Iridium-fluorobenzenethiolato complexes: Crystal structures of [Ir(SC6F5)(CO)(PPh3)2], [Ir3(μ-SC6F5)3(μ-CO)(CO) 4(PPh3)2] and [Ir(SC<s

Article abstract of DOI:10.1016/S0277-5387(98)00379-9

Iridium-fluorobenzenetiolate complexes of general formula [Ir(SR_F)(CO)(PPh₃)₂], (R_F=C₆F₅ 1a, C₆HF₄-4 1b, C₆H₄F-4 1c, and C₆H₄

Full text of DOI:10.1016/S0277-5387(98)00379-9

Polyhedron 18 (1999) 959–968
Iridium–fluorobenzenethiolato complexes: crystal structures of
[Ir(SC6F5)(CO)(PPh3)2], [Ir3(m-SC6F5)3(m-CO)(CO)4(PPh3)2] and
[Ir(SC6F5)(h-O2)(CO)(PPh3)2]
a
b
c
d
b
c
e,
*
˜
A. Antinolo , I. Fonseca , A. Ortiz , M.J. Rosales , J. Sanz-Aparicio , P. Terreros , H. Torrens
aU. de Castilla-La Mancha, Campus Universitario, 13071 Ciudad Real, Spain
bInstituto Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain
c
´
Instituto de Catalisis y Petroleoquimica, CSIC, Campus UAM, Cantoblanco 28049 Madrid, Spain
d
´
CINVESTAV, Instituto Politecnico Nacional, A.P. 14-740, 07000 Mexico D.F., Mexico
e
´
´
Facultad de Quımica, UNAM, Cd. Universitaria, 04510 Mexico D.F., Mexico
Received 5 February 1998; accepted 14 September 1998
Abstract
Iridium–fluorobenzenetiolate complexes of general formula [Ir(SRF)(CO)(PPh3)2], (RF5C6F5 1a, C6HF4-4 1b, C6H4F-4 1c, and
C6H4CH3-2 1d), were prepared by methatetical reactions with Tl(SRF) or HSRF. The unexpected trimetallic compound [Ir3(m-
SC6F5)3(m-CO)(CO)4(PPh3)2] 2 was also isolated when RF5C6F5. Oxidative addition of fluorothiols to the corresponding Ir(I)
precursors, afforded the compounds [Ir(H)(Cl)(SRF)(CO)(PPh3)2] (RF5C6F5 3a, C6HF4-4 3b and C6H4F-4 3c) and
[Ir(H)(SRF)2(CO)(PPh3)2])] (RF5C6F5 4a, C6HF4-4 4b and C6H4F-4 4c). Irreversible oxygen uptake by compounds 1 gives rise to the
oxo-derivatives [Ir(SRF)(O2)(CO)(PPh3)] (RF5C6F5 5a, C6HF4-4 5b, C6H4F-4 5c and C6H4CH3-2 5c). The crystal and molecular
structures of [Ir(SC6F5)(CO)(PPh3)2] 1a, [Ir3(m-SC6F5)3(m-CO)(CO)4(PPh3)2] 2 and [Ir(SC6F5)(h2-O2)(CO)(PPh3)2] 5a were
determined by X-ray diffraction crystallography. Compound 2 contains an asymmetrical Ir3S3 ring with one iridium–iridium bond
2
˚
(2.665(1)A) doubly bridged by CO and (C6F5S) .
1999 Elsevier Science Ltd. All rights reserved.
Keywords: Fluorothiolato; Iridium; Dioxygen; X-ray
A great amount of attention has been paid to the
synthesis, characterisation and study of thiolate-containing
bi or polynuclear complexes of the platinum group metals.
Such complexes have rendered interesting, sometimes
unique, examples of mixed oxidation states [1], unusual
geometries [2–8], agostic bonds [9,10], neutral–ionic
equlibrium [11], etc. This class of compounds are also
relevant models to study co-operative effects between
metals in processes like conventional [12] or stereo-selec-
tive catalysis [13,14]. On the other hand, interest on
monometallic thiolate derivatives has grown steadily over
recent years due to the role that they probably play in
processes such as the activation of small molecules
[15,16], metal-catalysed carbon–sulfur bond cleavage and
formation [17–27], desulfurization of thio-compounds
[28–37], etc. Following our interest in fluorinated thiolate
derivatives of transition metals [38–40], we have studied a
series of iridium compounds, including mono- and
bimetallic complexes, bearing RFS2 ligands with RF5
C6F5, C6HF4-4 and C6H4F-4. In this paper results re-
garding
the
compounds
[Ir(SRF)(CO)(PPh3)],
[Ir(H)(Cl)(SRF)(CO)(PPh3)], [Ir(H)(SRF)2(CO)(PPh3)]
and [Ir(SRF)(O2)(CO)(PPh3)] are discussed as well as
the X-ray crystal and molecular structures of
[Ir(SC6F5)(CO)(PPh3)2], [Ir3(m-SC6F5)3(m-CO)(CO)4-
(PPh3)2] and [Ir(SC6F5)(h2-O2)(CO)(PPh3)]. A part of this
work has been the subject of a preliminary communica-
tion [1].
