The use of half-sandwich iridium dithiolate and diselenolate complexes, Cp*Ir(L)(ER)2 (L=CO, PMe3, PPh3; ER=SPh, SePh, SeMe), for the synthesis of heterodimetallic compounds. The molecular structure of Cp*Ir(CO)(μ-SePh)2[Mo(CO)4]

Article abstract of DOI:10.1016/S0022-328X(98)00739-6

Carbonyl-iridium half-sandwich compounds, Cp*Ir(CO)(EPh)₂ (E=S, Se), were prepared by the photo-induced reaction of Cp*Ir(CO)₂ with the diphenyl dichalcogenides, E₂Ph₂, and used as neutral chelating ligands in carbonylmetal complexes such as Cp*Ir(CO)(μ-EPh)₂[Cr(CO)₄], Cp*Ir(CO)(μ-EPh)₂[Mo(CO)₄] and Cp*Ir(CO)(μ-EPh)₂[Fe(CO)₃], respectively. A trimethylphosphane-iridium analogue, Cp*Ir(PMe₃)(μ-SeMe)₂[Cr(CO)₄], was also obtained. The new heterodimetallic complexes were characterized by IR and NMR spectroscopy, and the molecular geometry of Cp*Ir(CO)(μ-SePh)₂[Mo(CO)₄] has been determined by a single crystal X-ray structure analysis. According to the long Ir...Mo distance (395.3(1) A), direct metal-metal interactions appear to be absent.

Full text of DOI:10.1016/S0022-328X(98)00739-6

Journal of Organometallic Chemistry 570 (1998) 241–246
The use of half-sandwich iridium dithiolate and diselenolate complexes,
Cp*Ir(L)(ER)2 (L=CO, PMe3, PPh3; ER=SPh, SePh, SeMe), for the
synthesis of heterodimetallic compounds. The molecular structure of
Cp*Ir(CO)(v-SePh)2[Mo(CO)4]1
Max Herberhold a,*, Guo-Xin Jin b, Arnold L. Rheingold c
a Uni6ersita¨t Bayreuth, Laboratorium fu¨r Anorganische Chemie, Postfach 10 12 51, D-95440 Bayreuth, Germany
b Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PO Box 1022, China
c Uni6ersity of Delaware, Department of Chemistry, Newark, Delaware 19716, USA
Received 28 April 1998
Abstract
Carbonyl–iridium half-sandwich compounds, Cp*Ir(CO)(EPh)2 (E=S, Se), were prepared by the photo-induced reaction of
Cp*Ir(CO)2 with the diphenyl dichalcogenides, E2Ph2, and used as neutral chelating ligands in carbonylmetal complexes such as
Cp*Ir(CO)(v-EPh)2[Cr(CO)4], Cp*Ir(CO)(v-EPh)2[Mo(CO)4] and Cp*Ir(CO)(v-EPh)2[Fe(CO)3], respectively. A trimethylphos-
phane–iridium analogue, Cp*Ir(PMe3)(v-SeMe)2[Cr(CO)4], was also obtained. The new heterodimetallic complexes were charac-
terized by IR and NMR spectroscopy, and the molecular geometry of Cp*Ir(CO)(v-SePh)2[Mo(CO)4] has been determined by a
˚
single crystal X-ray structure analysis. According to the long Ir…Mo distance (395.3(1) A), direct metal–metal interactions appear
to be absent. © 1998 Elsevier Science S.A. All rights reserved.
Keywords: Half-sandwich iridium complexes; Heterodimetal complexes; Chromium; Molybdenum; Iron; NMR spectra; Crystal
structure
1. Introduction
have been structurally characterized. Tri- and te-
tranuclear cations such as [Cp3*Ir3(v3-S)2]2+ and
[Cp4*Ir4(v3-S)4]2+ have also been described [3]. The
intermediate formation of a coordinatively unsaturated
dimer, {Cp*Ir(v-S)}2, has occasionally been postulated
[2,3].
In the light of the nucleophilic behaviour of chalco-
gen ligands and the easy formation of v2-chalcogen
bridges in binuclear iridium complexes, it is not surpris-
ing that bis(chalcogenato) iridium compounds of the
type Cp*Ir(L)(ER)2 (E=S, Se) are able to act as biden-
tate ligands through their chalcogen atoms. These bis(-
chalcogenato)iridium educts are accessible either from
the iridium(I) dicarbonyl, Cp*Ir(CO)2 (1), or from the
iridium(III) dihalides, Cp*Ir(L)Cl2 (L=PMe3 (2), PPh3
(3)).
