Hydrido-derivatives of [Ir4(CO)10(diphosphine)]: X-ray analyses of [Ir4H(CO)9(μ-Ph2PH(CH3)PPh2)]- and [Ir4 H(CO)9(μ-Ph2P(CH2)nPPh2)]- (n = 2, 3)

Article abstract of DOI:10.1016/j.ica.2006.02.030

Some novel hydrido-anions of general formula [Ir₄H(CO)₉(μ-L-L)]^- (L-L = Ph₂PCH(CH₃)PPh₂, Ph₂P(CH₂)₂PPh₂, Ph₂P(CH₂)₃PPh₂ and Ph₂AsCH₂AsPh₂) have been obtained by the reaction of [Ir₄(CO)₁₀(μ-L-L)] with the base 1,8-diazabicyclo[5.4.0]undec-7-ene in wet dichloromethane. According to IR and ¹H, ³¹P and ¹³C NMR data at low temperature, these anionic derivatives display a single conformation in solution: three edge-bridging COs around the triangular basal face and both the hydride and the bidentate ligands located in axial positions relative to this face. The structures of four compounds were established by X-ray diffraction studies, which confirmed the configuration proposed on the basis of spectroscopic data.

Full text of DOI:10.1016/j.ica.2006.02.030

Inorganica Chimica Acta 359 (2006) 2417–2423
www.elsevier.com/locate/ica
Hydrido-derivatives of [Ir4(CO)10(diphosphine)]: X-ray analyses
of [Ir4H(CO)9(l-Ph2PH(CH3)PPh2)]ꢀ and
[Ir4H(CO)9(l-Ph2P(CH2)nPPh2)]ꢀ (n = 2, 3)
a,
a
b
b
c
Renzo Ros *, Augusto Tassan , Serena Detti , Raymond Roulet , Kurt Schenk
a
Dipartimento dei Processi Chimici dell’Ingegneria, Via Marzolo 9, 35131 Padua, Italy
b
Ecole Polytechnique Fe´de´rale de Lausanne, ISIC, CH-1015 Lausanne, Switzerland
Ecole Polytechnique Fe´de´rale de Lausanne, LCR1, CH-1015 Lausanne, Switzerland
c
Received 30 November 2005; received in revised form 8 February 2006; accepted 23 February 2006
Available online 3 March 2006
Abstract
Some novel hydrido-anions of general formula [Ir4H(CO)9(l-L–L)]ꢀ (L–L = Ph2PCH(CH3)PPh2, Ph2P(CH2)2PPh2, Ph2P(CH2)3PPh2
and Ph2AsCH2AsPh2) have been obtained by the reaction of [Ir4(CO)10(l-L–L)] with the base 1,8-diazabicyclo[5.4.0]undec-7-ene in wet
1
dichloromethane. According to IR and H, 31P and 13C NMR data at low temperature, these anionic derivatives display a single con-
formation in solution: three edge-bridging COs around the triangular basal face and both the hydride and the bidentate ligands located in
axial positions relative to this face. The structures of four compounds were established by X-ray diffraction studies, which confirmed the
configuration proposed on the basis of spectroscopic data.
Ó 2006 Elsevier B.V. All rights reserved.
Keywords: Cluster; Iridium; Carbonyl; Diphosphine; Hydrido; Crystal structure
1. Introduction
ethane
(5),
1,2-bis(diphenylphosphino)ethane
(6),
1,3-bis(diphenylphosphino)propane (7) and bis(diphenylar-
sino)methane (8), and we report the synthesis and charac-
terization of their anionic hydrido-derivatives [B][Ir4H-
(CO)9(l-L–L)] (L–L = Ph2PCH(CH3)PPh2 with B = PPN
(Ph3PNPPh3) (5a), dbuH (5b), dbuCH3 (5c); L–L =
Ph2P(CH2)nPPh2: n = 2 (6a); 3 (7a); L–L = Ph2AsCH2-
AsPh2 (8a) with B = PPN (Scheme 1). The molecular struc-
tures of 5b, 5c, 6a and 7a determined by X-ray diffraction
are also reported.
The reactions of [Ir4(CO)10(l-Ph2PCH2PPh2)] (1) with
bases have been examined previously [1]. In the presence
of excess of anhydrous KOH in CH2Cl2 at ꢀ20 °C, the
Ph2PCHPPh2)]ꢀ (2) is rapidly formed, which converts in
a second step into the decarbonylated anion [Ir4(CO)9(l3-
Ph2PCHPPh2)]ꢀ (3). Similar reactions with excess of the
weaker bases K2CO3 or 1,8-diazabicyclo[5.4.0]undec-7-
ene (dbu) produce the hydrido-derivative [Ir4H(CO)9(l-
Ph2PCH2PPh2)]ꢀ (4).
bis(diphosphino)-methanide
derivative
[Ir4(CO)10(l-
2. Experimental
This study has now been extended to the series of
di-substituted clusters [Ir4(CO)10(l-L–L)] (L–L = bis(diph-
enylphosphino)methane (1), 1,1-bis(diphenylphosphino)-
2.1. General
[Ir4(CO)10(L–L)] (L–L = Ph2PCH(CH3)PPh2 (ddpmMe)
[2], Ph2P(CH2)2PPh2 (dppe), Ph2P-(CH2)3PPh2 (dppp) [3],
Ph2AsCH2AsPh2 (dpam) [4]), and their analogues enriched
in 13CO [5] were prepared as previously described. KOH
*
Corresponding author. Tel.: +39 49 8275518; fax: +39 49 8275525.
