Water, water, everywhere. Synthesis and structures of perfluoroalkyl rhodium and iridium(III) compounds containing water ligands

Article abstract of DOI:10.1039/b102482p

The aqua complexes [M(η⁵-C₅Me₅)(PMe₃)(R _F)(H₂O)]⁺[X]^-, {M = Rh, Ir; R_F = CF(CF₃)₂; X = BF₄; M = Ir; R_F = CF₂CF₃, CF₂CF₂CF₃; X = CF₃SO₃; M = Rh; R_F = CF₂CF₂CF₃; X = CF₃SO₃} have been prepared and their molecular structures determined by single crystal X-ray diffraction studies. In addition, the aqua complexes [M(η⁵-C₅Me₅)(PR₃)(R _F)(H₂O)]⁺[X]^-·0.5H ₂O {M = Ir; R = CH₃; R_F = CF(CF₃)₂; X = B(Ar_F)₄; M = Ir; R = C₆H₅; R_F = CF₂CF₂CF₃; X = BF₄} containing both inner and outer sphere water molecules have been prepared and crystallographically characterized. The complexes exhibit hydrogen bonding networks in the solid state involving the aqua ligand and the BF₄^- or CF₃SO₃^- anions, and in one case, to the BF₄^- anion and an outer sphere water molecule. In the presence of a non-coordinating anion, such as B(Ar_F)₄, hydrogen bonding to an outer sphere water molecule is still observed. A number of close contacts between the coordinated water molecule and α- and/or β-fluorines of the fluoroalkyl ligands are observed and discussed.

Full text of DOI:10.1039/b102482p

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Water, water, everywhere.† Synthesis and structures of
perfluoroalkyl rhodium and iridium(III) compounds
containing water ligands
Russell P. Hughes,a Danielle C. Lindner,a Jeremy M. Smith,a Donghui Zhang,a
Christopher D. Incarvito,b Kin-Chung Lam,b Louise M. Liable-Sands,b Roger D. Sommerb
and Arnold L. Rheingoldb
a Burke Chemistry Laboratory, Department of Chemistry, Dartmouth College, Hanover,
New Hampshire, 03755-3564, USA
b Department of Chemistry, University of Delaware, Newark, Delaware, 19716, USA
Received 6th March 2001, Accepted 17th May 2001
First published as an Advance Article on the web 16th July 2001
The aqua complexes [M(η5-C5Me5)(PMe3)(RF)(H2O)]ϩ[X]Ϫ, {M = Rh, Ir; RF = CF(CF3)2; X = BF4; M = Ir;
RF = CF2CF3, CF2CF2CF3; X = CF3SO3; M = Rh; RF = CF2CF2CF3; X = CF3SO3} have been prepared and
their molecular structures determined by single crystal X-ray diffraction studies. In addition, the aqua complexes
[M(η5-C5Me5)(PR3)(RF)(H2O)]ϩ[X]Ϫؒ0.5H2O {M = Ir; R = CH3; RF = CF(CF3)2; X = B(ArF)4; M = Ir; R = C6H5;
RF = CF2CF2CF3; X = BF4} containing both inner and outer sphere water molecules have been prepared and
crystallographically characterized. The complexes exhibit hydrogen bonding networks in the solid state involving
the aqua ligand and the BF4Ϫ or CF3SO3Ϫ anions, and in one case, to the BF4Ϫ anion and an outer sphere water
molecule. In the presence of a non-coordinating anion, such as B(ArF)4, hydrogen bonding to an outer sphere
water molecule is still observed. A number of close contacts between the coordinated water molecule and
α- and/or β-fluorines of the fluoroalkyl ligands are observed and discussed.
Hydrogen bonding appears to be an important factor in
Introduction
stabilizing many coordinated aqua ligands. In the solid state,
hydrogen bonding of the aqua ligand to counterions or oxygen-
donor solvent molecules is often observed. While hydrogen
bonding may also occur with other ligands on the metal or even
on adjacent molecules,13 the majority of the aqua complexes
reported are cationic species which contain weakly coordin-
While water is a ubiquitous ligand in classical inorganic
coordination chemistry, far fewer examples of organometallic
complexes containing aqua ligands are known. Following a
useful compilation of some crystallographically characterized
organometallic complexes containing water ligands, and a dis-
cussion of hydrogen bonding to counterions,2 some more recent
references have appeared.3 Coordinating water to a metal,
particularly in a cationic complex, increases its acidity. Thus,
deprotonation of the aqua ligand is possible to give hydroxo
complexes,4,5 which may be further transformed to give oxo
species.6–8 The aqua ligand may also hydrolyze the counter-
ion9,10 or ancillary ligands on the complex, as has been illus-
trated in some fluoroalkyl(aqua) complexes of rhodium (vide
infra).11
Ϫ 10,14
Ϫ 15
Ϫ
ating anions, such as BF4 ,
PF6 , or CF3SO3 (OTfϪ),16
hydrogen bonded to the coordinated water ligand. This type of
interaction is considered to represent a hydrogen bond if the
distance between the two heavy atoms is less than 3.0 Å.17
In a preliminary communication, we described the reaction
of the rhodium fluoroalkyl complexes 1a,b with AgBF4 to give
the crystallographically characterized aqua complexes 2a,b.11
Complexes 2a,b underwent facile hydrolysis of the α-CF2 of the
perfluoropropyl and perfluorobenzyl ligands by the coordin-
ated water, a reaction whose facility was greatly increased
Aqua complexes of the late second and third row transition
metals are also often less stable due to their relatively unfavor-
able hard–soft interactions. Consequently, the water ligand can
often be displaced by better donor ligands. In addition, the rate
of exchange of free and ligated water is often facile in such
systems and has been determined for [Rh(C5Me5)(OH2)32ϩ]-
Ϫ
Ϫ
by changing the counterion from BF4 to B(ArF)4 [ArF = 3,5-
bis(trifluoromethyl)phenyl].11 Removing the ability to hydrogen
bond to a counterion apparently increased the reactivity of the
aqua ligands in these compounds, presumably by increasing its
acidity. Here we describe the synthesis and crystallographic
characterization of a further series of fluoroalkyl(aqua) com-
plexes of rhodium and iridium that participate in various
hydrogen bonding networks in their solid state structures.11
These aqua compounds are also useful precursors to hydrido-
(fluoroalkyl) complexes and have been shown to activate
molecular H2, leading to eventual hydrogenolysis of the
iridium–carbon and carbon–fluorine bonds.18
[OTfϪ]2 (OTfϪ = CF3SO3 ) to be 8150 sϪ1.4 Other factors which
Ϫ
affect the rate of exchange of water depend on the ancillary
ligands and their ability to act as σ-donors and π-acceptors.12
Ϫ
Ligands such as C6H6 and C5H5 have been found to increase
the lability of an aqua ligand.12 For example, [Ru(η6-C6H6)-
(H2O)3]2ϩ exchanges water 640 times faster than [Ru(H2O)6]2ϩ.12
The rate of exchange of water is decreased by a factor of 2
when two aqua ligands in [Rh(η5-C5Me5)(H2O)3]2ϩ are replaced
by 2,2Ј-bipyridine to give [Rh(η5-C5Me5)(bpy)(H2O)]2ϩ.12 Steric
effects can also result in changes in lability, with dissociation
of an aqua ligand from a crowded metal center being more
favorable. For example, [Co(CH3NH2)5(H2O)]3ϩ exchanges
water 123 times faster than [Co(NH3)5(H2O)]3ϩ.12
Results
Syntheses and characterization
As observed in the synthesis of other rhodium analogues,11
treating the perfluoro-iso-propyl iodo complexes 3a,b with
AgBF4 in CH2Cl2 solvent in the presence of added water gives
† See ref. 1.
