Nucleophilic addition to the g6-iridathiabenzene ligand in [g6-Cp*Ir(C,S-2,5-Me2T)]FeCp+

Article abstract of DOI:10.1016/j.ica.2004.11.022

The η⁶-iridathiabenzene ring coordinated to CpFe⁺ in [η⁶-Cp*Ir(C,S-2,5-Me₂T)]FeCp⁺ (2) undergoes attack by nucleophiles. Phosphorus-donors, CN-Buⁿ, and CN^- add to the Ir to give

Full text of DOI:10.1016/j.ica.2004.11.022

Inorganica Chimica Acta 358 (2005) 1623–1634
www.elsevier.com/locate/ica
Nucleophilic addition to the g6-iridathiabenzene ligand in
[g6-Cp*Ir(C,S-2,5-Me2T)]FeCp+
1
Jiabi Chen , Victor G. Young Jr. , Robert J. Angelici
2
*
Ames Laboratory and Department of Chemistry, Iowa State University, Gilman Hall, Ames, IA 50011-3111, USA
Received 22 September 2004; accepted 21 November 2004
Available online 11 February 2005
With many thanks to Gordon and Judy for a very enjoyable sabbatical in Bristol
Abstract
The g6-iridathiabenzene ring coordinated to CpFe+ in [g6-Cp*Ir(C,S-2,5-Me2T)]FeCp+ (2) undergoes attack by nucleophiles.
Phosphorus-donors, C„N–Bunꢀ, and CNꢀ add to the Ir to give products with an g5-coordinated iridathiabenzene ligand. Hydride
(Et3BHꢀ, HFeðCOÞ ꢀ) and Ph nucleophiles attack at the sulfur to give products with Ir–SH and Ir–SPh groups and an iridacy-
4
clopentadiene unit. Other reactions of 2 are described together with structure determinations of key compounds.
ꢀ 2005 Elsevier B.V. All rights reserved.
1. Introduction
Very limited studies show that such g6-metallathiaben-
zene complexes undergo reactions with phosphines and
CO that result in addition to either the metal in the
LxM unit (in structure C) or in the M0Yy unit. Examples
of addition to the metal in the LxM unit, Cp*(C,S-2,5-
Me2T) (1) in these cases, are given in Eqs. (1) and (2) [6,7].
Metallabenzenes are a relatively new class of com-
pounds that incorporate a metal into the benzene ring
as in A [1,2]. A less well-known family of related com-
pounds is the metallathiabenzenes (B), which contain
both a metal and a sulfur [1,3]. Previously, it was shown
[4,5] that metallathiabenzenes are able to form g6-com-
plexes C, analogous to those of g6-benzenes.
Cp*
Ir
LxM
LxM
C
O
LxM
S
M'Yy
S
CO
S
(1)
(2)
Cr(CO)3
C
A
B
Cp* Ir
S
PEt3
PEt3
Ir
Cr(CO)3
*
Corresponding author. Tel.: +1 515 294 2603; fax: +1 515 294
0105.
E-mail address: angelici@iastate.edu (R.J. Angelici).
Cp*
S
1
Present address: Shanghai Institute of Organic Chemistry, Chi-
nese Academy of Sciences, 345 Fenglin Lu, Shanghai 200032, PR
China.
Cr(CO)3
2
Present address: Department of Chemistry, University of Minne-
sota, 139 Smith Hall, 207 Pleasant St. SE, Minneapolis, MN 55455,
USA.
Examples of addition to the M0Yy unit are shown in
Eqs. (3) and (4) [7,8].
0020-1693/$ - see front matter ꢀ 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2004.11.022

1624
J. Chen et al. / Inorganica Chimica Acta 358 (2005) 1623–1634
C4H9)4N]CN, and HgCl2 were purchased from Aldrich
Chemical Co. The complex Cp*Ir(C,S-2,5-Me2T) (1)
Cp*
O
Ir
S
Cp* Ir
+ PEt3
ð3Þ
ð4Þ
was prepared as previously described [11]. Thþe
C
S
½ðg6 ꢀ ClC6H5ÞFeCpꢁþPF6
[12],
½CpFeðg5 ꢀ TÞꢁþ
W
C
ꢀ
PEt3
O
W(CO)3
C
O
PF6ꢀðT ¼ thiopheneÞ [13], ½CpFeðg5 ꢀ 2; 5 ꢀ Me2TÞꢁ
ꢀ
PF6 (2,5-Me2T = 2,5-dimethylthiophene) [13], LiCo-
+
(CO)4 [14], (Me4N)HFe(CO)4 [15], LiMn(CO)5 [14],
{[(C6H5)3P]2N}FeCo(CO)8 [16], and (l-S)2Fe2(CO)6
[17] were prepared by literature methods. All elemental
analyses were performed by Galbraith Laboratory,
Inc. or National Chemical Consulting, Inc. The IR spec-
tra were measured on a Nicolet 710 FT-IR spectropho-
tometer using a solution cell with NaCl salt plates. All
1H NMR spectra were recorded at ambient temperature
in CDCl3 solution with CHCl3 as the internal reference
or in acetone-d6 solution with (CH3)2CO as the internal
reference using a Nicolet NT-300 spectrometer. Electron
ionization mass spectra (EIMS) and chemical ionization
mass spectra (CIMS) were run on a Finnigan 4500 spec-
trometer at 70 eV, while fast atom bombardment (FAB)
spectra were run on samples in a 3-nitrobenzyl alcohol/
CH3NO2 matrix using a Kratos MS-50 mass spectrom-
eter. Melting points were recorded in sealed nitrogen-
filled capillaries and are uncorrected.
(Et3P)3Ir
+ 2 PMe3
S
Mo(CO)3
+
-PEt3
(Et3P)2(CO)Ir
S
Mo(CO)2(PMe3)2
On the basis of these reactions, it appears that the most
favorable sites of attack are either M or M0 (structure
C). On the other hand, if the M0Yy unit were cationic,
one might consider the possibility that nucleophiles
would add at a carbon of the g6-metallathiabenzene ring
as occurs in reactions of a variety of nucleophiles with
cationic M(g6-arene)+n complexes [9,10].
In a previous communication [4], we briefly reported
the synthesis and structural characterization of the cat-
ionic [g6-Cp*Ir(C,S-2,5-Me2T)FeCp]+ (2) containing
an g6 iridathiabenzene coordinated to CpFe+. In this
paper, we present details of the synthesis of 2 as well
as its reactions with a variety of nucleophiles/ligands
that give products resulting from attack on the iridium
or the sulfur.
2.2. Syntheses
2.2.1. Photolytic reaction of Cp*Ir(C,S-2,5-Me2T) (1)
with [(g6-C6H5Cl)FeCp](PF6) to give f[g6-Cp*Ir(C,S-
2,5-Me2T)]FeCpgPF6 (2)
A solution of 1 (0.050 g, 0.114 mmol) and [(g6-
C6H5Cl)FeCp](PF6) (0.035 g, 0.092 mmol) in 25 mL of
CH2Cl2 in a quartz photolysis tube was photolyzed with
a 450 W ultraviolet lamp for 4.5 h during which time the
red solution gradually turned dark purple. The resulting
solution was evaporated under vacuum to dryness, and
the dark purple residue was redissolved in acetone and
purified by passage through a short alumina (neutral,
Activity I, 80–100 mesh) column. The acetone filtrate
was reduced in vacuo to ca. 5 mL; 80 mL of Et2O was
added to precipitate dark-purple 2, yield 0.052 g (80%,
based on [(g6-C6H5Cl)FeCp](PF6)); mp 199–200 ꢁC
2. Experimental
2.1. General procedures
All operations were performed under an N2 atmo-
sphere following standard Schlenk techniques. All sol-
vents employed were reagent grade and were dried by
refluxing over appropriate drying agents; they were
1
˚
stored over 4-A molecular sieves under an N2 atmo-
(dec). H NMR (CDCl3): d 6.81 (d, 1H), 5.99 (d, 1H),
sphere prior to use. Tetrahydrofuran (THF) and diethyl
ether (Et2O) were distilled from sodium benzophenone
ketyl, while hexanes and CH2Cl2 were distilled from
4.46 (s, 5H), 3.15 (s, 3H), 2.96 (s, 3H), 2.14 (s, 15H).