1. Experimental
All reactions were routinely performed under dry,
oxygen-free dinitrogen atmospheres, using standard
Schlenk-tube techniques. Solvents were dried and degassed
using published techniques [41], stored over molecular
sieves and distilled under nitrogen prior to use. Thin layer
chromatography (TLC) (Merck, 5X7.5cm2 Kieselgel 60
*
Corresponding author.
0277-5387/99/$ – see front matter
PII: S0277-5387(98)00379-9
1999 Elsevier Science Ltd. All rights reserved.

˜
A. Antinolo et al. / Polyhedron 18 (1999) 959–968
960
F254) was used when possible to monitor the progress of
the reaction under study.
Literature methods were used for the synthesis of [(Ir(m-
SC6F5)(CO)2j2] [1], Pb(SC6F5)2 [42], and TlSC6F5 [42].
All other chemicals were commercial products used as
received without further purification.
All metal complexes were collected on sintered-glass
frits and washed with the appropriate solvents before being
dried in a stream of nitrogen.
Complexes were characterised by infrared spectra re-
corded over the 4000–200 cm21 range on a Perkin–Elmer
1330 with a Data Station 1300 using samples mulled in
Nujol between KBr plates or as CsI pellets. Data are
expressed in wavenumbers (cm21) with relative intensities
(s5strong, m5medium, w5weak)
Yield 89%. IR n(CO) 1992.1 cm21 1H NMR: 6.73,
.
SC6H4F-4; 19F NMR: 2117.3 Fp; 31P NMR: 27.36. MS
(m/e) Found: 871, Calc: 871.
[Ir(SC6H4Me-2)(CO)(PPh3 )2 ] 1d. Yellow. Anal. Found:
C, 60.8; H, 3.7. C44H37IrOP2S. Calc.: C, 60.9; H, 4.3.
Yield 90%. IR n(CO) 1948.0 cm21. 1H NMR: 6.43, 2.82
SC6H4Me-2; 31P NMR: 26.22. MS (m/e) Found: 868,
Calc.: 868.
[Ir3(SC6F5 )3(CO)5(PPh3 )2 ] 2. A solution of P(C6H5)3,
(0.2g, 1.0 mmol) in acetone (15 ml) was added dropwise
to [hIr(SC6F5)(CO)2j2] (0.44g, 0.5 mmol) dissolved in 20
ml of acetone. The solution rapidly turned yellow and it
was stirred for 1 h. The solution was concentrated to ca. 5
mL under vacuum. Toluene (5mL) was added and the
solution keep at ca. 08C for 24 h. Two distinct crystalline
products separated, yellow crystals corresponding to com-
pound (Ir(SC6F5)(CO)(PPh3)2] 1a and reddish crystals of
(Ir3(SC6F5)3(CO)5(PPh3)2] 2.
1H, spectra were obtained on a Bruker ACP 200 (200.13
MHz) spectrometer in the deuterated solvent. 19F, spectra
were measured with a SDS-360 MHz operating at 282.23
MHz, by Spectral Data Services Inc. (Illinois USA). 31P-
h1Hj, spectra were obtained on a Bruker ACP 200 spec-
trometer operating at 81.01 MHz. Chemical shifts are
relative to internal TMS d50 (1H), external CFCl3 d50
(19F) and external 85% H2PO4 d50 (31P) with downfield
values reported positive. A standard variable-temperature
unit was used to control the probe and it was checked
periodically by thermocouple to ensure temperature read-
ings were within 618C.
[IrH(Cl)(SC6HF4-4)(CO)(PPh3 )2 ] 3b. A solution of
HSC6HF4-4, (0.095g, 0.5 mmol) in acetone (15 mL) was
added dropwise to a suspension of (IrCl(CO)(PPh3)2]
(0.40g, 0.5 mmol) in 20 mL of acetone. The suspension
mixture rapidly turns white and it was magnetically stirred
for 1 hour. After concentrating to ca. 5 mL under vacuum
it was filtered off to separate [IrH(Cl)(SC6HF4-
4)(CO)(PPh3)2] 3b. Anal. Found: C, 53.4; H, 3.2.
C4 3H3 2ClF4IrOP2S. Calc.: C, 53.7; H, 3.4. Yield 78%. IR
1
((CO) 2024.0; n(MH) 2218.0 cm21. H NMR: 214.7
Elemental analyses were determined by Galbraith Labs.
Inc., USA.
M-H, J(H-P)511.3; 6.7, SC6HF4-4; 19F NMR: 2127.8 Fo,
2138.6 Fm; 31P NMR: 27.7. MS (m/e) Found: 962, Calc.:
962.
