t, J (P,C) ) 3.0 Hz, Ird
P r ep a r a tion of tr a n s-[Ir (OP h ){dCdCdC(P h )tBu }-
(P iP r 3)2] (19). This compound was prepared as described for
18 from 12 (40 mg, 0.06 mmol) and phenol (5.4 mg, 0.06 mmol)
in 10 mL of benzene. Brown solid: yield 41 mg (89%); mp 131
°C. Anal. Calcd for C37H61IrOP2: C, 57.26; H, 7.92. Found: C,
57.43; H, 7.80. IR (C6H6): ν(CdCdC) 1875 cm-1 1H NMR
.
(C6D6, 200 MHz): δ 7.26, 7.17, 7.03, 6.86, 6.65, 6.48 (all m, 10
H, C6H5), 2.44 (m, 6 H, PCHCH3), 1.20 [dvt, N ) 13.4, J (H,H)
) 6.7 Hz, 36 H, PCHCH3], 1.10 [s, 9 H, C(CH3)3]. 13C NMR
(C6D6, 50.3 MHz): δ 240.8 [t, J (P,C) ) 3.7 Hz, IrdCdCdC],
219.3 [t, J (P,C) ) 13.4 Hz, IrdCdCdC], 169.1 (s, ipso-C of
OC6H5), 163.0 [t, J (P,C) ) 2.4 Hz, IrdCdCdC], 146.5 (s, ipso-C
of C6H5), 129.7, 126.5, 126.0, 121.3, 116.5, 115.0 (all s, C6H5),
56.4 [s, C(CH3)3], 23.4 (vt, N ) 24.4 Hz, PCHCH3), 23.0 [s,
C(CH3)3], 20.0 (s, PCHCH3). 31P NMR (C6D6, 162.0 MHz): δ
27.2 (s).
P r ep a r a tion of tr a n s-[Ir {CtCCP h (OP h )tBu }(CO)-
(P iP r 3)2] (20). A slow stream of CO was passed through a
solution of 19 (45 mg, 0.06 mmol) in 10 mL of pentane for 30
s at -78 °C. After the solution was warmed to room temper-
ature, the solvent was evaporated in vacuo, the residue was
dissolved in 2 mL of acetone, and the solution was stored for
18 h at -78 °C. Yellow crystals precipitated, which were
separated from the mother liquor, washed with small quanti-
ties of pentane (-20 °C), and dried: yield 39 mg (83%); mp
157 °C. Anal. Calcd for C38H61IrO2P2: C, 56.76; H, 7.65.
Found: C, 56.51; H, 7.69. MS (70 eV): m/z 804 (M+ for 193Ir),
711 (M+ - OC6H5). IR (C6H6): ν(CO) 1930 cm-1. 1H NMR (C6D6,
400 MHz): δ 7.65, 7.10, 7.05, 6.96, 6.67 (all m, 10 H, C6H5),
2.67 (m, 6 H, PCHCH3), 1.30 [s, 9 H, C(CH3)3], 1.27, 1.22 [both

Square-Planar Allenylidene Ir Complexes
Organometallics, Vol. 20, No. 17, 2001 3793
CdCdC], 56.7 [s, C(CH3)3], 24.7 (vt, N ) 26.9 Hz, PCHCH3),
23.1 [s, C(CH3)3], 19.6 (s, PCHCH3). 31P NMR (acetone-d6, 81.0
PCHCH3), 20.4, 20.2 (both s, PCHCH3). 31P NMR (C6D6, 162.0
MHz): δ 13.0 (s).
MHz): δ 21.6 (s). 19F NMR (acetone-d6, 188.0 MHz):
-150.7 (s).
δ
P r ep a r a tion of [Ir (CtCP h )2{η1-(E)-CDdCP h CDdCd
CP h 2}(P iP r 3)2] (26-d 2). This compound was prepared as
described for 26 from 11 (42 mg, 0.06 mmol) and excess PhCt
CD (60 µL, 0.60 mmol). Violet solid: yield 51 mg (85%). 1H
NMR (C6D6, 200 MHz): δ 7.70, (all m, 25 H, C6H5), 3.26 (m, 6
H, PCHCH3), 1.29 (m, 36 H, PCHCH3). 31P NMR (C6D6, 81.0
MHz): δ 13.5 (s).