MS: m/e 561 (M+–PF6). Anal. Calc. for C21H28SPF6IrFe:
C, 35.75; H, 4.00. Found: C, 36.35; H, 4.20.
˚
CaH2. Acetone was dried over 4-A molecular sieves
An analogous photolytic (7 h) reaction of 1 (0.040 g,
0.091 mmol) and [CpFe(g5-2,5-Me2T)](PF6) (0.030 g,
0.079 mmol) in 25 mL of CH2Cl2 gave 0.027 g (48%)
and distilled under N2 atmosphere. The neutral Al2O3
(Brockman, Activity I, 80–100 mesh) used for chroma-
tography was deoxygenated under vacuum at room
temperature for 16 h, deactivated with 5% (w/w) N2-
saturated water, and stored under N2. Chromatography
columns were 1.5· (5–15) cm. The reagents PEt3,
P(OEt)3, PPh2Me, HPPh2, LiBEt3H (1.0 M solution in
THF), C6H5Li (1.8 M in cyclohexane–ether), n-butyliso-
cyanide (n-C4H9NC), [Me3O]BF4, [(n-C4H9)4N]I, [(n-
1
of 2, which was identified by its melting point and H
NMR spectrum.
An analogous photolytic (7 h) reaction of 1 (0.040 g,
0.091 mmol) and [CpFe(g5-T)]PF6 (0.030 g, 0.086
mmol) in CH2Cl2 (25 mL) yielded 0.019 g (32%) of 2,
which was identified by its melting point and 1H
NMR spectrum.

J. Chen et al. / Inorganica Chimica Acta 358 (2005) 1623–1634
1625
2.2.2. Reaction of 2 with PEt3 to give
f[Cp*Ir(C,S-2,5-Me2T)(PEt3)]FeCpgPF6 (3)
561 (M+–PF6–HPPh2). Anal. Calc. for C33H39SP2-
F6IrFe: C, 44.45; H, 4.41. Found: C, 44.40; H, 4.49.
There was no evidence for a product in which the PHPh2
ligand was deprotonated by the Et3N.
To a solution of 2 (0.025 g, 0.035 mmol) in THF (20
mL) at ꢀ60 ꢁC was added 0.024 g (0.030 mL, 0.203
mmol) of PEt3. The reaction solution was stirred for 8
h at ꢀ60 to ꢀ20 ꢁC, during which time the dark-purple
solution turned gradually dark red. After vacuum re-
moval of the solvent, the residue was recrystallized from
CH2Cl2:Et2O:hexanes (1:2:4) solution at ꢀ80 ꢁC to give
0.021 g (72%, based on 2) of dark-red crystals of 3 (m.p.
2.2.6. Reaction of 2 with n-C4H9NC to give
f[Cp*Ir(C,S-2,5-Me2T)(CN-Bun)]FeCpgPF6 (7)
Compound 2 (0.030 g, 0.043 mmol) was dissolved
in 20 mL of THF at ꢀ50 ꢁC. To this solution was
added n-C4H9NC (0.035 mL, 0.336 mmol). This solu-
tion was stirred at ꢀ50 to ꢀ40 ꢁC for 3 h during
which time the dark purple solution turned light pur-
ple red. After vacuum removal of the solvent, the res-
idue was recrystallized from hexanes:CH2Cl2 at ꢀ80
ꢁC to afford 0.029 g (85%, based on 2) of black crys-
1
136–138 ꢁC, dec). H NMR (CDCl3): d 7.30 (d, 1H),
4.22 (d, 1H), 4.39 (s, 5H), 2.30 (s, 3H), 1.97 (s, 3H),
1.84 (s, 15H), 1.20 (m, 6H), 0.81 (m, 9H). MS: m/e 737
(M+–3Et), 595 (M+–3Et–PF6). Anal. Calc. for
C27H43SP2F6IrFeCH2Cl2: C, 37.01; H, 4.99. Found: C,
37.46; H, 5.03.
1
tals of 7 (m.p. 54–56 ꢁC, dec). H NMR (CDCl3): d
7.25 (d, 1H), 4.51 (d, 1H), 4.37 (s, 5H), 2.36 (s, 3H),
1.85 (s, 15H), 1.83 (s, 3H), 1.77–1.63 (m, 4H), 1.50-
1.42 (m, 2H), 1.00 (t, 3H). MS: m/e 644 (M+–PF6),
561 (M+–PF6–CNC4H9). Anal. Calc. for C26H37-
NSPF6IrFe: C, 39.60; H, 4.73; N, 1.78. Found: C,
39.45; H, 4.62; N, 1.49.
2.2.3. Reaction of 2 with P(OEt)3 to give
fCp*Ir(C,S-2,5-Me2T)[P(OEt)3]FeCpgPF6 (4)
To a solution of 2 (0.030 g, 0.043 mmol) in THF
(20 mL) was added P(OEt)3 (0.028 g, 0.169 mmol) at
ꢀ60 ꢁC. The solution was stirred at ꢀ60 to ꢀ20 ꢁC for
7 h during which time the dark-purple solution turned
dark-red. Further treatment of the resulting mixture as
described above for 3 gave 0.028 g (76%, based on 2)
2.2.7. Reaction of 2 with [(n-C4H9)4N]CN to give
[Cp*Ir(C,S-2,5-Me2T)(CN)]FeCp (8)
1
of dark-red crystals of 4 (m.p. 178–180 ꢁC, dec). H
Following the procedure described for the reaction of
2 with [(n-C4H9)4N]I, 2 (0.042 g, 0.060 mmol) was re-
acted with [(n-C4H9)4N]CN (0.050 g, 0.186 mmol) at
ꢀ60 to ꢀ40 ꢁC for 3 h and worked up as described for
14 to give 0.026 g (74%, based on 2) of black crystalline
NMR (CDCl3): d 7.18 (d, 1H), 4.39 (s, 5H), 3.76 (m,
6H), 3.46 (d, 1H), 2.31 (s, 3H), 2.22 (s, 3H), 1.83 (s,
15H), 1.32 (t, 9H). MS: m/e 626 (M+–PF6). Anal. Calc.
for C27H43O3P2SF6IrFe: C, 37.21; H, 4.97. Found: C,
37.26; H, 5.01.
1
8 (m.p. 64–66 ꢁC, dec). H NMR (CDCl3): d 7.24 (d,
1H), 4.35 (d, 1H), 4.19 (s, 5H), 2.32 (s, 3H), 1.82 (s,
15H), 1.80 (s, 3H). MS: m/e 587 (M+). Anal. Calc. for
C22H28NSIrFe: C, 45.05; H, 4.81; N, 2.39. Found: C,
45.55; H, 5.10; N, 2.09.