2270
J. Chem. Soc., Dalton Trans., 2001, 2270–2278
This journal is © The Royal Society of Chemistry 2001
DOI: 10.1039/b102482p

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Fig. 2 ORTEP diagram and atom numbering scheme of 4b with
Ϫ
thermal ellipsoids at 30% probability. Hydrogen atoms and the BF4
anion are omitted for clarity.
Fig. 1 ORTEP diagram and atom numbering scheme of 4a with
Ϫ
thermal ellipsoids at 30% probability. Hydrogen atoms and the BF4
anion are omitted for clarity.
the corresponding aqua complexes 4a,b in good yield. When
these reactions are carried out on a small scale in the absence of
added water, compounds 4 are still formed, implying that the
intermediate cations [M(η5-C5Me5)(PMe3)(CF(CF3)2]ϩ are
voracious scavengers of adventitious moisture, even from glass
surfaces. In all these reactions, it is important to add a solution
of the metal complex slowly to a slurry of the silver salt, other-
wise the reaction is not clean. We speculate that on addition in
the inverse sense there may be competition between water and
the terminal iodide of unreacted starting material 3 for the
vacant site on the intermediate cation [M(η5-C5Me5)(PMe3)-
(RF)]ϩ, to give a bridging iodo species whose iodide ligand is far
less easily removed by Agϩ. We have not attempted to isolate
such bridging iodo complexes. Unlike their analogues 2a,b
containing an α-CF2 group,11 the aqua complexes 4a,b appear
to be stable towards any hydrolysis chemistry.
Fig. 3 Labeling schemes used in discussing structures with (a)
perfluoro-n-alkyl ligands 5c,d,e and 8 and (b) perfluoro-i-propyl ligands
4a,b and 6.
observed in other aqua complexes,10 and a similar arrangement
is depicted more fully later in this paper for some analogous
triflate complexes. Each structure includes a half-equivalent of
CH2Cl2, which is not shown. Despite the presence of a bulky
perfluoro-i-propyl group in 4a the interligand bond angles are
surprisingly similar to those in its perfluoro-n-propyl relative
2a.11 However, while the Rh–O bond distances for 2a [2.219(5)
Å]11 and 4a [2.203(3) Å] are identical within experimental error,
and are both significantly longer than that for the benzyl com-
plex 2b [2.164(7) Å].11 they are well within the range for typical
Rh–O distances shown in Table 3. On the other hand all three
Rh–Cα bond lengths are the same within experimental error
[2.086(7) (2a), 2.113(9) (2b), 2.113(4) Å (4a)]. The angles within
the perfluoro-i-propyl ligand of 4a [C(45)–C(46)–C(47) =
108.4(4) and Rh–C(46)–F(6) = 110.3 (3)Њ] do not deviate sig-
nificantly from a tetrahedral geometry. The metric parameters
for the iridium analogue 4b do not differ significantly, except for
a slightly longer M–O distance of 2.252(7) Å.
There are several close H ؒ ؒ ؒ F contacts in 4a and 4b
as shown in Fig. 4. For the Rh complex 4a, the α-fluorine [F(4)],
a CF3 β-fluorine [F(1)], and two positions of the disordered
BF4 anion are in close contact with the aqua ligand
[O ؒ ؒ ؒ F(4) = 2.914, O ؒ ؒ ؒ F(1) = 2.834, O ؒ ؒ ؒ F(10) = 2.805,
O ؒ ؒ ؒ F(10Ј) = 2.815 Å]. These distances are within the sum of
the van der Waals’ radii of fluorine (1.55 Å as listed by Bondi;19
1.47 Å as listed by Smart20) and oxygen (1.50 Å),19 strongly
suggestive of hydrogen bonding. Clearly, some close H ؒ ؒ ؒ F
interactions may be unavoidable due to steric congestion, but it
seems more likely that those involving the aqua ligand are a
result of hydrogen bonding. In fact, the α-F(4) ؒ ؒ ؒ O interaction
shown in Fig. 4A is conformationally analogous to that
observed in 2-fluoroethanol, and which has been found to
stabilize the gauche conformation of that molecule.21
Analogous contacts are observed in the iridium analogue 4b,
with O ؒ ؒ ؒ F(1) = 2.898, O ؒ ؒ ؒ F(4) = 2.792, O ؒ ؒ ؒ F(12) = 2.694,
and O ؒ ؒ ؒ F(13Ј) = 2.886 Å.
The structures of 4a,b were determined by single crystal
X-ray diffraction studies. They are isomorphous, and ORTEP
diagrams of the cationic part of each molecule are shown in
Fig. 1 and 2. Details of the crystallographic determinations are
presented in Table 1, and some characteristic bond lengths and
angles are provided in Table 2. Because of the differing atom
numbering schemes in the various crystallographically deter-
mined structures described herein, a common system used in all
comparisons of metric parameters is described in Fig. 3.