P r ep a r a tion of [Ir H2(CHdCdCP h 2)(CO)(P iP r 3)2] (24).
A solution of 11 (55 mg, 0.08 mmol) in 10 mL of methanol was
stirred for 30 min at room temperature. The solvent was
evaporated in vacuo, and the residue was suspended in 40 mL
of pentane. After the suspension was irradiated for 10 min in
an ultrasonic bath, a pale yellow solid was formed, which was
separated from the mother liquor and dried: yield 51 mg
(88%); mp 28 °C dec. Anal. Calcd for C34H54IrOP2: C, 55.67;
H, 7.42. Found: C, 55.89; H. 7.38. IR (KBr): ν(IrH) 2209, ν(CO)
1978, ν(CdCdC) 1885 cm-1. 1H NMR (C6D6, 200 MHz): δ 7.53,
7.13 (both m, 10 H, C6H5), 6.54 (m, 1 H, HCdCdC), 2.14 (m,
6 H, PCHCH3), 1.13 [dvt, N ) 13.5, J (H,H) ) 6.8 Hz, 36 H,
PCHCH3], -9.27 [dt, J (P,H) ) 13.6, J (H,H) ) 3.4 Hz, 2 H,
Ir-H]. 13C NMR (C6D6, 50.3 MHz): δ 208.1 [t, J (P,C) ) 3.0
Hz, HCdCdC], 176.1 [t, J (P,C) ) 9.7 Hz, Ir-CO], 141.3, 132.1
(both s, ipso-C of C6H5), 130.1, 129.9, 129.3, 126.6, 125.4, 121.5
(all s, C6H5), 98.9 (s, HCdCdC), 63.4 [t, J (P,C) ) 11.0 Hz, HCd
P r ep a r a t ion of [Ir (CtCP h )2{η1-(E)-CHdCP h CHdCd
C(P h )tBu }(P iP r 3)2] (27). This compound was prepared as
described for 26 from 12 (38 mg, 0.05 mmol) and excess
phenylacetylene (50 µL, 0.50 mmol). Violet solid: yield 48 mg
(91%); mp 121 °C dec. Anal. Calcd for C55H73IrP2: C, 66.84;
H, 7.44. Found: C, 66.59; H, 7.54. IR (KBr): ν(CtC) 2084,
2071, ν(CdCdC) 1874 cm-1. 1H NMR (C6D6, 200 MHz): δ 8.80
(s, 1 H, HCdCdC), 7.52 (br s, 1 H, IrCH), 7.66, 7.44, 7.21,
7.05 (all m, 2 OH, C6H5), 3.26, 3.17 (both m, 3 H each,
PCHCH3), 1.31, 1.17 (both m, 18 H each, PCHCH3), 1.09 [s, 9
H, C(CH3)3]. 13C NMR (C6D6, 100.6 MHz): δ 211.8 (s, HCd
CdC), 144.9, 139.4 (both s, ipso-C of C6H5), 133.9 [t, J (P,C) )
4.1 Hz, Ir-CHdC], 128. 3, 128.0, 127.8, 127.1, 125.9, 125.1,
122.6 (all s, C6H5), 115.8 (s, Ir-CtC), 101.1 [t, J (P,C) ) 8.1
Hz, IrCH], 99.3 (s, HCdCdC), 97.4 (s, HCdCdC), 53.3 [s,
C(CH3)3], 30.1 [s, C(CH3)3], 24.3, 22.6 (both m, PCHCH3), 20.0,
19.8 (both s, PCHCH3), signal of IrCtC not exactly located.
31P NMR (C6D6, 81.0 MHz): δ 13.0, 12.9 (both s).