2.2.4. Reaction of 2 with PPh2Me to give
f[Cp*Ir(C,S-2,5-Me2T)(PPh2Me)]FeCpgPF6 (5)
As in the reaction of 2 with PEt3, 2 (0.025 g, 0.035
mmol) was reacted with PPh2Me (0.035 g, 0.175 mmol)
for 8 h at ꢀ60 to ꢀ20 ꢁC. Subsequent workup of the
reaction mixture as described for 3 gave dark-red crys-
tals of 5 (m.p. 200–203 ꢁC, dec); yield 0.021 g (66%,
2.2.8. Reaction of 2 with LiBEt3H to give
[Cp*Ir(C4Me2H2)(SH)]FeCp (9)
1
based on 2). H NMR (CDCl3): d 7.45–7.20 (m, 10H),
To a solution of 2 (0.040 g, 0.057 mmol) in 25 mL of
THF at ꢀ70 ꢁC was added LiBEt3H (0.06 mL of 1.0 M
solution, 0.057 mmol). The reaction solution turned
immediately from dark-purple to dark red. After being
stirred at ꢀ70 to 0 ꢁC for 12 h, the solution was evapo-
rated under vacuum to dryness, and the residue was
chromatographed on Al2O3 (neutral) with hexanes:
CH2Cl2 (15:1) as the eluant. After a small orange-yellow
band, a dark band was eluted with hexanes:CH2Cl2:
Et2O (10:1:1). The dark red eluate was evaporated in
vacuo and the red residue was recrystallized from
hexanes:CH2Cl2 at ꢀ80 ꢁC to yield 0.020 g (63%, based
on 2) of brick-red crystalline 9 (m.p. 110–112 ꢁC, dec).
1H NMR (CDCl3): d 5.31 (s, 2H), 3.98 (s, 5H), 2.90
(s, 6H), 1.81 (s, 15H), ꢀ3.30 (s, 1H). MS: m/e 562
(M+), 561 (M+–H). Anal. Calc. for C21H29SIrFe: C,
44.91; H, 5.21. Found: C, 45.35; H, 5.32.
6.36 (d, 1H), 4.28 (s, 5H), 4.21 (d, 1H), 2.00 (s, 3H),
1.92 (s, 3H), 1.70 (d, 3H), 1.62 (s, 15H). MS: m/e 591
(M+–PF6-Ph2Me–H). Anal. Calc. for C34H41SP2F6IrFe:
C, 45.09; H, 4.56. Found: C, 45.06; H, 4.88.
2.2.5. Reaction of 2 with PHPh2 to give
f[Cp*Ir(C,S-2,5-Me2T)(PHPh2)]FeCpgPF6 (6)
The reaction of 2 (0.080 g, 0.113 mmol) for 10 h at
ꢀ60 to ꢀ10 ꢁC with PHPh2 (0.042 g, 0.226 mmol) and
Et3N (0.024 g, 0.237 mmol) was performed as described
for the reaction of 2 with PEt3. Workup of the reaction
mixture as described for 3 afforded 0.066 g (65%, based
on 2) of dark-red crystals of 6 (m.p. 202–204 ꢁC, dec).
1H NMR (CDCl3): d 7.42 (d, 1H), 7.41-7.28 (m, 10H),
4.85 (s, 1H), 4.36 (s, 5H), 4.26 (d, 1H), 2.01 (s, 3H),
1.74 (s, 3H), 1.61 (s, 15H). MS: m/e 747 (M+–PF6),

1626
J. Chen et al. / Inorganica Chimica Acta 358 (2005) 1623–1634
2.2.9. Reaction of 2 with [Me4N]HFe(CO)4 to give 9
and [Cp*Ir(C4Me2H2)(H)Fe(CO)4]FeCp (11)
Co(CO)4 was added to a solution of 2 (0.040 g, 0.057
mmol) in THF (30 mL) at ꢀ60 ꢁC. This reaction solu-
tion was stirred at ꢀ60 to 10 ꢁC for 10 h during which
time the dark solution turned dark purple. After vac-
uum removal of the solvent, the residue was chromato-
graphed on Al2O3 (neutral) with hexanes:CH2Cl2 (5:1)
and then hexanes:CH2Cl2:Et2O (1:1:1) as the eluant. A
dark purple band was eluted and collected. The solvent
was removed in vacuo and the residue was recrystallized
from hexanes:CH2Cl2:Et2O (1:1:2) at ꢀ80 ꢁC to yield
0.031 g (76%, based on 2) of dark-purple crystals of 12
(m.p. 132–134 ꢁC, dec). IR (CH2Cl2): m(CO) 2026 (w),
To compound 2 (0.040 g, 0.057 mmol) dissolved in 30
mL of THF at ꢀ60 ꢁC was added 0.020 g (0.082 mmol)
of [Me4N]HFe(CO)4. The mixture was stirred at ꢀ60 to
10 ꢁC for 10 h during which time the dark solution
turned gradually dark purple-red. After evaporation of
the solvent under vacuum, the residue was chromato-
graphed on Al2O3 (neutral) with hexanes:CH2Cl2
(15:1) as the eluant. A brick-red band was eluted first;
then
a
dark-red band was eluted with hex-
anes:CH2Cl2:Et2O (10:1:1). After vacuum removal of
the solvents from the above two eluates, the residues
were recrystallized from hexanes:CH2Cl2 at ꢀ80 ꢁC.
From the first fraction, 0.017 g (41%, based on 2) of
dark-red crystals of 11 were obtained (m.p. 137–139
ꢁC, dec). IR (CH2Cl2) m(CO): 2051 (s), 2007 (vs.), 1979
1936 (m), 1889 (vs, br), 1712 (w) cmꢀ1 1H NMR
.
(CDCl3): d 6.74 (d, 1H), 5.96 (d, 1H), 4.43 (s, 5H),
3.17 (s, 3H), 2.95 (s, 3H), 2.15 (s, 15H). MS: m/e 648
(M+–3CO), 561 (M+–Co(CO)4). Anal. Calc. for
C25H28O4SIrFeCo: C, 41.05; H, 3.86. Found: C, 40.85;
H, 3.92.
1
(s), 1938 (s) cmꢀ1. H NMR (CDCl3): d 4.84 (s, 2H),
3.85 (s, 5H), 2.81 (s, 6H), 2.03 (s, 15H), –25.38 (s, 1H).
MS: m/e 730 (M+). Anal. Calc. for C25H29O4SIrFe2: C,
41.16; H, 4.01. Found: C, 41.66; H, 3.95. From the sec-
ond fraction, 0.012 g (38%, based on 2) of brick-red 9
were obtained; it was identified by its mp, H NMR
and MS spectra.
2.2.12. Reaction of 2 with
f[(C6H5)3P]2Ng[FeCo(CO)8] to give
f[g6-Cp*Ir(C,S-2,5-Me2T)FeCp]gFeCo(CO)8] (13)
The reaction of 2 (0.050 g, 0.071 mmol) with
{[(C6H5)3P]2N}FeCo(CO)8 (0.080 g, 0.091 mmol) was
performed as described for the reaction of 2 with
[Me4N]HFe(CO)4 for 12 h at ꢀ50 to 10 ꢁC. After re-
moval of the solvent under vacuum, the residue was
chromatographed on Al2O3 (neutral) with hex-
anes:CH2Cl2 (10:1) first and then CH2Cl2:Et2O (5:1) as
the eluant. A dark band was collected. The solvent
was removed in vacuo, and the residue was recrystallized
from hexanes:CH2Cl2 at ꢀ80 ꢁC to yield 0.040 g (62%,
based on 2) of black crystals of 13 (m.p. 139–140 ꢁC,
dec). IR (CH2Cl2) m(CO): 2029 (w), 1892 (vs, br), 1886
1
2.2.10. Reaction of 2 with LiC6H5 to give 1 and
[Cp*Ir(C4Me2H2)(SC6H5)]FeCp (10)
A solution of 2 (0.020 g, 0.028 mmol) in THF (20
mL) was treated with LiC6H5 (0.006 g, 0.032 mL of
1.8 M solution, 0.071 mmol) at ꢀ50 ꢁC. The solution
immediately turned from dark purple to dark red.