E-mail address: renzo.ros@unipd.it (R. Ros).
0020-1693/$ - see front matter Ó 2006 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2006.02.030

2418
R. Ros et al. / Inorganica Chimica Acta 359 (2006) 2417–2423
g
obtained suspension was cooled at ꢀ20 °C overnight. The
g
e
yellow-orange precipitate was recrystallised at ꢀ30 °C from
dichloromethane/isopropanol in the presence of [PPN]Cl
(0.15 g), and the crystals of 5a were washed with cold iso-
propanol and then with pentane.
a
+
d
f
[B]
5a. As yellow micro-crystals, yield 0.60 g (80%). Anal.
Calc. for [C71H55Ir4NO9P4]: C, 43.53; H, 2.83; N, 0.72; P,
6.32. Found: C, 43.28; H, 2.71; N, 0.78; P, 6.17%. IR
b
a
H
XPh
f
2
(CH2Cl2)mCO: 2007 s, 1958 vs, 1827 w, 1767 m, cmꢀ1. H
XPh
1
2
(CHR)n
X
NMR (CD3CN, 240 K) dH: 7.0–7.3 (50H, m, Ph); 2.58
(1H, m, CH); 0.36 (3H, m, CH3); ꢀ15.4 (1H, s, Ir–H).
6a. As yellow-orange micro-crystals, yield 0.57 g (77%).
Anal. Calc. for [C71H55Ir4NO9P4]: C, 43.53; H, 2.83; N,
0.72; P, 6.32. Found: C, 43.65; H, 2.90; N, 0.81, P,
6.19%. IR (CH2Cl2)mCO: 2026 m, 2007 m, 1992 m, 1958
L − L
B
R
n
4* dppm
5a dppmMe
5b dppmMe
5c dppmMe
6a dppe
7a dppp
8a dpam
PPN
PPN
P
P
P
P
P
P
As
H
1
1
1
1
2
3
1
CH3
CH3
CH3
H
H
H
dbuH
dbuCH3
PPN
1
vs, 1832 w, 1765 s, cmꢀ1. H NMR (CD2Cl2, 298 K) dH:
PPN
PPN
7.5–7.3 (50H, m, Ph); ꢀ16.1 (1H, s, Ir–H).
7a. As yellow-orange crystals, yield 0.65 g (87%). Anal.
Calc. for [C72H57Ir4NO9P4]: C, 43.83; H, 2.91; N, 0.71; P,
6.28. Found: C, 43.63; H, 3.66; N, 0.84, P. 6.14%. IR
(CH2Cl2) mCO: 2026 m, 2008 m, 1988 m, 1958 vs, 1827 w,
Scheme 1. Arrangement of the ligands in the hydrido-derivatives (*Ref.
[1]).
(Fluka) was dried at 150 °C under reduced pressure (10ꢀ4
mm Hg). 1,8-diazabicyclo[5.4.0]undec-7-ene (dbu, >98%
Fluka) was dried with KOH and distilled under reduced
pressure. [dbuCH3]I was prepared as described in the litera-
ture [6]. Dichloromethane, pentane and hexane were
refluxed and distilled from calcium hydride. CD2Cl2 and
CDCl3 were treated with anhydrous Na2CO3 and stored
1764 s, cmꢀ1 1H NMR (CD2Cl2, 298 K) dH: 7.6–7.4
.
(50H, m, Ph); ꢀ15.3 (1H, s, Ir–H).
8a. As orange-red crystals, yield 0.62 g (81%). Anal.
Calc. for [C70H53As2Ir4O9P2]: C, 41.36; H, 2.65; N, 0.69;
P, 3.05. Found: C, 41.24; H, 2.73; N, 0.79, P. 3.14%. IR
(CH2Cl2) mCO: 2021 m, 1961 vs, 1821 w, 1765 m, cmꢀ1
.
1H NMR (CD2Cl2, 298 K) dH: 7.6–7.1 (50H, m, Ph);
ꢀ16.5 (1H, s, Ir–H).
˚
over 4 A molecular sieves (Fluka) under nitrogen. Other sol-
vents and reagents of purissimum quality were used as pur-
chased. Manipulations were performed in Schlenk systems
under an atmosphere of dry nitrogen, and the progress of
reactions was monitored by IR and NMR spectroscopy.
All Ir4-clusters were stored under inert atmosphere at ca.