CdC], 24.5 (vt, N ) 29.3 Hz, PCHCH3), 19.0 (s, PCHCH3). 31
NMR (C6D6, 81.0 MHz): δ 32.8 (s).
P
P r ep a r a tion of [Ir D2(CDdCdCP h 2)(CO)(P iP r 3)2] (24-
d 3). This compound was prepared as described for 24 (50 mg,
0.07 mmol) from 11 and 5 mL of CD3OD. Pale yellow solid:
yield 44 mg (86%). 1H NMR (C6D6, 200 MHz): δ 7.68, 7.52,
7.09 (all m, 10 H, C6H5), 2.12 (m, 6 H, PCHCH3), 1.13 [dvt, N
) 13.1, J (H,H) ) 7.3 Hz, 36 H, PCHCH3]. 31P NMR (C6D6, 81.0
MHz): δ 32.8 (s).
P r ep a r a tion of [Ir H2{CHdCdC(P h )tBu }(CO)(P iP r 3)2]
(25). This compound was prepared as described for 24 from
12 (80 mg, 0.11 mmol) and 10 mL of methanol. Pale yellow
P r ep a r a tion of [Ir (CtCCO2Me)2{η1-(E)-CHdC(CO2Me)-
CHdCP h 2}(P iP r 3)2] (28). This compound was prepared as
described for 26 from 10 (57 mg, 0.08 mmol) and excess
methylpropiolate (50 µL, 0.80 mmol). Red-orange solid: yield
71 mg (89%); mp 62 °C dec. Anal. Calcd for C45H63IrO6P2: C,
56.65; H, 6.66. Found: C, 56.95; H, 6.51. IR (C6H6): ν(CtC)
2084, ν(OCO)as ) 1686, ν(OCO)sym ) 1431 cm-1. 1H NMR (C6D6,
400 MHz): δ 9.40 (s, 1 H, HCdCdC), 8.63 (br s, 1 H, IrCH),
7.80, 7.24, 7.11 (all m, 10 H, C6H5), 3.41 (s, 6 H, CO2CH3),
3.33 (s, 3 H, CO2CH3), 3.11 (m, 6 H, PCHCH3), 1.13 [dvt, N )
14.0, J (H,H) ) 7.1 Hz, 36 H, PCHCH3]. 13C NMR (C6D6, 100.6
MHz): δ 211.4 (s, HCdCdC), 162.8, 154.5 (both s, CO2CH3),
138.7 (s, ipso-C of C6H5), 129.5, 128.5, 126.8 (all s, C6H5), 126.4
[t, J (P,C) ) 4.1 Hz, Ir-CtC], 123.5 [t, J (P,C) ) 7.1 Hz, Ir-
CHdC], 111.4 (s, HCdCdC), 94.2 (s, HCdCdC), 51.4, 51.3
(both s, CO2CH3), 25.1 (vt, N ) 27.3 Hz, PCHCH3), 19.9 (s,
PCHCH3), signals for Ir-CHdC and Ir-CtC not exactly
located. 31P NMR (C6D6, 162.0 MHz): δ 16.9 (s).
solid: yield 75 mg (91%): mp 72 °C dec. Anal. Calcd for C32H59
-
IrOP2: C, 53.83; H, 8.33. Found: C, 54.08; H, 8.11. IR (KBr):
ν(IrH) 2053, ν(CO) 1972, ν(CdCdC) 1764 cm-1. 1H NMR (C6D6,
400 MHz): δ 7.27, 7.12, 7.02 (all m, 5 H, C6H5), 6.31 (m, 1 H,
HCdCdC), 2.16 (m, 6 H, PCHCH3), 1.30 [s, 9 H, C(CH3)3], 1.18,
1.09 [both dvt, N ) 13.7, J (H,H) ) 7.6 Hz, 18 H, PCHCH3],
-9.47 [dt, J (P,H) ) 13.8, J (H,H) ) 4.6 Hz, 2 H, Ir-H]. 13C
NMR (C6D6, 100.6 MHz): δ 207.5 [t, J (P,C) ) 3.0 Hz, HCd
CdC], 176.5 [t, J (P,C) ) 9.2 Hz, Ir-CO], 142.0 (s, ipso-C of
C6H5), 130.4, 127.6, 125.0 (all s, C6H5), 102.7 (s, HCdCdC),
63.3 [t, J (P,C) ) 11.2 Hz, HCdCdC], 50.8 [s, C(CH3)3], 31.7
[s, C(CH3)3], 24.5 (vt, N ) 29.3 Hz, PCHCH3), 19.0 (s,
PCHCH3). 31P NMR (C6D6, 81.0 MHz): δ 33.0 (s).