FAB spectra were obtained on a JEOL SX102 mass
spectrometer operated at an accelerating voltage of 10 KV.
Samples were desorbed from nitrobenzyl alcohol matrix
using 3KeV xenon atoms. Mass measurements in FAB are
performed at 3000 resolution using magnetic field scans
and the matrix ions as the reference material, or electric
field scans with the sample peak bracketed by two (poly-
ethylene glycol or cesium iodide) reference ions.
Preparation of complexes 1 to 5. Since synthetic
experimental set-up were relatively similar for each class
of compounds, only a representative example of each type
is described as follows.
[IrH(Cl)(SC6H4F-4)(CO)(PPh3 )2 ] 3c. White. Anal.
Found: C, 57.0; H, 3.9. C43H35ClFIrOP2S. Calc.: C, 56.9;
H, 3.9. Yield 84%. IR n(CO) 2025.6; n(MH) 2218.7
cm21. 1H NMR: 216.15, MH, J(H-P)512; 6.10, SC6H4F-
4; 19F NMR: 2119.0, Fp; 31P NMR: 213.99. MS (m/e)
Found: 908, Calc.: 908.
[IrH(SC6HF4-4)2(CO)(PPh3 )2 ] 4b.
HSC6HF4-4, (0.097g, 0.5 mmol) in acetone (15 mL) was
added dropwise to suspension of (Ir(SC6HF4-
A
solution of
a
4)(CO)(PPh3)2] (0.47g, 0.5 mmol) in 20 mL of acetone.
The suspension mixture rapidly turns white and it was
magnetically stirred for 1 h. After concentrating to ca. 5
mL under vacuum it was filtered off to separate
(IrH(SC6HF4-4)2(CO)(PPh3)2] 4b. White. Anal. Found:
C, 52.8; H, 2.8. C49H33F8IrOP2S2. Calc.: C, 53.1; H, 3.0.
[Ir(SC6HF4-4)(CO)(PPh3 )2 ] 1b.
A
solution of
Tl(SC6HF4-4), (0.195g, 0.505 mmol) in acetone (15 ml)
was added dropwise to (IrCl(CO)(PPh3)2] (0.39g, 0.5
mmol) dissolved in 20 ml of acetone. The mixture rapidly
turns yellow while a white solid precipitates off. The
yellow solution was stirred for 1 h. TlCl was filtered off
and the solution concentrated to ca. 5 ml under vacuum.
Slow evaporation of the solvent renders yellow crystals of
[Ir(SC6HF4-4)(CO)(PPh3)2] 1b. Anal. Found: C, 55.5; H,
3.4. C43H3 1F4IrOP2S. Calc.: C, 55.7; H, 3.4. Yield 91%.
1
Yield 82%. IR n(CO) 2059.0; n(MH) 2225.0 cm21. H
NMR: 214.9 M-H, J(H-P)59.1; 6.65, SC6HF4-4; 19F
NMR: 2128.5 Fo, 2139.6 Fm; 31P NMR: 26.9. MS (m/e)
Found: 1108, Calc.: 1108.
[IrH(SC6H4F-4)2(CO)(PPh3 )2 ] 4c. White. Anal. Found:
C, 58.7; H, 3.5. C49H39F2IrOP2S2. Calc.: C, 58.9; H, 3.9.
1
IR n(CO) 1965.4 cm21. H NMR: 6.49, SC6HF4; 19F
1
Yield 87%. IR n(CO) 2220.0; n(MH) 2045.0 cm21. H
NMR: 2128.5 Fo, 2139.4 Fm; 31P NMR: 24.98. MS (m/e)
Found: 925, Calc: 925.
NMR: 215.7, MH, J(H-P)510.9; 6.12, SC6H4F-4; 19F
NMR: 2122.3, Fp; 31P NMR: 28.45. MS (m/e) Found:
1000, Calc.: 1000.
[Ir(SC6H4F-4)(CO)(PPh3 )2 ] 1c. Yellow. Anal. Found:
C, 59.9; H, 4.3. C43H34FIrOP2S. Calc: C, 59.2; H, 3.9.

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A. Antinolo et al. / Polyhedron 18 (1999) 959–968
961
[Ir(SC6HF4-4)(O2 )(CO)(PPh3 )2 ] 5b. Dry oxygen was
bubbled through a solution of [Ir(SC6HF4-4)(CO)(PPh3)2]
(0.46g, 0.5 mmol) in 20 mL of acetone. The solution turns
yellow and after ca. 1 hour it concentrated to ca. 5 mL
under vacuum. Slow evaporation of this solution renders
(Ir(SC6HF4-4)(O2)(CO)(PPh3)2] 5b. Yellow. Anal.