ꢀ22 °C. Infrared spectra as solids (KBr, Nujol mulls) and
in dichloromethane solutions (KBr or CaF2 cells) were
recorded on a Perkin–Elmer 2000 FT-IR spectrometer
(between 4000 and 1500 cmꢀ1), and 1H, 13C{1H} and
31P{1H} NMR spectra on Bruker AC-200, WH-360 or
DRX-400 spectrometers. The chemical shifts (d) are referred
to Me4Si (using the residual proton peaks and carbon reso-
nances of deuterated solvents) and to external 85% H3PO4
(31P), respectively.
2.2.2. [dbuH][Ir4H(CO)9(dppmMe)] (5b) and
[dbuCH3][Ir4H(CO)9(dppmMe)] (5c)
These two compounds containing the same hydrido-
cluster anion were the sole derivatives isolated from the
reaction described for 5a, but operating in the absence of
[PPN]Cl. After stirring for 3 h at r.t., the solution cooled
at 0 °C for 2 h, deposited crystals mostly consisting of com-
pound 5c (ca. 1%) which were removed, and the yellow
dichloromethane solution, containing 5b as a major prod-
uct, was added dropwise to isopropanol (40 ml) at 0 °C.
After stirring for 30 min, the volume of the mixture was
reduced until nearly all dichloromethane was removed,
and the suspension cooled to ꢀ30 °C overnight. A precip-
itate containing 5b (yield 0.45 g, 75%) was filtered off and
recrystallised from dichloromethane/hexane. Compound
5c may be nearly quantitatively isolated if one operates in
the presence of a large excess of preformed salt [dbuCH3]I
[6].
2.2. Syntheses
2.2.1. [PPN][Ir4H(CO)9(L–L)], (L–L = Ph2PCH-
(CH3)PPh2 (5a); Ph2P(CH2)nPPh2, n = 2 (6a), 3 (7a);
Ph2AsCH2AsPh2 (8a)
5b. As yellow-orange micro-crystals. Anal. Calc. for
[C44H42Ir4N2O9P2]: C, 33.59; H, 2.69; N, 1.78; P, 3.94.
Found: C, 33.64; H, 2.73; N, 1.80; P, 3.91%. IR (CH2Cl2)
These compounds were prepared by the following proce-
dure described below for 5a. A yellow solution of
[Ir4(CO)10(Ph2PCH(CH3)PPh2)] (5) (0.55 g, 0.38 mmol)
and [PPN]Cl (0.42 g, 0.73 mmol) in wet dichloromethane
(30 ml) was treated with dbu (0.6 ml, 0.73 mmol). The solu-
tion was stirred for 2 h at room temperature, then cold iso-
propanol (40 ml) was added and the volume of the mixture
was reduced until all dichloromethane was removed. The
m
CO: 2008 s, 1959 vs, 1829 w, 1764 m, cmꢀ1; mC@N: 1646
m (from [dbuH]+). IR (nujol) mCO: 2005 vs, 1972 vs, 1960
s, 1947 vs, 1813 m, 1757 s, 1740 m; others for [dbuH]+:
3317 m (mN–H); 1648 m, cmꢀ1(mC@N). H NMR (CD3CN,
1
240 K) dH: 7.5–7.2 (20H, m, Ph); 3.46–3.27 (6H, m,
N–CH2); 2.58 (1H, m, P–CH); 2.56 (2H, br s, CH2C@N);

R. Ros et al. / Inorganica Chimica Acta 359 (2006) 2417–2423
2419
1.76 (8H, m, CH2); 0.36 (3H, dt, 3J(H,H) 7.7, 3J(P,H) 12.3 Hz;
CH3); ꢀ15.40 (1H, s, Ir–H); N–H was not identified.
5c. As yellow-orange micro-crystals (yield ꢁ1% from the
reaction mixture, but more than 85% operating in the pres-
operating in the presence of a large excess of preformed
[dbuCH3]I. No evidence was found for the direct formation
of the analogous hydrido-anions 5b–8b or 5c–8c with coun-
terions [dbuH]+ or [dbuCH3]+, respectively. Therefore, it is
proposed that the lack of site selectivity observed in the
nucleophilic attack of the strong base dbu [7] on the
diphosphinic chain (Scheme 2, II and III) is related to the
weak acidity of the methylenic group of the coordinated
bis(diphenylphosphino)methane ligand [8–11].
1
ence of a large excess of [dbuCH3]+). H NMR (CD2CCl2,
297 K) dH: 7.4–7.2 (20H, m, Ph); 3.60–3.52 and 3.42–3.36
(6H, 2 m, CH2N); 3.17 (3H, s, CH3N+); 2.7 (2H, m,
CH2C@N+); 1.7–1.6 (8H, m, CH2) [6]; ꢀ15.30 (1H, s, Ir–
H).
