Five-coordinate fluorobenzothiolate osmium(IV) complexes [Os(SR F)4(PR3)] (RF = C6F 4H-4, R3 = Ph2(C6F5); RF = C6F4H-4, R3 = (OPh) 3; RF = C6F5, R3 = (OPh)3)

Article abstract of DOI:10.1016/j.poly.2011.02.001

Reactions of OsO₄ with excess of HSR_F and PR ₃ in ethanol afford five-coordinate compounds [Os(SR _F)₄(PR₃)] (R_F = C₆F ₄H-4, R₃ = Ph₂(C₆F₅) (1); R_F = C₆F₄H-4, R₃ = (OPh) ₃ (2); and R_F = C₆F₅, R₃ = (OPh)₃ (3)). Single crystal X-ray diffraction studies of 1-3 exhibit a common pattern with an osmium center in a trigonal-bipyramidal coordination arrangement. Axial positions are occupied by mutually trans thiolate and phosphine or phosphite ligands, while the remaining three equatorial positions are occupied by thiolate ligands. In compound 1 the tetrafluorophenyl rings of the equatorial ligands are directed away from the axial phosphine ligand in a "3-up" arrangement. In contrast, a "2-up, 1-down" arrangement was found in compounds 2 and 3, where only two of the fluorinated rings from the equatorial thiolates are directed towards the axial thiolate, while the fluorinated substituent of the third equatorial thiolate is directed towards the phosphine ligand. Structural characterization in solution by ¹H, ³¹P{¹H} and ¹⁹F NMR, variable temperature and COSY ¹⁹F-¹⁹F NMR studies are discussed.

Full text of DOI:10.1016/j.poly.2011.02.001

Polyhedron 30 (2011) 1250–1257
Contents lists available at ScienceDirect
Polyhedron
journal homepage: www.elsevier.com/locate/poly
Five-coordinate fluorobenzothiolate osmium(IV) complexes [Os(SRF)4(PR3)]
(RF = C6F4H-4, R3 = Ph2(C6F5); RF = C6F4H-4, R3 = (OPh)3; RF = C6F5, R3 = (OPh)3):
Single-crystal structures and solution structural characterization
Margarita Cerón a, Verónica Cortina a, Armando Ramírez-Monroy a, Sylvain Bernès b, Hugo Torrens c,
Maribel Arroyo a,
⇑
a Centro de Química del Instituto de Ciencias de la Benemérita Universidad Autónoma de Puebla, Edificio 193 del Complejo de Ciencias,
Ciudad Universitaria, San Manuel 72571, Puebla, Pue., Mexico
b DEP, Facultad de Ciencias Químicas, UANL, Guerrero y Progreso S/N, Col. Treviño 64570, Monterrey, N.L., Mexico
c División de Estudios de Posgrado, Facultad de Química, UNAM, Cd. Universitaria, 04510 México D.F., Mexico
a r t i c l e i n f o
a b s t r a c t
Article history:
Reactions of OsO4 with excess of HSRF and PR3 in ethanol afford five-coordinate compounds
[Os(SRF)4(PR3)] (RF = C6F4H-4, R3 = Ph2(C6F5) (1); RF = C6F4H-4, R3 = (OPh)3 (2); and RF = C6F5, R3 = (OPh)3
(3)). Single crystal X-ray diffraction studies of 1–3 exhibit a common pattern with an osmium center in
a trigonal-bipyramidal coordination arrangement. Axial positions are occupied by mutually trans thiolate
and phosphine or phosphite ligands, while the remaining three equatorial positions are occupied by thio-
late ligands. In compound 1 the tetrafluorophenyl rings of the equatorial ligands are directed away from
the axial phosphine ligand in a ‘‘3-up’’ arrangement. In contrast, a ‘‘2-up, 1-down’’ arrangement was found
in compounds 2 and 3, where only two of the fluorinated rings from the equatorial thiolates are directed
towards the axial thiolate, while the fluorinated substituent of the third equatorial thiolate is directed
towards the phosphine ligand. Structural characterization in solution by 1H, 31P{1H} and 19F NMR, variable
temperature and COSY 19F–19F NMR studies are discussed.
Received 1 December 2010
Accepted 2 February 2011
Available online 4 March 2011
Keywords:
Five-coordinate osmium
Fluorinated thiolates
Phosphines
Fluxional processes
Ó 2011 Elsevier Ltd. All rights reserved.
1. Introduction
molecules and dynamic 19F NMR studies of fluoro-thiolate com-
plexes have revealed that isomeric forms exist due to different ori-
The first examples of five-coordinate ruthenium and osmium
complexes bearing a formal +4 oxidation state, [M(SR)4(CH3CN)]
(M = Ru, Os; R = C6HMe4-2,3,5,6 or C6H2 Pr3-2,4,6), were reported
entations of the SRF ligands and that such isomers can undergo
positional exchange as a result of rotations about MASRF bonds.
For a long time, we have also been involved in the synthesis and
reactivity studies of five-coordinate OsIV–polythiolate-complexes
[6,15–23] of general formula [OsX(SRF)3(PR3)] (X = Cl, SRF;
SRF = SC6F5, SC6F4H-4, SC6H4F-4, SC6H5; PR3 = tertiary phosphine).