Each structure adopts the arrangement in the crystal pre-
viously described for 2a,b, in which two cationic subunits are
Ϫ
bridged by two BF4 anions, hydrogen bonded to the aqua
ligands.11 The two halves of the dimer are related by a two-fold
rotational axis. Similar hydrogen bonded dimers have been
J. Chem. Soc., Dalton Trans., 2001, 2270–2278
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Table 1 Summary of X-ray crystallographic data collection, solution, and refinement parameters
Compound
Formula
4a
4b
5c
5d
5e
6
8
C16.5H27BClF11-
OPRh
630.52
C16.5H27BClF11-
IrOP
719.81
C16H26F8-
IrO4PS
689.60
C17H26F10-
IrO4PS
C17H26F10O4-
PRhS
C49H41BCl2-
C31H34BF11-
IrO2P
881.56
F31IrO1.5
1547.70
P21/n
P
M
739.61
650.32
¯
¯
Space group
P41212
P41212
P21/c
P1
P1
P21/n
a/Å
b/Å
c/Å
α/Њ
13.70290(10)
13.70290(10)
25.88380(10)
90
90
90
13.7267(6)
13.7267(6)
26.1103(18)
90
90
90
17.8926(2)
8.4162(2)
32.0068(2)
90
99.5855(5)
90
8.7018(2)
11.1491(2)
13.5780(2)
80.5213(5)
76.3566(5)
81.7157(7)
1255.02(3)
2
7.9856(2)
10.2371(2)
15.1273(4)
83.2160(10)
85.286(2)
82.0550(10)
1213.47(6)
2
12.9162(3)
34.8748(6)
13.2920(3)
90
98.6911(3)
90
9.3292(2)
35.4589(7)
10.4739(2)
90
107.0288(7)
90
β/Њ
γ/Њ
V/Å3
Z
4860.19(5)
8
4919.7(9)
8
4752.50(8)
8
5918.6(3)
4
3312.90(13)
4
Crystal color, habit orange block
yellow block
1.944
56.91
yellow plate
1.928
58.55
yellow plate
1.928
55.61
orange plate
1.780
9.54
orange plate
1.737
25.08
yellow plate
1.767
41.65
D(calc)/g cmϪ3
µ/cmϪ1
1.723
9.70
T /K
Total data
Unique data, Rint
R1, wR2 [I > 2σ(I )] 0.0426, 0.0737
(all data) 0.0641, 0.0806
218(2)
29356
5929, 0.0795
198(2)
15639
3861, 0.1174
0.0519, 0.0871
0.0885, 0.1006
173(2)
20916
173(2)
8600
4388, 0.0320
173(2)
7315
173(2)
27462
10390, 0.0450
173(2)
13618
4988, 0.0435
0.0378, 0.1221
0.0415, 0.1273
8861, 0.0407
0.0523, 0.1679 0.0714, 0.2745
0.0618, 0.1781 0.0741, 0.2764
5461, 0.0215
0.0454, 0.1122 0.0877, 0.2404
0.0464, 0.1130 0.1155, 0.2607
Table 2 Selected bond lengths (Å) and angles (Њ) of the crystallographically studied complexes. The labeling scheme is shown in Fig. 3
4a
4b
5c
5d
5e
6
8
M—O
M—P
M—Cα
M—cen
Cα—FA
Cα—FB
Cα—M—P
Cα—M—O
O—M—P
M—Cα—FA
M—Cα—FB
2.203(3)
2.3406(10)
2.113(4)
1.844(11)
1.409(4)
—
91.93(12)
86.9(2)
85.90(12)
110.3(3)
—
2.252(7)
2.333(4)
2.09(2)
1.890(13)
1.389(14)
—
91.3(5)
83.9(5)
85.9(3)
114.5(11)
—
2.205(6)
2.350(2)
2.090(9)
1.880(8)
1.420(10)
1.407(10)
87.3(2)
2.184(14)
2.300(4)
2.13(2)
1.849(14)
1.37(3)
1.58(4)
84.5(6)
88.2(8)
86.1(4)
125.1(16)
118.6(17)
2.175(3)
2.3151(10)
2.078(4)
1.857(9)
1.376(4)
1.400(5)
93.82(12)
83.42(13)
88.00(9)
112.6(2)
107.5(2)
2.258(9)
2.363(4)
2.160(11)
1.924(6)
1.456(14)
—
92.6(4)
83.6(4)
85.7(4)
109.1(7)
—
2.200(4)
2.3568(13)
2.116(5)
1.876(6)
1.377(6)
1.416(6)
92.03(15)
88.88(18)
88.58(11)
116.0(3)
110.6(4)
85.6(3)
87.16(16)
114.8(5)
112.6(6)
Table 3 Rh–O bond distances in some aqua complexes
Compound
Rh–O distance/Å
Ref.
[Rh(η5-C5Me5)(CF2C6F5)(OH2)(PMe3)][BF4] 2b
[Rh(η5-C5Me5)(n-C3F7)(OH2)(PMe3)][BF4] 2a
[RhCl{C4(CF3)4}(AsMe3)2(H2O)]
[RhCl(C4O2Cl2)(PMe2Ph)2(H2O)]
[RhCl2(PPh3){ONN(C6H4Me-p)O}(H2O)]
[Rh(PPh3)2(CO)(H2O)][BF4]ؒ0.5H2O
[Rh(PPh3)2(CO)(H2O)][CF3SO3]
2.164(7)
2.219(5)
2.243(11)
2.280(6)
2.202(3)
2.115(5)
2.316(12)
2.107(6)
2.215(5)
2.213(8), 2.137(8), 2.131(8)
11
11
28
29
30
31
32
33
14
4
[Rh(PPЈ)(CO)(H2O)][PF6]a
Rh(triphos)(C2H4)(H2O)][BF4]b
[Rh(η5-C5Me5)(H2O)3][CF3SO3]2
a PPЈ = 1,11-bis(diphenylphosphino)-3,6,9-trioxaundecane-P,PЈ. b triphos = MeC[(CH2)PPH2)]3.
The spectroscopic data for 4a and 4b are consistent with
their solid state structures. Their IR spectra show broad bands
centered at 3425 cmϪ1 with a shoulder at 3280 cmϪ1 due to the
antisymmetric and symmetric O–H stretching modes, and
the HOH bend at 1655 cmϪ1.2 The coordinated water in these
alkyl ligands described below, and elsewhere,18 in which such
exchange is apparently much slower. Since the perfluoro-
isopropyl ligand clearly has the largest steric requirement as
evidenced by cone angle measurements,22 and that steric
crowding is known to accelerate dissociative exchange of water
ligands,12 it seems reasonable that compounds 4 would have the
most labile aqua ligands since nearly all other factors in the
system are identical.
Analogous iridium complexes 5a,b containing perfluoro-n-
alkyl ligands were also prepared by treatment of the iodo pre-
cursors with AgBF4, and were characterized by IR and NMR
spectroscopy and by elemental analysis. The IR spectrum of 5a
shows a broad band centered at 3422 cmϪ1 while that of 5b
shows a broad band centered at 3340 cmϪ1, presumably due to
the two overlapping O–H stretching absorptions. Once again,
the coordinated water does not give a sharp signal in the
1H NMR spectrum of either complex. The two fluorines of
1
complexes does not give a sharp signal in the H NMR spec-
trum, but rather a broad concentration-dependent peak
between δ 2–4. Their 19F NMR spectra show only one signal for
the CF3 groups at room temperature. This result suggests that
the compounds are fluxional in solution, with dissociation of
water, inversion at the metal via a planar intermediate or trans-
ition state, and recoordination of water being fast on the NMR
timescale. Variable temperature NMR studies showed the CF3
resonances became non-equivalent only below Ϫ60 ЊC. Since
the resonances could not be fully separated, the rate of the
exchange process was not determined. These results are in con-
trast to analogous aqua compounds containing perfluoro-n-
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Fig. 4 ORTEP diagram of the cores of 4a (A) and 4b (B) with thermal ellipsoids at 30% probability. Dotted lines indicate those contacts closer than
3 Å between the oxygen atom of the aqua ligand and neighboring F atoms.
the α-CF2 group are diastereotopic, and appear as a strongly
coupled AX spin system, indicative of coordination to an
asymmetric metal center. Thus, in contrast to the perfluoro-
isopropyl complexes 4, the rate of water dissociation coupled
with inversion at iridium appears to be relatively slow on the
NMR timescale. These compounds also appear to be more
stable towards subsequent hydrolysis of the α-CF2 group than
do their rhodium analogues.11
Fig. 5 ORTEP diagram and atom numbering scheme of 5c with
thermal ellipsoids at 30% probability. Hydrogen atoms are omitted for
clarity.