Homodinuclear pentamethylcyclopentadienyl irid-
ium (Cp*Ir) complexes containing sulfur and sele-
nium bridges—e.g. [Cp*Ir(L)(v-E)]2 (L=CO, E=S
[1,2], Se [1]; L=tBuNꢀC, E=S [2]), Cp*Ir(PMe3)(v-
S)2Ir(L)Cp* (L=CO [2], tBuNꢀC [2]), Cp*
(PMe3)Ir(v-S)2IrCp* [2] and Cp*Ir(v-Se)(v-Se4)
IrCp* [1]—are well-known, and pseudocubane te-
tramers, [Cp*Ir(v-E)]4 (E=S [1–3], Se [1,4], Te [4]),
* Corresponding author. Tel.: +49 921 552540; fax: +49 921
552157.
1 Dedicated to Professor Bernt Krebs, Mu¨nster, on the occasion of
his 60th birthday.
0022-328X/98/$ - see front matter © 1998 Elsevier Science S.A. All rights reserved.
PII S0022-328X(98)00739-6

242
M. Herberhold et al. / Journal of Organometallic Chemistry 570 (1998) 241–246
The carbonyliridium compounds Cp*Ir(CO)(EPh)2
(4a,b) react with the norbornadiene-stabilised tetracar-
bonylmetal fragments, M(CO)4(nor–C7H8) (M=Cr,
Mo), to give the heterodimetallic complexes
Cp*Ir(CO)(v-EPh)2[M(CO)4] (9a,b and 10a,b) in which
the phenylchalcogenido ligands assume a bridging
function:
2. Results and discussion
Related tricarbonyliron complexes 11a,b are obtained
by a photo-induced reaction of Cp*Ir(CO)(EPh)2 (E=
S (4a), Se (4b)) with Fe(CO)5. The solubility of the
molybdenum- and iron heterodimetal complexes is low,
also in polar solvents such as THF and acetonitrile.
2.1. Syntheses
Irradiation of Cp*Ir(CO)2 (1) in THF solution in the
presence of disulfides or diselenides, E2R2, leads to the
monocarbonyls 4a,b,b% under formal oxidation of iridi-
um(I) to iridium(III), (Eq. 1):
h, −CO
Cp*Ir(CO)2 (1)+E2R2 ꢁꢁꢁꢁꢁꢂ Cp*Ir(CO)(ER)2
(1)
(THF)
ER=SPh (4a), SePh (4b), SeMe (4b%)
The yields of 4a,b,b% after column chromatography
and recrystallization are in the range of 85–95%. Subse-
quent displacement of the remaining carbonyl ligand by
excess trimethylphosphane gives 5a,b,b% in good yields.
The triphenylphosphane complexes Cp*Ir(PPh3)
(EPh)2 (6a,b) were prepared by substitution of chloro
ligands according to Eq. 2:
In contrast to the carbonyl–iridium complexes 4a,b,
the triphenylphosphane–iridium compounds 6a,b did
not add tetracarbonylmetal fragments such as
[Cr(CO)4] and [Mo(CO)4] under comparable conditions.
Some reactions with the trimethylphosphane complex,
Cp*Ir(PMe3)(SeMe)2 (5b%), have also been carried out,
Cp*Ir(PPh3)Cl2 (3)+2 LiEPh
ꢁ−ꢁꢁ2ꢁLꢁiCꢁlꢂ Cp*Ir(PPh3)(EPh)2
(2)
and
a heterodinuclear derivative, Cp*Ir(PMe3)(v-
THF
E=S (6a), Se (6b)
SeMe)2[Cr(CO)4] (12b%), has been characterized. Prelim-
inary studies of the reaction between 5b% and
bis(cycloocta-1,5-diene)nickel indicated the formation
of a red, paramagnetic product of the composition
[Cp*Ir(SeMe)3]2Ni (13).