Up to now, all members of these series characterized by X-ray crys-
tallography had shown, invariably, the ‘‘3-up’’ orientation for the
substituents of equatorial thiolates, probably because of the axial
tertiary phosphine hinders that a RF group lie near of such axial
position. Interestingly, on the recently reported systems
[Os(SC6F5)4(P(C6H4X-4)3)], where X = OCH3, CH3, F, Cl or CF3, [21]
the X-ray diffraction studies showed a configuration ‘‘3-up’’,
although exhaustive NMR studies revealed the presence of the
‘‘3-up’’ and ‘‘2-up, 1-down’’ isomers in solution. Now, we used
these fluorinated ligands, which offer the possibility to distinguish
clearly the structural details of these types of molecules, to inves-
tigate how the variations in PR3 ligands influence the configuration
of the complexes. Thus, we report here the preparation of analo-
gous compounds [Os(SRF)4(PR3)] (RF = C6F4H-4, R3 = Ph2(C6F5) (1);
RF = C6F4H-4, R3 = (OPh)3 (2); and RF = C6F5, R3 = (OPh)3 (3)) and
i
by Koch and Millar in 1983 [1]. In these complexes two of the aro-
matic rings of equatorial thiolates are projected towards the axial
CH3CN ligand and the other one is directed towards the axial sulfur
(‘‘2-up, 1-down’’ arrangement). In 1985, these authors reported [2]
the compounds, [M(SR)4(CO)], where the overall structure is simi-
lar to that of [M(SR)4(CH3CN)], with the CO occupying an axial po-
sition in the trigonal bipyramidal coordination arrangement,
however the three substituents of equatorial thiolates are oriented
in the direction of the CO (‘‘3-up’’ arrangement). Other five-coordi-
nate ruthenium and osmium compounds with these sterically
hindered aromatic thiolate ligands were reported [3,4].
On the other hand, restricted rotation of polyfluoro-phenyl/
alkyl groups has been observed in a variety of coordination and
organometallic compounds [5–14]. The corresponding fluxional
processes can be accompanied by conformational changes in the
⇑
Corresponding author. Tel.: +52 222 2295500; fax: +52 222 2295551.
E-mail address: slarroyo@siu.buap.mx (M. Arroyo).
0277-5387/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2011.02.001

M. Cerón et al. / Polyhedron 30 (2011) 1250–1257
1251
discuss their structural characterization both in the solid-state and
in solution by 1H, 31P{1H} and 19F NMR studies.
compared to the cone angle of diphenyl(pentafluorophenyl)phos-
phine (158°) [24]. This difference in the cone angle allows a relaxed
arrangement around the metal center, minimizing the steric hin-
drance for the aryl groups in the molecule. Regardless of the lower
basicity of the phosphite compared to that of phosphine ligands,
Os1–P1 bond lengths for complexes 2 and 3 are shorter by ca.
0.1 Å than the Os1–P1 bond distance in 1 (Table 2), corroborating
the low steric requirement of the triphenylphosphite ligand. The
bonds trans to the phosphine or phosphite ligands vary in the
opposite way, albeit spanning a short range.
2. Results and discussion
Reactions of OsO4 with excess of HSRF and PR3 in refluxing eth-
anol afford the five-coordinated compounds [Os(SRF)4(PR3)]
(RF = C6F4H-4, R3 = Ph2(C6F5) (1); RF = C6F4H-4, R3 = (OPh)3 (2);
and RF = C6F5, R3 = (OPh)3 (3)).
Ethanol
As for all the complexes [OsX(SRF)3(PR3)] where PR3 is a phos-
phine, compound 1 exhibits a hemidirected arrangement for the
equatorial SRF substituents, which are oriented toward the axial
thiolate (arrangement referred to ‘‘3-up’’, see Fig. 1). In contrast,
the equatorial substituents in compounds 2 and 3 show a ‘‘2-up,
1-down’’ arrangement (Fig. 2), with two RF rings directed toward
the axial thiolate while the third is found in the phosphite hemi-
sphere. The observed distribution for RF groups within the coordi-
nation spheres in 1–3 is thus consistent with the different steric
requirement of the P-containing ligands. Interestingly, the ‘‘2-up,
1-down’’ arrangement had been detected in solution for complexes
[Os(SC6F5)4(P(C6H4X-4)3)] (X = CF3, Cl, F, H, CH3, OCH3), on the basis
of variable-temperature 19F NMR experiments [21]. However, this
arrangement accounted only for the minor isomer in solution,
while the major isomer in solution and all crystal structures were
invariably found to correspond to the ‘‘3-up’’ isomer.
OsO4 þ HSRF þ PR3
! ½OsðSRFÞ4ðPR3Þꢀ
RF ¼ C6F4H-4; R3 ¼ Ph2ðC6F5Þ ð11ꢁÞ3; RF ¼ C6F4H-4; R3 ¼ ðOPhÞ3 ð2Þ;
RF ¼ C6F5; R3 ¼ ðOPhÞ3 ð3Þ
The osmium(IV) diamagnetic complexes 1–3 were isolated by
column chromatography and characterized by elemental analyses,
FAB+-mass spectrometry, single crystal X-ray structure determina-
tions and 1H, 31P{1H} and 19F NMR studies.
The FAB-mass spectra show low intensity signals for M+ (1 and
2) or [M+ꢁH] (3), [M+ꢁF] (1, 2 and 3), [M+ꢁPh] (1) or [M+ꢁOPh] (2
and 3). A common high intensity signal on all the spectra is that
corresponding to [Os(SRF)3(PR3)]+. Compounds 2 and 3 also show
low intensity signals corresponding to [M+ꢁHꢁ2SRF], [M+ꢁ3SRF
ꢁ3H], [M+ꢁ2SRFꢁP(OPh)3] and more considerable intensity signals
of [P(OPh)2+].