P r ep a r a tion of [Ir (CtCCO2Me)2{η1-(E)-CHdC(CO2Me)-
CHdCdC(P h )tBu }(P iP r 3)2] (29). This compound was pre-
pared as described for 26 from 12 (34 mg, 0.05 mmol) and
excess methylpropiolate (60 µL, 0.67 mmol). Red-orange
P r ep a r a tion of [Ir (CtCP h )2{η1-(E)-CHdCP h CHdCd
CP h 2}(P iP r 3)2] (26). A solution of 11 (55 mg, 0.08 mmol) in
10 mL of benzene was treated with an excess of phenylacety-
lene (81 µL, 0.80 mmol) and stirred for 30 min at room
temperature. A change of color from orange to deep violet
occurred. The solvent was evaporated in vacuo, the residue
was dissolved in 1 mL of benzene, and the solution was
chromatographed on Al2O3 (neutral, acitivity grade V, height
of column 5 cm). With pentane, a violet fraction was eluted,
which was brought to dryness in vacuo. Recrystallization from
pentane at -78 °C gave violet crystals, which were separated
from the mother liquor and dried: yield 70 mg (87%); mp 53
°C. Anal. Calcd for C57H69IrP2: C, 67.90; H, 6.90. Found: C,
solid: yield 42 mg (92%); mp 98 °C. Anal. Calcd for C43H67
IrO6P2: C, 55.29; H, 7.23. Found: C, 54.97; H, 7.21. IR (KBr):
ν(CtC) 2081, ν(OCO)as ) 1684, ν(OCO)sym ) 1457 cm-1 1H
-
.
NMR (C6D6, 400 MHz): δ 9.02 (s, 1 H, HCdCdC), 8.11 (br s,
1 H, IrCH), 7.57, 7.22, 7.13 (all m, 5 H, C6H5), 3.43 (br s, 9 H,
CO2CH3), 3.08 (m, 6 H, PCHCH3), 1.39 [s, 9 H, C(CH3)3], 1.13
(m, 36 H, PCHCH3). 13C NMR (CD2Cl2, 50.3 MHz): δ 206.2 (s,
HCdCdC), 163.6, 154.6 (both s, CO2CH3), 138.9 (s, ipso-C of
C6H5), 129.7, 128.6, 127.7 (all s, C6H5), 126.7 [t, J (P,C) ) 3.7
Hz, Ir-CHdC], 126.1 (br s, Ir-CHdC), 121.6 [t, J (P,C) ) 4.2
Hz, Ir-CtC], 119.9 (br s, Ir-CtC), 114.3 (s, HCdCdC), 91.8
(s, HCdCdC), 66.4 [s, C(CH3)3], 51.9, 51.4 (both s, CO2CH3),
30.1 [s, C(CH3)3], 25.0 (vt, N ) 26.8 Hz, PCHCH3), 19.9, 19.8
(both s, PCHCH3). 31P NMR (C6D6, 162.0 MHz): δ 16.3 (s).