Analogous iridium and rhodium triflate complexes 5c,d,e
were prepared by treatment of the corresponding iodo pre-
cursors with AgOTf in CH2Cl2, and were also characterized by
X-ray crystallographic analysis. The ORTEP diagrams are
shown in Fig. 5–7, with relevant bond lengths and angles shown
in Table 2. Complex 5d (Fig. 6) exhibits some disorder in the
perfluoro-n-propyl ligand; only the major occupancy structure
is shown; the middle carbon atom resides in two locations
separated by 0.68 Å causing the presence of a rotationally
disordered terminal CF3 group. The F atoms on the central
CF2 also occur in two locations; one of the positions was
unresolvably close to another and it was modeled as a diffuse
single atom.
Ϫ
Like their analogues with the BF4 counterion described
above, and elsewhere,11 all three complexes form a dimeric
structure in the solid state, held together by a hydrogen bonding
network involving the aqua ligands and the triflate counterions.
Fig. 8 illustrates this using 5c as an example. In the perfluoro-
ethyl complex 5c, which contains two crystallographically
independent molecules in the asymmetric unit related by a
pseudo inversion center. The two molecules are chemically very
similar; the major difference is that in one the fluoroalkyl group
is staggered with regard to the Cp* ring, and eclipsed in the
other. Close OH ؒ ؒ ؒ O contacts between the coordinated water
and the triflate counterion are observed as shown, all of which
are within the sum of the van der Waals’ radii of the two
oxygen atoms [O(1) ؒ ؒ ؒ O(3) = 2.724, O(1) ؒ ؒ ؒ O(2Ј) = 2.756,
O(1Ј) ؒ ؒ ؒ O(3Ј) = 2.751, O(1Ј) ؒ ؒ ؒ O(2) = 2.693 Å].19 There are
Fig. 6 ORTEP diagram and atom numbering scheme of 5d with
thermal ellipsoids at 30% probability. Hydrogen atoms are omitted for
clarity. Fluorines on the perfluoropropyl ligand are disordered and only
the major occupancy structure is shown.
also two close OH ؒ ؒ ؒ F contacts between the aqua and the
β-CF2
fluorines
of
the
perfluoroalkyl
ligand
[O(1) ؒ ؒ ؒ F(5) = 2.849, O(1Ј) ؒ ؒ ؒ F(3Ј) = 2.955 Å], as shown in
Fig. 8. Comparable OH ؒ ؒ ؒ O contacts are observed for 5d and
J. Chem. Soc., Dalton Trans., 2001, 2270–2278
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Fig. 9 ORTEP diagram and atom numbering scheme of the cation of
Fig. 7 ORTEP diagram and atom numbering scheme of 5e with
thermal ellipsoids at 30% probability. Hydrogen atoms are omitted for
clarity.
6 with thermal ellipsoids at 30% probability, showing the shared outer-
sphere water molecule. Hydrogen atoms and the tetraarylborate anion
are omitted for clarity. Dotted lines indicate those contacts closer than
3 Å between the oxygen atom of the aqua ligand and neighboring O or
F atoms.
isopropyl ligand similar to those observed in the cation of 4b.
The observation of three such interactions may indicate that the
two fluorine interactions with O(5) may involve a bifurcated
hydrogen bond. There are no close contacts from fluorines
to the outer sphere water molecule. So the aqua ligand is still
stabilized by hydrogen bonding, not to the counterion but to an
additional piggybacked water molecule. The different counter-
ion appears to have an insignificant effect on the structure of
the cationic portion of the molecule compared to 4b.
Fig. 8 ORTEP diagram and atom numbering scheme of 5c with
thermal ellipsoids at 30% probability, showing the dimeric bridged
structure. Hydrogen atoms are omitted for clarity. Dotted lines indicate
those contacts closer than 3 Å between the oxygen atom of the aqua
ligand and neighboring O or F atoms.
5e but the O–F contacts are different. Whereas it is a β-F that
is in close contact with the aqua ligand in perfluoroethyl com-
plex 5c, the perfluoro-n-propyl analogue 5e adopts a different
conformation that brings an α-fluorine F(2) to within 2.688 Å
of O(1). The disorder in the fluoropropyl ligand of 5d precludes
a meaningful comparison for this complex.
Finally, the ease in forming aqua complexes does not appear
to be dependent on using PMe3 as the phosphine. If the tri-
phenylphosphine complex 7 is treated with AgBF4 in the pres-
ence of water, the aqua complex 8 is formed. The spectral data
for this complex is similar to that of the trimethylphosphine
analogue 5b. The complex was characterized crystallograph-
ically and exhibited the same kind of outer sphere water
molecule as observed in 6; the ORTEP diagram is shown in Fig.
10, with pertinent bond lengths and angles in Table 2. As shown
in Fig. 11, this complex exhibits a more extensive hydrogen-
bonding network than any of the other complexes, involving
An example of an aqua complex containing an anion incap-
able of hydrogen bonding was also isolated. Treatment of the
perfluoroisopropyl complex 4b with NaB(ArF) results in clean
anion metathesis to give the analogous aqua complex 6,
which has been characterized spectroscopically and by crystal-
lography. The solid state IR and solution NMR spectral data of
the cation are very similar to that of the tetrafluoroborate com-
plex 4b. Since hydrogen bonding to the anion appears to be
improbable in this compound, an X-ray crystallographic study
of this complex was undertaken, and revealed a second mol-
ecule of water in the structure. The ORTEP is shown in Fig. 9,
along with relevant bond lengths and angles in Table 2. The
crystal structure reveals a close contact with the outer sphere
water molecule and the aqua ligand, with an O(1) ؒ ؒ ؒ O(2) dis-
tance of 2.518 Å, well within the sum of the van der Waals’
radii of the two oxygen atoms. There also close contacts
between O(1) ؒ ؒ ؒ F(1) of 2.804 and O(1) ؒ ؒ ؒ F(5) of 2.805 Å
between the aqua ligand two fluorine atoms of the perfluoro-
Ϫ
the aqua ligand, the outer sphere water molecule and the BF4
counterion. The O(1) ؒ ؒ ؒ O(2) distance of 2.679 Å is slightly
longer than that observed in 6, and the bound water exhibits
interactions with two fluorines in the disordered BF4Ϫ counter-
ion, with O(1) ؒ ؒ ؒ F(13) = 2.769 and O(1) ؒ ؒ ؒ F(13Ј) = 2.642 Å.