No significant intermolecular contacts like
actions seem to help in crystal structures stabilization. For instance,
in the case of 3, contacts are limited to two S1-benzene rings
related by inversion, the centroid–centroid separation being
3.82 Å. Indeed, a stronger intramolecular interaction is present
p–p or C–H–p inter-
The solid-state structures of complexes 1–3 were determined
by X-ray diffraction (Table 1). The trigonal-bipyramidal coordina-
tion geometry is consistent with all the five-coordinated Os(IV)
complexes [OsX(SRF)3(PR3)] (X = Cl, SC6F5, SC6F4H; RF = C6F5,
C6F4H; PR3 = tertiary phosphine) previously reported [15–
17,19,21]. In all the X-ray characterized structures 1–3, the axial
positions are occupied by thiolate and P-containing ligands, with
trans S4–Os1–P1 angles in the range 172.40(6)–177.10(5)°. In the
case of compounds 2 and 3 bearing axial triphenylphosphite li-
gands, S4–Os1–P1 angles are closer to linearity than the corre-
sponding angle in compound 1, probably as a result of the
smaller cone angle of the ligand triphenylphosphite (128°)
p–p
p–p
in 1, with a distance of 3.54 Å, because of the claw like geometry of
the thiolates hemisphere. A consequence of the poor packing in this
family of compounds is that very small change in formula may in-
duce crystal symmetry modification, even if molecules are almost
isostructural. This is the case for 2 and 3, which, in spite of being
chemically closely related and having similar molecular structures
(r.m.s. for the best fit on non-H atoms: 0.82 Å), crystallize in differ-
ent space groups (see Table 1).
Table 1
Summary of data collection and refinementa for complexes 1–3.
Complex
1
2
3
Chemical formula
Formula weight
Crystal size (mm3)
T (K)
C
42H14F21OsPS4
C42H19F16O3OsPS4
1224.98
C42H15F20O3OsPS4
1296.95
1266.94
0.46 ꢂ 0.40 ꢂ 0.06
298(2)
0.62 ꢂ 0.28 ꢂ 0.14
0.42 ꢂ 0.32 ꢂ 0.24
298(2)
298(2)
Crystal system
Space group
a (Å)
b (Å)
c (Å)
monoclinic
P21/c
10.7253(8)
17.7966(12)
23.2151(18)
90.00
96.446(7)
90.00
4403.1(6)
4, 1
monoclinic
P21/n
11.0196(16)
10.4846(9)
37.795(3)
90.00
92.974(9)
90.00
4360.8(8)
4, 1
triclinic
P1
ꢀ
9.8938(6)
12.9027(12)
19.3854(12)
100.836(6)
97.643(4)
109.169(5)
2244.6(3)
2, 1
a
(°)
b (°)
c
(°)
V (Å3)
Z, Z0
l
(mmꢁ1
)
3.244
1.911
3–52
3.261
1.866
4–55
3.186
1.919
3–60
Dcalc.(g cmꢁ3
2h Range (°)
)
Completeness (%)
100
99.9
99.4
R1, wR2 [I > 2 (I)]
R1, wR2 (all data)
Reflections collected/unique
Rint
r
0.049, 0.113
0.079, 0.129
15 273/8672
0.051
0.041, 0.079
0.069, 0.091
12 782/10 010
0.037
0.035, 0.071
0.050, 0.077
15 093/13 006
0.021
Data/parameters ratio
8672/623
1.015
10 010/605
1.034
13 006/641
1.043
Goodness of fit (GOF) on F2
a
Formula used for computing R1, wR2, Rint and S indices are those applied by SHELXL [25].

1252
M. Cerón et al. / Polyhedron 30 (2011) 1250–1257
Table 2
Coordination bond lengths (Å) and angles (°) for complexes 1, 2, and 3.
1
2
3
Bond lengths (Å)
Os1–S1
Os1–S2
Os1–S3
Os1–S4
2.1990(17)
2.2170(18)
2.2362(18)
2.4001(17)
2.4031(18)
2.2103(13)
2.2051(15)
2.2195(14)
2.4433(13)
2.3031(13)
2.2402(9)
2.1872(9)
2.2352(9)
2.4404(8)
2.2954(8)
Os1–P1
Bond angles (°)
S1–Os1–S2
S1–Os1–S3
S2–Os1–S3
S1–Os1–S4
S2–Os1–S4
S3–Os1–S4
S1–Os1–P1
S2–Os1–P1
S3–Os1–P1
S4–Os1–P1
114.77(7)
124.35(8)
119.14(8)
96.13(6)
88.81(6)
97.67(7)
87.20(6)
83.60(6)
85.97(7)
172.40(6)
118.62(6)
120.09(6)
121.28(6)
91.98(5)
93.18(5)
85.39(5)
86.72(5)
85.18(5)
97.51(5)
177.10(5)
117.51(4)
126.60(4)
115.82(4)
91.02(3)
95.99(3)
86.10(3)
84.78(3)
87.58(3)
94.93(3)
175.42(3)
Fig. 2. Molecular structure of complex [Os(SC6F4H-4)4(P(OPh)3)] 2 with displace-
ment ellipsoids drawn at the 25% probability level. H atoms have been omitted.