All reported hydrido-compounds are soluble in common
organic solvents and thermally stable for several hours
under nitrogen atmosphere. They show three IR bands
characteristic of bridging COs (see Section 2). The 31P
NMR spectra at low temperature (Table 1) of 5a–7a exhi-
bit at low frequency an unique signal for the –PPh2 groups,
which indicates structures similar to those of starting com-
pounds [Ir4(CO)10(l-L–L)] [2–4] with both phosphorus
3. Results and discussion
3.1. Synthesis and characterization
The anionic hydrido-compounds 5a–8a were obtained in
high yields (>76%) from the reactions of [Ir4(CO)10(l-L–
L)] with a large excess of dbu in wet dichloromethane,
and isolated as PPN salts (Scheme 2, I). The same reaction
starting with [Ir4(CO)10(l-dppmMe)], in the absence of
[PPN]Cl, surprisingly gave [dbuH][Ir4H(CO)9(l-dppmMe)]
(5b) in 75% yields, together with ca. 1% of by-product
[dbuCH3][Ir4H(CO)9(l-dppmMe)] (5c) (see Section 2).
The latter could be isolated in good yield (>85%) when
1
atoms located in axial positions. Their H NMR spectra
show at low frequency (ꢀ15 to ꢀ16 ppm) a signal similar
to that found for 4 [1], suggesting a terminal hydrido-
ligand, coordinated in the remaining axial position (see
Section 2). The limiting low-temperature 13C NMR spectra
of samples of 5a–c and 6a–8a, enriched in 13CO (ca. 30%),
O
H2O
Δ
Ir
Ir
C
(I)
CO
Ir
H
+ CO2
- H+
OH
Ir
Ir
P
P
Ir
Ir
P
P
(i)
(iii)
CH(CH3) (II)
C
C
CH3
Ir
Ir
P
P
5b (75 %)
5c (~1 %)
H
CH3
+dbu
C
Ir
Ir
P
P
Ir
Ir
P
P
(ii)
(iv)
H
CH2
(III)
4 (~ 1 %)
Scheme 2. Formation of hydrido-derivatives: mechanism involving the well known nucleophilic attack of an OH– (generated from dbu + H2O) on a metal
carbonyl (I), and the two plausible types of direct attack of dbu on the bridged methylenic group of the coordinated diphosphine (dppmMe) (II and III). (i)
+
+
ꢀdbuH+; (ii) ꢀdbuCH3þ; (iii) +H , with counterion dbuH (5b), dbuCH3 (5c). (iv) +H+ as [Ir4H(CO)9(dppm)]ꢀ (4, ꢁ1%) from NMR measurements.
þ
Table 1
Low-temperature 13C {1H} and 31P{1H} NMR data for the hydrido compounds [PPN][Ir4H(CO)9(L–L)] in CD2Cl2 (d/ppm, J/Hz)
Cluster
L–L
dC
dP
T/K
a
b
d
f
e
g
T/K
PPN+
–PPh2
4aa
5ac
6a
dppm
dppmMe
dppe
200
190
250
190
225.0
229.5
227.3
228.7
224.5
224.5
224.3
226.3
224.0
224.8
227.5
186.7
186.3
189.0
188.7
185.1
185.5
182.1
182.4
181.4
179.3
183.1
165.0
165.0
164.7
162.3
164.9b
164.9b
164.8b
166.8d
164.9d
165.4e
163.0
210
210
298
200
20.1
20.9
20.9
21.1
ꢀ52.9
ꢀ40.4
ꢀ11.9
ꢀ10.9
ꢀ11.1
ꢀ19.4
7a
8a
a
dppp
dpam
200
186
227.8
227.7
190.0
187.8
161.8
164.0
280
200
20.7
21.0
Data from Ref. [1].
Unresolved multiplet.
b
c
The 13C NMR spectra of 5b and 5c exhibit a coincident pattern as in 5a.
d
e
3J(P,C) 28 Hz.
3J(P,C) 27 Hz.

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R. Ros et al. / Inorganica Chimica Acta 359 (2006) 2417–2423
Table 2
Schematic drawing and 13C NMR data for dbu and the cations [dbuH]+ and [dbuCH3]+ in 5b and 5c, in CD3CN at 298 K, d in ppm, J in Hz (data in good
agreement with the published values for dbu and [dbuH]+ [12])
+
2
11
3
2
11
1
N
3
5
1
N
10
9
10
9
4
4
7
7
N
H
N
5
8
6
8
6
dbuH+
dbu
+
dbuCH3
CH3
dbuH+
dbuCH3
þ
dbu
d
1J(C,H)
d
1J(C,H)
d
1J(C,H)
2
3
4
5
52.99
134
123
126
124
125
54.77
26.74
29.22
24.16
33.11
167.20
138
128
130
131
130
53.36
26.53
29.00
22.56
28.72
167.19
41.64a
49.28
20.28
49.32
141
129
130
131
130
29.14
30.26
26.85
37.62
160.91
6
7
CH3–N
142
144
135
145
9
10
11
a
44.70
23.38
48.63
136
128
139
38.73
19.65
48.99
144
138
144
Only the signal at d
¼ 42:00 was reported [13].