The perfluoro-n-propyl group adopts a conformation such that
both the β-fluorine atoms are within hydrogen bonding distance
to the aqua ligand with O(1) ؒ ؒ ؒ F(3) = 2.851 and O(1) ؒ ؒ ؒ F(4) =
2.739Å.Theouterspherewatermoleculeliesoutsidetherangeof
H-bonding interactions with the counterion or the fluoroalkyl
ligand.
2274
J. Chem. Soc., Dalton Trans., 2001, 2270–2278

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Experimental
General Procedures
All reactions were performed in oven-dried glassware, using
standard Schlenk techniques, under an atmosphere of nitrogen,
which had been deoxygenated over BASF catalyst and dried
over molecular sieves, or in a Braun drybox. Solvents were
deoxygenated and dried over activated alumina using an appar-
atus modified from that described in the literature.23 1H (300
MHz), 19F (282 MHz) and 31P (121.4 MHz) NMR spectra
were recorded on a Varian Unity-300 Spectrometer at 25 ЊC.
Chemical shifts are reported as ppm downfield of TMS (1H,
referenced to solvent) or internal CFCl3 (19F) and external
85% H3PO4 (31P). Coupling constants are reported in Hz.
IR spectra were recorded on a Perkin-Elmer 1600 FTIR
spectrophotometer. Elemental analyses were performed by
Schwartzkopf (Woodside, NY)
Fig. 10 ORTEP diagram and atom numbering scheme of the cation of
8 with thermal ellipsoids at 30% probability, showing the shared outer-
sphere water molecule. Hydrogen atoms and the tetrafluoroborate
anion are omitted for clarity.
Perfluoroalkyl iodides were purchased from PCR and used
without further purification. Trimethylphosphine was obtained
from Aldrich, silver tetrafluoroborate from ACROS, and silver
trifluoromethanesulfonate from Johnson Matthey/Alfa Aesar.
The complexes [Rh(η5-C5Me5)(CO)2],24,25 [Ir(η5-C5Me5)(CO)2],
[Ir(η5-C5Me5)(CO)(CF2CF2CF3)I],22
[Ir(η5-C5Me5)(PMe3)-
(RF)I] {RF = CF2CF3, CF2CF2CF3, CF(CF3)2},22 [Rh(η5-
C5Me5)(PMe3)(CF2CF2CF3)I]11 and Na[B{3,5-(CF3)C6H3}4],26
were prepared as previously reported.
Syntheses
[Rh(ꢀ5-C5Me5){CF(CF3)2}I(CO)]. Rh(η5-C5Me5)(CO)2 (250
mg, 0.850 mmol) was dissolved in benzene (12 mL) to give a
pale orange colored solution. Then i-C3F7I (327 mg, 1.1 mmol)
was added as a solution in benzene in two 1.5 mL portions.
Immediately, the reaction mixture became darker red in color
and effervesced. The reaction mixture was stirred at room tem-
perature for 2 h, and the volatiles were removed under vacuum
affording a red solid (357 mg, 75%). Analytically pure samples
were obtained by dissolving the product in methylene chloride
and allowing hexanes to diffuse slowly into the methylene
chloride layer at Ϫ20 ЊC. Mp: >200 ЊC. 1H NMR (CDCl3):
δ 2.03 (15H, C5Me5); (C6D6): δ 1.41 (15H, C5Me5). 19F NMR
(CDCl3): δ Ϫ66.5 (m, 3F, CF3), Ϫ69.0 (m, 3F, CF3), Ϫ165.4 (s,
1F, CF); (C6D6): δ Ϫ65.2 (m, 3F, CF3), Ϫ68.3 (m, 3F, CF3),
Ϫ166.2 (s, 1F, CF). IR (C6H6): νCO = 2065 cmϪ1. Anal. calc. for
C14H15F7IORh: C, 29.92; H, 2.64; found: C, 29.93; H, 2.61%.
Fig. 11 ORTEP diagram of the core of 8 with thermal ellipsoids at
30% probability. Dotted lines indicate those contacts closer than 3 Å
between the oxygen atom of the aqua ligand and neighboring O or F
atoms.
[Rh(ꢀ5-C5Me5){CF(CF3)2}I(PMe3)] (3a). [Rh(η5-C5Me5)-
{CF(CF3)2}I(CO)] (200 mg, 0.356 mmol) was dissolved in
benzene (5 mL) and PMe3 (37 mL, 0.356 mmol) was added. The
reaction was monitored by IR until the terminal carbonyl band
disappeared (ca. 2 h). The volatiles were removed under
vacuum to give an orange powder, which was washed with
hexanes and dried, again under vacuum, affording the product,
Conclusions
1
(911 mg, 91%). Mp: 185–189 ЊC. H NMR (CDCl3): δ 1.82 (d,
JHRh = 2.9, 15H, C5Me5), 1.68 (d, JHP = 10.5, 9H, PMe3);
(C6D6): δ 1.40 (d, JHRh = 3.2, 15H, C5Me5), 1.28 (d, JHP = 10.5,
JHRh = 1.7, 9H, PMe3). 19F NMR (CDCl3): δ Ϫ62.2 (m, CF3),
Ϫ69.5 (m, CF3), Ϫ161.8 (m, CF); (C6D6): δ Ϫ61.2 (m, CF3),
Ϫ68.8 (m, CF3), Ϫ160.9 (m, CF). 31P{1H} NMR (CDCl3): δ 1.8
(dm, JPRh = 151, PMe2Ph); (C6D6): δ 1.3 (dm, JPRh = 150, PMe3).
Anal. calc. for C16H24F7IPRh: C, 31.50; H, 3.97; found: C,
31.45; H, 4.08%.
Rhodium() and iridium() cations containing fluoroalkyl
and aqua ligands are readily prepared from the corresponding
iodides. Even in the absence of water, the complexes are easily
formed, suggesting that these d6 M() perfluoroalkyl cations
are very hydrophilic, perhaps due to the relative hardness of the
metal center induced by the perfluoroalkyl ligand.
The tendency of these complexes to form hydrogen bonds to
counterions or to additional outer sphere water molecules dom-
inates the solid state structures of these compounds. It also
seems clear that close contacts between fluorines on the fluoro-
alkyl group and the coordinated water molecule can play a role
in determining the solid state conformation of the perfluoro-
alkyl ligand. Whether these intramolecular contacts are truly
examples of hydrogen bonding, or whether they are dictated
by the steric requirements of all the ligands, cannot be
distinguished.