H
F
F
H
F
F
c
F
F
F
F
b
H
S
F
F
F
b
F
S
F
F
Os
S
H
b
S
F
F
Fig. 1. Molecular structure of complex [Os(SC6F4H-4)4(PPh2(C6F5))] 1 with displace-
F
ment ellipsoids drawn at the 25% probability level. H atoms have been omitted.
P
F
a
2.1. NMR studies
F
F
2.1.1. [Os(SC6F4H-4)4(PPh2(C6F5))] 1
F
At room temperature the 31P{1H} NMR spectrum of compound 1
(Scheme 1) shows one multiple signal corresponding to the phos-
phorous coupled to the fluorine atoms of the ring C6F5 (a), while
the 1H NMR spectrum exhibits: at low field three signals corre-
sponding to the ortho, meta and para hydrogen atoms of two equiv-
alent C6H5 rings (relative intensities 4:4:2). Yet on the aromatic
region, at higher field, the spectrum exhibits a broad singlet from
three equatorial ꢁSC6F4H ligands (rings b, relative intensity 3,
Scheme 1), and a triplet of triplets corresponding to the axial
ꢁSC6F4H (ring c, relative intensity 1, Scheme 1). The 19F NMR spectra
of 1, from +80 °C to room temperature, show: a group of three sig-
nals corresponding to ortho, para and meta fluorine atoms of the
C6F5 group (ring a, Scheme 1), at low, medium and high field,
respectively (A2BC2 spin system, relative integrals 2:1:2); a group
Scheme 1. Drawing of [Os(SC6F4H-4)4(PPh2(C6F5))] 1 showing the different fluori-
nated phenyl rings as in the X-ray structure.
of two signals from ortho and meta-fluorine atoms of three equiva-
lent equatorial ꢁSC6F4H-4 ligands (rings b, Scheme 1) (A2B2 spin
system, relative integrals 6:6); and a group of another two signals
corresponding to ortho and meta-fluorine atoms of an axial
ꢁSC6F4H-4 ligand (ring c, Scheme 1) (A2B2 spin system, relative inte-
gral 2:2). 19F–19F NMR experiments were used to unambiguously
identify each set of signals. All these NMR spectra are consistent
with a configuration ‘‘3-up’’ of three equivalent C6F4H-substituents
of the equatorial thiolates. However, as the temperature is de-
creased (Fig. 3) the original sharp singlets 6:6 from ortho and

M. Cerón et al. / Polyhedron 30 (2011) 1250–1257
1253
Fig. 3. Variable temperature 19F NMR spectra of [Os(SC6F4H-4)4(PPh2(C6F5))] 1 in C6D5CD3.
meta-fluorine atoms of the equatorial thiolates broaden and each
one eventually collapses giving rise to two signals [relative inte-
grals ca. 2:4 (ortho) and 2:4 (meta)], a fact which is congruent with
a set of equatorial thiolates where one substituent is non-equiva-
lent respect to the other two. On additional decreasing of tempera-
ture, each signal integrating four experiences a second collapse
giving two signals 2:2. In contrast, the absorptions from the rings
a and c remain unaltered along the full range of temperatures stud-
ied. At low temperatures, the spectrum is consistent with the ‘‘2-up,
1-down’’ isomer (with the two 2-up equivalent C6F4H groups re-
stricted to rotate about their CAS bonds) without evidence of an
equilibrium between the two different molecular species. The fact
that the ‘‘3-up’’ isomer suddenly disappear to produce the ‘‘2-up,
1-down’’ isomer is not probable at all. For these reasons we ruled
out the ‘‘2-up, 1-down’’ configuration. We think that the ‘‘3-up’’
configuration remains in all the range of temperatures analyzed
and propose as a more congruent possibility that, as the tempera-
ture decreases, the equatorial thiolates are gradually frozen (two
sequential collapses) giving a configuration probably nearly to that
found in the X-ray diffraction structure.
spectrum is consistent with two equivalent equatorial ꢁSC6F4H li-
gands in the orientation ‘‘2-up’’ (rings b), in which each ring has
non-equivalent ortho fluorine atoms and non-equivalent meta fluo-
rine atoms (ortho, ortho0, meta, meta0; 1:1:1:1) (AA0BB0 spin sys-
tems), one equatorial ꢁSC6F4H ligand in the orientation ‘‘1-down’’
(ring a) with equivalent ortho fluorines and equivalent meta fluo-
rines (ortho, meta; 2:2; A2B2 spin system), and one axial ꢁSC6F4H
ligand (ring c) also with equivalent ortho fluorines and equivalent
meta fluorines (ortho, meta; 2:2; A2B2 spin system). The COSY
19F–19F NMR spectra confirm these three sets of signals. At lower
temperatures the number of signals and their integrals remain
constant. However, when the temperature is increased (Fig. 5)
the two ortho and ortho0 signals and the two meta and meta0 signals
from the rings b coalesce, confirming a fluxional process that in-
volves the two equivalent equatorial ꢁSC6F4H ligands in the orien-
tation ‘‘2-up’’ (rings b, Scheme 2). This is congruent with two C6F4H
rings (b) exhibiting restricted rotation about their CAS bonds at
low temperatures but becoming free to rotate as the temperature
increases.
Thus, as seen in the 1H NMR studies, the 19F NMR spectra are
also consistent with the conformation ‘‘2-up, 1-down’’ for the sub-
stituents of the equatorial thiolates in solution.