After 8 h of stirring at ꢀ50 to ꢀ20 ꢁC, the solvent
was removed under vacuum. The residue was chro-
matographed on Al2O3 (neutral) with hexanes:CH2Cl2
(15:1) as the eluant. An orange-red band which eluted
first was collected; then a dark-green band was eluted
with hexanes:CH2Cl2:Et2O (10:1:1). After vacuum re-
moval of the solvent from the above two eluates,
the residues were recrystallized from hexanes or hex-
anes:CH2Cl2 at ꢀ80 ꢁC. From the first fraction,
0.003 g (25%, based on 2) of dark-red crystals of 1
were obtained and identified by the mp and 1H
NMR spectrum. From the second fraction, 0.010 g
(50%, based on 2) of brick-red crystals of 10 were ob-
tained (m.p. 93–95 ꢁC, dec). 1H NMR (CDCl3): d
6.93–6.76 (m, 5H), 5.32 (s, 2H), 3.98 (s, 5H), 2.93
(s, 6H), 1.87 (s, 15H). MS: m/e 638 (M+). Anal. Calc.
for C27H33SIrFe: C, 50.86; H, 5.22. Found: C, 51.03;
H, 5.07.
1
(vs, br), 1864 (w) cmꢀ1. H NMR (CDCl3): d 6.83 (d,
1H), 6.01 (d, 1H), 4.46 (s, 5H), 3.16 (s, 3H), 2.97 (s,
3H), 2.15 (s, 15H). MS: m/e 561 (M+–FeCo(CO)8). Anal.
Calc. for C29H28O8SIrFe2Co: C, 38.73; H, 3.14. Found:
C, 38.67; H, 3.06.
2.2.13. Reaction of 2 with [(n-C4H9)4N]I to give
f[g6-Cp*Ir(C,S-2,5-Me2T)]FeCpgI (14)
To a stirred, dark-purple solution of 2 (0.035 g, 0.050
mmol) in THF (20 mL) at ꢀ60 ꢁC was added 0.030 g
(0.081 mmol) of [(n -C4H9)4N]I. The mixture was stirred
at ꢀ60 to ꢀ20 ꢁC for 7 h during which time the dark-
purple solution turned dark red. After vacuum removal
of the solvent, the residue was recrystallized from
CH2Cl2:THF:hexanes solution at ꢀ80 ꢁC to give 0.027
g (79%, based on 2) of black crystals of 14 (m.p. 128–
2.2.11. Reaction of 2 with LiCo(CO)4 to give
1
f[g6-Cp*Ir(C,S-2,5-Me2T)]FeCpg[Co(CO)4] (12)
To a solution of Co2(CO)8 (0.012 g, 0.035 mmol) in 7
mL of THF at ꢀ20 ꢁC was added 0.090 mL of 1.0 M Li-
BEt3H solution (0.090 mmol). The mixture was stirred
at ꢀ20 to 20 ꢁC for 15 min. The resulting solution of Li-
130 ꢁC, dec). H NMR (CDCl3): d 7.04 (d, 1H), 6.09
(d, 1H), 4.54 (s, 5H), 3.17 (s, 3H), 3.01 (s, 3H), 2.15 (s,
15H). MS: m/e 688 (M+), 561 (M+–I). Anal. Calc. for
C12H28ISIrFe: C, 36.69; H, 4.11. Found: C, 36.14; H,
3.82.

J. Chen et al. / Inorganica Chimica Acta 358 (2005) 1623–1634
1627
2.2.14. Reaction of 2 with LiMn(CO)5 to give
gradually deep red. After vacuum removal of the sol-
vent, the residue was recrystallized from THF:hexane
at ꢀ80 ꢁC to give 0.020 g (83%, based on 2) of brick-
red crystals of 17 (m.p. 172–174 ꢁC, dec). 1H NMR (ace-
tone-d6): d 7.03 (d, 1H), 6.50 (d, 1H), 5.01 (s, 5H), 3.62
(m, 4H, THF), 3.32 (s, 3H), 3.06 (s, 3H), 2.53 (s, 15H),
1.79 (m, 4H, THF). MS: m/e 843 (M+–PF6), 561 (M+–
PF6–HgCl2). Anal. Calc. for C21H28Cl2SPF6IrFeHg-
C4H8O(THF): C, 28.62; H, 3.45. Found: C, 28.13; H,
3.55.
f[g6-Cp*Ir(C,S-2,5-Me2T)]FeCpgMn(CO)5 (15)
To a solution of 2 (0.080 g, 0.113 mmol) in THF (30
mL) at ꢀ60 ꢁC was added fresh LiMn(CO)5 prepared by
the reaction of Mn2(CO)10 (0.028 g, 0.072 mmol) with
LiBEt3H (0.180 mL, 0.179 mmol) as described in the
reaction of Co2(CO)8 with LiBEt3H. The reaction solu-
tion was stirred for 8 h at ꢀ60 to 10 ꢁC. During this
time, the dark solution gradually turned dark red. After
vacuum evaporation of the solvent, the residue was
chromatographed on Al2O3 (neutral) with hex-
anes:CH2Cl2 (10:1) first and then hexanes:CH2Cl2:Et2O
(10:1:1) as the eluant. A dark band was collected. The
solvent was removed in vacuo, and the residue was
recrystallized from hexanes:CH2Cl2 at ꢀ80 ꢁC to give
0.026 g (30%, based on 2) of black crystals of 15 (m.p.
131–133 ꢁC, dec). IR (CH2Cl2) m(CO): 2035 (m), 2011
2.2.17. Reaction of 2 with Na/Hg and then [Me3O]BF4 to
give [Cp*Ir(C,S-2,5-Me2T)]FeCp(CH3) (18)
Compound 2 (0.050 g, 0.071 mmol) was reacted with
0.006 g (0.261 mmol) of Na in Na/Hg (1%), prepared by
the reaction of Na (0.006 g, 0.261 mmol) with Hg (0.394
g), at ꢀ40 to ꢀ30 ꢁC for 3 h during which time the dark
solution turned deep brown. After separation from Na/
Hg, the solution was treated with 0.015 g (0.101 mmol)
of [Me3O]BF4. The mixture was stirred at ꢀ30 to
ꢀ20 ꢁC for 3 h. After evaporation of the solvent under
vacuum to dryness, the residue was chromatographed
on Al2O3 (neutral) with hexanes:CH2Cl2 (10:1) as the
eluant. After the purple-red band was eluted and col-
lected, the solvent was removed in vacuo, and the pink-
red residue was recrystallized from hexanes:CH2Cl2 at
ꢀ80 ꢁC to give 0.013 g (41%, based on 2) of pink-red
crystals of 18 (m.p. 118–120 ꢁC, dec). 1H NMR (CDCl3):
d 4.84 (d, 1H), 4.01 (d, 1H), 3.86 (s, 3H), 3.07 (s, 3H), 2.81
(s, 5H), 2.04 (s, 15H), 1.79 (s, 3H). MS: m/e 576 (M+), 561
(M+–CH3). Anal. Calc. for C22H31SIrFe: C, 45.91; H,
5.43. Found: C, 46.22; H, 5.32.
1
(s), 1927 (vs), 1834 (vs, br) cmꢀ1. H NMR (CDCl3): d
6.57 (d, 1H), 5.84 (d, 1H), 3.96 (s, 5H), 2.82 (s, 3H),
2.44 (s, 3H), 2.14 (s, 15H). MS: 700 (M+–2CO), 561
(M+–Mn(CO)5). Anal. Calc. for C26H28O5SIrFeMn: C,
41.33; H, 3.74. Found: C, 40.69; H, 3.26.