The analogous reaction of 2 with NaSR in ethanol had
been used by Bergman and co-workers [5] to prepare
the related trimethylphosphane complexes Cp*Ir(PMe3)
t
(SR)2 (R=H, Me, Bu). On the other hand, the coordi-
natively unsaturated pentafluorthiolato- and 2,3,5,6-te-
trafluorthiolato complexes, Cp*Ir(SC6F5)2 and Cp*Ir(S-
C6F4–H(p))2 [6], were reported to add carbon mon-
oxide and triphenylphosphane, respectively, to give
complexes of type 7a and 8a [7], which are analogous to
4a and 6a.
2.2. Spectroscopic characterization
The relevant spectroscopic data of the mononuclear
Cp*Ir complexes are collected in Table 1, those of
typical heterobimetallic derivatives in Table 2.
In the IR spectra, the Cp*Ir(CO)(ER)2 compounds
(4a,b,b%) each contain a strong carbonyl absorption
(Ir–CO) close to 2000 cm−1 which appears with
roughly the same frequency (1995–2011 cm−1) in the
heterobimetallic complexes (Table 2). The number of
carbonyl bands equals the total number of CO ligands.
All IR spectra contain the strong Cp* absorption at
137593 cm−1 which is ascribed to the out-of-plane
vibrations (k(CH3)) of the methyl substituents.

M. Herberhold et al. / Journal of Organometallic Chemistry 570 (1998) 241–246
243
Table 1
IR- and NMR spectroscopic dataa of the mononuclear Cp*Ir complexes
Complex
IR (CsI) w(CO) [cm−1
]
1H-NMRb
13C-NMR
31P-NMR
4a
Cp*Ir(CO)(SPh)2
1994
1.73s
6.99m, 7.38m
(15)
(10)
8.6; 101.4 (Cp*)
123.9, 127.6, 132.2 (Ph)
141.4 (Ci)
171.2 (CO)
4b
Cp*Ir(CO)(SePh)2
1994
1999
1.77s
7.05m, 7.56m
(15)
(10)
8.9; 100.3 (Cp*)
125.1, 127.8, 134.6 (Ph)
137.1 (Ci)
170.8 (CO)
9.1; 99.8 (Cp*)
−1.1 (SeMe)
4b%
Cp*Ir(CO)(SeMe)2
1.96s
1.88s
(15)
(6)
174.4 (CO)
5a
Cp*Ir(CO)(PMe3)(SPh)2
14.7d [1.8]
1.53d [10.8]
6.92 m, 7.37m
(15)
(9)
(10)
9.3s, 94.9d [3.2] (Cp*)
12.3d [40.5] (PMe3)
122.2, 127.8, 132.0 (Ph)
140.8 (Ci)
9.5s; 94.3d [3.4] (Cp*)
16.3d [40.5] (PMe3)
123.8; 127.2; 134.9 (Ph)
132.8d [5.9] (Ci)
−40.6
−43.8
5b
Cp*Ir(PMe3)(SePh)2
1.78d [2.7]
1.62d [9.9]
6.96m,7.48m
(15)
(9)
(10)
5b%
Cp*Ir(PMe3)(SeMe)2
Cp*Ir(PPh3)(SPh)2
1.74d [2.0]
1.53d [8.6]
1.68s
1.46d [2.2]
6.75m, 6.91m
7.30m
(15)
(9)
(6)
9.1s; 93.6d [3.4] (Cp*)
16.6d [41.0] (PMe3)
−5.2s (SMe)
8.6s; 96.3d [3.4] (Cp*)
122.8, 126.5, 133.9 (SPh)
141.2d [4.3] (Ci)
−39.9
−4.0
6a
(15)
(25)
127.3, 127.6, 129.9 (PPh3)
134.9d [7.7] (Ci)
6b
Cp*Ir(PPh3)(SePh)2
1.52d [2.7]
6.86m, 7.25m
(15)
(25)
9.1s; 95.8d [2.5] (Cp*)
124.5, 126.9, 136.3 (SePh)
131.8 (Ci)
−3.0
127.2, 127.6, 129.9 (PPh3)
134.9d [7.7] (Ci)
a All NMR spectra were measured in CDCl3 solution at r.t. Coupling constants nJ(31P, 1H) and nJ(31P, 13C) are given in square brackets.
b Relative intensities in parentheses.