2.1.2. [Os(SC6F4H-4)4(P(OPh)3)] 2
At room temperature, the 31P{1H} NMR spectrum of compound
2 shows a singlet, consistent with the presence of one species in
solution, as found above for the product 1. The room temperature
1H NMR spectrum exhibits (Fig. 4), at low field, the signals corre-
sponding to the ortho, meta and para hydrogen atoms of the C6H5
rings of the P(OPh)3 ligand, along the residual protio atoms of
the solvent. Also on the aromatic region, at higher field, the
spectrum shows a broad singlet (relative integral 2) attributable
to the para hydrogen atoms of two equivalent equatorial ꢁSC6F4H
ligands in the orientation ‘‘2-up’’ (rings b, Scheme 2) and two
triplets of triplets (relative integrals 1:1) attributable to the para-
hydrogen atoms of two non-equivalent equatorial ‘‘1-down’’ and
axial ꢁSC6F4H ligands (rings a and c, Scheme 2). The 19F NMR spec-
trum, at room temperature, shows eight signals of the same
integral, four of these at low field in the ortho fluorine region and
the other four, at higher field, in the meta fluorine region. This
2.1.3. [Os(SC6F5)4(P(OPh)3)] 3
As for the complex 2, the room temperature 31P{1H} NMR spec-
trum of compound 3 shows a singlet, while the 1H NMR spectrum
only exhibits the signals corresponding to the aromatic-hydrogen
atoms of the three C6H5 rings of the P(OPh)3 ligand. The room tem-
perature 19F NMR spectrum shows four signals at low field on the
ortho region (relative integrals 2:2:2:2), three well defined triplets
(relative integrals 1:2:1) at medium field on the para region, and
three additional multiplets (relative integrals 2:4:2) at high field
on the meta region. These results can be rationalized with the con-
formation ‘‘2-up, 1-down’’ for the substituents of the equatorial
thiolates, and a restricted rotation about the CAS bonds of the
two equivalent equatorial thiolates ‘‘2-up’’ to make thus non-
equivalent ortho fluorine and non-equivalent meta fluorine atoms
in each of the rings b, although meta and meta0 fluorine atoms

1254
M. Cerón et al. / Polyhedron 30 (2011) 1250–1257
Fig. 4. 1H NMR spectrum of [Os(SC6F4H-4)4(P(OC6H5)3)] 2 at RT, in C6D5CD3.
the equatorial thiolate-substituents in a trigonal bipyramidal
X
F
geometry. In solution, the NMR spectra are consistent with this
conformation. However, in the solid state, the presence of one oxy-
gen atom in the PAC6H5 bonds of the compounds 2 and 3, related
to compounds [Os(SC6F4H-4)4(PPh3)] 4 [16,20] and [Os(SC6F5)4
(PPh3)] 5 [19], causes a conformational change, thus 2 and 3 show
the conformation ‘‘2-up, 1-down’’ while 4 and 5 exhibit the confor-
mation ‘‘3-up’’. In solution, 2 and 3 also exhibit the conformation
‘‘2-up, 1-down’’, while 5 shows both of these conformations, being
more abundant the isomer ‘‘3-up’’ [21].
X
F
F
c
F
F
F
b
F
F
S
F
S
F
F
Os
S
X
b
F
a
S
F
F
4. Experimental
F
X
F
All reactions were carried out under argon atmospheres using
conventional Schlenk-tube techniques. Thin-layer chromatography
(Merck, silica gel 60 F254) was used to monitor the progress of the
reactions under study with hexane–dichloromethane (4:1) as elu-
ent. The starting materials: osmium tetraoxide, pentafluorobenze-
nethiol, 2,3,5,6-tetrafluorobenzenethiol, triphenylphosphite and
pentafluorophenyldiphenylphosphine were used as received from
Aldrich Chemical Co.
P
O
O
O
Scheme 2. Drawing of [Os(SC6F4X-4)4(P(OPh)3)] 2 (X = H) or 3 (X = F) showing the
different fluorinated phenyl rings as in the X-ray structures. The 19F NMR signals of
rings b, could be assigned, while those for a and c remain interchangeable.
Melting points were obtained on a Fisher-Johns apparatus and
are uncorrected.
Infrared spectra were recorded on a 750 Nicolet Fourier Trans-
form Magna-IR Spectrometer as KBr pellets. Data are expressed in
wavenumbers (cmꢁ1) with relative intensities (vs = very strong,
s = strong, m = medium, w = weak).
would be both coupled to only one para fluorine atom. It is worth
to notice that, although the meta region does not exhibit four sig-
nals 2:2:2:2 but three signals 2:4:2, the signal integrating four is
broad by the overlap of two meta signals 2:2. This interpretation
is corroborated by the COSY 19F–19F NMR spectra (Fig. 6).
1H, 31P{1H}, 19F, and COSY 19F–19F NMR spectra were recorded
using
a
Varian Mercury VX400 spectrometer. 1H NMR data
(400 MHz) were referenced internally using the residual protio sol-
vent resonance (PhCHD2, quintuplet, 2.08 ppm or CHCl3, singlet,
7.26 ppm) relative to SiMe4 (d = 0), 19F (376 MHz) externally to
CFCl3 (d = 0) and 31P (162 MHz) externally to 85% H3PO4 (d = 0).