2.2.15. Reaction of 2 with (l-C6H5S)(l-LiS)Fe2(CO)6
to give [Cp*Ir(C,S-2,5-Me2T)(l-C6H5S)(l-S)Fe2-
(CO)6]FeCp (16)
To a solution of (l-S2)Fe2(CO)6 (0.030 g, 0.087
mmol) in THF (10 mL) at ꢀ78 ꢁC was added 0.060
mL of 1.8 M LiC6H5 solution (0.11 mmol) with vigorous
stirring. The mixture was stirred at ꢀ78 ꢁC for 0.5 h.
The resulting emerald green solution of (l-C6H5S)(l-
LiS)Fe2(CO)6 [18] was then added to a solution of 2
(0.050 g, 0.071 mmol) dissolved in THF (20 mL) at
ꢀ78 ꢁC. The reaction solution was stirred at ꢀ78 to 0
ꢁC for 20 h during which time the dark solution gradu-
ally turned dark-red. After vacuum removal of the sol-
vent, the residue was chromatographed on Al2O3
(neutral) with hexanes:CH2Cl2 (10:1) as the eluant.
The brick-red band was collected. The solvent was re-
moved in vacuo, and the residue was recrystallized from
hexanes:CH2Cl2 at ꢀ80 ꢁC to yield 0.048 g (69%, based
on 2) of pink-red crystalline 16 (m.p. 70–72 ꢁC, dec). 1H
NMR (CDCl3): d 7.37–7.17 (m, 5H, C6H5), 6.67 (d, 1H),
5.78 (d, 1H), 5.44 (m, 2H, CH2Cl2), 4.97 (s, 5H), 2.68 (s,
3H), 2.29 (s, 3H), 1.88 (s, 15H). IR(hexane) m(CO): 2064
(s), 2024 (vs), 2011 (m), 1995 (s) cmꢀ1. MS: m/e 561
(M+-(l-C6H5S)(l-S)(Fe2(CO)6)). Anal. Calc. for
C33H33O6S3IrFe3CH2Cl2: C, 38.29; H, 3.31. Found: C,
37.62; H, 3.39.
2.3. X-ray crystal structure determinations of complexes
3, 9, and 12
The single crystals of complexes 3, 9, and 12 suitable
for X-ray diffraction study were obtained by recrystalli-
zation from hexanes:CH2Cl2 solution at ꢀ80 ꢁC. The
single crystals were mounted on a glass fiber and sealed
with epoxy glue. The X-ray diffraction intensity data for
3, 9, and 12 were collected with Enraf-Nonius CAD4,
Siemens P4RA, and Rigaku AFC7R diffractometers,
respectively.
The structures of complexes 3, 9, and 12 were solved
by direct methods and expanded using Fourier tech-
niques. For 3, many non-hydrogen atoms were placed
directly from the E-map. The remaining atoms were lo-
cated in several difference-Fourier maps. One molecule
of CH2Cl2 was located in addition to the subject of
study. For 9 and 12, all non-hydrogen atoms were
placed directly from the E-map. For the four com-
plexes, all non-hydrogen atoms were refined with aniso-
tropic displacement parameters. The hydrogen atoms
for complexes 3 and 12 were treated as riding-atoms
with individual isotopic displacement parameters. For
2.2.16. Reaction of 2 with HgCl2 to give
[Cp*Ir(C,S-2,5-Me2T)FeCp(HgCl2)]PF6 (17)
To a solution of 2 (0.020 g, 0.028 mmol) in THF (20
mL) at ꢀ30 ꢁC was added 0.015 g (0.055 mmol) of
HgCl2. The mixture was stirred at ꢀ30 to 20 ꢁC for
48 h during which time the dark purple solution turned

1628
J. Chen et al. / Inorganica Chimica Acta 358 (2005) 1623–1634
complex 9, the hydrogen atoms were included but not
refined. All calculations were performed using the
of 2 ranged from 32% to 80% depending on the starting
complex.
SHELXTL-PLUS programs or the TEXSAN crystallo-
graphic software package of the Molecular Structure
Corporation.
[CpFe(arene)]PF6 + Cp* Ir
S
1
Crystallographic data and procedures for data collec-
tion and reduction for complexes 3, 9, and 12 are given
in Table 1. Selected bond lengths and angles are listed in
Tables 2 and 3. Molecular structures of 2, 3, 9, and 12
are given in Figs. 1–4, respectively. Structure solution
details were previously reported for 2 [4].
–
+ PF6
hν (UV)
– arene
Cp* Ir
ð5Þ
S
Fe
2
arene = η6-C6H5Cl, η5-T, or η5-2,5-Me2T
3. Results and discussion
The highest yield is achieved with the g6-C6H5Cl
complex which suggests that Cp*Ir(C,S-2,5-Me2T) (1)
is more strongly coordinating than C6H5Cl. The molec-
ular structure of 2 determined by X-ray diffraction stud-
ies [4], shows (Fig. 1) that the six-membered
3.1. Synthesis and characterization of
f[g6-Cp*Ir(C,S-2,5-Me2T)]FeCpgPF6 (2)
Complex 2 was prepared by UV-photolytic substitu-
tion of the g6-C6H5Cl, g5-thiophene (T) or g5-2,5-dim-
ethylthiophene (2,5-Me2T) ligand in CpFe(arene)+ by
Cp*Ir(C,S-2,5-Me2T) (1) according to Eq. (5). Yields
˚
iridathiabenzene ring is planar ( 0.07 A) as it is in 1,
and the bond distances within this ring are the same,
within experimental error, as those in uncoordinated 1.
Table 1
Crystal data and experimental details for complexes 3, 9 and 12
3
9
12
Formula
C28H45Cl2F6P2SirFe
908.59
P1/c (No. 14)
C21H29SIrFe
561.59
P21/c (No. 14)
C25H28O4SCoIrFe
731.5
P21/n (No. 14)
Formula weight
Space group
Unit cell dimensions
˚
a (A)
11.059(2)
14.539(2)
20.875(4)
90.79(1)
3356.1(10)
4
8.308(4)
15.698(7)
15.934(5)
101.31(3)
2037(1)
9.555(2)
21.989(6)
12.787(2)
104.07(2)
2606.0(9)
4
˚
b (A)
˚
c (A)
b (ꢁ)
3
˚
V (A )
Z
4
1.830
Dcalc (g/cm3)
1.798
1.865
Crystal size (mm)
Absorption coefficient (mmꢀ1
F(0 0 0)
0.55 · 0.50 · 0.45
14.439
1800
0.20 · 0.20 · 0.30
0.36 · 0.20 · 0.08
6.383
1424
)
1096
˚
˚
˚
Radiation (monochromated in incident beam)
Diffractometer
Cu Ka (k = 1.54178 A)
Siemens P4RA
ꢀ60(1)
Mo Ka (k = 0.71069 A)
Rigaku AFC7R
20.0
Mo Ka (k = 0.71073 A)
Enraf-Nonius CAD4
Temperature (ꢁC)
Scan method
ꢀ60(1)
2h–h
x–2h
2h–x
Data collected range, 2h(ꢁ)
No. of unique data, total
With I > 3.00r(I)
No. of parameters refined
Correction factors, maximum minimum
Ra
3.70–56.96
4506
5–50.0
3296
2501
4.0–50.0
4594
3741 (I P 2r(I))
391
2997 (F P 4.0r(F))
309
217
0.9050–1.2140
0.025
0.032c
1.27
0.00
0.435–1.000
0.0414
0.1055b
1.08
0.5474–0.6542
0.0595
0.0653a
1.61
0.005
Rw
Quality-of-fit indicatord
Largest shift/esd. final cycle
0.001
1.321
ꢀ
3
Largest peak (e /A )
˚
ꢀ
1.11
ꢀ0.47
2.90
ꢀ3.65
3
Minimum peak (e /A )
˚
ꢀ2.198
a
R = RiFoj ꢀ jFci/RjFoj.