The Cp* ring ligands are easily recognized both in
The central four-membered ring connecting the two
metals via selenolate bridges is almost planar. The long
distance Ir…Mo (395.3(1) A) and the obtuse angles
1
the H- and 13C-NMR spectra by the intense signals of
˚
their methyl substituents. The methyl proton signal is
split into a doublet in the phosphane-containing com-
pounds by 31P–1H spin-spin coupling (4J(P,H)=2–3
Hz), whereas the 13C-NMR methyl signal always ap-
pears as a singlet (Table 1 and Table 2).
Ir–Se–Mo (98.8(1)°) indicate that direct bonding inter-
actions between the two metals are absent. The bond
distance of the selenolate ligands to their central metal
˚
iridium(III) (250.3(1) A) are distinctly shorter than the
The electron impact (EI) mass spectra (see Section 3)
of the mononuclear carbonyl (4a,b,b%) and trime-
thylphosphane (5a,b,b%) compounds contain the molec-
ular ion (M+), whereas the heterodimetallic complexes
only show CO-deficient species in the higher mass
region.
corresponding distances to the attached molybde-
num(0) unit (270.3(2) A). It is therefore fitting to con-
sider the Cp*Ir(CO)(SePh)2 molecule as a neutral
chelate ligand which has formally replaced two cis-car-
bonyl groups in the Mo(CO)6 octahedron.
˚
2.3. Molecular structure of
3. Experimental
Cp*Ir(CO)(v-SePh)2[Mo(CO)4] (10b)
All manipulations were routinely carried out under
argon using Schlenk techniques. The solvents (hexane,
THF) were heated under reflux over an Na/K alloy and
then distilled off in a stream of argon. Separation of
The bond distances and angles related to the coordi-
nation spheres of both iridium(III) and molybdenum(0)
are given in Table 3, cf. Fig. 1.

244
M. Herberhold et al. / Journal of Organometallic Chemistry 570 (1998) 241–246
Table 2
IR- and NMR spectroscopic dataa of the heterodimetallic complexes
Complex
IR (CsI) w(CO)[cm−1
]
1H-NMRb
13C-NMR
9a
Cp*Ir(CO)(SPh)2[Cr(CO)4]
2004c
2042, 1893
1869, 1816
1.97s
7.13m, 7.44m
(15)
(10)
(15)
9.1s; 102.0s (Cp*)
126.1, 128.5, 131.1 (Ph)
142.0 (Ci)
211.3 (CO)
9b
Cp*Ir(CO)(SePh)2[Cr(CO)4]
Cp*Ir(CO)(SPh)2[Mo(CO)4]
Cp*Ir(CO)(SePh)2[Mo(CO)4]
Cp*Ir(CO)(SePh)2[Fe(CO)3]
Cp*Ir(PMe3)(SeMe)2[Cr(CO)4]d
1995c
2030, 1898
1869, 1834
2011c
2047, 1897
1870, 1827
2009c
2031, 1909
1870, 1840
1997c
2.03s
7.16m, 7.59m
(10)
(15)
10a
10b
11b
12b%
1.98s
7.13m, 7.46m
9.1s; 102.3s (Cp*)
126.1, 128.2, 131.1 (Ph)
131.6 (Ci)
(10)
(15)
2.03s
7.16m, 7.59m
(10)
(15)
2.21s
7.18m, 7.34m
2064
2031, 1980
1983, 1873
1855, 1815
(10)
(15)
(9)
1.73d [2.5]
1.89d [9.8]
1.64s
9.4s; 94.9s (Cp*)
1.67d [40.5] (PMe3)
0.68s (SeMe)
(6)
1
a All NMR measurements were carried out in CDCl3 at r.t. Coupling constants J(31P, H) and J(31P, 13C) are given in square brackets. b Relative
intensities in parentheses. c Carbonyl ligand at iridium. d 31P-NMR: l=−28.4.
product mixtures and purification of the components
was accomplished by column chromatography over sil-
ica (Merck, Kieselgel 60, 0.06–0.2 mm) which had been
activated at 600°C over night and then kept under
argon before use.
using the CHCl3 trace as a reference. The IR spectra
were measured on a Perkin-Elmer 983G (as CsI pellets),
and the electron-impact mass spectra on a Varian MAT
8500 spectrometer (70 eV).