ðCH3Þ
exhibit a very similar pattern: six resonances due to
carbonyls a, b, c, f, e, g with relative intensities 2:1:1:2:1:2
(Table 1). At room temperature, 5b and 5c display at lower
frequency the sets of signals attributable to cations
[dbuH]+ and [dbuCH3]+, respectively, on the basis of their
similarity with the signals of dbu itself (Table 2). The struc-
ture proposed for these hydrido-derivatives on the basis of
NMR data was confirmed by single-crystal X-ray diffrac-
tion (see below).
[Ir4(CO)10(l-dppmMe)] (5) and [Ir4(CO)10(l-dppp)] (7)
(Table 3). The mean Cterm–O distances are longer and the
Ir(4)–Ir(3)–C(31) angles are significantly larger than those
of 5 and 7. This is probably the result of higher electron
density on Ir(3) and thus more effective Ir(3) p–Ir(4) and
Ir(3) p–C(31) donation. The two Ir–P distances in all five
hydrido-clusters are slightly shorter than those of starting
compounds 5 and 7.
3.2. Crystal and molecular structures of 5b, 5c, 6a and 7a
O
42
C
O
43
42
N
206
C
43
The molecular structures of 5b, 5c, 6a and 7a are rep-
resented in Figs. 1–4, respectively. Selected intramolecular
bond lengths and angles are given in Table 3. The
description of these structures will involve comparisons
with that of 4a, which has been previously reported [1],
and structural correlations with precursors 5 and 7, all
listed in Table 3. The structures of the hydrido-com-
pounds exhibit similar distorted tetrahedral arrangements
of the Ir-atoms with the two phosphorus atoms of the
diphosphinic ligands and the hydride ligand, all located
in axial positions with respect to the plane containing
the three bridging carbonyls. The Ir–Ir distances follow
the same trends.
O
N
202
41
C
O
41
Ir
4
O
21
H
23
202
C
21
C
23
Ir
2
Ir
3
C
O
12
3
C
31
O
O
11
12
O
13
Ir
C
1
13
H
3
C
1
The comparison between the five hydrido-derivatives
shows a prevalent trans-influence of a hydride ligand with
respect to a terminal CO group: the Ir(3)–Ir(4) bonds are
slightly longer than the other five Ir–Ir bonds and, in par-
ticular, longer than those of the starting compounds
Fig. 1. ORTEP plot, at the 50% level, of the molecular structure of 5b
with atom labelling scheme.

R. Ros et al. / Inorganica Chimica Acta 359 (2006) 2417–2423
2421
O
41
C
41
O
O
43
42
C
C
43
42
N
202
Ir
4
O
11
C
11
O
N
13
206
O
O
C
12
C
13
Ir
12
1
O
31
C
31
Ir
3
21
Ir
C
2
C
21
23
O
23
H
P
3
1
P
2
C
1
H
1
Fig. 2. ORTEP plot, at the 50% level, of the molecular structure of 5c with atom labelling scheme.
O
O
O
41
42
41
C
42
O
Ir
O
42
43
C
43
C
41
C
O
C
41
43
42
C
43
O
Ir
31
O
4
C
4
31
O
31
13
O
11
C
O
C
O
31
23
O
13
13
Ir
23
C
Ir
C
2
3
C
23
3
23
13
O
11
C
O
C
11
21
11
O
C
21
C
Ir
1
21
21
1
Ir
Ir
1
Ir
2
C
12
12
H
3
O
H
3
C
12
O
P
12
P
2
C
C
1b
2b
C
2
C
1
C
3a
C
1a
C
C
3b
2a
Fig. 3. ORTEP plot, at the 50% level, of the molecular structure of 6a
Fig. 4. ORTEP plot, at the 50% level, of the molecular structure of 7a
with atom labelling scheme.
with atom labelling scheme.
The determination of the Ir–H distances has turned out
in dbu, and the spreading of the positive charge on the
three atoms.
rather difficult for all derivatives. For 5c, a value of
˚
1.32(5) A was obtained. This value is too short with respect
Close inspection of the intramolecular interactions in 5b
shows a cation–anion hydrogen bond, involving the oxygen
atom of carbonyl C–O(12) (Fig. 1), with a distance
˚
to the value of 1.618(14) A for 4a, recently determined by
neutron diffraction [14]. Attributing a Ir(3)–H(3) distance
˚
˚
of 1.62 A for 5c (Fig. 2), one obtains, like for 4a, a
O(12)ꢂ ꢂ ꢂH(202)–N(202) of 2.97 A and the corresponding
˚
H(3)ꢂ ꢂ ꢂH(1) distance of 2.44 A between the hydride and
angle close to 180° (Table 4).
the syn-hydrogen atom of the methylenic group of the
diphosphinic ligand. The shortening of the distances
between the carbon atom and the two adjacent N(202)
and N(206) atoms in cations [dbuH]+ (5b) and [dbuCH3]+
3.3. X-ray crystallographic determination of 5b, 5c, 6a and
7a
˚
(5c) (C(201)–N(206), 1.35(2), 1.32(1) A, and C(201)–
All the crystals of 5b, 5c, 6a and 7a were red-brown.