P r ep a r a tion of [Ir (CtCP h )2{η1-(E)-CHdCP h CHdCd
CP h 2}(CO)(P iP r 3)2] (30). A slow stream of CO was passed
through a solution of 26 (30 mg, 0.03 mmol) in 5 mL of benzene
for 15 s at room temperature. A change of color from violet to
light yellow occurred. After the solution was stirred for 5 min,
the solvent was evaporated in vacuo. The oily residue was
dissolved in 1 mL of pentane and the solution stored for 6 h
at -78 °C. A pale yellow solid precipitated, which was
1
68.01; H, 7.04. IR (C6H6): ν(C≡C) 2078, 2076 cm-1. H NMR
(C6D6, 400 MHz): δ 9.36 (s, 1 H, HCdCdC), 7.93 (br s, 1 H,
IrCH), 7.63, 7.46, 7.34, 7.23, 7.15-6.93, 6.74 (all m, 25 H,
C6H5), 3.27 (m, 6 H, PCHCH3), 1.32 [dvt, N ) 13.2, J (H,H) )
6.6 Hz, 18 H, PCHCH3], 1.27 [dvt, N ) 13.2, J (H,H) ) 7.0 Hz,
18 H, PCHCH3]. 13C NMR (C6D6, 100.6 MHz): δ 211.6 (s, HCd
CdC), 177.3 [t, J (P,C) ) 4.0 Hz, Ir-CHdC], 153.3, 148.5,
143.5, 138.4 (all s, ipso-C of C6H5), 132.9, 132.6, 131.3, 130.4,
128.8, 128.6, 128.4, 128.3, 127.9, 127.6, 126.8, 126.1 (all s,
C6H5), 119.3 [t, J (P,C) ) 12.2 Hz, Ir-CtCPh], 115.3 [t, J (P,C)
) 4.1 Hz, Ir-CtCPh], 111.4 (s, HCdCdC), 104.5 [t, J (P,C) )
8.1 Hz, IrCH], 100.9 (s, HCdCdC), 24.6 (vt, N ) 26.4 Hz,

3794 Organometallics, Vol. 20, No. 17, 2001
Ilg and Werner
separated from the mother liquor and dried: yield 28 mg
(93%); mp 136 °C dec. Anal. Calcd for C58H69IrOP2: C, 67.22;
H, 6.71. Found: C, 67.53; H, 6.66. IR (CH2Cl2): ν(C≡C) 2114,
ν(CO) 2031, ν(CdCdC) 1936 cm-1. 1H NMR (C6D6, 200 MHz):
δ 9.51 (s, 1 H, HCdCdC), 8.15 [t, J (P,H) ) 3.5 Hz, 1 H, IrCH],
7.65, 7.42, 7.0 (all m, 25 H, C6H5), 2.89 (m, 6 H, PCHCH3),
1.42 [dvt, N ) 14.3, J (H,H) ) 6.0 Hz, 18 H, PCHCH3], 1.27
[dvt, N ) 13.5, J (H,H) ) 6.6 Hz, 18 H, PCHCH3]. 13C NMR
(C6D6, 50.3 MHz): δ 210.6 (s, HCdCdC), 172.0 [t, J (P,C) )
12.7 Hz, Ir-CO], 147.7 (s, ipso-C of C6H5), 142.7 [t, J (P,C) )
3.6 Hz, Ir-CHdC], 135.4 [t, J (P,C) ) 12 Hz, Ir-CHdC], 132.0,
131.1, 131.0, 129.5, 129.4, 126.7, 125.9, 125.6, 125.5 (all s,
C6H5), 112.6 (s, Ir-CtC), 110.9 (s, HCdCdC), 107.4 (s, Ir-
CtC), 101.9 (s, HCdCdC), 86.4 [t, J (P,C) ) 12.2 Hz, Ir-Ct
C], 80.4 [t, J (P,C) ) 11.0 Hz, Ir-CtC], 24.9 (vt, N ) 28.0 Hz,
PCHCH3), 20.2, 19.6 (both s, PCHCH3). 31P NMR (C6D6, 81.0
MHz): δ -3.8 (s).