Found: C, 54.6; H, 3.5. C43H31F4IrO3P2S. Calc.: C, 53.9;
NMR: 6.10, SC6H4F-4; 19F NMR: 2118.4, Fp; 31P NMR:
2.93. MS (m/e) Found: 903, Calc.: 903.
[Ir(SC6H4Me-2)(O2 )(CO)(PPh3 )2 ] 1d. Yellow. Anal.
Found: C, 59.9; H, 4.4. C4 4H3 7IrO3P2S. Calc.: C, 58.7; H,
4.1. Yield 85%. IR n(CO) 1994.0, n(O2) 848.0 cm21. 1H
NMR: 6.42, 2.31, SC6H4Me-2; 31P NMR: 1.01. MS (m/e)
Found: 900, Calc.: 900.
Single-Crystal X-Ray Structure Analysis. Details on
crystallographic data, data collection and structure refine-
ment for compounds 1a, 2 and 5a are listed in Table 1.
Due to the low quality of crystals the C-scan technique
gave no clear corrections and DIFABS was used as an
alternative.
H, 3.3. Yield 76%. IR ((CO) 1988.9; n(O2) 848.5 cm21
.
1H NMR: 6.72, SC6HF4-4; 19F NMR: 2126.6 Fo, 2137.7
Fm; 31P NMR: 6.71. MS (m/e) Found: 957, Calc.: 957.
[Ir(SC6H4F-4)(O2 )(CO)(PPh3 )2 ] 5c. Yellow. Anal.
Found: C, 57.1; H, 3.8. C43H34FIrO3P2S. Calc.: C, 57.1;
H, 3.8. Yield 87%. IR ((CO) 1988.0; ((O2) 850.0 cm21. 1H
Table 1
Crystallographic data, data collection and structure refinement
Compound
1a
2
5a
Crystal data
Empirical formula
Molecular weight
Space group
Unit cell
determination
C43H30OSF5P2Ir
943.43
C59H30O5S3F15P2Ir3
1838.65
C43H30O3SF5P2Ir
975.93
Triclinic, P1
¯
Monoclinic, P21/n
Least-squares
fit from 25
reflexions
(4,2u ,458)
0.430.430.3
12.082(3)
15.473(3)
20.048(7)
90.0
92.97(2)
90.0
3743(2)
4
1.67
Monoclinic, P21/a
Lease-squares
fit from 100
reflexions
(4,2u ,468)
0.3830.2430.21
16.229(1)
30.817(4)
12.758(1)
90.0
Least-squares
fit from 100
reflexions
(4,2u ,438)
0.2830.2130.20
19.141(5)
11.817(2)
9.885(1)
68.57(1)
108.99(1)
110.54(2)
1898.5(7)
2
Crystal size mm
˚
a, A
˚
b, A
˚
c, A
a, deg
b, deg
112.18(1)
90.0
5908(1)
g, deg
3
˚
V, A
Z
4
rcalc gcm23
F(000)
m, cm21
2.0669
2720
69.64
1.7072
960
37.01
1856
37.48
Experimental data
Four circle
Diffractometer
Radiation
CAD4-Enraf-Nonius
Philips PW 1100
Bisecting geometry
MoKa
Philips PW 1100
Bisecting geometry
MoKa
MoKa
˚
˚
˚
(l50.71069A)
(l50.71069A)
(l50.71069A)
Scan type
v/2u
v/2u
v/2u
u limits, deg
Data collected
Unique data used
1-25
7040
4143
2–22
7290
5806
(I.2s(I))
219/19, 0/37, 0/15
2–25
6746
5340
(I.3s(I))
(Fo)2.3s(Fo)2
214/14; 0/18; 0/23
Range of hkl
222/22, 214/14, 0/12
Solution and refinement
Solution
Refinement
H atoms
Absorption correction
Direct methods
L.s. on Fobs
Calculated
DIFABS [43]
1.19–0.88
0.032
Direct methods
L.s. on Fobs
Calculated
DIFABS [43]
1.39–0.75
0.058
Direct methods
L.s. on Fobs
Calculated
DIFABS [43]
2.004–0.656
0.106
Ra
Rwb
0.035
0.084
0.131
Goodness of fit, s
1.57
0.364
0.653
No. of variables
Drmax (e/A )
571
0.74
775
1.60
871
5.84
3
˚
aR5SuuFou2uFcuu/SuFou. bRW 5[Sw(uFou2uFcu)2 /SwuFou2]1 / 2
.

˜
A. Antinolo et al. / Polyhedron 18 (1999) 959–968
962
[Ir(SC6F5)(CO)(PPh3)2] 1a. An absorption correction
described for compound 2, was applied in order to give no
trends in ,D2F. vs. ,uFou. and ,sin u/l..The final
difference map showed two large peaks (5.84 and 5.43 e
following the DIFABS procedure [43] was applied to
isotropically refined data. Maximum and minimum absorp-
tion factors 1.19 and 0.88 respectively. The positions of the
hydrogen atoms were calculated geometrically and intro-
duced in the refinement with all parameters fixed. A
2
3) in the neighbourhood of the Ir atom. Final R and Rw
˚
A
values 0.106 and 0.131. Computer and programs: VAX
11/750, SIR92 [48], XRAY80, DIFABS, PESOS [49],
PARST and CRYSTALS [50]. Anomalous dispersion and
scattering factors: International Tables for X-ray Crys-
tallography [47].