They were glued on a glass fibre and cooled, using an
Oxford Cryostream, for the collection of Bragg intensities
˚
N(202), 1.37(2), 1.31(1) A, respectively) may be explained
by the electronic delocalization of the C@N double bonds

2422
R. Ros et al. / Inorganica Chimica Acta 359 (2006) 2417–2423
Table 3
˚
Selected bond distances (A) and bond angles (°) for [Ir4(CO)10(dppmMe)] (5), [Ir4(CO)10(dppp)] (7), [dbuH][Ir4H(CO)9(dppmMe)] (5b),
[dbuCH3][Ir4H(CO)9(dppmMe)] (5c), [PPN][Ir4H(CO)9(P–P)] (P–P = dppm, 4a [1], dppe 6a and dppp 7a) with standard deviations in parentheses (as
subscript values for mean SD)
(5)
(7)
(4a)
(5b)
(5c)
(6a)
(7a)
Ir(1)–Ir(2)
Ir(1)–Ir(3)
Ir(1)–Ir(4)
Ir(2)–Ir(3)
Ir(2)–Ir(4)
Ir(3)–Ir(4)
Ir(1)–P(1)
2.700(2)
2.775(2)
2.6848(3)
2.6803(8)
2.6929(6)
2.7175(5)
2.7740(6)
2.724(2)
2.745(2)
2.751(2)
2.725(2)
2.724(2)
2.315(5)
2.313(5)
2.743(2)
2.726(2)
2.740(2)
2.722(2)
2.724(2)
2.311(7)
2.327(7)
2.7430(4)
2.7449(3)
2.7278(4)
2.7600(4)
2.7861(4)
2.2736(15)
2.2920(15)
2.06(6)
2.052(6)
2.174(6)
2.100(6)
2.154(6)
2.041(7)
2.054(6)
1.87218
2.7247(8)
2.7573(12)
2.7287(10)
2.7696(8)
2.7837(8)
2.298(4)
2.300(4)
2.42(16)
2.117(16)
2.098(17)
2.072(15)
2.130(14)
2.068(16)
2.043(13)
1.87152
2.7263(5)
2.7593(6)
2.7263(5)
2.7632(6)
2.7779(5)
2.2936(11)
2.2832(11)
1.32(5)
2.112(4)
2.141(5)
2.059(5)
2.180(5)
2.067(5)
2.034(5)
1.87837
2.7379(6)
2.7559(7)
2.7405(8)
2.7680(6)
2.7812(6)
2.2798(13)
2.2902(11)
1.69(4)
2.087(5)
2.138(5)
2.049(5)
2.178(5)
2.061(5)
2.052(5)
1.87032
2.7310(6)
2.7523(6)
2.7495(5)
2.7539(6)
2.7966(5)
2.2996(17)
2.2975(18)
1.31(5)
2.083(5)
2.156(5)
2.105(5)
2.151(6)
1.994(6)
2.047(6)
1.86631
Ir(2)–P(2)
Ir(3)–H(3)
Ir(1)–C(12)
Ir(1)–C(13)
Ir(2)–C(12)
Ir(2)–C(23)
Ir(3)–C(13)
Ir(3)–C(23)
Mean Ir–Cterm
Mean Cterm–O
Mean Cbr–O
2.039(16)
2.081(19)
2.102(18)
2.043(17)
2.122(19)
2.225(19)
1.90832
2.08(2)
2.05(2)
2.07(2)
2.00(2)
2.15(2)
2.12(2)
1.89733
1.10731
1.17030
1.11342
1.17312
1.15717
1.1763
1.14763
1.17223
1.15615
1.1719
1.1549
1.17712
1.1779
1.1825
P(1)–Ir(1)–C(11)
P(1)–Ir(1)–Ir(2)
P(1)–Ir(1)–Ir(3)
P(1)–Ir(1)–Ir(4)
P(2)–Ir(2)–C(21)
P(2)–Ir(2)–Ir(1)
P(2)–Ir(2)–Ir(3)
P(2)–Ir(2)–Ir(4)
Ir(1)–Ir(2)–C(12)
Ir(1)–Ir(3)–C(13)
Ir(2)–Ir(1)–C(12)
Ir(2)–Ir(3)–C(23)
Ir(3)–Ir(1)–C(13)
Ir(3)–Ir(2)–C(23)
Ir(4)–Ir(1)–C(11)
Ir(4)–Ir(2)–C(21)
Ir(4)–Ir(3)–C(31)
Ir(4)–Ir(3)–H(3)
Mean Ir–Cbr–Ir
Mean Ir–Ir–Ir
96.7(6)
95.36(10)
100.97(12)
153.46(12)
98.1(5)
96.91(11)
103.97(12)
156.44(11)
48.3(4)
48.9(5)
50.3(5)
47.0(4)
50.3(5)
92.4(9)
114.18(15)
109.37(17)
168.80(17)
90.5(8)
113.70(19)
109.36(17)
168.77(18)
48.2(7)
47.6(6)
47.9(6)
46.5(6)
50.9(7)
92.23(19)
96.11(4)
102.02(4)
155.85(4)
100.65(19)
94.93(4)
99.31(4)
153.39(4)
48.93(16)
51.53(18)
50.49(16)
51.22(18)
47.34(19)
48.00(17)
105.85(18)
105.66(18)
110.6(2)
162.5(18)
80.83
97.1(4)
95.95(8)
98.15(9)
154.09(9)
98.8(5)
95.01(8)
96.20(8)
152.07(8)
51.0(4)
49.6(5)
49.5(4)
50.5(4)
48.7(5)
47.8(3)
108.8(4)
109.0(5)
117.1(5)
n.d.