2
2 0:5
b
wR2 ¼ ½R½wðj F 2o j ꢀF c2Þ ꢁ=R½wðF 2oÞ ꢁꢁ
.
c
Rw = [Rw(jFoj ꢀ jFcj)2/RWjFoj2]1/2; w = 1/r2(jFoj).
d
Quality-of-fit = [Rw(jFoj ꢀ jFcj)2/(Nobs ꢀ Nparameters)]1/2
.

J. Chen et al. / Inorganica Chimica Acta 358 (2005) 1623–1634
1629
Table 2
Selected bond lengths (A) and angles (ꢁ)a for 2, 3, and 12
Table 3
a
a
Selected bond lengths (A) and angles (ꢁ)a for 9
˚
˚
2
3
12
Ir(1)–Fe(1)
Ir(1)–S(1)
2.623(1)
2.374(2)
2.025(7)
2.035(7)
2.000(8)
2.020(8)
2.004(7)
2.006(7)
1.41(1)
1.40(1)
1.38(1)
1.52(1)
1.52(1)
2.262
Fe–S
Fe–C(2)
2.332(2)
2.091(9)
2.073(8)
2.097(8)
2.207(9)
2.758(1)
2.212(2)
2.004(8)
2.269(2)
2.043(8)
2.011(8)
2.041(7)
2.283(7)
2.348(5)
2.09(2)
2.06(2)
2.07(2)
2.20(2)
2.744(2)
2.211(5)
1.98(2)
Ir(1)–C(20)
Ir(1)–C(21)
Fe–C(3)
Fe–C(4)
Fe(1)–C(17)
Fe(1)–C(18)
Fe(1)–C(20)
Fe(1)–C(21)
C(17)–C(18)
C(18)–C(21)
C(17)–C(20)
C(16)–C(20)
C(19)–C(21)
Ir(1)–C(Cp*) (avg.)
Fe(1)–C(Cp) (avg.)
Fe–C(5)
Ir–Fe
Ir–S
Ir–C(5)
2.310(2)
2.085(7)
2.292(2)
1.735(8)
1.39(1)
1.42(1)
1.42(1)
1.51(1)
1.50(1)
2.275
Ir–P(31)
S–C(2)
1.742(9)
1.37(1)
1.41(1)
1.39(1)
1.51(2)
1.51(1)
2.204
1.67(2)
1.39(3)
1.43(3)
1.46(2)
1.52(3)
1.45(3)
2.213
C(2)–C(3)
C(3)–C(4)
C(4)–C(5)
C(1)–C(2)
C(5)–C(6)
Ir–C(Cp*) (avg.)
Fe–C(Cp) (avg.)
Co–C(CO) (avg.)
2.063
Fe(1)–Ir(1)–S(1)
S(1)–Ir(1)–C(20)
S(1)–Ir(1)–C(21)
Fe(1)–Ir(1)–C(20)
Fe(1)–Ir(1)–C(21)
C(20)–Ir(1)–C(21)
Ir(1)–C(20)–C(16)
Ir(1)–C(21)–C(19)
Fe(1)–C(20)–C(16)
Fe(1)–C(21)–C(19)
Ir(1)–C(20)–C(17)
Ir(1)–C(21)–C(18)
C(18)–C(17)–C(20)
C(17)–C(18)–C(21)
C(16)–C(20)–C(17)
C(18)–C(21)–C(19)
a
115.62(6)
84.6(2)
85.3(2)
2.047
2.031
2.038
1.731
49.1(2)
49.1(2)
78.6(3)
Fe–Ir–S
Fe–Ir–C(5)
S–Ir–C(5)
54.6(1)
52.4(3)
92.7(2)
114.6(7)
122.9(7)
127.8(8)
129.0(7)
129.5(6)
81.7(3)
118.4(6)
74.7(1)
116.9(3)
55.3(1)
52.6(5)
93.7(6)
116(2)
125(2)
126 (2)
129(2)
128(2)
81.8(6)
123(1)
73.9(2)
59.9(7)
122.3(5)
123.4(5)
128.1(6)
129.1(6)
114.0(6)
113.6(5)
115.1(6)
114.0(7)
122.4(6)
121.2(7)
79.8(2)
S–C(2)–C(1)
S–C(2)–C(3)
C(2)–C(3)–C(4)
C(3)–C(4)–C(5)
Ir–C(5)–C(4)
Ir–C(5)–Fe
Ir–C(5)–C(6)
Ir–S-Fe
117.5(6)
120.2(6)
124.3(7)
127.4(7)
128.3(5)
102.7(3)
117.5(5)
96.36(8)
117.3(3)
99.09(7)
93.8(2)
Ir–S–C(2)
S–Ir–P(31)
C(5)–Ir–P(31)
a
Estimated standard deviations in the least significant figure are
given in parentheses.
Estimated standard deviations in the least significant figure are
given in parentheses.
3.2. Addition of nucleophiles to iridium in
f[g6-Cp*Ir(C,S-2,5-Me2T)]FeCpgPF6 (2)
A series of phosphorus-donor and carbon-donor li-
gands react (Eq. (6)) with 2 below room temperature
to give adducts in which the ligand is bonded to the
iridium.
L
+, 0
Ir
+
Cp*
+ L0,–1
Cp* Ir
S
S
FeCp
FeCp
2
3 (L = PEt3), 4 (L = P(OEt)3), 5 (L = PPh2Me),
6 (L = PHPh2), 7 (L = CN–Bun), 8 (L = CN–)
ð6Þ
The products 3–8 were isolated in 66–85% yields and
characterized by their elemental analyses, 1H NMR
and mass spectra. The structure of 3, determined by
X-ray diffraction, shows (Fig. 2) that the PEt3 ligand
Fig. 1. Molecular structure of 2, showing the atom-numbering scheme.

1630
J. Chen et al. / Inorganica Chimica Acta 358 (2005) 1623–1634
Fig. 2. Molecular structure of 3, showing the atom-numbering scheme.
adds to the iridium on the opposite side of the six-mem-
bered ring from the CpFe+ unit. This same exo addition
occurred in the reaction of [g6-Cp*Ir(C,S-2,5-
Me2T)]Cr(CO)3 with PEt3 (Eq. (2)). The long Ir–Fe dis-
Fig. 3. Molecular structure of 9, showing the atom-numbering scheme.
cating that there is considerable delocalization in this
portion of the ring of both 2 and 3. The Ir–C(5) and
Ir–S bond distances are significantly longer in 3 than
in 2, suggesting that the addition of the PEt3 to Ir weak-
ens the bonding between Ir and the C(5) and S atoms.
The addition of PEt3 shortens the Fe bonds to S, C(2),
˚
tance (3.413 A) in 3 is non-bonding as compared with a
˚
bonding Ir–Fe distance (2.758(1) A) in 2.