[Rh(ꢀ5-C5Me5){CF(CF3)2}(OH2)(PMe3)][BF4] (4a). [Rh(η5-
C5Me5)(n-C3F7)I(PMe3)] (3a) (300 mg, 0.492 mmol) was dis-
solved in CH2Cl2 (10 mL) to give an orange colored solution
and distilled H2O (9 µL, 0.492 mmol) was added. Another flask
was charged with AgBF4 (115 mg, 0.590 mmol) and CH2Cl2
(10 mL) was added. As the rhodium–water solution was
cannula transferred (slowly over about 10 min) to the stirring
J. Chem. Soc., Dalton Trans., 2001, 2270–2278
2275

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slurry of the silver salt, a fluffy pale yellow precipitate formed
and the solution became more yellow. It is important to carry
out the addition in this manner. The reaction mixture was stirred
for 20 min after which it was filtered via cannula. The filtrate
was concentrated to about half the original volume and
hexanes (10 mL) were added to precipitate the product. The last
step was repeated twice more and after concentrating the last
time, the supernatant was removed. The yellow–orange solid
was dried under vacuum giving a fluffy yellow, analytically
via a cannula to a slurry of AgBF4 (92 mg, 471 µmol) in CH2Cl2
(10 mL). It is important to carry out the addition in this manner.
There was immediate formation of a light colored precipitate.
The reaction was stirred at room temperature for 1 h, by which
time the precipitate had turned black. Excess water was
removed by addition of MgSO4, and the resultant slurry filtered
to give a yellow solution. The solvent was removed in vacuo to
give a yellow powder, which was washed with hexanes and dried
under vacuum. Crystallization from CH2Cl2–hexane afforded
the product (231 mg, 77%). 1H NMR (CDCl3): δ 1.71 (d,
JHH = 2, 15H, C5Me5), 1.70 (d, JPH = 11, 9H, PMe3). 19F NMR
(CD2Cl2): δ Ϫ79.32 (t, JFF = 12, 3F, CF3); Ϫ71.96 (m, JAB = 261,
1F, CαFA), Ϫ94.96 (m, JAB = 261, 1F, CαFB), Ϫ116.40 (m, 2F,
CβF2), Ϫ149.67 (s, 4F, BF4). 31P{1H} NMR (CD2Cl2): δ Ϫ21.71
(br s, PMe3). IR (KBr): νOH = 3340 cmϪ1 (br). Anal. calc. for
C16H27BF11IrOP (677.35): C, 28.37; H, 3.87; found: 28.46; H,
3.79%.
1
pure, solid yield: 61–77%. Mp: decomposes up to 155 ЊC. H
NMR (CD2Cl2, Ϫ49 ЊC): δ 3.36 (br s, H2Obound), 2.16 (br s,
H2Ofree), 1.55 (d, JHRh = 3.3, 15H, C5Me5), 1.53 (dd, JHP = 12.9,
JHRh, HF = 2.7, 9H, PMe3); (CD2Cl2, 21 ЊC): δ 2.87 (br s,
H2Obound), 1.60 (d, JHRh = 3.4, 15H, C5Me5), 1.59 (dd,
JHP = 10.7, JHRh, HF = 2.4, 9H, PMe3); (CDCl3): δ 2.96 (s, 2H,
H2O), 1.62 (d, JHRh = 3.4, 15H, C5Me5), 1.61 (dd, JHP = 10.5,
JHRh, HF = 2.2, 9H, PMe3). 19F NMR (CD2Cl2, Ϫ49 ЊC): δ Ϫ68.8
(s, 3F, CF3), Ϫ69.0 (s, 3F, CF3), Ϫ149.0 (s, 4F, BF4), Ϫ186.6 (s,
1F, CF); (CD2Cl2, 21 ЊC): δ Ϫ68.9 (s, 6F, CF3), Ϫ149.9 (s, 4F,
BF4), Ϫ185.6 (s, 1F, CF); (CDCl3): δ Ϫ69.2 (s, 6F, 2CF3),
Ϫ150.2 (s, BF4), Ϫ185.5 (s, 1F, CF). 31P{1H} NMR (CD2Cl2,
Ϫ49 ЊC): δ 6.5 (ddm, JPRh = 154, JPF = 26, JPF = 8, PMe3);
(CD2Cl2, 21 ЊC): δ 4.9 (dm, JPRh = 149, PMe3); (CDCl3): δ 4.9
[Ir(ꢀ-C5Me5)(PMe3)(CF2CF3)(H2O)][OSO2CF3] (5c).
A
yellow solution of [Ir(η5-C5Me5)(PMe3)(CF2CF3)I] (400 mg,
616 µmol) in CH2Cl2 (10 mL) was slowly added to a slurry of
AgOTf (175 mg, 616 µmol) in CH2Cl2 (5 mL). It is important to
carry out the addition in this manner. The color of the solution
faded with the formation of a white precipitate. The reaction
mixture was stirred overnight, and the solvent removed by
vacuum pumping. The residue was extracted with CH2Cl2 and
filtered to give a yellow solution. Yellow crystals were obtained
by slow evaporation (335 mg, 79%). 1H NMR (CD2Cl2): δ 1.70
(s, 15H, C5Me5), 1.66 (d, JPH = 10.5, 9H, PMe3). 19F NMR
(CD2Cl2): δ Ϫ76.40 (d, JAB = 251, 1F, CαFA), Ϫ79.18 (s, 3F,
OSO2CF3), Ϫ82.54 (s, 3F, CF3), Ϫ90.87 (d, JAB = 251, 1F,
CαFB). 31P{1H} NMR (CD2Cl2): δ Ϫ24.0 (m, PMe3). Anal. calc.
for C16H26F8O4IrPS (689.60): C, 27.87; H, 3.80; found: C, 28.42;
H, 3.96%.
(br d, JPRh = 151, PMe3). IR (CH2Cl2) νHO = 3602, 3355 cmϪ1
.
Anal. calc. for C16H26BF11OPRh: C, 32.68; H, 4.46; found: C,
32.35; H, 4.19%.
[Ir(ꢀ5-C5Me5)(PMe3){CF(CF3)2}(H2O)][BF4] (4b). A solution
of [Ir(η5-C5Me5)(PMe3){CF(CF3)2}I] (500 mg, 715 µmol) in
CH2Cl2 (10 mL) with added distilled water (1 mL) was added
via a cannula to a slurry of AgBF4 (300 mg, 1.54 µmol) in
CH2Cl2 (10 mL). There was immediate formation of a light
colored precipitate. It is important to carry out the addition in
this manner. The reaction was stirred at room temperature for
1 h, by which time the precipitate had turned black. Excess
water was removed by addition of MgSO4, and the resultant
slurry filtered to give a yellow solution. The solvent was
removed in vacuo to give a yellow powder, which was washed
with hexanes and dried under vacuum. (467 mg, 99%). 1H
NMR (CD2Cl2): δ 1.66 (dd, JPH = 11, JHH = 2, 9H, PMe3); 1.61
(d, JPH = 2, 15H, C5Me5); 19F NMR (CD2Cl2): δ Ϫ69.91 (s, 6F,
CF3), Ϫ149.56 (s, 4F, BF4), Ϫ180.06 (s, 1F, CF). 31P{1H} NMR
(CD2Cl2): δ Ϫ69.90 (br s, PMe3). IR (KBr): νOH = 3442 cmϪ1
(br). Anal. calc. for C16H27BF11IrOP: (677.35) C, 28.37; H, 3.87;
found: C, 28.57; H, 3.98%.