The starting materials Cp*Ir(CO)2 (1) [8],
Cp*Ir(PMe3)Cl2 (2) [8], Cp*Ir(PPh3)Cl2 (3) [9], and
(nor–C7H8)M(CO)4 (M=Cr, Mo [10]) were prepared
following established procedures.
3.1. Preparation of the Cp*Ir half-sandwich complexes
3.1.1. Synthesis of carbonyl–iridium complexes,
Cp*Ir(CO)(ER)2 (4a,b,b%)
Cp*Ir(CO)(SePh)2 (4b): A yellow solution containing
0.25 g (0.65 mmol) Cp*Ir(CO)2 (1) and 0.20 g (0.65
The standard 1H- and 13C-NMR spectra were
recorded on a Jeol FX 90Q instrument (CDCl3, 0°C)
Table 3
Selected bond distances and angles for Cp*Ir(CO)(v-
SePh)2[Mo(CO)4] (10b)
˚
Bond distances (A)
Ir–C(1)
Ir–Center(Cp*)
Ir–Se(1)
Ir–Se(2)
Ir…Mo
186(1)
Mo–C(2)
Mo–C(3)
Mo–C(4)
Mo–C(5)
Mo–Se(1)
Mo–Se(2)
202(1)
195(1)
189(1)
204(1)
270.4(2)
270.2(2)
186.6(9)
250.3(1)
250.2(1)
395.3(1)
Bond angles (°)
Center(Cp*)–IrC(1)
Center(Cp*)–Ir–Se(1) 124.0(5)
Center(Cp*)–Ir–Se(2) 124.2(5)
C(1)–Ir–Se(1)
C(1)–Ir–Se(2)
Se(1)–Ir–Se(2)
Ir–Se(1)–Mo
Ir–Se(2)–Mo
Se(1)–Mo–Se(2)
132.2(5)
Se(1)–Mo–C(2)
Se(1)–Mo–C(3)
Se(1)–Mo–C(4)
Se(1)–Mo–C(5)
C(2)–Mo–C(3)
C(2)–Mo–C(4)
C(2)–Mo–C(5)
C(3)–Mo–C(4)
C(3)–Mo–C(5)
C(4)–Mo–C(5)
97.7(4)
98.4(4)
173.5(4)
88.1(4)
91.2(5)
87.4(5)
174.1(5)
85.5(6)
89.1(5)
86.8(6)
89.0(4)
90.6(4)
82.1(1)
98.7(1)
98.8(1)
74.9(1)
Fig. 1. Molecular structure of Cp*Ir(CO)(v-SePh)2[Mo(CO)4] (10b)

M. Herberhold et al. / Journal of Organometallic Chemistry 570 (1998) 241–246
245
mmol) Se2Ph2 in 60 ml of THF was irradiated for 40
min at 15°C. The colour changed gradually from yellow
to red while gas (CO) was liberated. The solvent THF
was evaporated in vacuo and the residue
chromatographed on a silica column. Elution with
CH2Cl2/pentane (1:1) gave a red zone of 4b, and
recrystallization from CHCl3/hexane at −25°C
produced 0.42 g (97%) of red needles (m.p. 152°C). The
complex 4b is soluble in polar solvents such as CH2Cl2,
CHCl3, Et2O, THF, acetone and acetonitrile, but
almost insoluble in saturated hydrocarbons. EI-MS:
m/e (Irel., %) 668 (M+, 10%), 640 (M+ –CO, 5%), 588
(M+ –Se, 3%), 513 (Cp*Ir(CO)Se2+, 39%), 486
(Cp*IrSe2+, 100%), 403 (Cp*IrSe+, 24%). Analogous
procedures were used to prepare 4a and 4b%.
perature (r.t.). A solution of 0.20 g (0.30 mmol)
Cp*Ir(PPh3)Cl2 in 40 ml of THF was added. The
reaction mixture was stirred for 1 h and then filtered.
The red filtrate was concentrated under vacuum and
transferred to the top of a chromatography column
containing silica. Elution with CH2Cl2/pentane (2:1)
and workup of the red zone gave red crystals which
were recrystallized from CHCl3/hexane (−25°C).