Chebychev
Polynomial
weighting
scheme
(w5
(weight)*(12(DF/6/*(F)**2)**2) was used. Final R and
Rw values 0.032 and 0.035. All calculations were carried
out using CRYSTALS [50,52].
[Ir3(SC6F5)3(CO)5(PPh3)2] 2. An absorption correction
following the DIFABS procedure [43] was applied to
isotropically refined data. Maximum and minimum absorp-
tion factors 1.39 and 0.75 respectively. The positions of the
hydrogen atoms were calculated geometrically and intro-
duced in the refinement with all parameters fixed. An
empirical weighting scheme of type w5w1?w2, w151/s21;
w251/s22; s15a1buFou, s225c1dsin u/l was applied, the
a, b, c and d coefficients being those to eliminate trends in
,D2F. vs. ,DuFou. and ,sin u/l.. Final R value
0.058. Computer and programs: VAX 11/750, DIRDIF
[44], XRAY80 [45], DIFABS [43], PARST [46]. Anomal-
ous dispersion and scattering factors International Tables
for X-ray Crystallography [47].
[Ir(SC6H5)(O2)(CO)(PPh3)2] 5a. An absorption correc-
tion following the DIFABS procedure [43] was applied to
isotropically refined data; maximum and minimum absorp-
tion factors 2.004 and 0.656 respectively. The temperature
factor of the C atom of the carbonyl group was fixed all
along the refinement process as it became negative. The
Ir-C1 coordinates were fixed along with its thermal param-
eter. The positions of the hydrogen atoms were calculated
geometrically and introduced in the refinement with all
parameters fixed. An empirical weighting scheme, as
2. Results and discussion
Analytical and other physical properties of the com-
pounds prepared, NMR parameters as well as n(C;O),
n(O5O) and n(M–H) frequencies are given in the ex-
perimental section. In general, other infrared frequencies
are consistent with the given formula but have been
omitted since they are of limited value to the following
discussion.
Reaction of [hIr(m-SC6F5)(CO)2j2] with triphenylphos-
phine. Addition of triphenylphosphine to a solution of the
sulfur-bridged dinuclear d8 metal complex [hIr(m-
SC6F5)(CO)2j2] in acetone at room temperature, rapidly
yields a clear pale-yellow solution, from which a mixture
of two kinds of crystals was obtained. Owing to their
lability in solution, spectroscopic studies of this mixture
gave rise to conflicting results and therefore, the crystals
were analysed by X-ray diffraction techniques. The re-
sulting complexes from this reaction are trans-
[Ir(SC6F5)(CO)(PPh3)2] 1a and [Ir3(SC6F5)3(CO)5-
(PPh3)2] (Scheme 1).
Trans-[Ir(SC6F5)(CO)(PPh3)2] 1a has been obtained
previously from the metathetical reaction of trans-
Scheme 1.

˜
A. Antinolo et al. / Polyhedron 18 (1999) 959–968
963
[Ir(Cl)(CO)(PPh3)2] with Tl(SC6F5) [51] which is a
general method to prepare Vaska’s type complexes [16].
From this reaction we found no traces of the trinuclear
compound 2.
Figs. 1 and 2 show perspective views of the molecular
structures of complexes 1a and 2, respectively, indicating
the atom numbering scheme.
Selected bond distances and angles for complexes 1a
and 2 are listed in Tables 2 and 3, Torsion angles involving
the central ring of [Ir3(m-SC6F5)3(m-CO)(CO)4(PPh3)2] 2
are collected in Table 4.
Ir2, S2, Ir3 and S3 are roughly coplanar; S1 and C19
(bridging CO) that form the flaps of the envelope, are
˚
˚
respectively below (21.916A) and above (0.358 A) this
plane. Two iridium atoms (Ir1 and Ir2) are formally
pentacoordinated, sharing a bridging carbonyl ligand. Each
of these iridium atoms are bonded to a terminal carbonyl
ligand and to a triphenylphosphine ligand. Iridium1–
˚
iridium2 is the shortest intermetallic distance (2.665(4)A)
and it suggests a metal–metal bond; which is in agreement
with the electron counting. This distance is slightly shorter
than those found in previously reported trinuclear com-
plexes [2–8]. It also shows significant differences when
compared with the other two iridium–iridium distances,
The molecule of trans-[Ir(SC6F5)(CO)(PPh3)2] 1a
shows, as expected, a substantially planar arrangement
around the metallic centre. Both iridium–phosphorus dis-
˚
both larger than 3.5A. Iridium–sulphur distances on this
˚
fragment are also significantly different (Ir1–S1 2.37(1),
tances are practically equal (2.305(2) and 2.315(2)A). The
˚
Ir1–S3 2.54(1) and Ir2–S1 2.39(1), Ir2–S2 2.58(1)A). The
C6F5 ring aligns itself parallel to a C6H5 ring from a
neighbouring intramolecular triphenylphosphine. This is a
fact that is often encountered in SC6F5 bearing compounds
and it probably results from packing effects. In solution,
NMR data are consistent with rapid rotation of the
pentafluorophenyl ring.