The C–C bond distances (Table 2) in the iridathia-
benzene ring are the same, within experimental error,
in both 2 and 3. These C–C distances are all similar indi-
Fig. 4. Molecular structure of 12, showing the atom-numbering scheme.

J. Chen et al. / Inorganica Chimica Acta 358 (2005) 1623–1634
1631
C(3), and C(4), which suggests that these atoms in the
g5-iridathiabenzene in 3 are stronger donors toward
CpFe+ than in 2. In contrast to these shorter bond dis-
tances to Fe, the Fe–C(5) distance is longer in 3
fraction
studies
(Fig.
3),
shows
an
g5-
iridacyclopentadiene group coordinated to the Fe and
an SH ligand bound to the Ir; each metal center has an
18-electron count.
˚
˚
(2.283(7) A) than in 2 (2.207(9) A). It is not clear why
this distance is longer, but the Cr–C(5) distance in [g5-
Cp*Ir(C,S-2,5-Me2T)(PEt3)]Cr(CO)3 (the product in
Eq. (2)) is also longer than this same distance in [g6-
Cp*Ir(C,S-2,5-Me2T)]Cr(CO)3.
–
+ PF6
Cp* Ir
Et3BH–
+
S
–
HFe(CO)4
FeCp
LiPh
2
Because the structure of uncoordinated Cp*Ir(C,S-
2,5-Me2T)(PEt3) is not known, we compare the structure
of Cp*Ir(C,S-2,5-Me2T)(PMe2Ph) [19] with that of 3. In
the PMe2Ph complex, the C(2)–C(3)–C(4) bond dis-
tances in the 6-membered ring have a short (1.347(8)
Cp*
ð7Þ
Ir
RS
˚
˚
˚
A)–long (1.458(8) A)–short (1.330(6) A) pattern which
indicates that the p-bonds are localized, as described
earlier [3,19]. On the other hand, these C–C distances
FeCp
9 (R = H)
10 (R = Ph)
˚
in 3 are nearly all the same (1.37–1.41 A) indicating that
˚
The Ir–Fe bond (2.623(1) A) is relatively short as com-
˚
pared with that in 2 (2.758(1) A). The Ir–SH distance
˚
(2.374(2) A) is the same as those (2.370(2) and 2.380(2)
˚
A) in the previously reported Cp*Ir(PMe3)(SH)2 [20].
The Ir–SH distance is also similar to those in other
less-closely-related complexes containing Ir–SH groups
˚
[21]. The Ir–C bonds to C(20) (2.025(7) A) and C(21)
the ring is more delocalized when it is g5-coordinated to
CpFe+. This g5-coordination changes the Ir–S (2.310(2)
˚
A) and Ir–C(5) bonds (2.085(7) A) in 3 very little as
˚
˚
compared with those (2.348(1) and 2.074(5) A) in
Cp*Ir(C,S-2,5-Me2T)(PMe2Ph).
1
A comparison of the H NMR spectra of 2 and 3
shows that the difference between chemical shifts for
H(3) and H(4) is relatively small (ꢂ0.8 ppm) in 2. On
the other hand, this difference is substantially larger
(ꢂ3 ppm) in 3. In fact, this difference is also large (2–
3.6 ppm) in the other phosphorus ligand adducts 4–6,
where the ligand is P(OEt)3, PPh2Me, or PHPh2. It is
this relatively large difference in the H(3)–H(4) chemical
shifts that leads to the conclusion that the C„N–Bun
(ꢂ2.7 ppm) and CNꢀ (ꢂ2.9 ppm) adducts, 7 and 8, also
have the same structure (Eq. (6)).
˚
(2.035(7) A) in the iridacyclopentadiene ring are dis-
˚
tinctly shorter than those (2.080(5), 2.081(5) A) in D
[22]. While the C–C distances in the iridacyclopentadi-
ene ring in D have alternating short-long-short distances
˚
(1.326(8), 1.445(9), 1.345(9) A), these distances (1.38(1),
˚
1.41(1), 1.40(1) A) in 9 are very similar. This difference
in C–C bond distance patterns was also observed (see
Section 3.2) in the comparison of C–C distances in the
iridathiabenzene ring of Cp*Ir(C,S-2,5-Me2T)(PMe2Ph)
and 3, where the g5–C,S-2,5-Me2T ring in 3 has nearly
equal C–C distances. Thus, g5 complex formation of
both the iridathiabenzene and iridacyclopentadiene
rings causes delocalization of the bonding in the
C–C–C–C portion of the ring.
The difference between the H(3) and H(4) chemical
shifts in Cp*Ir(C,S-2,5-Me2T)(PMe2Ph) is also small
(ꢂ0.5 ppm), which is characteristic of the other
Cp*Ir(C,S-2,5-Me2T)(PR3) adducts, where PR3 = PMe3
PMePh2, PPh3, or P(OPh)3 [19]; in this series of com-
plexes, the difference between the H(3) and H(4) chemi-
cal shifts is only 0.2–0.5 ppm. However, when
Cp*Ir(C,S-2,5-Me2T)(PEt3) is g5-coordinated to CpFe+
in 3, H(3) and H(4) are separated by ꢂ3 ppm. Although
the origin of this large separation upon coordination to
CpFe+ is not obvious, it is helpful for the assignment of
Cp*
Ir
C
O
D
1
structures to adducts with this H NMR signature.
3.3. Addition of nucleophiles to sulfur in
f[g6-Cp*Ir(C,S-2,5-Me2T)]FeCpgPF6 (2)
The 1H NMR spectrum of 9 shows equivalent methyl
groups (2.90 ppm) and C–H hydrogens (5.31 ppm) in
the iridacyclopentadiene ring, which is consistent with
the solid state structure. The Ir–SH signal occurs upfield
at –3.30 ppm, which is similar to that (–1.93 ppm) for
Cp*Ir(PMe3)(SH)2 [20] and is in the range typical of
M–SH groups [21].
Unlike the nucleophiles described in the previous sec-
tion, Et3BHꢀ reacts below room temperature with 2 to
give a product 9 (63% yield) in which Hꢀ has added to
the S of the coordinated iridathiabenzene ring, and the
sulfur is cleaved from the ring to give a terminal SHꢀ li-
gand (Eq (7)). The structure of 9, established by X-ray dif-
Complex 9 is also formed (38% yield) in the reaction
of HFe(CO)4ꢀ with 2 below room temperature. Another

1632
J. Chen et al. / Inorganica Chimica Acta 358 (2005) 1623–1634
product 11 whose composition corresponds to
[Cp*Ir(C4Me2H2)(H)Fe(CO)4]FeCp on the basis of its
elemental analysis and parent ion in the mass spectrum,
Rather than obtaining products resulting from nucleo-
philic addition to the g6-iridathiabenzene ligand, only
exchange of the PF6 anion for the metal carbonyl an-
ꢀ
1
is also formed. Like 9, its H NMR spectrum shows
ion occurred in yields ranging from 30% to 76%. The
ꢀ
equivalent methyl (2.81 ppm) and C–H (4.84 ppm) pro-
tons, which suggests the presence of an iridacyclopent-
adiene unit. The fact that it is formed along with 9
and has the composition of a 1:1 adduct of 9 and
Fe(CO)4 suggests that its structure, may be related to
CoðCOÞ salt 12 was obtained as crystals that were
4
suitable for X-ray diffraction studies (Fig. 4). The struc-
tural parameters (bond distances and angles) for the
{[g6-Cp*Ir(C,S-2,5-Me2T)]FeCp}+ cation in 12 are
nearly identical (Tꢀable 2) to those of the same cation
1
that of 9. The presence of a H NMR peak at –25.38
in 2. The CoðCOÞ anion in 12 has a tetrahedral struc-
4
ppm corresponding to one proton suggests that there
is a metal–metal bridging hydride ligand. Unfortunately,
we were unable to obtain X-ray quality crystals for a
definitive structure determination.
ture with average C–Co–C angles of 109.4ꢁ (average
deviation = 1.1ꢁ). The Co–CO bond distances average
1.73 A. All of these structural parameters are very sim-
˚
ilar to those reported for CoðCOÞ ꢀ in other compounds
4
In a reꢀaction analogous to that of Et3BHꢀ and
[23].