Data are given as chemical shifts (d) using the high positive
convention [multiplicity, relative intensity, assignment, J/Hz]; s,
singlet; d, doublet; t, triplet; m, multiplet; br, broad.
3. Conclusion
As all the members of the series [OsX(SRF)3(PR3)], where X is a
Clꢁ or ꢁSRF ligand (RF is a fluorinated phenyl group), and PR3 is a
tertiary phosphine [15,16,19–23], in the solid state the compound
[Os(SC6F4H)4(PPh2(C6F5))] 1 presents the conformation ‘‘3-up’’ for
Positive ion FAB mass spectra were recorded on a Jeol JMS-
SX102A mass spectrometer operated at an accelerating voltage of

M. Cerón et al. / Polyhedron 30 (2011) 1250–1257
1255
Fig. 5. Variable temperature 19F NMR spectra of [Os(SC6F4H)4(P(OC6H5)3)] 2 in C6D5CD3.
10 kV. Samples were desorbed from
a
3-nitrobenzyl alcohol
(br s, 6Fo, 3SC6F4H-eq), ꢁ138.26 (br s, 6Fm, 3SC6F4H-eq); ring c of
(NOBA) matrix using 3 keV xenon atoms. Mass measurements in
FAB are performed at a resolution of 3000 using magnetic field
scans and the matrix ions as the reference material.
Elemental analyses were determined by Galbraith Laboratories
Inc.
the axial SC6F4H ligand,
d
ꢁ129.38 (br s, 2Fo, 1SC6F4H-ax),
ꢁ140.87 (m, 2Fm, 1SC6F4H-ax). 1H NMR (C6D5CD3, RT): d 7.96
3
3
(dd, 4Ho, PPh2C6F5, JHo–Hm = 7.6 Hz, JHo–P = 12.2 Hz), 7.22 (td,
3
4
4Hm, PPh2C6F5, JHm–Ho/p = 7.6 Hz, JHm–P = 2.8 Hz), 7.17–7.13 (m,
2Hp, PPh2C6F5,), 6.02 (br s, 3Hp, 3SC6F4H-eq (rings b)), 5.85 (tt,
Hp, 1SC6F4H-ax, JHp–Fm = 10.0 Hz, JHp–Fo = 7.2 Hz (ring c)). FAB+-
3
4
MS {m/z (%) [fragment]}: 1268 (5) M+, 1249 (1) [M+ꢁF], 1191 (1)
4.1. [Os(SC6F4H-4)4(PPh2(C6F5))] 1
[M+ꢁPh],
1087
(100)
[M+ꢁ(SC6F4H)],
938
(3)
[M+ꢁ(SC6F4H)ꢁ(C6F4H)].
2,3,5,6-Tetrafluorofluorobenzenethiol (0.8 mL, 6.0 mmol) was
dissolved in ethanol (25 mL), then osmium tetraoxide (0.25 g,
1.0 mmol) was added. The mixture rapidly turned black, PPh2(C6F5)
(2.11 g, 6.0 mmol) was added and the mixture refluxed for 3 h
turning green. The solvent was distilled off under vacuum and
the solid product was purified through a silica gel chromatographic
column eluted with hexane–dichloromethane 4:1. Compound 1
was isolated as a green microcrystalline powder (0.265 g, 21%
yield). Dark green single crystals of 1 were obtained by slow evap-
oration of the eluent. Anal. Calc. for C42H14F21OsPS4: C, 39.82; H,
1.11; S, 10.12. Found: C, 39.63; H, 1.14; S, 10.30%. Mp: 175 °C
decomposes. IR (KBr, cmꢁ1): mthiolate 1492(vs), 1431(m), 1228(m),
1177(m), 918(vs), 712(m); mphosphine 1521(m), 1474(s), 1097(m),
985(w), 747(w), 693(w). 31P{1H} NMR (C6D5CD3, RT): d 3.23 (br s,
PPh2(C6F5)). 19F NMR (C6D5CD3, 80 °C): ring a of PPh2C6F5, d
ꢁ119.06 (br s, 2Fo, C6F5), ꢁ144.32 (br s, 1Fp, C6F5), ꢁ158.21 (m,
2Fm, C6F5); rings b of the equatorial SC6F4H ligands, d ꢁ128.19
4.2. [Os(SC6F4H-4)4(P(OPh)3)] 2
The procedure is analogous to that for 1. Dark green single crys-
tals of 2 were obtained by slow evaporation of a hexane–dichloro-
methane 4:1 solution of the compound (0.208 g, 17% yield). Anal.
Calc. for C42H19F16O3OsPS4: C, 41.18; H, 1.56; S, 10.47. Found: C,
41.37; H, 1.73; S, 10.65%. Mp: 110 °C decomposes. IR (KBr,
cmꢁ1): mthiolate 1492(vs), 1432(w), 1229(m), 1181(s), 924(vs),
713(m); mthriphenylphosphite 1591(w), 1204(m), 1181(s), 1158(s),
763(m), 692(w). 31P{1H} NMR (C6D5CD3, RT):
d
ꢁ12.0 (s,
P(OC6H5)3). 19F NMR (C6D5CD3, RT): ring a of the equatorial 1-
down-SC6F4H ligand, d ꢁ129.34 (m, 2Fo, 1SC6F4H-eq-‘‘1-down’’),
ꢁ138.84 (pq, 2Fm, 1SC6F4H-eq-‘‘1-down’’, 3JFm–Fo = 12.4 Hz, 3JFm–H
=
10.9 Hz); rings b of the equatorial 2-up-SC6F4H ligands, d ꢁ130.48
(br s, 2Fo, ½(2SC6F4H)-eq-‘‘2-up’’), ꢁ131.73 (br s, 2Fo0,

1256
M. Cerón et al. / Polyhedron 30 (2011) 1250–1257
Fig. 6. COSY 19F–19F NMR spectrum of [Os(SC6F5)4(P(OC6H5)3)] 3 in CDCl3 at room temperature.