The structure of the complex [Ir3(m-SC6F5)3(m-
CO)(CO)4(PPh3)2] 2 has a basic skeleton formed by three
iridium atoms bridged by three SC6F5 groups. Atoms Ir1,
third iridium atom has a square planar arrangement with
˚
cis carbonyls (1.77(3) and 1.85(4)A) and two essentially
equal iridium–sulphur distances (Ir3–S2 2.36(1) and Ir3–
˚
S3 2.37(1)A). Both angles around sulfur atoms are quite
different, Ir1–S1–Ir2 angle is 68.1o consistent with the
shorter distance, and the related Ir2–S1 and Ir1–S1
˚
distances are 2.39(1) and 2.37(1)A respectively, but the
˚
Ir1–S3–Ir3 angle is 123.58, and Ir1–S3 is 2.54(1)A. While
Fig. 1. ORTEP [27] view of the molecular structure of trans-[Ir(SC6F5)(CO)(PPh3)2] 1a showing the atomic numbering.

˜
964
A. Antinolo et al. / Polyhedron 18 (1999) 959–968
Fig. 2. ORTEP [27] view of the molecular structure of [Ir3((-SC6F5)3(m-CO)(CO)4(PPh3)2] 2 showing the atomic numbering.
the Ir2–S2–Ir3 angle is 126.28 and the Ir2–S2 distance is
2.58(1)A. Clearly, angles around S1 indicate a tetrahedral
higher nuclearity promoted by PPh3 has been previously
observed for several systems [53]. Unfortunately no evi-
dence regarding the mechanism leading to 2 could be
gained from the experimental outcome of this reaction
˚
environment, as is usually observed in thiolate derivatives
[2–8]. However, those around S2 and S3 indicate an
unusual planar structure. These data are in agreement with
previous results found for the crown-like complex [Ir3(m-
S-t-Bu)3(m-CO)(CO)4(PMe3)2] reported previously [2–8].
Rearrangement of metal complexes to derivatives of
Table 3
˚
Selected bond distances (A) and angles (8) with standard deviations for
complex [Ir3(m-SC6F5)3(m-CO)(CO)4(PPh3)2]
Ir1-Ir2
Ir1-Ir3
Ir2-Ir3
Ir1-S1
Ir1-S3
Ir2-S1
Ir2-S2
Ir3-S2
Ir3-S3
Ir1-C19
Ir1-P1
Ir2-P2
Ir3-C22
Ir3-C23
2.665(1)
4.323(2)
4.406(1)
2.37(1)
2.54(1)
2.39(1)
2.58(1)
2.36(1)
2.37(1)
2.07(3)
2.36(1)
2.34(1)
1.77(3)
1.85(4)
S1-Ir1-S3
S1-Ir2-S2
S2-Ir3-S3
S3-Ir3-C22
S3-Ir3-C23
S2-Ir3-C23
S2-Ir3-C22
S1-Ir2-C21
S1-Ir2-C19
Ir1-S1-Ir2
81.2(2)
86.4(2)
92.5(2)
89(1)
175(1)
92(1)
178(1)
161(1)
86(1)
68.1(2)
126.2(3)
123.5(3)
80(1)
Table 2
˚
Selected bond distances (A) and angles (8) with standard deviations for
complex trans-[Ir(SC6F5)(CO)(PPh3)2]
Ir1-S1
Ir1-P1
Ir1-P2
Ir1-C1
S1-C1
C1-O1
P1-C*
P2-C*
2.382(2)
2.315(2)
2.305(2)
1.799(8)
1.761(8)
1.157(9)
1.826
S1-Ir1-P1
S1-Ir1-P2
P1-Ir1-P2
S1-Ir1-C1
P1-Ir1-C1
P2-Ir1-C1
S1-C1-C2
Ir1-C1-O1
83.44(7)
96.89(7)
176.87(7)
173.0(3)
89.5(3)
90.2(3)
122.3(7)
178.0(8)
Ir2-S2-Ir3
Ir1-S3-Ir3
Ir1-C19-Ir2
Ir2-C19-O19
1.823
139(2)
*Average length.