[Ir(ꢀ5-C5Me5)(PMe3)(CF2CF2CF3)(H2O)][OSO2CF3] (5d). A
solution of [Ir(η5-C5Me5)(PMe3){CF(CF3)2}I] (200 mg, 286
µmol) in CH2Cl2 (5 mL) was slowly added to a slurry of AgOTf
(81 mg, 315 µmol) in CH2Cl2 (5 mL). It is important to carry out
the addition in this manner. There was immediate formation of
a white precipitate. After 30 min, the solution was filtered via a
cannula to give a yellow solution. The solvent was removed by
vacuum pumping to give a yellow solid (124 mg, 59%). 1H
NMR (CD2Cl2): δ 1.69 (s, 15H, C5Me5), 1.68 (d, JPH = 11.7, 9H,
PMe3), 1.68 (d, JPH = 1.8, 15H, C5Me5). 19F (CD2Cl2): δ Ϫ78.67
(d, JAB = 281, 1F, CαFA), Ϫ78.99 (s, 3F, OSO2CF3), Ϫ79.86 (br
s, 3F, CF3), Ϫ87.87 (d, JAB = 281, 1F, CαFB), Ϫ115.95 (d,
JAB = 284, 1F, CβFA), Ϫ118.41 (d, JAB = 284, 1F, CβFB). 31P{1H}
NMR (CD2Cl2): δ Ϫ 20.92 (br s, PMe3). IR (KBr): νOH = 3346,
3238 cmϪ1. Anal. calc. for C17H26F10IrO4PS (739.61): C, 27.61;
H, 3.54; found: C, 27.57; H, 3.18%.
[Ir(ꢀ5-C5Me5)(PMe3)(CF2CF3)(H2O)][BF4] (5a). A solution
of [Ir(η5-C5Me5)(PMe3)(CF2CF3)I] (800 mg, 1.23 mmol) in
CH2Cl2 (10 mL) with added distilled water (1 mL) was added
via a cannula to a slurry of AgBF4 (264 mg, 135 mmol) in
CH2Cl2 (10 ml). It is important to carry out the addition in this
manner. There was immediate formation of a light colored
precipitate. The reaction was stirred at room temperature for
1 h, by which time the precipitate had turned black. Excess
water was removed by addition of MgSO4, and the resultant
slurry filtered to give a yellow solution. The solvent was
removed in vacuo to give a yellow powder, which was washed
with hexanes and dried under vacuum. Crystallization from
CH2Cl2–hexane afforded the product (644 mg, 84%). 1H NMR
(CDCl3): δ 1.70 (s, 15H, C5Me5), 1.68 (d, JPH = 11, 9H, PMe3).
19F NMR (CDCl3): δ Ϫ82.29 (s, 3F, CF3); Ϫ82.22 (d, JAB = 303,
1F, CαFA), Ϫ90.10 (d, JAB = 303, 1F, CαFB), Ϫ150.33 (s, 4F,
BF4). 31P{1H} NMR (CDCl3): δ Ϫ23.48 (dd, JPF = 16.0,
JPF = 8.0, PMe3). IR (KBr): νOH = 3422 cmϪ1 (br). Anal. calc. for
C15H26BF9IrOP (627.34): C, 28.72; H, 4.18; found: C, 28.96; H,
4.43%.
[Rh(ꢀ5-C5Me5)(CF2CF2CF3)(H2O)][OSO2CF3] (5e). [Rh(η5-
C5Me5)(n-C3F7)(I)(PMe3)] (250 mg, 0.410 mmol) was dissolved
in CH2Cl2 (5 mL) to give a red–orange colored solution. Then,
AgSO3CF3 (105 mg, 0.410 mmol) was added to a different
Schlenk flask and CH2Cl2 (12 mL) was added. The rhodium
solution was cannula transferred to the silver triflate mixture,
dropwise. It is important to carry out the addition in this manner.
Additional CH2Cl2 (3 mL) was added to the rhodium flask and
the contents were transferred to the reaction mixture via
cannula. The reaction mixture was stirred for 30 min over which
time a white precipitate was formed. The solution was dried
over MgSO4. The mixture was then filtered and washed with
CH2Cl2 several times. The yellow solution was concentrated
and hexane was added to precipitate the product as an orange
powder in 94% yield (241 mg). Mp: 172–173 ЊC. 1H NMR
(CDCl3): δ 1.69 (d, JHRh = 2.7, C5Me5), 1.63 (d, JHP = 11.2,
PMe3). 19F NMR (CDCl3): δ Ϫ78.4 (d, JAB = 271, 1F, CαFA),
Ϫ78.6 (s, 3F, OTf ), Ϫ79.9 (t, JFF = 11, 3F, CF3), Ϫ85.4 (d,
[Ir(ꢀ5-C5Me5)(PMe3)(CF2CF2CF3)(H2O)][BF4] (5b). A solu-
tion of [Ir(η5-C5Me5)(PMe3)(CF2CF2CF3)I] (300 mg, 429 µmol)
in CH2Cl2 (10 mL) with added distilled water (1 mL) was added
2276
J. Chem. Soc., Dalton Trans., 2001, 2270–2278

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JAB = 271, 1F, CαFB), Ϫ115.6 (d, JAB = 288, 1F, CβFA), Ϫ118.7
(d, JAB = 288, 1F, CβFB). 31P{1H} NMR (CDCl3): δ 7.6 (dm,
JPRh = 151, PMe3); (C6D6): δ 7.6 (ddm, JPRh = 155, JPF = 35,
PMe3). Anal. calcd. for C17H24F10O3PRhS: C, 31.40; H, 4.03;
found: C, 31.99; H, 3.81%.
DIFABS27 absorption corrections were applied to the data sets
of 5c and 5d.
The asymmetric unit of 5c contains two cationic iridium
complexes and two triflate counterions. The atoms C(12), and
F(3) to F(7) of PrF/OTf are equally disordered over two
positions. All non-hydrogen atoms, except C(12), C(12Ј) and
the fluorine atoms of the n-C3F7 group for 5d were refined with
anisotropic coefficients. The hydrogen atoms of the ligated
water molecule for 5c and 5d were ignored for both structures
and all other hydrogen atoms were treated as idealized
contributions.
For 4a and 4b the systematic absences in the diffraction data
are uniquely consistent for the tetragonal space groups P41212
or P43212. The structure was solved using direct methods,
completed by subsequent difference Fourier syntheses and
refined by full-matrix least-squares procedures. Semi-empirical
absorption corrections were applied to the data sets. Structure
refinement indicated that the correct space group was P41212,
which was verified by refinement of the Flack parameter
[Ϫ0.03(3) for 4a; 0.009(2) for 4b]. The asymmetric unit contains
one ion pair and one-half of a solvent molecule of dichloro-
methane, which is located on a two-fold axis. Three fluorine
atoms in the tetrafluoroborate counterion are rotationally
disordered around the fourth boron–fluorine axis in two orien-
tations with a 60 : 40 distribution. All non-hydrogen atoms
were refined with anisotropic displacement coefficients. The
hydrogen atoms on the aqua ligand were located from the dif-
ference map and refined. All other hydrogen atoms were treated
as idealized contributions.