3
½(2SC6F4H)-eq-‘‘2-up’’), ꢁ139.06 (m, 2Fm, ½(2SC6F4H)-eq-‘‘2-up’’),
ꢁ139.71 (m, 2Fm0, ½(2SC6F4H)-eq-‘‘2-up’’); ring c of the axial
SC6F4H ligand, d ꢁ131.42 (m, 2Fo, 1SC6F4H-ax), ꢁ140.51 (m, 2Fm,
1SC6F4H-ax). 1H NMR (C6D5CD3, RT): d 7.17–6.83 (m, P(OC6H5)3;
and aromatic protio atoms of residual non-deuterated solvent),
6.24 (br s, 2Hp, 2SC6F4H)-eq-‘‘2-up’’), 6.09 (tt, 1Hp, 1SC6F4H,
3JHp–Fm = 9.6 Hz, 3JHp–Fo = 7.2 Hz), 6.00 (tt, 1Hp, 1SC6F4H,
NMR (CDCl3, RT): d 7.35 (t, 6Hm, P(OC6H5)3, JHm–Ho/p = 7.8 Hz),
3
7.26 (t, 3Hp, P(OC6H5)3, JHp–Hm = 9 Hz; and aromatic protio atoms
of residual non-deuterated solvent), 7.15 (d, 6Ho, P(OC6H5)3,
3JHo–Hm = 8.1 Hz). FAB+-MS {m/z (%) [fragment]}: 1297 (1)
[M+ꢁH], 1279 (1) [M+ꢁF], 1205 (1) [M+ꢁ(OPh)], 1099 (100)
[M+ꢁ(SC6F5)], 1051 (10) [M+ꢁ(OPh)ꢁ2Ph)], 899 (5) [M+ꢁHꢁ2
(SC6F5)], 698 (3) [M+ꢁ3(SC6F5)ꢁ3H], 590 (4) [M+ꢁ2(SC6F5)ꢁ
(P(OPh)3)], 217 (30) [P(OPh)2+].
3
3JHp–Fm = 9.6 Hz, JHp–Fo = 7.2 Hz). The FAB+-MS {m/z (%) [frag-
ment]}: 1226 (2) M+, 1207 (1) [M+ꢁF], 1133 (2) [M+ꢁ(OPh)],
1045 (92) [M+ꢁ(SC6F4H)], 863 (3) [M+ꢁHꢁ2(SC6F4H)], 680 (4)
[M+ꢁ3(SC6F4H)ꢁ3H], 554 (3) [M+ꢁ2(SC6F4H)ꢁ(P(OPh)3)], 217
(23) [P(OPh)2+].
4.4. X-ray diffraction data
Air stable single-crystals of complexes 1 (dark green), 2 (dark
green) and 3 (deep green) were obtained by slow evaporation of
the corresponding solutions in hexane–dichloromethane 4:1.
X-ray diffraction data were measured at 298(2) K, using a Bruker
4.3. [Os(SC6F5)4(P(OPh)3)] 3
P4 diffractometer [26] equipped with the Mo K
(k = 0.71073 Å). Data were corrected for absorption effects on the
basis of -scans (1–2) or crystal faces indexation (3). The struc-
tures were solved and refined using SHELX software [25]. In all cases,
final refinements were carried out without neither restraints nor
constraints for non-H-atoms. H atoms were placed in idealized
positions and refined as riding on their C atoms with fixed isotropic
U. Data collection parameters and structure refinement are sum-
marized in Table 1. Details may be found in the deposited CIF along
with full geometric parameters.
a radiation
The procedure is analogous to that for 1 and 2. Deep green sin-
gle crystals of 3 were obtained by slow evaporation of a hexane–
dichloromethane 4:1 solution of the compound (0.259 g, 20%).
Anal. Calc. for C42H15F20O3OsPS4: C, 38.83; H, 1.16; S, 9.85. Found:
C, 38.70; H, 1.22; S, 9.85%. Mp: 160 °C. IR (KBr, cmꢁ1): mthiolate
1509(vs), 1488(vs), 1086(vs), 982(vs), 849(s); mtriphenylphosphite
1589(m), 1203(s), 1178(s), 1156(s), 765(vs), 686(m). 19F NMR
(CDCl3, RT): ring a of the equatorial 1-down-SC6F5 ligand, d
w
3
ꢁ128.5 (d, 2Fo, 1SC6F5-eq-‘‘1-down’’, JFo–Fm = 23.7 Hz), ꢁ149.9 (t,
3
1Fp, 1SC6F5-eq-‘‘1-down’’, JFp–Fm = 20.7), ꢁ161.4 (m, 2Fm, 1SC6F5-
eq-‘‘1-down’’); rings b of the equatorial 2-up-SC6F5 ligands, d
ꢁ129.9 (br s, 2Fo, ½(2SC6F5)-eq-‘‘2-up’’), ꢁ131.4 (br s, 2Fo0,
Acknowledgements
3
½(2SC6F5)-eq-‘‘2-up’’), ꢁ150.5 (t, 2Fp, (2SC6F5)-eq-‘‘2-up’’, JFp–Fm
=
20.7), ꢁ162.1 (br m, 2Fm and 2Fm0, 2SC6F5-eq-‘‘2-up’’); ring c of the
axial SC6F5 ligand, d ꢁ131.9 (br d, 2Fo, 1SC6F5-ax), ꢁ157.8 (t, 1Fp,
We are grateful to VIEP (ARCS-NAT-09-G) and PROMEP for
financial support. S.B. acknowledges BUAP for the use of diffraction
facilities.