˜
A. Antinolo et al. / Polyhedron 18 (1999) 959–968
965
Table 4
Addition of the thiols HSRF (RF 5C6F5, C6HF4-4 or
C6H4F-4) to a suspension of trans-[Ir(Cl)(CO)(PPh3)2] in
toluene at room temperature yields an off-white precipitate
of the complexes [IrH(Cl)(SC6F5)(CO)(PPh3)2] 3a,
[IrH(Cl)(SC6HF4-4)(CO)(PPh3)2] 3b or [IrH(Cl)-
(SC6H4F-4)(CO)(PPh3)2] 3c.
Torsion angles (8) involving the central ring of [Ir3(m-SC6F5)3(m-
CO)(CO)4(PPh3)2]
C20–Ir1–C19–Ir2
P1–Ir1–C19–Ir2
S3–Ir1–C19–Ir2
S1–Ir1–C19–Ir2
S1–Ir1–S3–Ir3
C19–Ir1–S1–Ir2
S3–Ir1–S1–Ir2
S2–Ir2–C19–Ir1
S1–Ir2–C19–Ir1
S2–Ir2–S1–Ir1
C19–Ir2–S1–Ir1
C19–Ir2–S2–Ir3
S1–Ir2–S2–Ir3
S2–Ir2–S3–Ir1
S3–Ir2–S2–Ir2
2115(1)
149.4(4)
218(2)
47(1)
262.7(3)
243(1)
109.3(2)
32(2)
247(1)
299.2(2)
43(1)
236(1)
43.0(3)
2.9(3)
The 19Fh-1Hj NMR spectra of [Ir(H)(Cl)(SC6F5)-
(CO)(PPh3)2] 3a show three complex absorptions corres-
ponding to ortho-(d52127.75 ppm), metha-(d52162.75
ppm) and para-(d52160.65 ppm) fluorine atoms (A2B2C
magnetic system) with the expected 2:2:1 relative ratio.
The 31P NMR spectra show a broad signal centred at
d527.2 ppm, whereas 1H NMR spectra show the ex-
pected multiplet on the phenyl region (PPh3) and two
triplets arising from hydride-phosphorus coupling on two
different isomers. The relative populations of these isomers
depends on reaction conditions. Obtained as described
here, their relative ratio is ca. 1:9, with d5214.99 ppm,
2JH-P 58.19 Hz and d5215.51 ppm, 2JH-P 57.46 Hz
respectively.
6.6(4)
although the formation of this trinuclear complex may be
rationalised following the pathway suggested by Poilblanc
et al. [2–8] involving five co-ordinated species or through
tetra-co-ordinated complexes as shown on the following
diagram.
NMR magnetic couplings suggest that both observed
isomers bear equivalent phosphine ligands. There are three
possible isomers on which such an equivalence is found:
trans-H-Ir-SRF, trans-H-Ir-Cl and trans-H-Ir-CO.
1
Considering the relative similarities of H NMR param-
eters (Dd50.6 ppm and D2JH-P 50.3 Hz) it seems likely
that those isomers with chloride ions or the pseudohalogen
(SC6F5)2 both on the same relative position trans to the
H2 ligand, are the more reasonable structures to rationalise
the experimental observations. On the other hand, a d
value around 215 ppm in the 1H spectra of these
complexes is consistent with the hydrido ligand being
trans to a ligand of low trans-influence such as Cl2 or
SR2 [54–56].
It has been suggested [51] that compounds 1a and 3a
establish the equilibrium shown in reaction 1.
Reactions of trans-[Ir(Cl)(CO)(PPh3 )2 ] with Tl(SRF ).
Reactions of trans-[Ir(Cl)(CO)(PPh3)2] with Tl(SRF)
(RF 5C6F5, C6HF4-4, C6H4F-4 or C6H4Me-2) in acetone
at room temperature yield yellow solutions, together with
white precipitate of thallium chloride. From these solu-
tions, the complexes trans-[Ir(SC6F5)(CO)(PPh3)2] 1a,
trans-[Ir(SC6HF4-4)(CO)(PPh3)2] 1b, trans-[Ir(SC6H4F-
4)(CO)(PPh3)2] 1c or trans-[Ir(SC6H4Me-2)(CO)(PPh3)2]
1d were isolated under dry, oxygen-free-nitrogen as yellow
crystalline solids.
However, attempts to reductively eliminate HCl from
1a-by treatment with KOH, NEt3 etcetera-have all been
unsuccessful. The reductive elimination of HCl from
chloro hydrido transition metal complexes has been recent-
ly reviewed [57]. It is now well established that reductive
elimination under biphasic or phase transfer catalysis
conditions is a more suitable and accurate experimental
method. Indeed, HCl elimination is cleanly accomplished
by treating [IrH(Cl)(SC6F5)(CO)(PPh3)2] 3a under phase
transfer conditions (toluene, 60% KOH-18-crown-6),
yielding trans-[Ir(SC6F5)(CO)(PPh3)2] 1a. On the other
hand, attempts to dechlorinate [IrH(Cl)(SC6F5)-
(CO)(PPh3)2] 3a in order to yield cationic complexes, as
shown in reaction 2, have also failed to yield the desired
products.