X-r a y Str u ctu r a l Deter m in a tion of Com p ou n d s 4, 22,
a n d 26. Single crystals of 4 were grown by cooling a solution
in ether to -60 °C, those of 22 by cooling a solution in acetone
to -60 °C, and those of 26 by cooling a solution in ether to 5
°C. The data were collected on an Enraf-Nonius CAD4 dif-
fractometer using monochromated Mo KR radiation (λ )
0.71073 Å). Crystal data were corrected by Lorentz and
polarization effects, and empirical absorption corrections were
applied (Ψ-scan method, minimum transmission 61.25% (4),
90% (22), 84.03% (26)). The structures were solved by direct
methods (SHELXS-97).31 Atomic coordinates and anisotropic
thermal parameters of non-hydrogen atoms were refined by
full-matrix least squares on F2 (SHELXL-97).32 The positions
of all hydrogen atoms were calculated according to ideal
geometry and refined using the riding method.
Ack n ow led gm en t . We thank the Deutsche For-
schungsgemeinschaft (Grant SFB 347) and the Fonds
der Chemischen Industrie for financial support, the
latter in particular for a Ph.D. Grant to K.I. Moreover,
we gratefully acknowledge support by Mrs. R. Schedl
and Mr. C. P. Kneis (elemental analyses and DTA), Mrs.
M.-L. Scha¨fer and Dr. W. Buchner (NMR measure-
ments), BASF AG for various gifts of chemicals, and in
particular Mr. S. Stellwag for practical assistance.
P r ep a r a tion of [Ir (CtCP h )2{η1-(E)-CHdCP h CHdCdC-
(P h )tBu }(CO)(P iP r 3)2] (31). This compound was prepared
as described for 30 from 27 (50 mg, 0.05 mmol) and CO in 10
mL of benzene/pentane (1:1). Pale yellow solid: yield 47 mg
(92%); mp 136 °C dec. Anal. Calcd for C56H73IrOP2: C, 66.81;
H, 7.24. Found: C, 67.53; H, 6.66. MS (70 eV): m/z 1017 (M+).
IR (CH2Cl2): ν(CtC) 2115, ν(CO) 2027, ν(CdCdC) 1928 cm-1
.
1H NMR (C6D6, 200 MHz): δ 8.97 (s, 1 H, HCdCdC), 7.78 [t,
J (P,H) ) 2.9 Hz, IrCH], 7.64, 7.50, 7.39-7.19, 7.10-6.94 (all
m, 20 H, C6H5), 2.94, 2.74 (both m, 3 H each, PCHCH3), 1.30
[dvt, N ) 13.5, J (H,H) ) 6.6 Hz, 36 H, PCHCH3], 1.13 [s, 9 H,
C(CH3)3]. 13C NMR (C6D6, 50.3 MHz): δ 205.0 (s, HCdCdC),
171.8 [t, J (P,C) ) 7.3 Hz, Ir-CO], 148.7 (s, ipso-C of C6H5),
143.9 [t, J (P,C) ) 3.7 Hz, Ir-CHdC], 131.1, 131.0, 130.0,
129.6, 126.4, 125.7, 125.5, 125.4 (all s, C6H5), 115.5 (s, HCd
CdC), 112.4, 107.3, 100.3 (all s, Ir-CtC and HCdCdC), 86.5
[t, J (P,C) ) 12.2 Hz, Ir-CtC], 80.9 [t, J (P,C) ) 11.0 Hz, Ir-
CtC], 67.9 [s, C(CH3)3], 34.8 [s, C(CH3)3], 24.9 (m, PCHCH3),
20.3, 20.2 (both s, PCHCH3). 31P NMR (C6D6, 81.0 MHz): δ
-4.0, -4.2 (both s).
Su p p or tin g In for m a tion Ava ila ble: Tables of crystal
data and refinement parameters, bond lengths and angles, and
positional and thermal parameters for 4, 22, and 26. This
material is available free of charge via the Internet at
http://pubs.acs.org.
OM010353M
(31) Sheldrick, G. M. Acta Crystallogr. Sect. A 1990, 46, 467-473.
(32) Sheldrick, G. M. SHELXL-97, Program for Crystal Structure
Refinement; Universita¨t Go¨ttingen, 1997.