Cp*Ir(PPh3)(SPh)2 (6a), m.p. 160–161° (dec.), yield
0.22 g (90.8%). EI-MS: m/e (Irel.) 546 (M+ –PPh3,
22%), 514 (M+ –PPh3–S, 2%), 469 (M+ –PPh3–Ph,
5%), 437 (Cp*Ir(SPh), 100%), 360 (Cp*Ir(S)+, 6%).
Cp*Ir(PPh3)(SePh)2 (6b), m.p. 163–164°C, yield 0.25
g (92.4%). EI-MS: m/e (Irel.) 640 (M+ –PPh3, 18%), 562
(M+ –PPh3–Se, 78%), 485 (Cp*Ir(SePh)+, 45%), 482
Cp*Ir(Se2)+, 42%.
Cp*Ir(CO)(SPh)2 (4a): orange–yellow prismatic
crystals, m.p. 147°C (yield 88%). EI-MS: m/e (Irel.) 574
(M+, 6%), 546 (M+ –CO, 10%), 465 (M+ –PhS, 22%),
437 (Cp*Ir(SPh)+, 100%), 360 (Cp*IrS+, 9%).
3.2. Preparation of heterodimetallic complexes
Cp*Ir(CO)(SeMe)2 (4b%): orange–golden plates, m.p.
124°C, (yield 95%). EI-MS: m/e 544 (M+, 45%), 516
(M+ –CO, 4%), 504 (M+ –CO–Me, 34%), 486
(Cp*IrSe2+, 70%), 451 (M+ –SeMe, 84%), 421
(Cp*Ir(SeMe)+, 100%).
3.2.1. General procedure
A solution containing 0.3–0.5 mmol of the ligand
Cp*Ir(CO)(EPh)2 (E=S (4a), Se (4b)) and an equimo-
lar amount (0.3–0.5) of the p4-norbornadiene complex,
M(CO)4(nor–C7H8) (M=Cr, Mo), in 50 ml of a
toluene/THF (1:1) mixture was stirred for 2–4 h at
ambient temperature. The colour of the solution be-
came intensely dark-red or brown. Evaporation of the
solvents and purification of the residue by column
chromatography on silica (elution with CH2Cl2 (9a,b)
or CH2Cl2/THF (10a,b; 12b%)) gave a red–brown zone
containing the desired product which was recrystallized
from chloroform/hexane mixtures.
3.1.2.
Synthesis
of
trimethylphosphane–iridium
complexes, Cp*Ir(PMe3)(ER)2 (5a,b,b%)
Cp*Ir(PMe3)(SPh)2 (5a): A yellow THF solution (50
ml) of 0.20 g (0.35 mmol) Cp*Ir(CO)(SPh)2 (4a) was
irradiated in the presence of 0.09 ml (1 mmol) PMe3.
After 20 min the w(CO) stretching absorption had
vanished. The solvent was removed under reduced pres-
sure and the residue chromatographed on a silica
column. A red zone of 5a was eluted using CH2Cl2
from which prismatic orange crystals (m.p. 137–138°C)
were obtained by crystallization from toluene/hexane at
−78°C. Yield 0.19 g (87.6%). EI-MS: m/e (Irel.) 622
(M+, 11%), 546 (M+ –PMe3, 8%), 513 (M+ –SPh,
100%), 437 (Cp*Ir(SPh)+, 74%).
In a similar manner 4b and 4b% were photo-decar-
bonylated in the presence of a 3-fold molar excess of
PMe3 in THF solution to give 5b and 5b%.
Cp*Ir(PMe3)(SePh)2 (5b), red prisms m.p. 140–
141°C, yield 95%. EI-MS: m/e (Irel.) 716 (M+, 8%), 640
(M+ –PMe3, 5%), 563 (M+ –PMe3–Ph, 24%), 559
(M+ –SePh, 100%), 583 (Cp*Ir(SePh)+, 60%).
Cp*Ir(CO)(SPh)2[Cr(CO)4] (9a): yield 0.28 g (90.7%),
dark–brown needles, m.p.166–168° (dec.). EI-MS: m/e
(Irel.), M+ not observed, 684 (M+ –2CO, 0.5%), 656
(M–3CO,
4%),
628
(M+ –4CO,
5%),
384
(Cr(CO)4(SHPh)2+, 68%), 352 (Cr(CO)4SPh2H+,
100%).