1SC6F5-ax, JFp–Fm = 20.7 Hz); ꢁ163.5 (m, 2Fm, 1SC6F5-ax). 1H
3

M. Cerón et al. / Polyhedron 30 (2011) 1250–1257
1257
[10] J. Forniés, M.A. Gómez-Saso, A. Martín, F. Martínez, B. Menjón, J. Navarrete,
Organometallics 16 (1997) 6024.
Appendix A. Supplementary data
[11] A. Gelling, M.D. Olsen, K.G. Orrell, A.G. Osborne, V. Sik, Inorg. Chim. Acta 264
(1997) 257.
[12] J.A. Casares, S. Coco, P. Espinet, Y.-S. Lin, Organometallics 14 (1995) 3058.
[13] W.A.W.A. Bakar, J.L. Davidson, W.E. Lindsell, K.J. McCullough, J. Chem. Soc.,
Dalton Trans. (1990) 61.
[14] W.A.W.A. Bakar, J.L. Davidson, W.E. Lindsell, K.J. McCullough, K.W. Muir, J.
Chem. Soc., Dalton Trans. (1989) 991.
[15] A. Hills, D.L. Hughes, R.L. Richards, M. Arroyo, D. Cruz-Garritz, H. Torrens, J.
Chem. Soc., Dalton Trans. (1991) 1281.
CCDC 802483, 802484, and 802485 contain the supplementary
crystallographic data for 1–3. These data can be obtained free of
charge via http://www.ccdc.cam.ac.uk/conts/retrieving.html, or
from the Cambridge Crystallographic Data Centre, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: (+44) 1223-336-033; or e-mail:
deposit@ccdc.cam.ac.uk.
[16] M. Arroyo, J.A. Chamizo, D.L. Hughes, R.L. Richards, P. Román, P. Sosa, H.
Torrens, J. Chem. Soc., Dalton Trans. (1994) 1819.
[17] M.-L. Abasq, C.J. Pickett, R.L. Richards, M. Arroyo, J.A. Chamizo, A. Calderón, P.
Sosa, H. Torrens, Polyhedron 15 (1996) 3623.
[18] M. Arroyo, C. Mendoza, E. Mayoral, H. Torrens, R.L. Richards, Rev. Mex. Fís. 46
(Suppl. 2) (2000) 120.
[19] C. Mendoza, S. Bernès, M. Arroyo, Acta Crystallogr. C62 (2006) m201.
[20] M. Cerón, M. Arroyo, S. Bernès, Acta Crystallogr. E62 (2006) m2167.
[21] M. Arroyo, C. Mendoza, S. Bernès, H. Torrens, H. Morales-Rojas, Polyhedron 28
(2009) 2625.
[22] A. Arias, L. Meléndez, S. Bernès, M. Arroyo, Acta Crystallogr. E66 (2010)
m477.
[23] C. Mendoza, S. Bernès, H. Torrens, M. Arroyo, Organometallics 29 (2010) 2646.
[24] C.A. Tolman, Chem. Rev. 77 (1977) 313.
[25] G.M. Sheldrick, Acta Crystallogr. A64 (2008) 112.
[26] XSCAnS (Release 2.21) Users Manual, Siemens Analytical X-ray Instruments
Inc., Madison, WI, USA, 1996.
References
[1] S.A. Koch, M. Millar, J. Am. Chem. Soc. 105 (1983) 3362.
[2] M.M. Millar, T. O’Sullivan, N. de Vries, S.A. Koch, J. Am. Chem. Soc. 107 (1985)
3714.
[3] S.-L. Soong, J.H. Hain Jr., M. Millar, S.A. Koch, Organometallics 7 (1988) 556.
[4] S.P. Satsangee, J.H. Hain Jr., P.T. Cooper, S.A. Koch, Inorg. Chem. 31 (1992) 5160.
[5] C.J. Bourgeois, H. Huang, R.B. Larichev, L.N. Zakharov, A.L. Rheingold, R.P.
Hughes, Organometallics 26 (2007) 264.
[6] M. Arroyo, S. Bernès, M. Cerón, V. Cortina, C. Mendoza, H. Torrens, Inorg. Chem.
46 (2007) 4857.
[7] M.C. Carrión, A. Guerrero, F.A. Jalón, B.R. Manzano, A. de la Hoz, R.M.
Claramunt, V. Milata, J. Elguero, Inorg. Chem. 42 (2003) 885.
[8] L.R. Falvello, J. Forniés, C. Fortuño, A. Martín, A.P. Martínez-Sariñena,
Organometallics 16 (1997) 5849.
[9] M. Arroyo, S. Bernès, J.L. Briansó, E. Mayoral, R.L. Richards, J. Rius, H. Torrens, J.
Organomet. Chem. 599 (2000) 170.