HFeðCOÞ (Eq. (7)), LiPh reacts with 2 below room
The 1H NMR spectrum of 12 in CDCl3 shows signals
for the inequivalent methyl groups at 3.17 and 2.95 ppm
and the C–H groups at 6.74 d and 5.96 d ppm, which are
very similar to those of 2 in CDCl3 at 3.15, 2.96, 6.81 d,
5.99 d ppm. It is the similarity of the chemical shifts and
splittings of these peaks that allows us to assign the same
structure to the cation in 13, which must therefore con-
4
temperature to give red crystals of 10 in 50% yield.
Although its structure was not determined by X-ray
studies, its elemental analyses and mass spectrum (which
shows M+) are consistent with the proposed composi-
tion. Especially important for the structural assignment
are the equivalent methyl and C–H groups of the irida-
1
1
ꢀ
cyclopentadiene ring in the H NMR spectrum. More-
tain the FeCoðCOÞ anion. The H NMR spectrum of
4
over, the chemical shifts of the methyl and C–H
groups in 9 and 10 are nearly identical (2.90, 5.31 ppm
in 9 vs. 2.93, 5.32 ppm in 10).
Although the mechanism for the reactions in Eq. (7)
is not obvious, one possible pathway is direct attack of
Hꢀ or Phꢀ on the sulfur in the iridathiabenzene which
is activated to such an attack by the cationic CpFe+
unit. Subsequent cleavage of the C–S bond and forma-
tion of the Ir–C bond gives the product 9 or 10.
14 is also essentially the same as those of 2, 12, and 13,
which means that the Iꢀ in 14 is simply the anion in the
compound.
It is surprising that CoðCOÞ ꢀ; FeCoðCOÞ ꢀ, and Iꢀ
4
8
do not attack the cation in 2, while the other nucleo-
philes (Eqs. (6) and (7)) do. On the other hand,
ꢀ
MnðCOÞ does react with 2 to give a product 15 whose
5
analysis indicates that it has the composition {[g6-
Cp*Ir(C,S-2,5-Me2T)]FeCp}Mn(CO)5. However, the
positions of the methyl groups at 2.82 and 2.44 ppm
and C–H groups at 6.57 d and 5.84 d are distinctly dif-
ferent from those of the cation in 2, 12, 13, and 14; they
are also different than those of 8 in which the CNꢀ has
3.4. Exchange of the PF ꢀ6 anion in
f[g6-Cp*Ir(C,S-2,5-Me2T)]FeCpgPF6 (2)
ꢀ
Considering the reactivities of 2 toward phosphorus,
carbon and hydride nucleophiles shown in Eqs. (6) and
(7), we exploredꢀreactions of 2 witꢀh the metal carbonyl
anions CoðCOÞ and FeCoðCOÞ [Eq. (8)]. The reac-
added to the Ir. Therefore, MnðCOÞ does react with
5
the cation in 2, but the structure of the product 15 is un-
known because suitable crystals for X-ray diffraction
could not be obtained.
4
8
tions were performed under conditions (below room tem-
perature) very similar to those used in Eqs. (6) and (7).
Another metal carbonyl anion (l-PhS)(l-S)Fe2(Co)6,
that is known [17,24] to act as a nucleophile, also reacts
with 2. The product 16 has the composition [Cp*Ir(C,S-
2,5-Me2T)(l-PhS)(l-S)Fe2(CO)6]FeCp as established by
+ PF6
–
1
–
Cp* Ir
elemental analyses. Its H NMR spectrum shows peaks
+
Co(CO)4
FeCo(CO)8
I–
S
–
at 2.68 and 2.29 ppm for the inequivalent methyl groups
and at 6.67 d and 5.78 d ppm for the inequivalent C–H
protons. However, we were unable to obtain X-ray qual-
ity crystals for 16 that would allow its structure to be
established.
FeCp
2
+ X–
–
ð8Þ
–PF6
Cp* Ir
S
3.5. Other Reactions of
f[g6-Cp*Ir(C,S-2,5-Me2T)]FeCpgPF6 (2)
FeCp
–
12 (X– = Co(CO)4
13 (X– = FeCo(CO)8
14 (X– = I–)
)
–
)
From the reaction of 2 with HgCl2 in THF was iso-
lated a compound 17 whose composition [Cp*Ir(C,S-

J. Chen et al. / Inorganica Chimica Acta 358 (2005) 1623–1634
1633
2,5-Me2T)FeCp(HgCl2)]PF6THF includes one molecule
1
of THF, which was identified in the H NMR spectrum
a –SH or –SPh ligand and an iridacyclopentadiene unit
(Eq. (7)). This latter reaction represents a very different
type of reactivity for the g6-Cp*Ir(C,S-2,5-Me2T) ligand
than has been previously reported.
of 17. This spectrum also shows inequivalent methyl
groups (3.32, 3.06 ppm) and C–H groups (7.03 d, 6.50
d) with chemical shifts that are downfield of the analo-
gous signals (3.15, 2.96, 6.81 d, 5.99 d ppm) in 2. In
addition, the Cp* methyl groups (2.53 ppm) and Cp pro-
tons (5.01 ppm) are downfield of the corresponding
peaks (2.14, 4.46 pm) in 2. These significant downfield
shifts of both the Cp* and Cp ligands suggest that both
the Ir and Fe metals are oxidized upon reaction with
HgCl2. Therefore, a possible structure for 17 is one
resulting from oxidative-addition of HgCl2 across the
Ir–Fe bond to give a product with one of the –HgCl
and –Cl ligands bound to each of the metal atoms. Lack
of good crystals prevented its structure from being
established definitively.
4. Supplementary material
Crystallographic data for the structural analyses have
been deposited with the Cambridge Crystallographic
Data Centre, CCDC Nos. 254454 (3), 254455 (9),
254456 (12). Copies of this information may be obtained
from The Director, CCDC, 12 Union Road, Cambridge,
CB2 1EZ, UK (fax: +44 1223 336033; e-mail: deposit@
ccdc.cam.ac.uk or www.ccdc.cam.ac.uk).
With the goal of cleaving the Ir–Fe bond in 2 by
reduction with Na/Hg and then methylating the result-
ing anion, the sequence of reactions in Eq. (9) was per-
formed. The final product 18 was isolated in 41% yield
and has a composition that corresponds to [Cp*Ir(C,S-
2,5-Me2T)]FeCp(Me) on the basis of its elemental anal-
yses and parent ion in the mass spectrum.
Acknowledgments
The authors thank the US Department of Energy,
Office of Basic Energy Sciences, Division of Chemical
Sciences, under contract W-7405-Eng-82 with Iowa
State University. We also thank Mr. Jie Su, Shanghai
Institute of Organic Chemistry, Chinese Academy of
Sciences, Shanghai, PR China, for the crystal structure
determination of compound 12.
–
Me3O+
2 Na/Hg
2
Cp*Ir
18
ð9Þ
THF
S
°
–25 C
Cp
Fe
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