Cp*Ir(CO)(SePh)2[Cr(CO)4] (9b): yield 80.3%, dark-
red crystals, m.p.177–178° (dec.). EI-MS: m/e (Irel.) 720
(M+ –4CO, 3%), 692 (M+ –5CO, 5%), 614 (M+
–
5CO–Se, 5%), 538 (Cp*Ir(Se2)Cr+, 14%), 534
(Cp*IrPh2Cr+, 10%), 482 (Cp*IrPh2+, 100%), 405
(Cp*IrPh+, 100%).
Cp*Ir(CO)(SePh)2[Mo(CO)4] (10b): yield 84%, dark-
red prismatic crystals, m.p.191–192° (dec.). IR (CsI):
w(CO) 2031, 1909, 1870, 1840 [Mo(CO)4] and 2009
(Ir–CO) cm−1. The crystalline tetracarbonylmolybde-
num complexes 10a,b are only slightly soluble even in
polar solvents such as THF, acetone and acetonitrile.
Crystals suitable for an X-ray structure determina-
tion were grown at the interface between the solution of
4b in THF and the solution of Mo(CO)4(nor–C7H8) in
toluene.
Cp*Ir(PMe3)(SeMe)2 (5b%) orange–red prisms, m.p.
215°C, yield 94%. EI-MS: m/e (Irel.) 592 (M+, 10%),
577 (M+ –Me, 2%), 516 (M+ –PMe3, 1%), 497 (M+
SeMe, 100%), 482 (Cp*Ir(PMe3)Se+, 24%).
–
3.1.3.
Synthesis
of
triphenylphosphane–iridium
complexes, Cp*Ir(PPh3)(EPh)2 (6a, 6b)
A solution of 0.30 mmol S2Ph2 or Se2Ph2 in 10 ml
THF was treated with 0.60 ml (0.60 mmol) ‘superhy-
dride’, LiBHEt3, and stirred for 30 min at room tem-
Cp*Ir(CO)(SePh)2[Fe(CO)3] (11b): An orange solu-
tion containing 0.32 g (0.48 mmol) Cp*Ir(CO)(SePh)2

246
M. Herberhold et al. / Journal of Organometallic Chemistry 570 (1998) 241–246
(4b) and 0.4 ml (3.04 mmol) Fe(CO)5 in 40 ml of THF
was irradiated for 20 min. Gas evolution (CO) was
observed, and the colour of the solution turned dark-
red. The solvent was evaporated and the residue chro-
matographed on silica, using a CH2Cl2/pentane (1:1)
mixture for elusion. A dark-red zone was obtained
which contained 0.28 g (72.4%) 11b. Recrystallization
from CHCl3/hexane at −25° afforded dark-red crys-
scan range 4–54°. Data collected (h, k, l)918,+16,+
22. Collected reflections 6086, of which 5624 were inde-
pendent and 3508 independent observed (Fo\n|(Fo),
n=5). Control by three standard per 197 reflections,
variation in standards91%. Refinement: R(F) 5.08%,
3
R(wF) 5.33%, D|/(max.) 0.102, D(z) 1.23×10−6 e A .
˚
No/Nv 11.6; GOF 1.35.
tals, m.p. 140–142° (dec.). EI-MS: m/e (Irel.) 752 (M+
2CO, 0.2%), 696 0.4%), 538
(M+ –4CO,
(Cp*Ir(SePh)Fe+, 18%), 424 (Fe2(SePh)2+, 100%).
–
4. Supplementary data
Tables of all bond distances and bond angles, an-
isotropic thermal parameters, positional parameters of
the hydrogen atoms, and the lists of the observed and
calculated structure factors are deposited at Fachinfor-
mationszentrum Karlsruhe, Gesellschaft fu¨r wis-
senschaftlich-technische Information mbH, D-76344
Eggenstein–Leopoldshafen, under the registry number
CSD-59460.
Cp*Ir(PMe3)(SeMe)2[Cr(CO)4] (12b%): The reaction of
equimolar amounts of 5b and Cr(CO)4(nor–C7H8) in
toluene/THF (1:1) gave black prismatic crystals in 64%
yield, m.p. 198°C. EI-MS: m/e (Irel.) 728 (M+ –CO,
6%), 672 (M+ –3CO, 8%), 644 (M+ –4CO 15%), 629
(M+ –4CO–Me, 14%), 614 (M+ –4CO–2Me, 15%),
538 (Cp*IrSe2Cr+, 40%), 512 (Cp*Ir(PMe3)SeMe2+,
4%),
497
(Cp*Ir(PMe3)SeMe+,
40%),
432
(Cp*Ir(PMe3)Me2+, 100%).