97.29(15)
96.03(3)
102.90(4)
155.77(3)
98.42(4)
94.82(3)
96.90(3)
152.22(3)
50.64(12)
50.41(13)
48.94(14)
52.07(14)
48.08(13)
47.38(12)
106.44(14)
109.32(14)
109.64(14)
165(2)
96.37(17)
104.11(4)
108.69(4)
164.12(3)
96.19(13)
104.76(3)
100.98(3)
159.94(3)
49.55(13)
50.55(15)
48.31(14)
51.67(15)
48.09(15)
47.63(13)
99.30(16)
103.46(13)
109.86(16)
164.1(15)
81.4072
96.20(19)
112.11(4)
108.22(4)
168.68(4)
95.8(2)
114.44(4)
109.85(4)
170.61(4)
48.17(14)
51.46(15)
48.87(13)
50.75(15)
46.34(17)
47.48(15)
94.72(18)
92.96(19)
117.8(3)
164(2)
52.8(5)
50.2(7)
98.0(9)
100.1(8)
99.0(10)
109.4(6)
104.6(5)
89.4(7)
80.7765
60.0060
176.724
82.9(9)
59.9960
175.130
80.97118
60.00105
175.325
80.8360
60.0088
177.911
82.3259
60.0076
176.024
60.0097
177.814
60.0064
177.119
Mean Ir–Cterm–O
Table 4
and SHELXS97 [16], and were refined by means of SHELXL97
[17]. Non-hydrogen atoms were refined anisotropically and
all hydrogen atoms, but H3, were made to ride on their car-
rier atoms. H3 could be located in Fourier maps, but
refined to more or less unbelievable positions [14]. The
measured crystal of 5b has an unknown, but equidimen-
sional habit. The measured specimen of 5c displayed the
Interaction distances and angles Oꢂ ꢂ ꢂH–N in 5b
Aꢂ ꢂ ꢂH–D
˚
˚
˚
Oꢂ ꢂ ꢂH (A) Hꢂ ꢂ ꢂN (A) Oꢂ ꢂ ꢂH–N (°) Aꢂ ꢂ ꢂD (A)
O43ꢂ ꢂ ꢂH202–N202 2.82
0.86
118.81
3.32
O12ꢂ ꢂ ꢂH202–N202 2.14
0.86
177.90
2.97
ꢀ
ꢀ
ꢀꢀ
forms {011} prism, f110g, f101g pinacoids and a ð111Þ
that took place on a Stoe IPDS-I system equipped with Mo
Ka radiation. Crystal data and details of measurements are
summarised in Table 5. For all collections, 200 1°-wide-
images were recorded, but only 88 for 5b owing to an icing
problem. The intensities were corrected for Lorentz and
polarization effects, and no decay was encountered in any
of the collections. For all crystals but 5b, numerical absorp-
tion corrections based on the habit were computed. All
structures were solved, except that of 7a, by DIRDIF96 [15]
pedion. The measured crystal of 6a showed the forms
ꢀ
ꢀ ꢀ
{110} prisms, f101g pinacoid and a ð101Þ pedion. The
measured specimen of 7a displayed the forms {100},
{010} and {001} pinacoids. The propylic chain of 7a
and two of the phenyl rings were severely disordered and
treated by a split model. In all cases, inspection of the reci-
procal space ascertained that the diffraction figures con-
sisted almost exclusively of the spots corresponding to
the cells given in Table 5.