The 31P NMR spectra of compounds 1a–d show single
resonances (d525.19, 24.98, 27.36 and 26.22 ppm respec-
tively) arising from magnetically equivalent phosphine
ligands in a trans arrangement.
FAB mass spectrometry of compounds 1a–d show the
expected molecular ions-listed on Table 1-with a decompo-
sition patterns suggesting the consecutive loss of CO, PPh3
and the fluorinated thiolate substituents.
Reactions of trans-[Ir(Cl)(CO)(PPh3 )2 ] with HSRF.

˜
A. Antinolo et al. / Polyhedron 18 (1999) 959–968
966
MX 5 NaBPh4, AgNO3, etc .
The 19Fh-1Hj NMR spectra of [IrH(SC6F5)2-
(CO)(PPh3)2] 4a show the expected pattern due to ortho-,
metha- and para-fluorine substituents (A2B2C magnetic
system) from two non-equivalent C6F5 rings at do 5
2134.2, 2133.8; dm 52167.3, 2168.1 and dp 52161.2
ppm. In addition to absorptions due to the phenyl rings, 1H
Reactions of 3a with chloro abstracting reagents i.e.
NaBPh4 or AgNO3 result in mixtures of ill-defined prod-
ucts with loss of carbon monoxide or thiolate ion.
FAB mass spectrometry of compounds 3a–c show the
expected molecular ions and a decomposition pattern with
consecutive loss of CO, PPh3 and SRF.
Reactions of trans-[Ir(SRF )(CO)(PPh3 )2 ] with HSRF.
Reactions of trans-[Ir(SRF)(CO)(PPh3)2] 1a–c with their
corresponding thiols, HSRF (RF 5C6F5, C6HF4-4 or
C6H4F-4), in toluene suspensions, at room temperature,
yield the complexes [IrH(SC6F5)2(CO)(PPh3)2] 4a,
[IrH(SC6HF4-4)2(CO)(PPh3)2] 4b or [IrH(SC6H4F-
4)2(CO)(PPh3)2] 4c. Under the reaction conditions used in
this work, compounds 4a–c, are obtained as one of the two
possible isomers bearing mutually trans triphenylphosphine
ligands. Thus 31P NMR spectra show a single absorptions
at d526.4 4a, 26.9 4b and 28.45 4c ppm.
2
NMR spectra show a triplet at d5214.8 ppm with JP-H 5
9.7 Hz. Similarly, 19Fh21Hj NMR spectra of
[IrH(SC6HF4-4)2(CO)(PPh3)2] 4b show an absorption
pattern due to ortho- and metha-fluorine substituents from
two non-equivalent SC6HF4-4 rings at d52128.5, d52
128.9 and d52139.6, d52139.7 ppm. Besides absorp-
tions due to the phenyl rings, 1H NMR spectra of 4b show
two triplets of triplets (AX2Y2 system) for the para-H at
dp 56.45 ppm and a triplet due to the hydride ion at
2
d5214.9 ppm with a H-P coupling constant. JP-H 59.1
Hz. Finally [IrH(SC6H4F-4)2(CO)(PPh3)2] 4c shows
19Fh21Hj NMR spectra consisting of two absorptions due
to para-fluorine substituents from two non-equivalent
Fig. 3. ORTEP [27] view of the molecular structure of [Ir(SC6F5)(O2)(CO)(PPh3)2] 5a with thermal ellipsoids at 50% probability level. H atoms have
been omitted for sake of clarity.

˜
A. Antinolo et al. / Polyhedron 18 (1999) 959–968
967
Table 5
positional parameters of calculated hydrogen atoms, aniso-
tropic thermal parameters, and bond distances and angles.
Ordering information is given on any current masthead
page.
˚
Selected bond distances (A) and angles (8) with standard deviations for
complex [Ir(SC6F5)(O2)(CO)(PPh3)2]
Ir1–P1
Ir1–P2
Ir1–S1
Ir1–C1
Ir1–O2
Ir1–O3
O2–O3
2.376(4)
2.382(5)
2.407(7)
1.69(0)
2.02(3)
2.02(2)
1.42(3)
O2–Ir1–O3
C1–Ir1–O3
C1–Ir1–O2
S1–Ir1–O3
S1–Ir1–O2
Ir1–O2–O3
Ir1–O3–O2
41.2(8)
158.9(5)
118.0(5)
106.4(6)
147.0(6)
69(1)
Acknowledgements
70(1)
Financial support from the EU (Contract CI1*-
CT930329), DGAPA-IN121698 UNAM and CONACYT
(25108E) are gratefully acknowledged.
SC6H4F-4 rings dp 52122.3 and 2122. 4 ppm. 1H spectra
of 4c show absorptions due to the C6H5 and SC6H4F-4
rings and a triplet due to the hydride ion at d5215.7 ppm
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As with all compounds of these series, FAB mass
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