For 6 the phenyl rings and the pentamethylcyclopentadienyl
rings were fixed as rigid planar groups to conserve data. The
fluorine atoms of the B(ArF)4 counterion F(24)–F(26), F(31)–
F(33), F(44)–F(46), F(51)–F(53) were disordered over two
positions, 60 : 40 and F(34)–F(36), F(41)–F(43), F(54)–F(56)
were equally disordered over two positions. The fluorine atoms,
F(54)–F(56) and F(54Ј)–F(56Ј) were refined isotropically. The
carbon atom of the dichloromethane solvent molecule, C(61)
was disordered over two positions, 60 : 40. A water solvent mol-
ecule was located from the difference map, and its occupancy
was refined to 50%. All other non-hydrogen atoms were refined
with anisotropic displacement coefficients. The hydrogen atoms
on both the solvent water molecule and the coordinated water
molecule could not be located from the difference map and were
ignored. All other hydrogen atoms were treated as idealized
contributions.
[Ir(ꢀ5-C5Me5)(PMe3){CF(CF3)2}(H2O)][B{3,5-(CF3)2C6H34]ؒ
0.5H2OؒCH2Cl2 (6). To a yellow solution of [Ir(η5-C5Me5)-
(PMe3){CF(CF3)2}(H2O)][BF4] (20 mg, 30 µmol) in CH2Cl2
(5 mL) was added a solution of Na[B{3,5-(CF3)2C6H3}4] (29
mg, 32 µmol) in CH2Cl2 (5 mL). The reaction mixture darkened
a little, and was stirred at room temperature for 30 min, and
filtered to give a yellow solution. The solvent was removed by
rotary evaporation, and the residue dissolved in a minimum of
diethyl ether. Hexanes (ca. 20 mL) was added to form a yellow
precipitate. The solvent was evaporated down to ca. 10 mL, the
yellow solid filtered and dried in vacuo (35 mg, 80%).1H NMR
(CD2Cl2): δ 7.72 (s, 8H, o-H), 7.57 (s, 4H, p-H), 2.42 (br s, 2H,
OH2), 1.66 (dd, JPH = 10.5, 9H, PMe3), 1.53 (d, JPH = 1.8, 15H,
C5Me5). 19F NMR (CD2Cl2): δ Ϫ63.24 (s, 24F, CF3), Ϫ69.90 (br
s, 6F, CF3). 31P{1H} NMR (CD2Cl2): δ Ϫ18.7 (br s, PMe3). IR
(KBr): νOH = 3690, 3629 cmϪ1. Anal. calc. for C46H40BF31-
IrO2Pؒ0.5CH2Cl2 (1490.23): C, 37.48; H, 2.77; found: C, 38.73;
H, 2.81%.
[Ir(ꢀ5-C5Me5)(PPh3)(CF2CF2CF3)I] (7). [Ir(η5-C5Me5)(CO)-
(CF2CF2CF3)I] (100 mg, 154 µmol) and PPh3 (44 mg, 169 µmol)
were dissolved in toluene (10 ml) to give a yellow solution which
was heated to reflux and monitored by IR spectroscopy. On
completion, as evidenced by disappearance of the CO band
(24 h), the volatiles were removed by vacuum pumping. The
resultant yellow powder was crystallized from CH2Cl2–heptane
1
to give the product (75 mg, 55%). H NMR (CD2Cl2): δ 7.49–
7.20 (m, 15H, PPh3), 1.52 (d, JPH = 1.8, 15H, C5Me5). 19F NMR
(CD2Cl2): δ Ϫ59.03 (dd, JAB = 285.8, JPF = 38.7, 1F, CαFA),
Ϫ63.14 (d, JAB = 274.9, 1F, CαFB), Ϫ80.28 (t, JFF = , 3F, CF3),
Ϫ111.28 (d, JAB = 279.7, 1F, CβFA), Ϫ112.21 (d, JAB = 277.1, 1F,
CβFB). 31P{1H} NMR (CD2Cl2): δ Ϫ0.06 (d, JPF = 38.7). Anal.
calc. for C31H30F7IrIP (885.62): C, 42.04; H, 3.41; found C,
41.92; H 3.68%.
[Ir(ꢀ-5C5Me5)(PPh3)(CF2CF2CF3)(H2O)][BF4]ؒH2O (8). [Ir-
(η5-C5Me5)(PPh3)(CF2CF2CF3)I] (75 mg, 85 µmol) in CH2Cl2
(10 ml) with distilled water (1 ml) was added slowly to a slurry
of AgBF4CH2Cl2 (10 ml). A yellow slurry/solution formed.
After 1 h, MgSO4 was added, and the mixture filtered to give a
yellow solution. The solvent was removed by rotary evapor-
All software and sources of the scattering factors are con-
tained in the SHELXTL (5.1) program library.
CCDC reference numbers 164768–164774.
See http://www.rsc.org/suppdata/dt/b1/b102482p/ for crystal-
lographic data in CIF or other electronic format.
1
ation to give a yellow solid (38 mg, 51%). H NMR (CD2Cl2):
δ 7.50 [br s, 15H, P(C6H5)3], 1.39 (d, JPH = 1.2, 15H, C5Me5). 19
F
NMR (CD2Cl2): δ Ϫ71.0 (br s, 2F, α-CF2), Ϫ80.23 (s, 3F, CF3),
Ϫ114.8 (br s, 2F, β-CF2), Ϫ150.25 (s, 4F, BF4). 31P{1H} NMR
(CD2Cl2): δ 14.5 (br s, PPh3). Anal. calc. for C31H32BF11-
IrOPؒH2O (881.57): C, 42.23; H, 3.97; found: C, 41.92; H,
3.50%.
References
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Crystal structure analyses
All crystals were grown by crystallization from slowly cooled
CH2Cl2–hexane solutions. Crystal data collection, and refine-
ment parameters are given in Table 1. The data were collected
on a Siemens P4 diffractometer equipped with a SMART CCD
detector. The systematic absences in the diffraction data are
uniquely consistent for the reported space group for 4b, 5d, 5e,
6 and 8. For 5d and 5e, no evidence of symmetry higher than
triclinic was observed in the diffraction data, and the centro-
¯
symmetric space group option, P1, was chosen, which yielded
chemically reasonable and computationally stable results of
refinement. The structure was solved using direct methods,
completed by subsequent difference Fourier syntheses and
refined by full-matrix least-squares procedures. Empirical
J. Chem. Soc., Dalton Trans., 2001, 2270–2278
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