[Cp*Ir(SeMe)3]2Ni (13): The solution of 0.19 g (0.70
mmol) Ni(C8H12)2 in 10 ml of THF was slowly added
at −78°C to a solution containing 0.66 g (1.10 mmol)
Cp*Ir(CO)(SeMe)2 (4b%) in 80 ml of THF. The colour
changed immediately from orange to violet. The mix-
ture was kept at −78°C for 0.5 h. During this time two
w(CO) absorptions (at 2007 and 1935 cm−1) could be
observed if the spectra were measured quickly. The
mixture was then allowed to reach r.t. and stirred for
additional 2 h. The solvent was evaporated and the
residue given on a chromatography column filled with
silica. Elution with CH2Cl2 developed a red zone which
contained 0.24 g (34%) of the product 13 which was
recrystallized from CHCl3/hexane at −25°C. Calc. for
C26H48Ir2NiSe6 (1277.56): C 24.44, H 3.78, Ir 30.09, Se
37.08%. Found: C 24.42, H 3.74, Ir 29.8, Se 36.4%.
FD-MS: m/e 1277.7, correct isotope pattern. IR: 1377
(l(Cp*)), 1278 cm−1 (l(SeCH3)).
Acknowledgements
We gratefully acknowledge support by the Deutsche
Forschungsgemeinschaft and the Fonds der Chemis-
chen Industrie. G.-X. Jin thanks the Max-Planck-
Gesellschaft for a fellowship in the German–Chinese
Exchange Program (1998).
References
[1] M. Herberhold, G.-X. Jin, W. Milius, Chem. Ber. 128 (1995)
557.
[2] (a) D.A. Dobbs, R.G. Bergman, J. Am. Chem. Soc. 114 (1992)
6908. (b) D.A. Dobbs, R.G. Bergman, Inorg. Chem. 33 (1994)
5329.
[3] A. Venturelli, T.B. Rauchfuss, J. Am. Chem. Soc. 116 (1994)
4824.
[4] S. Schulz, M. Andruh, T. Pape, et al., Organometallics 13 (1994)
4004.
3.3. X-ray structure determination of
Cp*Ir(CO)(v-SePh)2[Mo(CO)4] (10b)
[5] D.P. Klein, G.M. Kloster, R.G. Bergmann, J. Am. Chem. Soc.
112 (1990) 2022.
[6] (a) J.J. Garcia, H. Torrens, H. Adams, N.A. Bailey, P.M.
Maitlis, J. Chem. Soc. Chem. Commun. (1991) 74. (b) J.J.
Garcia, H. Torrens, H. Adams, N.A. Bailey, A. Shacklady, P.M.
Maitlis, J. Chem. Soc. Dalton Trans. (1993) 1529.
[7] J. Andrade, J.J. Garcia, H. Torrens, F. del Rio, C. Claver, N.
Riuz, Inorg. Chim. Acta 255 (1997) 389.
[8] J.W. Kang, K. Moseley, P.M. Maitlis, J. Am. Chem. Soc. 91
(1969) 5970.
[9] K. Isobe, P.M. Bailey, P.M. Maitlis, J. Chem. Soc. Dalton
(1981) 2003.
[10] M.A. Bennett, L. Pratt, G. Wilkinson, J. Chem. Soc. (1961)
2037.
Crystal: C27H25IrMoO5Se2, red, with the dimensions
0.18×0.26×0.36 mm3. Space group P21/n (mono-
clinic) with the lattice parameters a=1346.6(3), b=
˚
1202.2(2), c=1735.7(4)
A
and, i=91.57(2)°;
3
V=2808.8(6)×106 A , Z=4. Dcalc. 2.07 g×cm−3
;
˚
v(Mo–Kh) 82.8, Transmission [T(max.)/T(min.)]
0.082/0.035.
Data collection: Nicolet R3, Mo–Kh radiation (u=
˚
71.073 A), graphite monochromator, T=292 K. 2q
.
.