R. Ros et al. / Inorganica Chimica Acta 359 (2006) 2417–2423
2423
Table 5
Crystal data and details of measurements for hydrido-compounds 5b, 5c, 6a and 7a
5b
5c
6a
7a
Formula
C44H42Ir4N2O9P2
1573.54
monoclinic
P21/n
C45H44Ir4N2O9P2
1587.56
monoclinic
P21/n
C71H55Ir4NO9P4
1958.84
monoclinic
P21/n
C72H57Ir4NO9P4
1972.87
orthorhombic
P212121
Formula weight
Crystal system
Space group
˚
a (A)
11.710(2)
20.931(4)
18.572(4)
95.62(3)
4530.1(16)
4
2.307
2920
11.839
13.583(3)
17.119(9)
19.906(4)
96.71(3)
4597.2(16)
4
2.294
2952
11.668
18.091(4)
16.730(3)
21.098(4)
90.61(3)
6385(2)
10.437(2)
20.126(4)
31.178(6)
˚
b (A)
˚
c (A)
b (°)
Volume (A )
3
˚
6549(2)
4
2.001
3744
8.259
Z
4
Dcalc (Mg mꢀ3
F(000)
l (mmꢀ1
)
2.038
3712
8.470
)
h Range (°)
Temperature (K)
2.41–27.92
160(1)
1.92–25.91
95(1)
2.43–25.92
130(1)
2.02–25.93
95(1)
˚
Wavelength (A)
0.71073
18385
8899 [0.0980]
8899/264/547
0.71073
35617
8357 [0.0494]
8357/0/563
0.71073
49272
12162 [0.0519]
12162/0/806
0.71073
51327
12438 [0.0510]
12438/61/803
Reflections collected
Independent reflections [Rint
Data/restraints/
parameters
]
R1 [I > 2r(I)]
wR2 [I > 2r(I)]
R1 (all data)
wR2 (all data)
0.0595
0.1045
0.0654
0.1048
13 ! 27
0.010
0.0227
0.0442
0.0272
0.0449
0.0265
0.0504
0.0324
0.0511
0.0233
0.0334
0.0305
0.0342
Profiles [pxs]
9 ! 21
13 ! 21
11 ! 21
Mosaic Spread
Crystal IP Dist.
Experimental time (min)
Habitus
0.009
0.008
0.008
60
2
70
4
70
3
70
10
equidimensional
stout-rhombohedral
[0.2222, 0.0925]
stout-rhombohedral
[0.2604, 0.1327]
tabular-euhedral
[0.5523, 0.4082]
Transmission factors
[4] A. Strawczynsky, G. Suardi, R. Ros, R. Roulet, Helv. Chim. Acta 76
(1993) 2210.
4. Supplementary crystallographic data
[5] R. Ros, A. Tassan, Inorg. Chim. Acta 260 (1997) 89.
[6] v.C. Heidelberg, A. Guggisberg, E. Stephanou, M. Hesse, Helv.
Chim. Acta 64 (1981) 399.
[7] R. Schwesinger, J. Willarendt, H. Schlemper, M. Keller, D. Schmitt,
H. Fritz, Chem. Ber. 127 (1994) 2435.
Crystallographic data (excluding structure factors) for
the structure reported in this paper have been deposited
with the Cambridge Crystallographic Data Centre as sup-
plementary publication numbers CCDC-281668 (6a),
281669 (7a), 281670 (5c) and 281671 (5b). These data can
be obtained free of charge via www.ccdc.cam.ac.uk/prod-
ucts/csd/request/ or from the Cambridge Crystallographic
Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK
(fax: +44 1223 336 033; or deposit@ccdc.cam.uk).
[8] H. Hashimoto, S. Okeya, Y. Nakamura, Bull. Chem. Soc. 61 (1988)
1593.
[9] A. Laguna, M. Laguna, J. Organomet. Chem. 394 (1990) 743.
[10] J. Ruiz, V. Riera, M. Vivanco, S. Garcia-Granda, A.
Gracia-Fernandez, Organometallics 11 (1992) 4077.
[11] J. Ruiz, M.E.G. Mosquera, V. Riera, M. Vivanco, C. Bois,
Organometallics 16 (1997) 3388, and references therein.
[12] J.W. Wiench, L. Stefaniak, E. Grech, E. Bednared, J. Chem. Soc.,
Perkin Trans. 2 (1999) 885.
Acknowledgements
[13] W.-C. Shich, S. Dell, O. Repic, J. Org. Chem. 67 (2002) 2188.
[14] S. Detti, V.T. Forsyth, R. Roulet, R. Ros, A. Tassan, K. Schenk, Z.
Kristallogr. 219 (2004) 47.
[15] P.T. Beurskens, G. Beurskens, W.P. Bosman, R. de Gelder, S.
Garcia-Granda, R.O. Gould, R. Israe¨l, M.M. Smits, The DIRDIF-96
System of Programs, Laboratorium voor Kristallografie, Katholieke
Universiteit Nijmegen, Nederland, 1996.
We thank the Swiss National Science Foundation and
MURST Cofin-2003-2005 (Italy) for financial support.
References
[16] G.M. Sheldrick, SHELXS-97, Release 97-2, Program for the
Solution of Crystal Structures, Universita¨t Go¨ttingen, Germany,
1997.
[17] G.M. Sheldrick, SHELXL-97, Release 97-2, Program for the
Refinement of Crystal Structures, Universita¨t Go¨ttingen, Germany,
1997.
[1] S. Detti, T. Lumini, R. Roulet, K. Sckenk, R. Ros, A. Tassan, J.
Chem. Soc., Dalton Trans. (2000) 1645.
[2] T. Lumini, G. Laurenczy, R. Roulet, A. Tassan, R. Ros, K. Schenk,
G. Gervasio, Helv. Chim. Acta 81 (1998) 781.
[3] R. Ros, A. Scrivanti, V.G. Albano, D. Braga, L. Garlaschelli, J.
Chem. Soc., Dalton Trans. (1986) 2411.